The Build Part III: How long is a bike chain?

Following on from the first two parts of the build project, in this part I finally connect up the cranks to the sprockets and get the derailleurs adjusted.  With combined 'brifters' it makes sense to cable up and adjust the brakes too, just in case the temptation to get on and pedal is too much!

Before the chain can be installed, it needs to be cut to the correct length.  For my build I'm using Campagnolo's Centaur groupset and hence the 10-speed, ultra-narrow Centaur chain.  Prior to the installation I did a bit of research on chain sizing.  Remarkably all bicycle chains come in the same pitch (the distance from one roller to the next) and this is set at 1/2" (half-inch).  Given the bewildering variation in almost every other aspect of the drivetrain, resulting in incompatibility between components from different suppliers, I'm surprised that chain-pitch has remained so constant.  Anyway, this means my 114 link Centaur chain is 57 inches long.

Replacing an existing chain is easy, you just count the links and make the new one the same size.  You have to be careful not to just measure the length because a worn out chain will have stretched a bit and you might end up with an extra inch or two on the new chain.  But with a new build you need a different method.

Chain Length Sizing - Park Tool

Given that I recently bought a Park Master Chain Tool (more below) I thought I'd start at Park's excellent pages aimed at the DIY mechanic.  They outline two methods of sizing the chain for a new build.  The first involves measuring the chain against the two largest cogs without threading it through the rear derailleur and then adding one inch (two links) to compensate.  Their second method is similar but uses a calculator instead, in other words, you put the size (in teeth) of the largest chainring and sprocket into an equation along with the distance from bottom bracket to rear axle.

From the formula they give I put in the distance to the rear axle (16 1/8 inches), my 50T chainring and 25T sprocket and, finally, the additional 1 inch to compensate for the derailleur.  The result is a 52 inch chain.

Chain Length - Sheldon Brown

Sheldon Brown deals with chain length in a longer article on derailleur adjustment.  He uses the same method, in essence, resulting in a chain 1 inch longer than the minimum required to run the large/large combination of chainring and sprocket.  He does hint at a possible reason for this algorithm being the accepted norm: a chain that is too short will cause damage whereas a chain that is too long will only affect gears that you shouldn't be using anyway.

(StackExchange: Setting Chain Length)

The accepted answer on StackExchange simply cites Sheldon Brown, but at the time of writing there is a comment from one of the moderators to the effect that you should allow 2 links (in this case meaning 2 inches I assume from the context) for Shimano.

WikiBooks: Read Derailleur Adjustment

While researching this topic I found another new source of information I didn't know about, there is a wiki book on Bicycles with a detailed section on Maintenance and Repair.  Again, the conventional wisdom is big/big + 1 inch.

Campagnolo Method (pdf)

With all this general advice to be around the large/large method I was surprised when I unpacked my Centaur 10-speed chain and found a completely different method of chain length sizing.  Whereas most people advocate a method which results in the shortest possible chain that can work (on the large/large combination) the Campy method is a small/small based method which results in the longest possible chain than can work without rubbing the derailleur.

The basic idea is to draw the chain tight enough to ensure a small gap at the point where the chain is at its closest approach.  This is the part of the chain feeding in to the lower jockey wheel.  When the derailleur is retracted to take up the slack the lower jockey wheel bends back and upwards reducing the gap to the part of the chain going around the upper jockey wheel to a minimum.  The instructions suggest setting this gap at a maximum of 10-15mm.

To make it easier to follow this method I cut a small piece of card diagonally, 15mm at one end and 10mm at the other:

The result of using this method was that I needed to remove 3 inches (6 links) from the chain.  That makes it a 108 link/54 inch chain, two inches longer than the chain predicted by the equation above.  I think there are several reasons for this difference.  Firstly, I could have stuck with the 34T chain ring that came with the crankset and that might have meant knocking out one more pair of links (taking me down to 53 inches) - which is within an inch of the length predicted by the equation.  And anyway, perhaps these new Centaur 10-speed derailleurs require 2 extra inches, rather than the 1 inch given in the formula.

   

In all of my internet searches (on a range of topics) I quite often got results from the blogger "Sprinter Della Casa" and he is the only one I found who seems to espouse the method of using the longer chain method.  I'm not sure about the rationale but I enjoyed the article: How To - Campy Chain Install, Illustrated.

The Mystery of the Missing Bearing

Installing these new chains always makes me a bit nervous.  Each time the technology is updated the tools become more specialised and the margin for error is reduced.  The Campy tool shown in the illustrated How-To above is obviously the right tool for the job but Park do make a more general purpose tool that might be more useful when working on other bikes too.  Not to mention being cheaper.

Park clearly have a good reputation and other tools I have from them have been flawless but this time they let me down, at least initially.  I had just started breaking the chain to remove the extra 3 inches when I heard an alarming and very audible popping sound.  I examined the tool and the chain and I couldn't see any signs of damage or anything that could have made the noise so I continued pushing the pin through until the handle on the chain tool would go no further.  At this point it was clear something was wrong because the roller had not been pushed all the way out of the link.

The design of the tool is for the pin to sit on a small bearing in the barrel of the tool.  The pin and bearing are held in place with a retaining nut so that they can be changed should the pin become worn or break.

So I unscrewed the retaining nut intending to take the pin out for a closer look.  The pin was stuck fast in the body of the tool.  Now I figured that if the pin didn't protrude from the tool far enough to drive the roller out of the chain then the bearing that should be in there is missing.  Sure enough, it came up short by what would have been the width of the bearing.  I returned the tool for a warranty replacement and got a replacement from the supplier pretty quickly.

This time I checked that the pin and bearing were present.  They were, and I noticed just how snuggly the pin sits in the tool, as you load the pin and bearing into the barrel you can feel the air trapped in the barrel pushing back against the pin.  You have to push it slowly in, giving time for the air to escape around the pin.  My theory is that the bearing was missing originally and that the final part of the barrel is an even tighter fit - as I turned the handle the pressure built up in the barrel until the air popped out, allowing the pin to jam itself in the barrel for good.

  

The Build Part II: Ergo Brifters: under the hood

In The Build Part I, I covered my experiences with installing the Power Torque Campagnolo cranks.  Attaching the other bits of the Centaur groupset to the bike looks pretty straightforward in comparison.

The Saetta frame comes with a 'braze-on' clamp for fixing the front derailleur and the hanger for the rear derailleur was already attached.  The frame was actually shipped with a spare hanger - useful if you come off on a right-hand bend and squash the derailleur in towards the back wheel.  In the past I've had to do this as a running repair but with the precise alignment required for the 10 speed system it looks like the accuracy needs to be more than just by eye.  So that spare hanger may come in handy - in the UK we have a lot of roundabouts and we go around them clockwise which must increase the risk of this sort of accident.

The hardest part of fixing the rear derailleur was tightening the fixing bolt to the correct torque.  The bolt head is recessed in a narrow channel that will not allow me to put the hex socket in so I had to do it by feel with a regular Allen Key.

The Centaur brakes appear identical in the box and it is hard to see, on first look, which is the front and which is the back.  The difference is so obvious to the experienced bike mechanic that it seems not to warrant a mention in the instructions.  I'm glad to see I'm not the only one who felt the need to consult the internet to make sure, as evidenced by this bike forum post.  The answer is of course that the front brake has a longer bolt to allow it to pass through the fork.  Given that fork widths vary, and carbon forks tend to be a bit fat at this point, you may need to get a longer nut to make contact with the brake bolt.  Both Campagnolo and Cinelli thought of this and I had multiple sizes shipped with the brakes and the correct size bolt shipped with the frameset - another item for the spares box but all good.

If I thought the rest of the job would go really quickly I was wrong.  The next step is to put the Ergo levers on the bars and connect them up to the derailleurs (you need to do this before you put the chain on because you are going to need to operate the derailleurs as part of the chain installation procedure - more on that next time).  It is always nice to learn a new word (especially one that dictionary.com doesn't know about yet) and I soon discovered that a 'brifter', far from being the long lost relative of the old Raleigh Grifter, was in fact a common synonym on the internet for 'lever' in this context; being a simple contraction of brake/shifter.

The instruction leaflet that comes with the Campagnolo brifters merely says "Raise the support cover to expose the securing screw" and shows a picture which appears to show the base of the rubber hood being peeled back (as it will be when you install the bar tape) far enough to get a clean line of sight into the head of the bolt which turns out to be a T25 torx head and not a plain hex.  I believe this is impossible.  I would not want to attempt this in a cool environment as I felt I needed all the warmth of my house, combined with the warmth of my hands to make the rubber supple enough to peel easily without tearing but try as I might I could not expose the bolt as shown in the diagram.

I'm not the only one, there are numerous threads in bike discussion forums where people are having trouble with this point.  My favourite is this one, which is a little old now but the technology and the lever shapes are basically the same: Campagnolo Ultra-Shift Mounting Bolt (or: stripping is awesome).  This thread makes a couple of important points.

(1) Don't try and get in from the base of the hood, instead, go in from the top of the hood.  I love this report in the above thread from someone who sought official advice: "The man with whom I spoke at Campy, however, advised instead pulling up the hood from the top of the lever and pushing it back toward the base (i.e., entirely opposite from what the instructions say)".

(2) Even with the hood completely clear of the bolt it may be impossible to get a straight line down to the bolt head for a torque wrench and you risk stripping the soft alloy bolt if you apply too much force this way.  Another quote from the above thread: "I wrestled with the hoods and managed to get enough clearance so that I could get the wrench in straight (or as straight as you can given the placement of the bolt on the body), but I still had that trouble".

There is now an excellent article on BikeRadar.com on How to Fit Campagnolo Ergo Levers.  It shows the solution to (1) and has a fabulous photo of the small rubber 'nib' being removed before the hood is peeled back from the top.  Here is my feeble attempt at a similar picture:

The left-hand lever showing a narrow screw driver head inserted through the lever to free the nib

Close up of the screw driver being used to push the rubber nib back into place

The BikeRadar article also clearly shows the extension on the torque wrench allowing the mechanic to get a straight line into the bolt head.  On my levers this was just not possible because the position and angle of the bolt caused the extension to foul the top of the lever.  So I didn't tighten it up this way because I was concerned about stripping the bolt head.  Instead, I went out to the local auto-parts store and bought a set of Torx-keys (assuming that's what you call something that looks like an Allen key but has Torx heads instead of a plain hex).  I was able to get the short end of the T25 wrench into the bolt head nice and squarely and therefore I could tighten up the bolt enough to prevent slippage, albeit by feel again.  It was still a tight fit, as this picture (this time of the right lever!) illustrates:

T25 wrench inserted under the hood to tighten the clamp bolt

The Build Part I: Power-Torque cranks

So to recap, I have bought my Cinelli Saetta frame and fork through my local bike shop, Howes.  The frame-set comes with its own Columbus headset and Cinelli-branded seat clamp.  My local bike shop fitted them all together for me with the Vai Bianca stem.  The next step for me was to protect the frame with pipe insulation (to prevent knocks during the build) and then fit the saddle and seat post.  I have hooks set up which allow me to suspend my bikes by stem and saddle so fitting these allows me to use the hooks as a work stand.

This seems like an excellent opportunity to introduce an emerging source of information on bike maintenance: bicycles.stackexchange.com.  People who work in the IT industry will be familiar with programmers' Q&A site StackOverflow.  There is a brief wikipedia page on the history of this site.  The stack exchange concept takes the success of this original idea and attempts to stamp it out across a wide range of topics.  The stack exchange on the subject of bicycles seems to be well populated with content.  I put this down to common elements between the mentality of the DIY-bike mechanic and the mentality of the programmer.  So if you are attempting to apply experience gained fiddling with computers to the more mechanical realm of fiddling with bicycles this site will probably be speaking your language.

It seems that my ceiling hooks have saved me from the dilemma of working on a carbon bike using a traditional work stand.  To summarise this thread from stackexchange, if in doubt don't do it and whatever you do don't do up the clamp too tightly!

In my last post, Cranky Delays..., I discussed my choice of gears and chain rings.  Installing the cranks seemed like a sensible first step but as I worked on the bike from my eye-level hooks I did realise that there was a better way to work on the cranks when you need to tighten things up - just add wheels!  It seemed much easier and more natural to applying the forces required to install the crank set with the bike on the ground with wheels and tyres fitted.  I guess it does depend how far from the ground you are.

I've installed a few square-tapered bottom-brackets over the years but the new breed of cranksets with their outboard cups and hollow axles are a completely new experience for me.  The instructions that come with the crankset are pretty scary, emphasising the need to face the bottom bracket before installation.  I actually checked back with the frame dealer before proceeding but they reassured me that the shell was ready to take the new cups and my measurement of the shell width came in at 67.87mm which is within the tolerance.

Fresh from my experience with the chainring bolts (which were stuck fast with thread lock) I must admit I was concerned about the amount of thread locking compound on the supplied cups.

I recall a stuck bottom bracket in my Bianchi many years ago, my local bike mechanic had a neat trick for removing it.  He removed the crank, closed the shop, then welded the spindle to the bottom bracket shell.  Once it had cooled, he refitted the crank and used that to unscrew the shell.  A few scorch marks later and I was upgraded into the world of cartridge bearings.  His summary of the situation: somebody was being mean with the grease.

The instructions that come with the crankset don't mention the need to apply a thread locking compound and in a close look at the installation video it appears that the threads are clean too.

One of the problems with information on the internet is that it tends to be strongly biased towards people with problems.  Bike riders with noiseless, trouble free bottom bracket installations are probably not logging on to complain or post to forums about the issues they're having.  Hopefully they are out riding and enjoying their bikes!  A search for the similar but high-end ultra-torque will throw up threads like this one from the RogueMechanic.  There are all sorts of interesting bits of information (and doubtless mis-information) in this post and its associated comments.  Anyway, for comparison here are the two videos of the Ultra-Torque installation:

Notice that the first 5 minutes of this video show the preparation of the shell, which emphasises the importance of this step.  It is interesting that they left this out of the Power-Torque video.  If you aren't content with doing something the correct way you can always follow the inferior (incorrect?) procedure instead, also documented in an official video!  This one uses copious quantities of Loctite 222, a liquid thread locking compound.

Given that thread-locking compound is basically glue, and that my experience has been skewed towards things getting stuck fast rather than shaking loose in this department, I scraped some of the thread lock out (it would be impossible to get it all out without a suitable solvent I think), applied some grease and tightened the cups up to the recommended torque.

Unlike the bike in the first video, which appears to have right-hand threads on both sides of the shell, my bottom bracket is BSA or 'English' threaded so you have to do up the drive side anti-clockwise.  There is a good article on Wikipedia about bottom brackets in general, including the various sizes.  When ordering the Power-Torque cups you do need to know which you have.  The reason that the drive side has a left-hand thread is to reduce the tendency of precession to undo the cups - the fact that it goes backwards may seem unintuitive but the linked article has a cute animation which demonstrates the effect so that you don't have to do the maths yourself.

If you are convinced that precession is your enemy here then the risk of loosening must be greatest on the drive-side of an italian threaded bottom bracket.  I expect I'll take the drive train apart for servicing at some point and I'll report back on the torque required to undo them - if I have a suitable torque wrench, which brings me to a bit of a gripe...

To help me get the torques right on this part of the project I bought a new torque wrench, on special offer, for a surprisingly cheap price.  I have a small wrench that goes up to 25Nm but this is not enough for the cups, the crank fixing bolt or the pedals.  The wrench I bought was a draper 1/2" drive ratchet type wrench.  I bought it from a fabulous local hardware shop called Mackays - this shop is famous in Cambridge for having the type of expert staff who can find replacements for pretty much any type of weird fixing you throw you at them.  Anyway, the wrench has a reversible ratchet and a scale marked from 30Nm up to a blood-vessel bursting 210Nm.

Armed with my new torque wrench I set about the cups, with the aid of the special purpose Campagnolo tool (I had expected this tool to fit more snuggly on the cups).  I started on the left (non-drive) side of the bike and tightened the cup without any problems.  I then flipped the ratchet and started tightening the drive side.  As I was just learning to use this tool I set the torque to the lowest setting each time (30Nm) to help get the feel of the thing before tightening to the recommended torque.  This was a good thing, because as I tightened the drive side I quickly realised that I was having to put in more effort than expected to get the wrench to break away.  It was only later I noticed the small print on the leaflet that came with the wrench: "IMPORTANT: The torque wrenches detailed in this instruction leaflet are for right hand torquing only.  They are not designed for left hand use."  I finished tightening the drive-side cup by flipping back and forth with the ratchet until I could no longer undo the cup using the specified torque.

So my gripe is why advertise these wrenches as having reversible ratchet heads?  Obvious you might say, it allows you to undo things, just like the guy in the Campagnolo video who clearly uses a similar torque wrench to undo the cups.  But this doesn't explain it, the warnings section of the leaflet kicks off straight away with "Never use the torque wrench to undo bolts, nuts or fasteners, as this will damage the ratchet and the calibrated setting".  I reckon that, at this price, they know that the tool will not be worth calibrating and that it will turn in to a fancy breaker bar after a year or two of use.

Cranky delays to my home-build project

Most of the components I bought for my new bike have come preassembled ready to be fitted.  However, there was one component I had difficulty sourcing: the crankset.  How can buying a crankset be so hard?  After years of cycling on 170mm cranks I've decided to go shorter and ride on 165mm cranks.  This is partly because I tend to spin a bit but also because I find that my saddle adjustment height has very little room for error.  Last time I changed my frame I suffered a little knee pain on longer climbs (especially if I was sitting back).  Moving the saddle up solved the problem.  This is a fairly well known effect, I found this blog post on an Audaxing blog in which the author covers some fine adjustment issues for injury prevention (though take note of the comments at the bottom of the page as the knee conditions have been transposed in the main article).

There is plenty on the net written about crank length, much of it contradictory.  Performance cyclists are always looking to gain an advantage so it is not surprising that the subject has been studied but the surprising conclusion seems to be that the optimum range of lengths for a given rider is quite large.  Sheldon Brown comes to a similar conclusion with a more general purpose outlook after experimenting with a wide range of sizes.

Despite all this orthodoxy telling riders that one of three sizes fits all I've still decided to go with the 165 and ride for enough miles to see if I like it.  Clearly shortening the crank length by 5mm will mean moving the saddle up by the same amount to maintain the same leg extension at the bottom of the pedal stroke.  At the top of the stroke the foot will then be 10mm lower than before - a significant reduction in the height of the knee.  There are so many articles on crank length on the internet it is hard to pick out particular ones - and anyway, I'll surely just pick the ones that agree with my own analysis!  Still, this blog post makes the point above very clearly: Crank Length - which one?.  The shorter crank will also reduce toe-overlap as my foot will be retreating by 5mm from the front wheel.

Starting from this year, Campagnolo are making a Centaur crank in a 165mm size.  According to the brochure "it allows for an agile pedal stroke and a correct movement in relation to the length of the lower limbs".  By the way, at the time of writing nobody has told the webmaster at Campagnolo so the product page still lists 170mm as the smallest size and the link to the 165mm crank goes to the Athena 11speed crank but I can confirm that I do have a 2012 10-speed 165mm Centaur crankset.

Campagnolo Centaur 50/30 Compact Crankset: including warning stickers!

The crankset is only available on the more expensive carbon version unfortunately and I struggled to find anyone in the UK who had anything other than the compact 50/34 and even that was hard work (and like buses, you wait ages for one and then two turn up at once - isn't internet shopping fun).  Judging by the number of people that offered me the 'black/red' version (which is the same crank with red bolts) this looks like a bit of an unnecessary addition to the product range and inventory might have been better served by reducing the colour options and concentrating on the different lengths and chain ring configurations.

The thought of a 34T chain ring scares me a bit, even with the shorter crank that would be a lot of gears that I only ever used when taking holidays to places with long steep climbs.  To put this in perspective, the average force required on each peddle stroke with the 165mm crank is roughly equivalent to adding a single tooth to the chainring, so my 34T would feel a bit more like a 35T.  That would still be a big change from the 50/39 I currently use.

On the plus side, a larger difference between the two chainrings reduces the overlap in gear ratios.  For example, on a standard 12-25 set of 10-speed sprockets only 5 of the sprockets used with the 50T ring result in longer gears than the longest available on the 39T ring (ignoring the small-small combination).  With a 34T inner ring this increases to 7 sprockets.  On the minus side the bigger spread of gears inevitably means more frequent changes between chain rings or more temptation to cross-chain.

Campagnolo don't make different chain ring sizes for the lower-end Centaur but there are third party rings available that fit the Campy 10s cranks so a little experimentation seems possible.  As a result, I did go with the 50/34 compact but I also bought myself a 36T ring made by TA, as the graph below shows, this basically represents a single downshift on all the sprockets with a new hill-climbing gear that may come in handy next time I visit Holme Moss.

Typical bike speeds for different chainring and sprocket sizes.

Before anyone gets the idea that this blog is recommending you attempt to change your own chainrings, let me remind you that Campagnolo suggest that this can only be done by them (doubtless with approved parts) and that you risk ending up with rings that are out of true, followed shortly afterwards by accident, injury and even death.  The cost of the carbon-wrapped cranks is a bit eye-watering so I don't think one should undertake this job lightly.

TA Nerius 36T ring for Camagnolo compact crnnkset

The 5th Chainring Bolt Mystery

Firstly, the chainrings are fixed with 5 bolts, 4 on the rings/spider and a 5th bolt that goes directly into a thread in the crank arm itself.  The bolts all have a T30 torx screw head but on the reverse the 4 main bolts have solid nuts (which are actually the bolts as it turns out) with wide slots.

Also, to make life interesting the 5th bolt has what looks like a tamper-proof plug in it.  A pair of tweezers reveals that is actually just a removable plastic plug - my assumption is that it is to keep the dirt and water from going down the Torx head and into the crank arm where it might cause trouble (such as corroding the thread in the crank itself).

Seeing red

The bolts are alloy rather than steel and the crankset stipulates a torque of 8Nm, however, the ones supplied with my crankset were stuck fast with what looks like a white, dry thread locking compound.  Most of them came away without too much trouble but two of them were stuck so fast that I damaged the slot-heads trying to remove them.  Beware, the teeth on those outer rings bite!

Initially I tried to undo them by holding the crank arm using the gentle grip of my workmate (which has soft wooden jaws) just to hold it still.  This frees up both hands to work on the bolts.  However, with stuck bolts I needed this lifesaving tip from the 'boston bicycle mechanic' to help me free them up.  With the torx head held fast by the jaws of a vice I could use the slot-headed driver in one hand and my other hand was free to turn the whole crank in sympathy with the nut.  If I had read that article first I might have saved myself some time and money!

So, having compromised a bit on getting a compact, mainly because I couldn't find anyone who could supply a 165 without red bolts, I now faced the prospect of sourcing replacements anyway.

Spare Parts

Full marks to Campagnolo's website for the pretty PDFs with clear pictures labelling the various spare parts.  It was clear they came as a set though it was a bit disconcerting that the picture didn't match the bolts I'd just taken out.  Also, my bolts are clearly marked with the codes from the Record bolts of 2010 and earlier (the images above can be expanded to read the FC-RE303 printed on the 5th bolt).  There are various (cheaper) third-party bolts which look like they've been designed as replacements for the Record bolts but nobody has updated their catalogs to say, one way or the other, if their bolts will fit the 2011 Athena/Centaur/Veloce cranks.  For the avoidance of doubt, BBB's BCR-53C product "specially designed to be compatible with Campagnolo compact cranksets" do not fit, though BCR-54C looks tantalisingly like the right thing, despite being described only as "compatible with Campagnolo 11 speed chainrings".

Having already had to wait to do the build due to work commitments, travel plans and then illness I was in a hurry to get this problem sorted so ordered a new set of Campy original bolts from Belgium (from All4Bikes) and watched my profit margin from doing a home build go up in smoke.

If the Bike fits, buy it!

When you do a Google search for information about choosing a frame size and fitting a bike you'll find a huge number of articles.  How do you choose whose advice to follow?  Also, at the end of the day the choice of frame size for all but the top end frames is going to be a simple multi-choice with most frames coming in 4 or 5 set sizes.

The starting point for selecting frame size is usually matching your height and inside leg measurement to the stated size of the frame.  For most bikes this is the measurement between the centre of the bottom bracket to the top of the seat tube.  The online bike shop Wiggle have quite a good page on bike fitting that covers the basics but also introduces perhaps the most important concept which is that the type of bike and what you intend to use it for makes a big difference.  Following the general advice on that site I'd expect to be looking at a 48-50cm road frame or XS-S compact frame.  I particularly liked their 'Ape Index' which introduces the idea that reach is also important and can be used as a sort of tie-breaker when you seem to be on the boundary between sizes.  Unfortunately it doesn't help me as my arm reach is basically identical to my height putting me on the boundary there too.

If you want to dig a bit deeper then you'll find that Wikipedia is a great resource for cycling information.  The page on Bicycle Frame Size goes into all the details.

Another highly respected source in the world of cycling is the late Sheldon Brown.  Sheldon Brown's website is a fantastic treasure trove of articles and advice on all aspects of choosing and maintaining bicycles.  His articles tend to go into a little more depth than other sites but I like his writing style and the way he is prepared to challenge existing ideas.  Unsurprisingly, in his "Revisionist Theory of Bicycle Sizing" he comes to the conclusion that the seat tube measurement should be secondary to the top tube measurement (the tube between the saddle and the head tube).

To help me visualise this problem I drew some pictures.  Using the published frame measurements it is possible to draw the range of saddle and bar positions for different frames, relative to the bottom bracket.  (The position of the bottom bracket relative to the ground and the wheels will change slightly with frame design and size.)  I used the adjustment ranges on my Cinelli Vai Bianca seat post and Selle Italia C2 saddle.

The first picture shows the range of saddle positions for a number of the frames mentioned in my first blog post.  The bold black circle has diameter 10mm and represents my current seat position.  Notice that the Ribble small frame appears too large here but in practice it is probably safe to insert the seat post further into the frame than the post markings indicate but on the more compact frames this would not be possible without the risk of fouling the bottle cage lugs (which protrude into the seat tube on a carbon frame).  This picture tells me that on seat tube length alone, the small Sportive and the medium Saetta are both likely to result in very small amounts of seat post being exposed.

My gut feel is that too much seat post inserted in the frame is as bad as too little, more contact area to get stuck perhaps?  In fact, the Saetta came with a 130mm alloy insert for the seat tube which you can see in the following picture.  Note that the fixings for the bottle cage lugs and 'braze-on' adaptor can be clearly seen in the tube (and will prevent the seat tube from being inserted too far anyway).

Moving to the front of the bike, a similar picture can be drawn for the bar position.  In this case the shaded areas result from changes in the number of spacers on the steering tube and the length of the stem.  Again, I chose to compare using a single product for comparison (the Cinelli Vai Bianca stem). You can get shorter or longer stems but the extremes seem best avoided if possible (as they leave less wiggle room later).  However, there is also considerable variation in stem angle which can be used to raise and lower the bars.  As far as I can see carbon frames tend to have taller head tubes (or it may just be the fashion of the day) but combined with the shallower angle of the Cinelli stem it makes for a higher bar position on the selected frames (key as above).

Despite my 'Ape Index' coming out neutral all of these frames represent a significant reach leaving me looking at the shorter stems, equivalent to selecting the right hand edge of each range.  The position of the Battaglin frame may be a bit inaccurate as they don't publish the head angle and I had to estimate this based on the likely fork dimensions and the top-tube length.

If you are having difficulty picturing the way these diagrams fit with the bike, here is both diagrams with the (fixed) bottom bracket position shown and the wheels added for context.

As I drew these diagrams (with a little help from my computer!) I did get to thinking about the triangle made by the three contact points: the cranks, centred on the bottom bracket, the saddle and the bar.  It is possible to rotate the triangle while keeping the same shape.  Rotating backwards will take a little of the weight off your arms while likely increasing your wind profile and rotating forward will do the opposite.  This point is made in another article on Sheldon Brown's website: The Myth of KOPS.  As a result, I marked rotations of 1 and 2 degrees either side of my current position on the diagrams which explains the smaller grey circles.

As you can see, within reason, adjustments to the stem and the saddle/seat-post can be used to adapt different frames to the same rider.  There was certainly a time when people were advised to ride the smallest bike they were able to get away with.  The argument then was that smaller frames weighed less.  These days, with materials like carbon fibre being affordable this may no longer be true.  Heavier riders can probably usefully use the extra strength provided by the larger frame sizes.  But as for the variation between manufacturers, perhaps the initial conclusion in "Bike Frame Sizes, Geometry, Angles and All That!" is valid in this price range: you might as well choose on the basis of colour.

So how did I choose?  Choosing a frame that I could source through my favourite bike shop was high on my list of priorities along with a little brand loyalty and romance (read 'colour') for Columbus/Cinelli.  The handling of my current bike could be improved by moving my centre of gravity back a little and increasing the distance between knee and handlebar - yes these have been known to collide when I'm out of the saddle at the end of a long day!  Strangely, the Saetta M is clearly too large for me but the S and XS are very similar in size.  I went for the S, rather than the XS - figuring that the slightly longer wheelbase might be more useful for reducing toe-overlap.

Crediamo in te, Saetta!

Or as Cinelli might translate it, "In Thunderbolt we trust!"

This is the first post in my new blog, swl10-speed. My other blog, called simply swl10 is about my work as a developer of software for e-Learning (and particularly e-Assessment).

The purpose of this blog is to document my experiences in buying, building and (hopefully!) riding my next road bike.  I decided to document this in the form of a blog because I often searched the internet for information to help me and found some excellent sources that I wanted to remember for future reference.  I also realised how hard it is to use search engines like Google to find genuine information about products.  In my work, I often search for information which has little or nothing to do with a product directly offered for sale and I've become used to finding useful information quickly.  But when browsing for information about the various bits of my bike I have found my search results swamped by online stores and the vast number of meta-stores that aggregate information from other online retailers surrounded by their own pick of targeted banner ads.

The Plan

I last bought a complete road bike back in 2001, over ten years ago.  In fact, the Shimano 105 9-speed components that came with that bike served me well right up until my front derailleur failed last year.  This event brought home to me the futility of persisting with 9-speed when the rest of the world had moved on to 10-speed, or even more.  I also decided to move from Shimano to Campagnolo (or SRAM) to better suit my short fingers.

With Europe's economy in particular need of a boost my starting point was to see if I could buy a European bike.  This may sound hopelessly romantic but I used to ride a Columbus-tubed Bianchi and it really made an impression on me.  In fact, it literally made an impression on me: we parted company after various sharp protrusions gouged my arms and legs as we slid across the tarmac in a tangled ball of limbs and twisted metal.  I followed my Bianchi with a British bike built with Reynolds 853 tubing before returning to the Columbus fold for an alloy Tifosi frame.  This time I was looking for a full carbon frame so I started leafing through magazines and buyers guides.

Provenance

When I came across this review of the Battaglin C12 bike I started thinking that it might be affordable to get a genuine Italian frame to support my Campy equipment - and perhaps even jump over 10 speed altogether and go straight to the 11-speed Athena range.  Battaglin's motto "Engineers of Emotions" (even when viewing the Italian language version of their site) certainly evokes the passion I recall witnessing the first time I told an Italian colleague that I rode a Bianchi road bike.  The company also boasts that their bikes are made in Italy but there is a fairly generous interpretation of what this actually means in EU law (as discussed in this forum post about the C14).  The general consensus about the provenance of the cheaper carbon frames seems to support the poster in this Italian forum: "c13 e c14 sono fatte a marostica, c12 no".

Firmly of the belief that, in my price range, the best carbon frames are made in the far east I could return to the basics of getting a bike that suited my riding position and my wallet.  I have to thank a fellow cyclist I met on the road for giving me a close up of Ribble's entry level carbon frame, the Sportive Bianco.  He was in training for an epic journey around the world, you can read more about Sean Conway's journey on his Cycling the Earth website.  The bike got sound reviews such as this one from Cycling Weekly.

A Sort of Homecoming

I must also thank another rider I met near Hitchin who was riding an updated version of the alloy-framed Tifosi I was riding.  He had recently tried their new carbon frame but hadn't enjoyed it and bought the new alloy frame instead (complete with retro graphics).

Still, that conversation put the idea in my head of going back and looking at the bikes/frames on offer from Chicken Cycles who sell bikes from a small number of brands including Tifosi and Cinelli.  The review of the Cinelli Saetta in Cycling Plus was positive, the main criticism seeming to be a mismatch between the quality of the frame and the components.  There's a more thorough review on bikerumour.com.  This year Chicken are offering a Centaur-equipped version (perhaps in response to this feedback) though the bike itself is no longer featured on Cinelli's website - only the Saetta Sprint is listed, a more expensive version of the same design.  The frame geometry seemed to be a better fit for me than some of the more exotic options I looked at and the Cinelli brand is not without romance, even if the frame really is made in China.

Having bought from Chicken before (through my local bike shop, Howes) I decided to stay with the Columbus theme and get myself a Saetta.  I contemplated getting the whole bike in one go but when I drilled down to the details I couldn't get all the components I wanted.  With no obvious savings for getting the complete bike compared with sourcing the components separately (except for my time putting it together of course) I decided to order the frame only, with matching Cinelli Vai Bianca seat post, stem and bars.

It's a long time since I last stripped down and rebuilt a bike from scratch so this is going to be something of a journey in itself.