Wednesday 26 September 2012

The Winter Bike: Up Cane Creek Without a Paddle

As the late UK Summer suddenly turns into Autumn it is time to start thinking about the winter bike.


My winter bike is an old fixie that I had built by Deeside Cycles. The shop appears to still be in business under the name Graham Weigh cycles. My fixie was a Graham Weigh alloy track bike with a road fork and no decals, for that minimalist look. The idea was minimum maintenance, maximum visibility for commuting. I had it painted bright yellow. Ten years on and the frame is looking seriously the worse for wear and the mirage bottom bracket is shot to pieces. Time for an upgrade.


Riding fixed is much more fashionable now and so there's a bit more choice. You don't have to ride a track frame anymore. That said, I'm still surprised how little choice there is if you want to get more generous clearance for mud-guards. I actually had my Graham Weigh frame drilled for mud-guards originally but the clearance is never going to be very good on a pure track frame and I ditched them in favour of a rear splatter guard later.


The whole thing about a winter bike is trying to keep costs down so I couldn't resist going back to steel and the special offers on the Pompino from On-One (aka, Planet-X). I've seen a few of these around Cambridge and someone I used to work with commuted on his and seemed pretty happy with it. On-One will fit headsets for you but when you get an end-of-season discount on a frame it seems like a good excuse to add to the tool collection. The headset press from Cyclus seems like a perfectly good tool for a DIY-er and will pay for itself fairly quickly.


Sticking with the 'cheap and cheerful' theme I bought a Cane Creek S2 headset. As the inventor of the AHead design, what could possibly go wrong? The supplier will remain nameless (I didn't buy it from On-One themselves) at this point as I haven't given them a chance to comment on the problems I had!


Although lots of online stores offer the S2 for sale the S-type headsets don't seem to be documented on Cane Creek's website. It looks a bit like they've had a make-over as the legacy product area is a bit thin. Fortunately, the old site is accessible through archive.org. The S2 page contains a useful diagram of the headset and the manual is still available too.




See the full size image on archive.org.

It is lucky that these sources are still around because when the headset arrived it was just a collection of bits in a poly bag. No instructions or diagram to check the bits off against. It looked like everything was there, the supplier had even packed an extra compression ring for some reason.


When I fitted the cups to the frame I must confess I thought it was odd that the two cups where identical and that, as a result, the logo on the top cup would be upside down. Manufacturers are normally rather vain about this sort of thing. But, the design of the S2 includes a top cap that fits over the upper head-tube cup completely. So the upside down logo is obscured when the headset is assembled. Having the two cups the same would certainly reduce the chances of people installing the cups the wrong way round. That must be it. I installed them.


Except, the cups are not supposed to be the same. If I'd looked more closely at the diagram I would have seen that the lower cup is supposed to be a bit deeper than the upper cup so that it comes down over the rubber seal on the crown. I didn't notice this and proceeded to build the bike. When I came to pre-load the headset by tightening the top-cap I just couldn't get the bearings to load properly. Either it was stiff and noisy or it was too loose.


It was only then that I started poking around on the web and realised from a few image search results that the upper cup should not have a printed logo at all. I'd been shipped two lower cups. I'm not sure if the diagram on the old Cane Creek site is really to scale but a bit of image editing shows the problem area. The longer cup comes too close to the top cap. Sure enough, before the bearings are properly loaded the top cap was starting to rub on the cup. This was confirmed by tightening the top-cap until the headset felt stable and then turning the handle bars. The top cap was sticking to the cup, instead of turning with the steerer and the spacers which are pressed against it.



I've edited and exploded a detail from the diagram to show how it should be (on the left) and how it turned out (on the right).


A Stroke of Luck


The next day my son took delivery of a freewheel and in the packet were a couple of 0.3mm spacers. As luck would have it they were exactly the right size to fit on a 1 1/8" steerer. I guess a proper 1mm spacer would have done the trick too but I didn't have a spare and it was a Sunday, not a great day for buying such a specialist part.


I fitted the two spacers just below the top-cap so that they sit on top of the compression ring. They provide just enough extra stack-height on the bearings to keep the top-cap away from the cup. The whole thing now works perfectly.


I do intend to take this up with the supplier but the hassle of removing the cups to send them back would have just meant delays. Also, I don't yet have a proper tool to remove headset cups and I'm not sure what I could improvise with. I know, I could just take it to my LBS and admit defeat but half the fun of buying cheap stuff online is getting yourself into, and out of, scrapes like this.






Wednesday 12 September 2012

Stripping My Old Frame: Removing a Stuck Octalink Bottom Bracket

My old Tifosi bike was fitted with 105 equipment. I've recently replaced the bike with a completely new home build after many thousands of trouble-free riding miles (see previous blog posts about that project). But I still have a fondness for the Tifosi frame so last weekend I set about stripping it down so that I could consider its future properly.


After almost 8 years of use and many thousands of miles without a complete strip-down and rebuild it was certainly possible that some of the components may be a bit hard to shift.


Carbon forks and 105 callipers: written off


I'm a bit gutted that my carbon fork and 105 brake callipers have simply been trashed by so many years, quite literally, in the front line against the British weather. Removing the securing nut from the back of the fork was stiffer than I'd expected. The exposed bolt has fused with the nut so when I removed the nut half the bolt came away with it. Unfortunately, it gets worse. It turns out that the alloy crown on the fork has corroded badly too and bonded to the brake calliper itself. I could get the drill out and start trying to remove the bolt from the crown but there's no point because the nut needs a surface at the back of the crown to tighten against and this has completely disappeared in a puff of white aluminium oxide. From now on I'm going to remove the front brake (from my other bikes) and re-grease at least once a year.


Crank Removal


The Shimano Octalink system replaces the traditional square-tapered spindle with a hollow spindle with eight splines that fit snuggly in the crank arms.


Despite so many years uninterrupted use removing the cranks was fairly straightforward once I had the right tool. My crank puller was designed for square tapered cranks. The puller really works by holding the crank still and pushing the spindle (and the rest of the bike) away from you. To do this it needs a firm surface on the spindle to push against. For square tapered cranks there is plenty to push against but the Octalink presents a very small lip (this is the older first generation Octalink system). To engage with this you need a specially designed crank puller or an adapter tool from Shimano. I've seen tips on the internet about using various coins to do this but I have quite a collection of British, European and US change and I wasn't happy with the fit on any of these coins. My local bike shop had the required adapter which made the job easy.


Bottom Bracket Removal


The real challenge came when I tried to remove the bottom bracket. Removing the non-drive side is easy because it is just a small plastic sleeve. The drive side actually contains the spindle, bearings and the housing and was firmly stuck in the frame.


Years ago a bike mechanic I used to use would weld the spindle to the bottom bracket shell and then reattach the crank and use that as a lever in this situation but that trick only works on the (even) older loose bearing types. However, for any type of job that required use of an extractor tool he would always place the tool in a vise and use the bike (or wheel) as the lever.


Even with the vise trick, getting the extractor tool to keep its grip while I applied the leverage was still a problem. Various people suggested using a skewer or other long bolt to clamp the extractor to the bottom bracket. I could not get this to sit securely with my tool which has a wide open end but I did hit on a slightly simpler solution. I used one of those cheap spanners you get in portable tool sets and the orignal crank bolt to clamp the extractor.



Finally I was able to securely apply the leverage I needed to remove the bottom bracket!