Sunday, 16 July 2017

When 10 becomes 11!

It's over 5 years since I started this blog with a collection of posts on my home-build bike project: a 10-speed Cinelli Saetta. In fact, it's been over 3 years since my last post, largely because the equipment has been working well and I've been out pretending to be a cyclist instead of pretending to be a mechanic.

That is, until about a month ago. I had noticed that the right-hand shifter had started to skip occasionally, sometimes I thought it was just due to vibration or hitting a bump at the wrong moment but it had been getting worse and after a 60 mile ride of up-and-down roads on a hot day it was just too much. The lightest press on the button to change gear and the chain would jump to the smallest cog. This question on the Bicycles Stack Exchange site contains a detailed description of the problem and the likely cause. This is a Centaur 2012 10-speed lever, most likely a new lever body is required. I could have stripped it down and sent it away and/or got a replacement, perhaps, but it's a carbon lever so getting a match might have been tricky. A replacement set would make sense but Campagnolo don't make the Centaur anymore (I know the name's about to be reborn but it's not the same thing).

Inevitably there were a number of other items due for replacement too. Although I was on only my second chain in 5-years (about 15K miles) both the chain and cassette were up for replacement. The more I looked in to it the more I felt that this was my Spinal Tap moment. Definitely not the cheapest option but a new learning curve and the only way to buy new levers that had the same multi-shift action that the 2012 Centaur shifters have.

Step 1: Chain Rings

So this is the first post in what I anticipate will be a short series as I upgrade my bike to 11-speed.

Can you run an 11-speed chain on a 10-speed chainset? Obviously the official advice is "No" from the manufacturer but the unofficial advice on the internet appears to be "yes". One thing is certain, I wasn't about to replace the cranks themselves. I have a Centaur 165mm crankset (only available in carbon) that is no longer available to buy new. I found this pretty disappointing, I don't feel like the 165 was given a proper chance as it was marketed as a special thing, not just as an option on the higher-end cranksets. I have personally found it very helpful. The good news is that I can keep using the same crank arms if I replace the chain rings. I was already using a hybrid Campy 50T outer with a TA Nerius 36T inner and was happy to see that SJS stocked the TA Nerius 11-speed equivalents.

I don't think the wear was too bad but the 50T ring (I live in the flat fens of East Anglia so I spend a lot of time on the outer ring) does look like it is beginning to show it's age. Perhaps I should have replaced the chain more often?

One quick note about removing the cranks themselves. I know there are a lot of special puller tools out there but the only special bit of kit I used was the special plug that inserts into the open end of the crank to act as a surface for the puller to push against. The carbon crank has a relatively flat service and I found it easy to use a general purpose gear puller (I have a Laser one) to remove it.

Chain Ring Bolts

Removing the crank bolts is a bit tricky because they are really soft and will be easily ruined. Yes, I did this to my cost 5 years ago when fitting the 36T. The trouble is, they came with blue thread-lock on them originally and required a fair amount of force to shift. The guide says you only need to do them up to 8Nm. I greased the threads when I put them on again (5 years ago) and have not had to touch them since so they will stay put if done up properly. As a result, I was able to undo them this time without too much difficulty: put the torx head in a vice and then use both hands to hold the crank and the chain ring bolt tool steady as you turn both to undo them. I kept the pedal in the crank as it give you something to hold on to.

New Chain Rings

Installing the new chain rings is pretty easy. The outer ring comes with a chain catcher that takes a small torx driver on the inner face and has a small hex nut on the outer face (I had to resort to my micro drivers for something that small). But, it lines up with the crank arm to stop the chain getting stuck between the arm and chain ring so you need to put this on before you put the ring on the crank; otherwise you won't be able to tighten it up very easily. (A reviewer on the SJS site says it has already fallen off - hopefully I've avoided this by tightening it up first.)

The end result, a Campagnolo Carbon 165mm crank with 50/36 11-speed TA chain rings.

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