Saturday, March 3, 2012


When I posted a while back about my Colossi track bike (TT conversion), I mentioned how the cranks were the hardest part. This was due to the fact that although I'd bought a C-Unit fixed gear crank, I hadn't bought a corresponding bottom bracket. As such I was trying to put a crank meant for a 111mm BB onto a 102mm Campagnolo BB. This meant that when I put these cranks on with the 46t chainring it came with the chain ring and bolts actually rubbed on the frame. I managed to get around this as a short term solution by putting a 51 tooth ring I happened to have knocking about that had the same 144mm BCD as the C-Unit, countersinking the bolts on the back of the C-Unit crank, then adding some washers. After which I had about 1mm clearance back to the frame and a bad chain line. But at least the bike was usable.

This brings me to the longer term solutions. I could either put a longer BB on, or search for a track chain ring to fit my Campagnolo cranks. I decided on the latter, as if I decide to covert back to geared TT then it would be nice to keep the same crank and BB. Actually finding this ring proved to be much harder than I thought- 135mm BCD track rings are pretty rare, as this is Campagnolo's road standard BCD, and for their track cranks they go to the 144mm BCD track standard, as do Shimano (normally 130mm BCD). Luckily, I came across the excellent who supplied me with a 'Made in the UK' 48t 1 1/8th 135mm BCD chain ring for a very reasonable 30 quid, and posted to the other side of the world within a week for a fiver. Problem solved, and pretty pimping with my gold chain ring bolts to boot. P Diddy eat your heart out.

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