I need to get a new BB to convert to single speed, what spindle length do I need?
Shell is 73mm and I'm using DMR conversion kit on rear hub, thanks.
Try it with your old BB first and check the available chainlines with the chainring in the middle and outer positions on the cranks. If you're converting a cassette hub (freehub) with spacers there should be some scope to make adjustments at the back as well. Don't get too anal about it - use a chain that's been designed for gears and it'll cope with the chainline being less than perfect.
I always use spacers from a couple of old cassettes to align the sprocket. I have some 8-speed ones which are slightly wider to allow for perfect fettling.
However, last week I went dinglespeed. I put a 36 and a 34 ring on the front and a 16 and 18 on the back. So I ride 36:16 from home to the Stepping Stones on Cannock Chase (35mins) Swap to 34:18 to ride around the Chase for a few hours then when I've got back to the road, swap back to 36:16 to pootle home.
What they said...and even if you did need a new axle we'd need to know what crank you are using.
The old BB was a hollowtech 2 and is on my new frame. The cranks are RPM with a 46 t chain ring to use for work city riding etc. The only BB I have is a 68mm shell.
get anything, stick it all on then work out your chainline, then space the back accordingly (requires a small amount of maths)
Big John what do you use for tension? I like the idea but sounds so much faff one of these might be better
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They're both magic ratios on my Cotic Soul so with a new chain I don't need a tensioner. However I use a DMR Tension seeker and even with moving the jockey over the job takes about 2 minutes.
Anybody who rides with me will confirm I'm a faster fitter rider on singlespeed. With gears I just plod up the hills and lose fitness over a few weeks. I can't understand it either.
Not too bad then, hmm cx ss...even with moving the jockey over the job takes about 2 minutes
Thanks all