BB sizing help

[jim55]

No it's not but it gets it fitted and useable ( if chain lines right , thanks for advice btw

 

[Tim Hall]

This is for a fixed wheel, yes?

When I did my first quick'n'dirty fixed conversion, I used an old style BB, much as you're doing. What I did find was that the axle wasn't symmetrical (unklike most cartridge BBs), giving more scope for fiddling around with things to get the chain line closer. I also found that the fixed sprocket had a shoulder on it, so screwing it on with the shoulder inboard gave a different chain line compared to having the shoulder outboard.

 

[jim55]

Yeah it's for fixed , cheers for the advice , il have a mess about with it , got my crank today , new chain and hopefully il get the wheels tomo , so I can fit it up and see what I'm dealing with , before stripping it for powder coating

 

[jim55]

Right guys more advice needed, I got my wheels today and fitted tyres and stuff and put them on bike so I can see. Where chain line needs to be , the crank needs to move inward ( towards frame )by about 3 mm I guess , this is obv just a visual measurement so it's in the ballpark .
My bb I fitted has a spindle width of 122 mm so is the size I want 116 or what ( as the measurement has to b applied twice ) il have to order one of the right size

 

[Citius]

What wheels are they? Might be easier to fit a spacer on the rear hub. Or re-fit the chainring on the inside of the crank spider.

 

[jim55]

No il have to buy a new bottom bracket anyway as when I screw in the cups it's compressing the bearings and the spindle won't turn , it must be designed for something with a bigger Bb shell , the wheels are condor uno so condor hubs that are very smooth so I'd rather not mess about with them , I need to buy a bb anway so il get the one that suits .
With the 122 one fitted the chainring sits a good 8-10 mm from chainstays so clearance is good I just need it brought in by about 3 mm and it'll b spot on