Saracen Hardtrax BB

[roboade]

Hiya,

Just removed a BB from a Hardtrax and I've a couple of questions if anyone can help. Size is 68 x 127, seems too large as the non original FD has the low screw fully screwed in before the left side plate gets near the chain when in low/low gear combo. Also distance from centre chainring (also non standard) to centre of seat tube is 60mm, I'd have expected 50mm (all my other bikes are). Can I safely drop down to 113/115 length BB spindle?

Thanks

 

[Bimly]

Sure it's the right crank. 127 sounds right for old shimano.

 

[roboade]

Probably not, it's a collection of random parts, not one for the purists. Previous owner had a 48T big ring. The entire unit sat much closer to the BB shell than the chainset I have fitted. Anyway, have spent an hour with a hammer and various tools, so I have a removed BB. Will try a 68 x 113 and see if that's any better, there's enough space so that cranks don't hit chainstays.

 

[Bimly]

If it's a more modern (modern being relative) like lx it will need a shorter bb. If your on 127 and you say your chain line is 60, you should be between 47 and 50. On a standard 28mm steel seat tube I would expect the bottom end of that range so....you need to loose 26mm . So 113 SHOULD be about right.

I have made this exact dimension swap many times going from late 80s shimano to say late 90s stuff. Is not a hard and fast rule.