Hello everyone,

So I am building up an old Campania frame and have to get a bottom bracket and crank. The crank i'm looking at getting needs a spindle length of 108mm, this is what the guy on JensonUSA chat told me. The crank is Retrospec 3 piece crank. Now for my bottom bracket options i am looking at the Shimano UN54 since i have a 70mm shell width. My options for spindle length on the bottom bracket are either 107mm or 113mm. Which one should i choose if I am making this a 1 x 5 bike NOT a fixie?

Thanks

You don't have all the needed info, because many spindles are asymmetric, meaning they're a few millimeters longer on the right side.

But assuming that both are symmetrical go with the 107. It's a difference of only 1/2mm per side, and makers don't write their specs that close.

https://harriscyclery.net/product/shi...24tpi-1802.htm

Thanks! ^ that is the bottom bracket I am looking at. Should that 107 work for my needs?

Should ? no clue, Retro Spec ? it is not a known crank, who are they?

get several lengths .. to make sure , and return the ones that don't work ..
Generally,
Low profile cranks use a short spindle, often symmetrical
wider profile type sit out further , come back in, use an Asym BB..
and need a longer spindle to place the chainring in the same place
the right angle type take the longest spindle. but can be lowest 'Q'


Guess if Jenson sold you that , go with what they said.