Icarus bottom bracket woes

[KermitGKona88]

I recently purchased an Icarus chainset, looked on the catalogue and saw the bottom bracket should be a 111mm, so I purchased a modern Centaur bottom bracket in 111mm, and it is nowhere near, right side slides all the way on, have the tapers changed ? If so which models have the old taper, or what axle length will compensate ?

Any advice appreciated thank you

 

[hookooekoo]

It is possible that the tapers are different. If you try to assemble JIS standard taper parts with ISO standard taper parts there may be a problem. Although the angle of taper (2 degrees) is the same across different standards, the length of the taper and the starting size of the taper can vary.

This website has a few details on different tapers:

Square Taper Bottom Bracket Interchangeability

Dimensional standards for square-taper bicycle bottom-bracket spindles, and the limits of interchangeability among them.

sheldonbrown.com

Elsewhere it is stated that:

Campagnolo and tifosi BB's are iso taper and fit iso taper campagnolo chainsets from 1995 onwards.

Square taper threaded BB's | The Cycle Clinic

Bottom brackets; Square taper ISO and JIS taper Campagnolo and tifosi BB's are iso taper and fit iso taper campagnolo chainsets from 1995 onwards. Shimano and tange seiki BB'S fit practicaly very other square taper chainset (tthere are exceptions though).

thecycleclinic.co.uk

Which might suggest that there was a change in the taper standard used by Campagnolo around 1995.

A further possibility is that the internal taper on the crank has been widened by overtightening and/or use of grease on the taper faces during assembly. I always assemble with grease on the threads, but with the taper faces dry and degreased to avoid the possibility of expanding the internal taper or possibly even cracking the aluminium crank.

If you have a digital vernier you could try making some measurements, and looking up the ISO and JSI standards for bottom bracket square tapers.

As an aside, LIDL were selling digital verniers in their middle aisle this week for under a tenner. Always useful to own one for measuring ball bearings etc.

 

[Rod_Saetan]

I think a modern Centaur BB is asymetric, or not, and the Icarus needs symetrical, or not.

I hope thats clear.