Mavic Starfish 631 Chainset on Look KG196

[John J]

I've heard the earlier dura ace square tapers being referred to as "JIS low profile", but they are not the same as ISO.

I hadn't heard the term "JIS low profile" before, so I've done a little research.

The phrase seems to originate with the Phil Wood company, and first appears on the internet in 2004 on Sheldon Brown's "Harris Cyclery" commercial website referring to certain short Phil Wood axles:

http://tinyurl.com/pnqqcmv

In Dura-Ace terms, the only cranks using such short axles were the 7410 series: the last square taper Dura-Ace cranks before the introduction of Octalink splined pipe-billet axles.

I've used the 103mm BB-7410 unit, and hadn't noticed that its tapers differed in form from other short Shimano JIS axles. I have a couple tucked away somewhere, and when I get a chance I'll dig them out and measure.

You can follow the evolution of the phrase "JIS low profile" here:

http://tinyurl.com/zgty9az


and here:

http://tinyurl.com/jp9pekl

The various mentions of "JIS low profile" on velobase seem to be conjecture based on a misunderstanding of the Phil Wood description of low-profile (i.e. 7410 series) Dura-Ace cranks as "older".

Hello Jim, and thank you for that interesting overview. If you do get around to measuring one I'd be interested to hear your conclusions.
Regards
John

 

[mdvineng]

I would use a Mavic BB unit, made to match and allows some chain alignment adjustment too.