Syncros Ti BB… different???

RockiMtn · Mar 17, 2011

Got two NOS recently. One's 122mm axle and the other is 107mm. But that's not the only difference. The cups are completely different on them and seems the shell lengths too.

My only guess is that I've read there are single and double row bearings. Can both be used for 68mm and 72mm applications???

malt · Mar 17, 2011

Could it be that the 107 x 68 is for low pro cranks and the 122 x 72 is for old cranks?

GT-Steve · Mar 17, 2011

Thread pitch on the cups looks different too?? Italian/English threads??

The difference in cup lengths looks greater than 5mm too :? :?

RockiMtn · Mar 17, 2011

Nope, both are marked 1.370x24 and should be english threading. At least that's what I confirmed before buying. :?

The 122mm, I have a similar used one which is installed.

RockiMtn · Mar 18, 2011

played with the lockrings and they are interchangeable between the two BB, confirming that it's the same pitch and thread direction.

comparing these to a Race Face taperlock BB that fits 68/72 shells, the Syncros are substantially longer. the shorter one is just long enough to accommodate the lockrings. The longer one has significantly excess threading, which i've also confirmed having installed a used one into a bike with a 68mm BB shell.

curiously though, the larger bb is a few grams lighter than the smaller one. :shock:

sancho · Mar 18, 2011

Looks like the 122mm bottom bracket is for 73mm bottom brackets only. It probably has a bigger space (5mm?) between the bearings.

one-eyed_jim · Mar 18, 2011

Check out the 1994 Syncros catalogue in the archive here:

http://www.retrobike.co.uk/gallery2/mai ... emId=15728

One is a Pro Series (single row bearings) and the other is a Hardcore (double row bearings). The catalogue mentions "radical outboard bearing placement" as a flex-reducing feature, so presumably the cups are supposed to protrude from the shell on the longer model. That also allows for some chainline adjustment.

FluffyChicken · Mar 18, 2011

The 107 would need to be that design to cater for the cranks as e.g the M900 needs the resess, that's why the shimano's are that design
The longer one wouldn't matter so can be made stronger witht he bearings wider apart..
But the answer is I don't know.
and would need to read the catalouges.

A 73mm can work in a 68 shell, but not vice versa (normally)

WD Pro · Mar 18, 2011

Off topic sorry

What frame is shown in the pictures ?

WD

one-eyed_jim · Mar 18, 2011

More here:

http://www.bikepro.com/products/bottom_ ... ncros.html

Syncros Ti BB… different???

RockiMtn

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malt

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GT-Steve

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sancho

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