Bionx for 145mm dropouts

[Erikt]

I recently got a decent deal on a Bionx 350 SL that I intended to put on my Cannondale tandem. But as it turns out, the dropouts on this tandem are 145mm and the Bionx is designed for 135mm. Had it been a steel frame, I could probably stretch each rear triangle 5mm quite easily, but this doesn't seem a good idea with aluminum. I could perhaps flex it about 2,5 + 2,5 mm and then add a 5 mm spacer, but I would then need to dish the wheel further, and the cassette would be offset by 5mm relative to the derailleur.
As far as I understand, the the (anti rotation) axle collar comes off (with a puller tool) - does Bionx provide a longer axle collar for 135+ dropouts? Or is there any other way to install a Bionx on a wide aluminum frame? I really can't seem to find a sollution on google. I've seen people install on wider than 135mm dropouts but I'm beginning to doubt if anyone did it on an aluminium frame.

Erik

 

[crichman]

The SL motors don't use a puller and an adjustable collar the way the older PL motors do. You need to use the correct interchangeable bit to ensure that the reaction collar and ultimately the torque sensor is at the correct angle.

No matter what you do, make sure that the non drive side (with the reaction bit) is fit properly into the dropout and torqued down tight -- you don't want that bit spinning out and destroying your dropout, your wiring, and various bits of the riders!

I share your concern -- there's no problem cold-setting a steel frame, but I wouldn't do that with aluminum. All of the shimming would have to be drive side, and I just don't know that you'll have enough axle left for proper engagement on that side.

Charlie

 

[Erikt]

crichman - I assume that the SL model still needs a puller to remove the collar even if it isn't adjustable, right?

If I could have someone machine a longer collar, wouldn't that solve the problem? If the collar would be made to be 8mm longer (rather than 10mm), I think I would still have just enough axle left for the nut to be properly tightened.