Tandem Cycling - 140mm tandem rear hub in a 135mm alu dropout?

Is there a problem/risk with fitting a 140mm hub in a 135mm aluminium frame rear dropout? I wouldn't cold set it obviously, but just spread it when putting the hub in.

Thanks in advance for your collective wisdom.

I'm no metal expert but I have always been told to never bend aluminum. On those occaisions when I have bent aluminum in non cycling applications I either broke the aluminum or clearly weakened it. So...I would never consider bending anything on an aluminum bike frame.

Bill J.

I guess it's really a matter of sematics or definition. All materials strech and bend. I guess the quesion I have is if I pre-flex ( not cold set as steal but pry open and flex) a tandem frame 5mm for the rear hub, is there a problem?

I'm sure there are a lot of people with opinions, but I want facts and figures. Can it be done and are there quantifiable risks?

If you want numbers you probably need to talk to a materials engineer, or at very least a framebuilder. Conventional wisdom though is that in an aluminum frame, you should always use the size hub it was designed for.

I've been doing it for about 3 years on my Cannondale without any problem.

i wouldn't worry about it. back in the old days i reset my bonded al fork on my single bike 2 or 3 times after crashes and it worked fine. i was only having to reset i couple of mm's not any huge amount.