Head tube reducers

[Double-E F]

Hi all,

Would you expect that using heat tube reducers (1 1/4" > 1 1/8") affects (positively or negatively) the chances of that head tube cracking, let's say for a '94 Yeti ARC that is not ridden vigorously?

Cheers!

 

[troje]

Does it not just simply make your headset thicker? I think it just reinforces the lot.

 

[elite504]

Shouldn't make any difference. (Simplified) a 1 1/4 cup is a 37.00mm shaft diameter, going into a 37.00mm headtube bore.
A smaller cup with an adaptor should still result in a shaft diameter of 37.00mm pressing into your frame.

If we were to split hairs and consider the minutiae of "tolerance stacks", you could double-stack a cup at highest tolerance, and an adaptor at biggest tolerance and end up with a ++ tolerance on the overall. But providing you measure it and it's not oversize, you should be fine.

In terms of "reinforcement" that I think you're hoping for, most adaptors I have seen are shallower than the headset cups that press into them, resulting in less distribution of load, not greater.

If we look at it another way, I know sometimes our backs are against the wall, but when there are parts available that are the right size, why would they not be chosen and preference given to adaptors?