Hi all,

I have recently acquired an older bike with 1" threadless steerer. I'd like to put a 1-1/8" stem on it. I know that I can get a shim to do the job. My question is: what size of headset spacers should I use below the stem?

It seems to me that 1-1/8" spacer would be more secure as the stem is pressing on it. But 1" spacer would look better on top of the headset cup. What would you do?

Thanks!

repeat :https://www.bikeforums.net/showthread...re-to-find-one

yea a 1" spacer will shoulder under the shim, that is inside the stem,
9/8 cap will push down on all..

Yes, you want 1" spacers so they are a no-slop fit on the steerer itself. The shim will support the spacers and the spacers have thick enough walls that they will overlap the bottom of the stem also. Just be sure the shim isn't so long it sticks out of the bottm of the stem clamp and trim the excess if it does.

BTW, many shims have a flange at one end so they won't slip all the way through the stem clamp. If you install the shim with the flange at the bottom of the stem, it will make a solid shoulder for the spacers to push against.