ok to run stem with exposed steerer shim?

[killacks]

Is it okay to run 1-2 mm of exposed shim above my stem (It's a 1" steel steerer with a Thomson shim and a Thomson X2 stem)?

[AngryScientist]

Is it okay to run 1-2 mm of exposed shim above my stem (It's a 1" steel steerer with a Thomson shim and a Thomson X2 stem)?

no worries, especially with a steel steerer. all the shim on top of the stem is doing is allowing you to preload the headset bearings before tightening the stem clamp. as far as stresses go, anything above the stem is effectively not there once the stem is tightened. it's gonna look a little funny with a 1" nub over your stem, but structurally you'll be cool.

[killacks]

Thanks!

[lhuerta]

Is it okay to run 1-2 mm of exposed shim above my stem (It's a 1" steel steerer with a Thomson shim and a Thomson X2 stem)?

What exactly are you referring to when you say "shim", the actual shim that reduces the stem clamp inner diameter from 1 1/8" to 1" OR a simply a headset spacer above the stem. If the former, then I don't see how you will be able to preload your headset bearings given that the shim may not allow you to properly install the top cap?
Lou

[dan682]

I had a similar issue using the Thomson shim and X2. The shim is 40mm long and the X2 is 36mm. I ended up using a 10mm 1 1/8" spacer above the stem and 1 1/8 top cap. The inside of the spacer fit over the 4mm of exposed shim and contacted the stem directly. Hope that makes some sense.

[Ralph]

I think he means no spacer above the stem. Open space beween stem and top cap. Not sure you can get enough pre load just by leaning on stem and tightening stem bolts.

[Mike748]

I think you should put a 3mm 1 1/8" spacer above the stem so that the shim is fully inside the spacer and stem.

[killacks]

I had a similar issue using the Thomson shim and X2. The shim is 40mm long and the X2 is 36mm. I ended up using a 10mm 1 1/8" spacer above the stem and 1 1/8 top cap. The inside of the spacer fit over the 4mm of exposed shim and contacted the stem directly. Hope that makes some sense.

^This.

As posted earlier, I tried AngryS' suggestion and it seemed to work fine, albeit with some nubbage. Later, I added a 1 1/8 spacer above the stem. Look a bit cleaner that way, and the stem is shim is completely inside the spacer.

It was suggested elsewhere that I put an the extra 1 1/8 shim below the stem. Haven't tried this yet. I'm not sure what the benefits might be.