Bought some 2nd-hand forks. Steerer's a tad short. With a Thomson stem (40mm steerer 'insert'), there's 12mm gap between end of steer and cap (ie. 28mm of the steerer is clamped, rather than c.35mm).

Is this not enough steerer clamped in the stem (it's on a SS so gets a fair bit of tugging as I labour uphill)? Is it risky or fine?

Ta

Thomson state no more than 3mm

What length is the steerer out of curiosity?

What could possibly go wrong?

I would want the top of the top bolt on the stem to at least be level with the top of the steerer tube, I had a similar problem once with a set of second hand forks, bought a low stack stem, funn something or other.

is it below the center of the top bolt?
that would realy be the critical question.

FFIW, Thomson stems do have a habit of breaking due to over stress on bolts. I personally know of 2.

3mm perfect.

Above top bolt legal minimum -me lord!

if your stem snaps off its not enough, if it does not then it's fine!!!

Sorted 😉

Thanks all.

Top bolt looks pretty much level with top of steerer.
Steerer's c.190mm (Pace RC36's)

My guess is it'd prob be fine, but just looks a bit 'apprehensive'!

Above top bolt legal minimum -me lord!
meh. I had a stem for which the top of the steerer was around the middle of the bottom bolt. It was fine.*

*this is a lie. I was on the tribars going round a corner at around 45kph and the stem decided to part company with the steerer. It hurt.

When you are ragging it down a hill, the last thing you want in the back of your mind is………will that stem hold ??

I think i know the answer personally !

hmmm on my hack bike the steerer is way too short only comes up to the first bolt on the stem…found an extra long bolt to secure the top cap.
seems firm and its only used to get round town…being used by a mate at the min, maybe il just check its secure tomorrow 😯

If you want to keep the stem, you could always change the headset. Changing from for example an FSA Orbit XL II to a Cane Creek will get you between 5 and 10mm more steerer to play with. I did the oppposite as my fork crown fouled the downtube.

If you tighten the top pinch bolt on the stem then you can be persuading it to slip off! also I have seen a few of my friends (monkey fisted) completely misshapen the top of their steerer!

I would say get a lower stack stem (and/or) go for a lower stack stack headset, I think the crank brothers headsets are one of the lowest stack around, something like 21mm!

Go for it would be my tip.

My other tip would be to set aside the money you saved on the 2nd hand fork so you can use it for expensive dental reconstruction when you need it 🙂

I like my steerers to be higher than the stem, and put a spacer on top to compensate. I also own all my own teeth.

I like my steerers to be higher than the stem, and put a spacer on top to compensate. I also own all my own teeth.

I do the same, but more because I would rather leave the steerer as long as possible 🙂

get a headdoctor

how will that help tom?

peace of mind

its no called that is it… its one of them long bolts that go to the bottom of the steerer then screws into a bolt like thing at the bottom and the top cap at the tom it replaces the star nut? use it on triple clampforks quite a bit

again how does that help with a steerer being too short?

what guitarhero said.. 😉

because it pulls the stess through all the front of the frame instead of the top of the steerer and stem

im tired

I like my steerers to be higher than the stem, and put a spacer on top to compensate. I also own all my own teeth.

I do the same, but more because I would rather leave the steerer as long as possible

me too! why cut it short as it limits who can buy it s/h, you can't muck about with stem height, what happens if you get another frame with a longer head tube. i could go on…

DON'T CUT STEERERS less than about 220mm IMO.

But it looks shit? If my steerer were 220mm I'd have about 50mm of spacers on top of my stem 😀 Thatd be just lovely getting that driven into your abdomen.

DON'T CUT STEERERS less than about 220mm IMO.

That's long! I don't have any forks with steerers over 195mm, my Revs have a 170mm steerer tube.

Can you get a new steerer from pace, i know on the older forks they were replaceable, iirc…
might be cheaper than a new headset?

I had the same from a set of ebay forks.. You can usually safely chuck the top cap from the steerer, and run the stem directly on the conical washer (only works on sealed bearing headsets) and get a nice low road stem. Sorted!

Not as nice as your thomson but a truvativ xr stem ( not the current version, mind ) is very low stack height and fixes with a single 6mm bolt in the middle. I used one for just this scenario and it was fine. Ss too.

I doh't think it's about any particular measurement generally, I think the main thing is that the top of the steerer goes above any hole in front of it, in the front part of the clamp.

Check for low stach height stems – truvativ & race face solved this problem for me