Morning all – building a bike for my eldest and he has a set of Bombers (yes I know, bit the additional weight may help me keep up).
Unfortunately, the steerer tube has been cut too short, rather than waste his money is there anything out there that can be used to lengthen it, or can the steerer tube be replaced?
Cheers,

low stack headset.
low stack stem.

How much is it too short by ?

Very old model Marzocchi forks had replaceable steerers but you’d have worked that out if it was those by the split crown with bolts in the back. Other option is a new upper assembly but you’re well into 2nd hand fork money for those.

You can buy steerer extenders. Essentially a quill like an old type stem with a selection of spacers to make up the external diameter of the extension as needed, then you just clamp the stem on the outside. They work with steel steerer but seem to be too big for alloy ones. Try the System X one, available from any LBS with an ExtraUK account.

The steerer just reaches the top of the top head set bearing shell, looks like someone was a bit overly quick with a hacksaw so not sufficient to use low stack kit.
So looks like the quill extension is the best option – fortunately it’s a steel steerer tube.
Thanks for the speedy replies.
Off to the LBS we go!

Depends what sort of use it’s going to get.
Anything other than pootling I’d be wary of the quill type.

Low stack stem, and a Crank Bros headset

http://www.chainreactioncycles.com/ie/en/funn-funnduro-stem/rp-prod91491

Sorry, but no way would I let a child of mine ride a mountain bike with a steerer extension. Canal path pootling maybe, but proper trails? No chance at all.

If you went for one the the quill type steerer extenders I don’t see what the problem is.

Time was we were all riding quill type stems and I don’t see why the passing of time and people’s view that we are all now hardcore freeriders should make any difference to the mechanical capabilities of this kind of set up.

If it’s steel, could you not get a welder to extend it? I guess it might not be worth the cost, but if you know someone locally who you can trust – 18 Bikes maybe? – it might be an option.

Is it the fact it is a quill rather than Aheadset type stem?
If so I have ridden for years with a quill set up and over some big stuff in the Lakes and Wales without mishap. We also did it with centre pull brakes.
If there is another reason then it would be great to know what.

I have a crank bross colbalt headset – still in box never used

i think its the lowest available

think this may be what u need

http://www.wiggle.co.uk/bbb-bhp-2021-stem-extender/

I used a stem extender like the above one on an old bike, and it was fine. Wasn’t as short as yours though, it was halfway through the stem already. I would definitely be cautious depending on riding!

What forks are they?

Replacement steerers for these aren’t that expensice at £20 or so from UK Bike Store. Windwave can press new steerer tubes into press fit crowns but I don’t know how much it costs. If it’s not too much, its probably preferable than using an extender.

Cool – I have a stem extender sitting on the shelf from ages ago.
Will also check out Windwave – guessing anyone with a press could do this?
Cheers again all.

The reason quills arent a good idea is because they were originally for threaded steerers. Threaded steerers are usually thicker to allow the strength to be maintained where the threads are cut into the steerer. Where the quill wedge came into contact with the steerer was past the threaded section.
Ahead steerers are usually thinner and IIRC most manufacturers advise against using quills because of this.

I did the low stack thing recently.

The cobalt headset and a low rise stem will get you 10mm.

I managed lose the spacers that the other pair of forks had to make up for the 30 mm shorter tube on another set of forks, but since you don’t have these you’ll only get back the 10mm.

guessing anyone with a press could do this?

Guess again !

Low stack headset. Had the same prob on a build ended up using one of the dmr ones.

If you used a quill type extender how would you get the correct adjustment for headset ?

the bbb one i am guessing u put the quill end in the steerer tighten up then the spacers shown bring it up to the correct size for the stem then you tighten down the top cap as you would normally but how would you tighten the stem onto the spacers or do you leave the spacers of and use a undersize stem?

Did exactly as Mav12 said, but left the spacers on and clamped the stem to them, there is a small compression space to allow them to grip the quill, all quite clever.
Been for a quick blat down a few descents locally and it feels fine, headset may be in need of replacement so a low stack option is on the cards.
Thanks for all the info and advice, much appreciated.