khatfull

Looking to replace my CDale Ultra with something lighter. Found something I like...the steerer is 7.75". By my measurement I have 8.00" from crown to the top edge of the stem with the spacers I want. Will the .25" pose a problem if using a compression plug?

Thanks!

electrik

If the stem can't be tightened down to the proper torque without crushing it then the steerer is too short.

That will depend on where the bolts are on your stem but, you're cutting it close i'd say... why can't you just alternate the spacers and say lose 5mm... is the stack that short?

khatfull

Yes, I'm down to the 18mm conical spacer for the integrated headset. Can't go any lower...and I'm FINALLY happy with this height. Good point about the bolts, I'll check and see where the 7.75" line falls, thanks.

khatfull

7.75" comes right to the center of the upper stem bolt....whatcha think?

HillRider

I wouldn't do it even if the new steerer is steel. If the steerer is carbon, don't even THINK about doing it.

In fact, most mechanics prefer to leave a carbon steerer long enough that it sticks up above the top of the stem and then add a thin spacer on top to get the adjustment gap. No way in hell would I leave a carbon steerer partially unsupported.

khatfull

Thanks HillRider. What do you consider a "thin spacer", 5mm? Less?

HillRider

Typically you need a 2-3 mm of gap between the top of the steerer tube and the top of the stem or top spacer, so if you cut the steerer so it extends 2 mm above the stem, a 5 mm top spacer will do.

I like to leave my steerers long enough to use a 10 mm top spacer but that so I have some height adjustment available if I want it. If you know you won't ever want to raise the bars at all, cutting the steerer to use a 5 mm spacer is enough.

operator

I'd recommend leaving about 15mm of spacers above - in case the headset decides to change stack height and/or stem is a little bit taller than normal.

HillRider

Well, I've never had a stem or headset grow. I assume you mean to allow for replacement headsets and stems with different stack or clamp heights.

DaveSSS 

I've "grown" a carbon steerer before. I've got one bike that has been in use for about 4 years with a steering tube that I lengthened by 10mm. It's really not that hard to do. The main requirements are some sort of thread insert with M5 or M6 threads. You can get either one at Ace Hardware. I first make a expansion plug replacement from epoxy putty formed around the thread insert. I then epoxy glue the plug into the steering tube so it will be about centered along the stem, or even a little lower. After that glue cures, screw a long bolt into the plug, so it extends above the top of the steerer. The bolt needs to be masked so epoxy resion will not stick to it. I found that an M6 bolt just fit into an ordinary plastci drinking straw and that worked great as a masking material. The last step, to extend the steerer requires at least two tubes of JB Weld epoxy and a no-stop 1" copper tube coupling that is 1-1/8" on the ID. Very lightly grease the ID of the coupling and place over the steering tube to the desired height. Fill the entire area with epoxy resin and allow to cure. The copper tube coupling should pull off easily and the center bolt removed. If the drinking straw remains, it should pull out easily with pliers.

When you're all done, you have the threads necessary for the top cap bolt and a steerer that is stronger than new and a little longer.

Here's a picture of one of my plugs with the bottom side shown. I use these glued-in plugs on my other two bikes, too.
[IMG]https://i34.tinypic.com/macwvt.jpg[/IMG]