My lbs says they can’t cut the extra length of the steerer tube on my P4. They said there is something inside the tube that is bonded in there and can’t be cut. Does this sound right? Are there any solutions to this? I hate having a fast looking bike with an inch of spacers on top of the stem!!! Help!!!
Good god I hope not, mine is all the way down.
Run away very fast…
Hi Russ,
There is probably a star nut bonded in there. If it is possible to make the cut below the level of the nut inside…and then discard the piece with the nut bonded into it…then you can sink a new star nut into the shortened steerer tube.
It’s also possible that is is not epoxied in place. That was the case with my P3C…so I was able to pound the star nut down to a new position.
Good luck!
It looks like I could cut below the nut.
Do you know how that sucker is stuck in there? How hard did you need to pound it down?
It looks like I could cut below the nut.
Do you know how that sucker is stuck in there? How hard did you need to pound it down?
If you’re asking how hard you need to pound it down you need to take it to a competent shop seriously.
There is a sleeve that is bonded into the fork and then the star nut acts like a normal star nut on the fork. But really take it somewhere and have them do it. You don’t want to mess up and be out a 300 dollar fork.
Cervelo provides instructions for proper installation of 3T Funda Forks which may or may not be relevant to your fork model:
http://www.cervelo.com/...Fork_instruction.pdf
The instructions above are for forks that come with a 75mm aluminum sleeve which is epoxied inside the fork steerer tube and the star nut is then pressed inside the sleeve.
My understanding is that you can still safely cut down a small portion of the steerer and sleeve off and then press the star nut down after it was glued just so that the star nut still rests inside the glued sleeve and not the bare fork. This process best left to experienced mechanics.
You absolutely should NOT cut below the glued in sleeve and try to insert a new star nut into a bare carbon fork! That sleeve is there specifically to provide a surface for the wings/prongs of the star nut to safely work against without damaging the carbon. Someone said the aluminum sleeve is 75 mm long and I believe that’s correct. If the star nut is only part way down the tube, you can drive it deeper, then cut off some of the excess at the top. Just be sure to leave some safety margin and that you don’t drive the star nut clear out of the bottom of the tube. (If you do, insert another star nut and make sure it stays in the aluminum tube. The original star nut won’t hurt anything as long as you aren’t actually bolting into it. It may require a star nut for a 1 inch tube since the aluminum tube is reducing the interior diameter of the 1 1/8" carbon steer tube. Something to check out if you get into that problem.)
To the poster who said their sleeve was not bonded in … YIKES!!! I guess once the stem is clamped down on the steer tube it really wouldn’t matter much, but it still sounds like some lazy bike building. Compromising on the stem/steer tube area doesn’t seem wise to me. I’ve assembled several 3T Funda forks and two P4s … all with the epoxied aluminum tube. It’s not hard to do it right. I like the arrangement. Nice, secure and solid. Way better than a compression plug, IMO.
Thanks for the comprehensive answer. I owe you a beer.
My lbs says they can’t cut the extra length of the steerer tube on my P4. They said there is something inside the tube that is bonded in there and can’t be cut. Does this sound right? Are there any solutions to this? I hate having a fast looking bike with an inch of spacers on top of the stem!!! Help!!!First of all you can cut the steerer if you want/need to. You are able to set the star nut further down into the insert, just be certain to stop at the bottom of the insert. You will know when you hit bottom because the insert is swaged to prevent the star nut from exiting the tube and to get past this you would have to use excessive force. If you end up needing to cut below the star nut that is no problem either. Forget the star nut, which was originally developed for steel steerers not carbon or aluminum and use a compression plug.
If you end up needing to cut below the star nut that is no problem either. Forget the star nut, which was originally developed for steel steerers not carbon or aluminum and use a compression plug.
Right. Didn’t think to add that to my response, but it’s correct.
It could also be that his P3C is one with a Wolf fork that has a steel steer tube.
bobby11 is right. also once you cut the steerer tube make sure the builder wasn’t lazy and only epoxied the top section of the sleeve. if you cut off the top part of the sleeve that was expoxied obviously this could be bad. once you cut the steerer tube snug up the headset pretty good then loosen and remove it to see if the sleeve has moved. i have seen this happen once. most likely the entire sleeve is glued in there but just to be safe check it…
"t could also be that his P3C is one with a Wolf fork that has a steel steer tube. "
Or, it could be that his P3C is actually a P4, per is original post.
I assume with the compression plug route you then do not need the insert? I ask because when I built my P4 years ago I decided to use a compression plug and did not glue the sleeve in the steerer tube. I have never had a problem.
Now that I have pretty much cut most of the steerer tube off I could safely put the sleeve in and would never regret the location.
Thanks in advance
putting a sleeve and start nut in will be safer/stronger and maybe even lighter. some of those compression plugs are huge.
I assume with the compression plug route you then do not need the insert? I ask because when I built my P4 years ago I decided to use a compression plug and did not glue the sleeve in the steerer tube. I have never had a problem.
Now that I have pretty much cut most of the steerer tube off I could safely put the sleeve in and would never regret the location.
Thanks in advance
I agree with what Jack said. The sleeve and star nut will likely weigh less, be more secure and be stronger (essentially reinforcing more of the steer tube where you’re going to be applying clamp force with the stem). But you can use a compression plug with no sleeve and be just fine. I have a couple of bikes with carbon steer tube forks where I’m using compression plugs. As long as they’re properly located in the steer tube and properly torqued, all should be fine.
I assume with the compression plug route you then do not need the insert? I ask because when I built my P4 years ago I decided to use a compression plug and did not glue the sleeve in the steerer tube. I have never had a problem.
Now that I have pretty much cut most of the steerer tube off I could safely put the sleeve in and would never regret the location.
Thanks in advanceYou will be ok either way but I prefer a compression plug. While I do like the fact that the glued in alloy tube reinforces the steerer from stem clamp forces it is hardly necessary. This is fairly clear as the majority of the fork market eschews star nuts for some type of removable nut or compression plug. The star mut predates any carbon or aluminum steerer tube forks and is not a goid idea in a modern carbon fork. I’m also not sure it really is a great idea to glue/bond an aluminum part to a carbon tube. Chemically speaking it is not really wise and the exact reason that many early bonded carbon/aluminum framed failed due to the corrosion that takes place when galvanic corrosion occurs. Most contemporary frame makers have figured this problem out but it usually requires some form of insulating layer between the carbon and aluminum. That is well beyond the simple DIY sleeve kit included with your fork. If you still want to use the insert my suggestion would be to remove the star nut from the tube before glueing and use a compression plug. Though the inner diameter is smaller you can use a 1" compression plug and it fits very well.
Gluing in the sleeve wont hurt anything. Galvanic reaction could occur, but even on the off chance it does the Al sleeve would come loose, no harm would come to the fork.
With glued al/c frames the frame is under stress and if the bond comes undone the frame comes apart, it just not the same with the insert and fork combo
Hi 1406racer,
Cervelo carbon forks use the bonded insert to add strength and reliability while saving weight. We avoid galvanic corrosion by adding a thin ply of fiberglas to the inside of the steerer. This sleeve system is simple and very effective; I like it a lot for the engineering elegance I can see in it.
An expanding plug is also an option, handy for those who don’t like the sleeve for whatever reason.
Details about the sleeve and a statement about the plug option are both in the fork instructions PDF linked earlier (sorry, can’t remember the poster’s name right now and can’t look while composing a post myself).
http://www.cervelo.com/r/3T%20Fork_instruction.pdf
Cheers,
Damon