Cutting a cervelo steerer help please

tomwaterfall

Hi
I've decided I'd like to cut down the steerer on my new Cervelo R3, but I understand theres a star nut and an aluminium insert in the 3T funda forks. I was wondering if anyone would be able to talk/walk me through what I need to do to cut down the steerer as I reckon its probably a bit more difficult than cutting a normal carbon one from another brand/company.

I can buy a 32tpi hacksaw blade no problem and I'll probably end up buying/using hose clamps as a guide if I do decide to do it myself, but what exactly do I need to do with regards to the insert? its essentially a brand new bike so i haven't done any glueing/messing around with it yet.
Thanks a lot!

pinarellokid

If the fork is carbon it won't have a star nut in it, but a bung that unscrews. Just search on you tube and watch a few videos before you even pick up the hacksaw

mrdsgs

new cervelo carbon forks do have an epoxied aluminium insert so that star nut can be used.

majormantra

Has the insert already been installed? I think Cervelo designed the system with the intention that it wouldn't be put in until the final steerer height had been determined. If it's already in there you may be limited in how far you can cut the steered down without making your life a bit complicated.

tomwaterfall

Well theres definitely a piece of what I assume is aluminium in there, the bike is brand new from the shop too so I'm a little confused. Maybe its not glued in but how am I supposed to remove it if its not?
Cheers for the responses anyway

majormantra

Remove all bolts and take a picture if you want us to tell you.

I would not expect a shop to fit the sleeve before selling a bike, because it would limit how much the customer could adjust their fit. If they were going to do it, it would typically be during a follow up service when the preferred stem height has been determined. I would guess you probably have a bung (expander) in there.

tomwaterfall

Yeah sorry photos would've been a much better idea from the start, heres a few:

pinarellokid

That's a star nut for sure. Must be an alloy sleeve

majormantra

Yup, that's the glued in sleeve. How many spacers are below the stem? It should still be possible to cut the steerer down, but if you cut too much it may be awkward as there'll be an odd sized bit of sleeve left in there.

tomwaterfall

bloody hell! Theres only one small spacer below the stem I think as I slammed it bar one spacer (to see how I get on tomorrow if I go for a ride), how would I go about cutting the steerer if the sleeves been glued in then? I suppose I can't knock it down if its been epoxied so I guess the only option would be cutting through the carbon steerer and alu sleeve together?
I've emailed the tri shop I bought the bike from to see what they have to say, can't say I'm too happy to be honest as it looks bloody awful with the amount of steerer showing at the moment and as you said they really shouldn't have glued it.
Cheers all for your help.

majormantra

It will be fine to cut through both using normal techniques. (A guide is wise, and you'll want to tape it to prevent splintering.) How much total steerer do you want to remove? That's the important question.

mitchgixer6

It's not really the bike shops fault, they would have to glue the insert in in order to let the bike out the door. Otherwise it would have been un rideable. This can be a benefit of building your own bike, you get everything the way you want it.

I'd take it to the shop and get them to cut it down. Other than the look the excess steerer won't be making any difference. That way if there are any issues with the insert being too high then it'll be purely they're fault and they'll need to sort it. Once you do anything yourself you'll give them an excuse to shirk any responsibility.

g00se

I've have two forks like that, both have had the sleeve slip as they weren't glued in properly.

So, Can I suggest the following: Loosen the stem a little so it's not exerting too much clamp on the steerer. Make sure there is a good amount of spacer above the stem. and tighten up the top cap. Do it quite tight to see if the glue seal breaks - but don't overdo it - as if the sleeve is well and truly stuck - you may damage the top cap or bolt.

majormantra

If it's been done properly it's araldited in there and isn't going anywhere. But you never know...

tomwaterfall

I've emailed the shop I bought the bike from, gonna see what they say about it, hopefully get it cut by them.
cheers

Semantik

The top of the aluminium sleeve should have a lip all the way round it that sits flush with the top of the carbon steerer. Can't see this lip on yours. hope they didn't fit it upside down!

majormantra

Really? I don't recall that on the last one I looked at. But it was a while ago. Anyway, they come with the starnut fitted, and that appears to be the right way up. (Although it's hard to be sure from the photo.)

Semantik

MajorMantra wrote:

Really? I don't recall that on the last one I looked at. But it was a while ago. Anyway, they come with the starnut fitted, and that appears to be the right way up. (Although it's hard to be sure from the photo.)

See below instructions.

Step 9. refers to the flared end of the insert which must be uppermost

BONDING 1)Wearing gloves and safety glasses, use silicon carbide (SiC) 120-180 grit sandpaper to carefully sand the cut end to remove any sharp edges or splinters.Do not remove material from the outer steerer wall. Always sand along with the grain of the material – not across or opposite the grain – which can lead to splintering. 2)Carefully sand the inside of the steerer from the cut end down 75mm to prepare the surface for bonding. 3)Tap the fork over a disposal bin to remove all excess carbon dust. 4)Using an isopropyl alcohol wipe, thoroughly clean the sanded area inside the fork steerer to remove all carbon dust. Allow 30 seconds for the alcohol to dry before proceeding. 5)Remove the insert from the plastic packaging, taking care to only touch the ends of the insert.Test fit the insert into the steerer without glue to ensure it will fully seat in the steerer. 6)If the insert will not fit completely into the steerer, measure to see how far it sticks out above the steerer. Remove the insert and mark that same distance as measured up from the bottom
of the insert (tapered end). Carefully cut the insert using a hacksaw, and file the cut end to remove any sharp edges. Note that the insert must be cut from the bottom only. Test fit the insert again to ensure it will fully seat in the steerer. 7)Ensure all bonding surfaces are cleaned of all debris and finger oils. Use isopropyl alcohol to clean the inside of the steerer tube and the outside of the insert as necessary. Note that the cleaning of both parts should be completed within 5 minutes of applying the epoxy. Once cleaned, the bonding surfaces must not be touched before the epoxy is applied. 8)Using gloves, the wooden mixing stick, and a clean disposable surface; fully mix the epoxy in the kit supplied with the fork according to the package instructions. Apply a layer to the outer surface of the insert. Concentrate the epoxy towards the bottom (tapered) end of the insert. Excess epoxy may be added to the inside of the steerer tube. 9)Carefully slide the insert into the steerer while rotating it slowly until the flared end sits flush with the top of the steerer.The rotation will help spread the glue over the bonding area – which needs to be completely covered. Attempt to minimize any drips due to epoxy squeezing out. 10)Wipe away any excess glue from the outside surface of the steerer tube with an isopropyl alcohol wipe. Once complete, visually re-check that the insert is sitting flush in the steerer tube. 11)Set the fork aside and allow it to sit undisturbed for the full curing time as noted on the epoxy packet. Do not attempt to fit the fork into a bike prior to the completion of the full curing cycle.

Mccaria

With the Cervelo you can carefully tap the star nut further down the length of the insert and then cut off the corresponding amount from the top of the post. To do this you have to be sure you do not tap the star nut beyond the length of the insert. This has to be done very carefully and maybe better handled by a good LBS or the original shop.

flasher

Let me get this right, it's a carbon steerer tube with a glued in ali insert?

If so it sounds like a very convoluted way of doing things!

majormantra

It's actually a good system in that it greatly reduces the chances of crushing the steerer, and also saves you from dealing with expander plugs. The downside is it's less flexible.

flasher

Do many carbon steerers get crushed and what's wrong with expander plugs?

Expander plugs are so much easier to use and work with than star-fangled nuts.

on-yer-bike

Cervelo/3T did this after the troubles they had ages ago with Wolff forks. Its normal to cut the steerer after the insert has been glued in but there is a limit to how much can be removed. The star nut has to be knocked down but no further than the depth of the insert. It has been documented on the Cervelo forums so worth a look there. I think its around 25mm you can remove but please check on the Cervelo website.

majormantra

Flasher wrote:

Do many carbon steerers get crushed and what's wrong with expander plugs?

Expander plugs are so much easier to use and work with than star-fangled nuts.

Having worked in a shop, you'd be surprised how many people manage to damage their steerers through over-tightening. And expanders are fine, unless you get one of the sh1t ones that constantly pulls out of the fork. Starnuts are fit on forget.

tomwaterfall

LBS refusing/ having 'major reluctancies' to do it now and the other local bike shop quoted me 45 POUNDS!!! to do it, bah

mitchgixer6

Having read the replies I'd be inclined to do it myself. A hacksaw and a good blade with high tooth count will do the job and will be much less than £45. It's a pretty easy job and you can practise on the steerer close to the top before making the final cut at the correct height.

tomwaterfall

Its the guide (or lack of a guide) part I'm slightly concerned about, would the hose clamp idea work do you think?
cheers!

mitchgixer6

Don't worry too much about getting the cut perfect. The top cap doesn't actually touch the top of the steerer so it's OK if it's not flat.

I wrap a piece of electrical tape round the tube and use that as a guide. You can then file it down if need be.

on-yer-bike

http://www.chainreactioncycles.com/x-to ... lsrc=aw.ds

paulbnix

I have cut 2 carbon steerers using the appropriate high tpi hacksaw blade and two hose clamps - one either side.
Both were easily and successfully done.
They were just carbon - there was no glued in aluminium tube - so would have easier than yours.
Just take care with the measurement and cutting.

keef66

I cut my carbon steerer freehand. Twice in fact. A lot easier than I thought it would be.

I might draw a guide line using a spacer if I was having to cut through aluminium too though.