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Cervelo carbon fork with aluminum insert questions
http://weightweenies.starbike.com/forum/viewtopic.php?f=3&t=92744
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Author:  5shot [ Wed Sep 07, 2011 6:46 pm ]
Post subject:  Cervelo carbon fork with aluminum insert questions

So, yesterday I recevied a replacement 2011 Cervelo R5 frameset. I crashed my 2010 R3 about a month ago and used Cervelo's crash replacement discount to upgrade to an R5. The new SL fork that comes with the R5 is super light and it seems a shame to glue the heavy aluminum sleeve insert into the steerer tube in order to then insert the star nut.

Is there a top cap/pre load adjustment system that will work with this fork that does not require gluing in the aluminum sleeve?

Thanks.

Author:  Weenie [ Wed Sep 07, 2011 6:46 pm ]
Post subject:  Cervelo carbon fork with aluminum insert questions


Author:  ghisallo2003 [ Wed Sep 07, 2011 7:44 pm ]
Post subject:  Re: Cervelo carbon fork with aluminum insert questions

I suspect this will be confirmed by others, but you can use a normal carbon expander. In the past I have used the Extralite expander.

I have to say though, that once you have your position dialled in, the glue-in insert does give a huge sense of fit-and-forget which I have not had since the old alloy inserts. I would just glue it in and forget about the extra weight. The peace of mind is worth a few extra grams.

You should read the fork instructions, which for my 3T ones, does say that you can use other expander plugs.

Author:  5shot [ Wed Sep 07, 2011 10:55 pm ]
Post subject:  Re: Cervelo carbon fork with aluminum insert questions

Ghisallo2003,

Thanks. The other concern I have with the aluminum insert is that I don't want to glue it in and then find that I need to cut the steerer below the top of the insert. With the 2011's different geometry than my old 2010, I am not sure where I'll end up in terms of the steerer tube length.

Author:  em3 [ Thu Sep 08, 2011 4:26 am ]
Post subject:  Re: Cervelo carbon fork with aluminum insert questions

...the R5 fork is just like any other carbon fork and it is safe to use any good quality expander/compression plug. I use the Extralite Ultrastar in my R5 fork without any problems...just be sure not to overtorque the plug when installing. EM3

Author:  thisisatest [ Thu Sep 08, 2011 4:28 am ]
Post subject:  Re: Cervelo carbon fork with aluminum insert questions

according to 3t, the aluminum insert increases the steerer's tolerance for mishandling. it is not required.
that said, i'm not opposed to cutting the steerer with the insert already glued in. a few things have to happen for that to work well:
the insert has to be properly glued in. that means it has to be fully and completely coated in epoxy, with any excess smeared in the inner wall of the fork. all that after sanding and cleaning.
second is to lower the star nut before cutting, so the top lip will still be present.
third, or first really, i did not choose a good order, the initial steerer length should be such that no more than 40mm of spacers are used.

my justification for this allowance is that the insert is good for support to a certain depth, say to the top cone of the headset. then lowering the stem, the insert is still supporting the same part of steerer. finally, cutting whatever is left over the stem is just excess, the reinforced part left is all that matters at that stem height.

side note, the fork is no longer a 3t, technically. but it clearly follows the same engineering, likely made at the same place...

Author:  drmutley [ Thu Sep 08, 2011 5:02 am ]
Post subject:  Re: Cervelo carbon fork with aluminum insert questions

i have just completed this process on a 3T funda pro fork...
i glued in the alu inserted to give the clamping are of the fork some extra strenght incase some silly person over torques it... u can onbviously safely use an expander plug and be careful of the torque u use on both the top cap and stem bolts...

to safe guard against glueing the insert above where your position may end up, install the fork without any spacers, and mark where the top of the stem sit on the steerer. When glueing the insert, make sure about 10 to 15mm of insert extends beyond this point....

Author:  edmundo [ Thu Sep 08, 2011 2:25 pm ]
Post subject:  Re: Cervelo carbon fork with aluminum insert questions

5shot wrote:
it seems a shame to glue the heavy aluminum sleeve insert into the steerer tube in order to then insert the star nut.

I agree. I glued in the insert on my R3 SL funda pro. I've cut it with the insert in place. All very straightforward.
But...
You don't need the insert. You don't need the starnut when riding, or the bolt and the endcap for that matter. This is WW, right?

Author:  drmutley [ Thu Sep 08, 2011 2:39 pm ]
Post subject:  Cervelo carbon fork with aluminum insert questions

edmundo wrote:
5shot wrote:
it seems a shame to glue the heavy aluminum sleeve insert into the steerer tube in order to then insert the star nut.

I agree. I glued in the insert on my R3 SL funda pro. I've cut it with the insert in place. All very straightforward.
But...
You don't need the insert. You don't need the starnut when riding, or the bolt and the endcap for that matter. This is WW, right?

Or a post or saddle, u just attack all the time right? Lol

Author:  Rodrego Hernandez [ Thu Sep 08, 2011 6:00 pm ]
Post subject:  Re: Cervelo carbon fork with aluminum insert questions

I've seen a fair few funda forks with broken steerers that have been apparently caused due to not using the alu insert. Apparently it is needed to prevent the steerer from breaking.

Have seen 3 broken steerers that haven't used the supplied alu insert - since using the insert with new forks, no problems since for either owner.

Author:  drmutley [ Sat Sep 10, 2011 2:49 am ]
Post subject:  Cervelo carbon fork with aluminum insert questions

Rodrego Hernandez wrote:
I've seen a fair few funda forks with broken steerers that have been apparently caused due to not using the alu insert. Apparently it is needed to prevent the steerer from breaking.

Have seen 3 broken steerers that haven't used the supplied alu insert - since using the insert with new forks, no problems since for either owner.


There's no doubt using the alu insert is the safer option, but I think with an appropriately torqued expander plug the option is still as safe. It's probably when (home) wrenchers start over torquing both the stem and top cap is when u would start running into probs.

Author:  thisisatest [ Sat Sep 10, 2011 5:18 am ]
Post subject:  Re: Cervelo carbon fork with aluminum insert questions

i agree. i've seen cracked steerers from practically every manufacturer, most can be attributed to heavy torque or a very sharp stem clamp area. i have certainly seen a number of the old Wolf SL forks with big issues, usually as the fork is being removed to be replaced with the Funda.
I have yet to see a funda cracked, with or without the insert. granted, 98% of them leave with the insert already glued. but zero failures is still pretty awesome. plenty of Wolf sl forks had cracking even with the insert there. worst thing seen is an insert coming loose. typically it's from a combination of someone ham-fisting the top cap bolt and poor gluing technique (insufficient epoxy coverage, you can see parts of the insert that never touched epoxy). some people get impatient and want to glue the insert first and then assemble the rest of the bike while the epoxy cures. the fork should not be handled while it's curing (4 hours) and certainly the stem should not be on it, even loose...

Author:  5shot [ Sat Sep 10, 2011 8:01 pm ]
Post subject:  Re: Cervelo carbon fork with aluminum insert questions

Thanks to everyone for the comments and input. I am still deciding whether to use the aluminum insert or purcahse an Extralite Ultrastar 2 expander. The aluminum insert came with epoxy, a stick for spreading the epoxy and a small patch of sandpaper. Is the sandpaper for roughing up the inside of the steerer tube so the epoxy adhears better?

Author:  maquisard [ Sat Sep 10, 2011 9:38 pm ]
Post subject:  Re: Cervelo carbon fork with aluminum insert questions

Yup. Roughen up the inside of the steerer then wash thoroughly to get ride of the dust. Once dry apply epoxy evenly to the insert and insert. Leave for 24hrs, go ride.

Author:  gerardvroomen [ Sun Sep 11, 2011 11:01 am ]
Post subject:  Re: Cervelo carbon fork with aluminum insert questions

People, you should always use the Alloy sleeve. It greatly increases the durability of the steerer. It is important that the sleeve extends below the top bearing, and it is indeed OK to cut the steerer after installing the sleeve. so you still have the flexibility to dial in your position, as long as with the initial set-up the sleeve extends below the bearings.

As for the weight, the weight is not much different from most expanders. Yes, it's a bit heavier than the lightest expanders, but it's the best safety feature I can think of on a bike fork - well worth the weight.

Author:  Weenie [ Sun Sep 11, 2011 11:01 am ]
Post subject:  Re: Cervelo carbon fork with aluminum insert questions


Author:  5shot [ Sun Sep 11, 2011 11:34 pm ]
Post subject:  Re: Cervelo carbon fork with aluminum insert questions

Mr. Vroomen,

Thank you for responding and thanks for engineers such nice bikes.

If one chooses to use a light weight expander instead of the alumimun sleever, what is the maximum torque at which the internal expander should be set in order to avoid damaging the steerer tube of the SL form that comes with a 2011 R5 frame?

Also, is the SL fork proprietary to Cervelo or is it, like the forks on 2010 models, made by another company such as 3T?

Thanks again.

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