How do I stop bar ends crushing carbon bars?

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  • How do I stop bar ends crushing carbon bars?
  • I’ve had the bar ends on my carbon bars slip a couple of times when I’ve been really pulling on them up a short steep climb.
    Each time I’ve tightened them up a bit more, but I can see the carbon splintering now.
    I reckon what’s needed is an aluminium internal plug to support the carbon, either expanding or just a tight fit solid plug.
    Does anyone make such a thing?

    Try using some carbon assembly paste. You shouldnt need more than about 5-7Nm of torque to keep them on.

    trail_rat
    Member

    You can buy bars that are designed to fit bar ends tooo…your not supposed to fit them to the carbon tube bars- unless the bars are a approve and b the bar ends designed for carbon bars…..for the reason you have found.

    Raceface bars had alloy bar end plugs i believe easton does thicker ends for bar ends. Truvativ has alloy plugs no idea on rest.

    Premier Icon scaredypants
    Subscriber

    I wondered about that years ago – reckon the internal diameters must vary and so a usable fit might be hard to achieve. SOme bars used to come with a reinforced tip, I think (alu ring)

    Then I started using cane creek bar ends and stopped worrying

    zero cool
    Member

    Easton grips are designed to work safely with carbon bars

    Premier Icon njee20
    Subscriber

    Easton grips are designed to work safely with carbon bars

    How does that help with bar ends…?

    IME certain bars are better than others – Easton split before the bar end is tight, even the ‘bar end compatible’ EC70s, and irrespective of the bar end clamp. Ritchey are good, they’re reinforced, Bontrager are fine. Race Face are reinforced, they used to sell their plugs after market – called BERPs, dunno if you can still get them?

    JoB
    Member

    you can get inserts for use on carbon bars that aren’t strengthened for bar ends

    Specialized for one, do them

    Thanks for the replies.
    Carbon paste sounds a good idea. I’ve always thought of it as being for seat posts and as mine’s never slipped, I’ve never looked at it before. It could be worth a try for bar ends.

    I’m trying to salvage what I’ve got, rather than buy some new bars, even if it means trimming 15mm off each end of the bars to get rid of the damaged parts.

    I’d thought about expanding rubber plugs, not ideal, but better than nothing.

    KCNC for £19 or Specialized for £14 looks like the answer.

    Premier Icon njee20
    Subscriber

    I’d get the Spesh ones, specifically designed for that purpose, the KCNC ones are more about being pretty bar end plugs! I’d forgotten they did them.

    scotroutes
    Member

    FWIW, I use Cane Creek Ergo bar ends on Easton bars and not had any problems.

    jimster01
    Member

    Beaten to it by Scotroutes

    PeterPoddy
    Member

    MTG – you’re missing the point of carbon paste there dude. 🙂
    You don’t use it if to stop your post slipping, you use it to stop corrosion and to stop the post seizing in place.
    And especially use it if you have an alloy post and a carbon frame, or visa versa. I’ve seen frames and posts scrapped through not using carbon paste, one of them mine.
    Do not use grease either, use the proper stuff.

    andyl
    Member

    Each time I’ve tightened them up a bit more, but I can see the carbon splintering now.

    I’m trying to salvage what I’ve got, rather than buy some new bars, even if it means trimming 15mm off each end of the bars to get rid of the damaged parts.

    Be very cautious. Even with some damage carbon fibre can retain a lot of strength but teeth are more expensive than bike parts.

    The specialised ones will be designed for their bars, not all will have the same internal diameter so it would be worth checking this. You con’t want to force them into an inner diameter that is too small and they might not expand evenly in an inner diameter that is too big giving high stress at crush points.

    Also be VERY careful when fitting any kind of expanding plug into a carbon tube. You are more likely to de-laminate the outer layers when expanding the tube. It is basically like you are turning it into a pressure vessel and composite pressure tanks are very strong but designed for it. Your bars are designed for bending stiffness and strength along the bar and an expansion force is just going to break apart the resin bonds between the fibres.

    They will probably come with instructions anyway but I would say to only start to expand when the bar end is in place.

    andyl
    Member

    You don’t use it if to stop your post slipping, you use it to stop corrosion and to stop the post seizing in place.

    eh?

    it is there to stop corrosion AND let you use lower clamping forces but not slip. That is what the grit is there for.

    scotroutes
    Member

    I mentioned the Ergos as their placement means less twisting force when pulling uphill and so less tightening force required.

    Onzadog
    Member

    BERTs. Bar End Reinforcement Things. Used to be sold for bontrager bars.

    Premier Icon njee20
    Subscriber

    it is there to stop corrosion AND let you use lower clamping forces but not slip. That is what the grit is there for.

    +1, principally the latter, to torque required to tighten potentially fragile carbon parts. It does happen to reduce instances of seizing parts too.

    PeterPoddy
    Member

    it is there to stop corrosion AND let you use lower clamping forces but not slip. That is what the grit is there for.

    I missed out the word ‘just’? So shoot me why not?

    You don’t JUST use it if to stop your post slipping, you use it to stop corrosion and to stop the post seizing in place.

    Better now, smartarse? 🙂

    Premier Icon tmb467
    Subscriber

    Ergon do bar end inserts as well

    Similar price to Specialized etc

    Graham, it’s the early 90s calling…can we have our bar ends back please?

    andyl
    Member

    I missed out the word ‘just’? So shoot me why not?

    You don’t JUST use it if to stop your post slipping, you use it to stop corrosion and to stop the post seizing in place.

    Better now, smartarse?

    Well that completely changes it now. Much better 😛

    I found the KCNC ones a bit cheaper, but then I found the Specialized ones even cheaper again, so went for them as they look a bit deeper so should spread the load a bit better.

    PeterPoddy
    Member

    Well that completely changes it now. Much better

    I grovel humbly for your forgiveness, master… 😉

    Syntace say you need to use plugs for their bars to stop them crushing – like these – suppose it just depends on the internal diameter of your current bars.

    stumpy01
    Member

    njee20 – Member
    I’d get the Spesh ones, specifically designed for that purpose, the KCNC ones are more about being pretty bar end plugs! I’d forgotten they did them.

    Looks like you went for the Spesh ones anyway, but….

    I’ve got some of those KCNC bar end plugs and i’m not sure they are designed to be used for supporting a carbon bar when fitting bar ends. They are just a plug.
    They are secured by squishing an o-ring as you tighten them. It’s the o-ring that holds them in place, which isn’t going to provide much resistance to crushing from a bar end. Other than the o-ring, they are a relatively loose fit in the end of the bar.

    The Specialized ones look like they are designed to specifically support the inside of a carbon bar against crushing from bar ends.

    Have a look on ebay or retrobike for a tidy set of Answer Hyper Ends. They use an expanding bolt rather then traditional clamp so won’t squeeze the bar and don’t take any width from the bar either. Light too and very well made.

    darkcyan
    Member

    Yes it’s the bolt set up that’s critical!

    Premier Icon njee20
    Subscriber

    Yes and no.

    Some – such as Smica ones have a clamp that Easton deem “suitable” for their carbon bars – a slot in line with the centre line of the bar – but they need quite a lot of clamping force on a narrow clamp to work, put them too close to the end and you’ll easily crunch the bars. Conversely Bontrager Race X Lite bar ends have the slot offset from the centre line (according to Easton this increases the risk of stress risers), but have a much deeper clamp, covering the end of the bar, and work far better to support the end of the bars, I’ve used those on non-bar end compatible EC90s with no issues. Cane Creek Ergos are similar, as mentioned before.

    So more specifically it’s about the bar and the bar end, not so much the bolt set up in itself.

    zero cool
    Member

    My mistake, I mis-read bar ends to mean the end locking rings of the grips rather than the extra handles on them.

    spicer
    Member

    I just linked the KCNC ones because they were the first ones I saw that looked like an expanding metal doo-da 😀 spesh ones look like they would work well. But they also look nowhere near as blingy. Which is important.

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