Easton Carbon bars require 2-bolt stem?

mikegibbons
mikegibbons Posts: 25
edited June 2016 in Workshop
Hi

I have a Giant TCR approx 2009 vintage. It has an Easton EC90 Equipe Carbon bar diameter 31.8, steerer 1 1/8 inch and an Easton EA70 110mm 2-bolt stem. I need to change the stem to an 80mm one. Under the clamp on the bars it says "use 2 bolt stem only". I have not been able to find a suitable 2 bolt stem. Does anyone know why it has to be 2-bolt? Could a modern 4 bolt stem work safely? Thanks in anticipation. Mike

Mike Gibbons
LE > JoG starts 18 Aug 2007

Comments

  • benmac75
    benmac75 Posts: 53
    I'd imagine a 4 bolt would be fine. I'd say the warning is more about not using a single bolt clamp stem.

    Two aspects would spring to mind there. That the clamping forces would be less even and that also a single bolt one would necessitate threading the bars through to install them so may result in scratching and scraping them.
  • crankycrank
    crankycrank Posts: 1,830
  • mikegibbons
    mikegibbons Posts: 25
    I have tried contacting Easton but no reply :(

    Mike Gibbons
    LE > JoG starts 18 Aug 2007
  • imposter2.0
    imposter2.0 Posts: 12,028
    Just googled some pics of the bars and there are several pics of them fitted to 4-bolt stems. As others have said, I doubt it is an issue. Just about every other set of carbon bars can be fitted to unspecified stems, so I don't see why these would be any different....
  • mikegibbons
    mikegibbons Posts: 25
    Chain reaction have some in their clearance sale. They will be a later version than mine and in the product description it says "31.8 can use 4 or 2 bolt stem, 26 requires 2 bolt stem" So there is definitely some sort of issue which possibly affects my earlier bar. But I can't figure what it might be. Just being nervous as I imagine a broken handlebar hurts a lot!

    Mike Gibbons
    LE > JoG starts 18 Aug 2007
  • andy_wrx
    andy_wrx Posts: 3,396
    benmac75 wrote:
    I'd imagine a 4 bolt would be fine. I'd say the warning is more about not using a single bolt clamp stem.
    Like wothesaid

    In 1999, 4 bolt stems would have been impossibly futuristic, but not exactly uncommon in 2009

    However, I expect '2 bolt only' should be read as 'not 1 bolt' rather than 'not 4'

    Don't use some sort of prehistoric quill stem, the sort you have to feed the bars through, rather than a removable faceplate 2 or 4 bolter
  • mikegibbons
    mikegibbons Posts: 25
    Hi, After much digging on archive.org I came up with this:

    https://web.archive.org/web/20030613150 ... 2Bolts.pdf

    I'm not certain but it seems to imply that if I tighten the four bolts carefully with a torque wrench then it should be OK.

    Mike Gibbons
    LE > JoG starts 18 Aug 2007
  • crankycrank
    crankycrank Posts: 1,830
    ^^^^After reading the Easton article from the link above about the advantages of 2 bolt stems (and drawbacks of 4 bolts) I noticed that all their current stems use 4 bolts. I would say you're safe using the 4 bolt versions.
  • andy_wrx
    andy_wrx Posts: 3,396
    I think that the fact that all the decent stem manufacturers now make 4bolt stems not 2 says something about their inherent superiority, both in terms of balancing the stress better across the bar and in terms of safety in case of bolt failure.

    You no more (or less) need a torque wrench for them than you did for 2 - winding-up the bolts on them silly-tight wasn't a good idea either.

    The only 2bolt stems now are those fitted to £49.99 "bikes" you buy from the back of the Daily Mail
  • Thanks everyone. The four bolt stem is now on :lol:

    Mike Gibbons
    LE > JoG starts 18 Aug 2007