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Seat clamp thread stripped...

whitebait01whitebait01 Posts: 610
edited September 2011 in The workshop
Hey there,

Most likely a moronic question, but worth a try.

Tried to adjust my seatpost yesterday, undid the allen bolt about a half turn (leaving the allen key in), adjusted the seatpost, tightened the bolt about a quarter turn and then all resistance stopped (wasn't huge to start with) and it appears I've stripped the thread, bolt appears fine and there was a little 'spring' of metal wrapped around it. Not sure how I've managed to do this but never mind.

So the seat clamp says 34 on the underside of it and the seatpost is 27.2.

What size do I need? Had to ride the rest of the way home 'dancing on the pedals', only shop open was Halfords (they only had QR clamps and nothing the same size as this one) and I'm back visiting the parents (sans bike) for the weekend. I'd like to be able to commute in on Monday sitting down, so what's the best bet? I've brought the clamp with me and can get out to some bike shops.

The bike's a Ridgeback Horizon, aluminium frame. Any ideas what I'll need, I haven't seen any '34' size seatclamps online. Can I just offer this one up to the new one and get one that looks the same diameter?


Ribble Audax - FCN 5
Dedacciai Pista - FCN 3


  • cooldadcooldad Posts: 32,599
    Could it be 34.9 with a bit rubbed off - that's a common size?
    Seatpost size is immaterial as it goes round the seatube.
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  • Hey,

    Thanks for the reply, had forgotten about this. Ended up taking it to a shop and offering it up to their Thomson CNCed clamp and it turns out it's a 31.8... No idea why it said 34 on it, definitely not .9 rubbed off or anything.

    Ended up balking at paying £20 for the Thomson, went to Halfords who only had QR clamps in stock, but (unbelievably!) the chap in the Harlow Halfords took pity on me and nicked one of a boxed up bike, saying he could RMA my one and get a replacement. I won't name names but he was very helpful and friendly and refused to take any money from me.

    Funnily enough the one he gave me also said 34 on it, measured it and definitely 31.8, very odd...
    Ribble Audax - FCN 5
    Dedacciai Pista - FCN 3
  • The RookieThe Rookie Posts: 27,809
    31.8 would be normal with a 27.2mm post, we have 6 in the household with that combi....

    Current steed - Whyte T129, 2013 frame, mongrel Revelations, Giant dropper, Stans S1 wheelset. 12, Magura Trail Sport brakes, 1x11. 12.8Kg
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