Giant Cyclocross Seat Camp (Allen Key) Bolts Rounded off

Mark1889
Mark1889 Posts: 19
edited May 2017 in The workshop
Hey - so I got the above bike second hand, looks new all apart from the above!

I've managed to take the bolts out (needed to adjust the saddled height) but no idea where to get replacements. I did notice that the drinks bottle holder had seemingly similar dimensions (both took a 4mm Allen key, 2cm in length) but on closer inspection the drinks bottle bolt was a little thicker and a little longer. Secondary problem may well be that I've ruined the thread/frame? Later being a little unlikely even by my pessimistic standards

Any suggestions?! Back on my old bike in the meantime :(

Comments

  • godders1
    godders1 Posts: 750
    Is the seat clamp not removable? If not just measure the bolt width, 4mm = M4, 5mm = M5 etc. I find eBay good for small quantities of bolts etc. Bottle cage bolts are usually M5 so suspect your seat clamp bolt is M4 but like I said just measure it.
  • Mark1889
    Mark1889 Posts: 19
    Thanks :)
    The clamp is removable
    Like I say I shoved a bottle cage bolt in; think that's caused a secondary issue?
    I did have a look and couldn't see any damage..

    Ugh... won't be doing that again!
  • The Rookie
    The Rookie Posts: 27,812
    Just get a new seatpost clamp, available from about £3, you need the diameter which will be marked on it but it's almost certainly a 34.9mm.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • Mark1889
    Mark1889 Posts: 19
    Thanks for the help. One positive is that I did get the sizing right - it is an M5, 20mm pin head bolt. So fortunately no damage to the frame.

    This is the style of seatpost clamp that I have (http://road.cc/sites/default/files/styl ... k=Y9C0pHsv).

    You can just about see that part of the bike is removeable and is affixed by two bolts. The problem I had was the bolts became rounded to allen keys.

    I went to the local hardware store and got two similar bolts (although flathead screw not allen key). The problem I had on my first outing since (12 miles) is some slippage of the seat post and the bolt appears to have come out a little.

    I will hopefully go to the Bike shop today & if not resolved I will go to the manufacturer shop this weekend.

    Any guidance/suggestions on solutions always appreciated.
  • The Rookie
    The Rookie Posts: 27,812
    Argh, not a removable clamp at all then! This is a removable one https://www.cyclestore.co.uk/system_ex_ ... t=UK%20All

    You need the right size bolts, flat head will not give the right torque, you also should be using some gripper paste.

    Get it right or you risk scrapping the frame!
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • Mark1889
    Mark1889 Posts: 19
    Thanks again for the help!

    I went to the cycle shop and it was really helpful! Replacement bolts, sizing me up for the seat & a general look over at the bike cost all of £3 (Scott Cycles, Rubery, Birmingham). Only a 2-mile cycle back to work during my lunch but seems much more stable.

    A number of suggestions were also made - including inserting an extension to lift the handle bar, which is presently a few inches below my seat, may be kinder on my back!

    Other than that, he told me it was a great purchase/bike.
  • The Rookie
    The Rookie Posts: 27,812
    I've heard good things about them before.

    Bars a few inches below the saddle is normal on that type of bike but may not suite you, its easy to flip the stem (so it points up not down) that will lift the bars about an inch for free, also look at any spacers you can move from above to below the stem.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.