Newbie needs urgent advice: Can i cause damage???

loxster71

Hi All,
Firstly let me start by explaining i am a total newbie when it comes to bikes and i have just got my first "PROPER" Road bike...Boardman ltd edition carbon!

I've just fitted a set of spd pedals on and sorted cleat positioning etc and realised my seat needed altering ( slightly raising) due to the difference in thickness between my trainers and spd shoes, I undid the 2, 4mm bolts on the post clamp and raised the seat to a height i thought would be fine ( good guess..it was spot on lol) but this is where advice is needed urgently!
I re-tightened the bolts without thinking and gave them a good nipping up then it suddenly hit me...CAN I OVERTIGHTEN THEM AND CAUSE DAMAGE TO THE CARBON FRAME????

All constructive advice is welcome. please bear in mind my tool collection is embarrisingly sparse ( set of Allen keys and a adjustable spanner lol).

Thanks Loxster71

Wheelspinner

Yep, you can damage carbon frames by over-tightening clamp bolts on the seat post. The (normal) torque required to correctly tighten seat clamps on carbon frames is surprisingly low, around 5 Nm is typical. You can do that easy with a standard Allen key with 2 fingers.

Any more and you can possibly crush the seat tube, particularly if you are also using a carbon seatpost?

Get to your LBS and ask them to check it with a torque wrench. If you've got the position right, once it's done wrap a strip of electrical tape round the post to mark the height. That was you can replace it next time to the same spot.

ALSO, note that seatposts in carbon frames should be removed, cleaned and replaced about every six months maximum, more if you ride in bad weather. Otherwise they can seize up and be impossible to get out.

There's a few threads on here about that, none of which have pretty endings.

:!:

loxster71

:shock:
Thanks for the reply, i will be loosening it off when i get home in 2 hours time!

Looks like a trip back to halfords is needed or i possibly could by a torque tool for tightening it up myself?
Where do i get one and what are they called lol :?
Thanks .

Wheelspinner

These are good, although if you are only going to do seat post adjustments once in a while it may be overkill.

http://www.chainreactioncycles.com/Models.aspx?ModelID=29803

There's plenty more out there from other manufacturers as well. For bike parts you want something that has an adjustment range from around 0 - 20 Nm max. The only fitting on your bike that needs more than that is the bottom bracket, and if you are messing with that much you'll require a few more tools than just a torque wrench.

Heckler1974

I wound up buying a torque wrench as I figured the cost of it would be absorbed the first time I didn't squash something expensive and carbon, but also when something did break on someone's carbon bike on here and the manufacturer wouldn't pay out on a warrenty call unless he could show he had one.

ballspondroad

Ritchey make this

http://www.chainreactioncycles.com/Mode ... elID=39478

it only covers 5 N/m and one bit size but this spec. is the commonest combination required. I think you can remove the bit if you are careful and fit other sizes, have a wander on the web.

Monty Dog

Ritchey Torque ket is all you need - is sufficient for your stem and handlebar bolts too. Bits are removeable so you can use a 5mm or Torqx too.

cougie

I've had a carbon bike for the last 5 years or so - never used a torque wrench, I just use 'feel'. A quick squirt of hairspray helps keep the seatpost from slipping i find, and the insulation tape at the right height is a very good idea.

skyd0g

There is less chance that you've caused damage by simply over-tightening in itself (although this is of couse possible). Damage would more likely be caused if you had over-tightened and then ridden on it for a period.