unknown hex/ torx bolt head; help please

ajmitchell

hi this is on a giant pro advanced 1 bike. None of my screwdriver heads fits this bolt head for the seatpost. They are all too small. Anyone help? Is it a special tool?? thank you!

k-dog

How many lobes does it have? Looks like a worn out Torx head.

sungod

hard to tell from that angle, if it's not torx it might be polydrive

though unless the idea was to make it harder to steal the saddle i can't see the point of using a weird bolt head, just makes it awkward for the user

ajmitchell

appears to be 6 lobes

k-dog

Whatever it was it's been mashed with something. I would be looking at cutting a slot for a screwdriver and then replacing it with a new one. It'll be tough to get something to grip that.

You could try hammering in a bigger torx bit to see if you can loosen it.

ajmitchell

looks a lot like the apple mac pentalobe but with six lobes not 5! wierd! http://guide-images.ifixit.net/igi/J2ZmCuhThPJdtneB

crankycrank

ajmitchell wrote:

looks a lot like the apple mac pentalobe but with six lobes not 5! wierd! http://guide-images.ifixit.net/igi/J2ZmCuhThPJdtneB

According to the link it looks like a torx plus head which I've never seen before or it could just be a rounded standard torx. There is a "T" marked at the base of the head and I would assume that designates "Torx" People often stick an allen wrench in their torx head bolts not realizing what it is and can strip it out. The proper Torx wrench may still be able to remove that bolt. Or just call your Giant dealer. The mechanic should be able to give you a quick answer.

sungod

yes, looks like a torx that's been messed up

a tight fitting sharp flat blade might do it, or as suggested above cut a slot

if necessary it can be drilled and taken out with an extractor

bbrap

sungod wrote:

yes, looks like a torx that's been messed up

a tight fitting sharp flat blade might do it, or as suggested above cut a slot

if necessary it can be drilled and taken out with an extractor

If you are lucky a large extractor (easyout) may give enough purchase to undo it without drilling. Then replace with something suitable. Obviously the drilling option remains if that fails.