Bloody Bontrager unique bolts

[anonymous-user]

Seat post bolt snapped last night all fine no damage to me or the rest of the bike(seat & post inc). I thought I'll just pick up a new one, but oh no not on our products you won't say Bontrager.

High Tensile zinc plated steel bolt at 10.9 grade, fine I thought I'll get a 12.9 to make sure next time, now lets find out what size it is.

Oh look at that, it's not an M6 or an M8 socket head cap bolt it's a never heard off or little known M7, with a 45mm length under the head and takes a 6mm allen key.

Argh!!!!!

I've found one stainless steel 50mm M7 bolt that I could cut down but don't want to risk less strength in the bolt again.

So anyone got any ideas short of a new seatpost, I don't think I could tap it out to M8 as the Cap head wouldn't fit in to the mounting slot?

Edited by anonymous-user on Friday 10th June 11:28

[ndg]

Get the 50mm and cut it down. The cut end is under no stress/strain so it won't have an effect. Can't remember the tensile strength of SS in comparison to 12.9 etc though, so check that.

N.

[CoolC]

Can you not just convert it to a usual metric thread. Measure the nut part and search for an M6 or M8 threaded version. They are called a cross dowel and come in many sizes.

This type of thing - http://www.woodfit.com/product_info.php?name=M6%20...

Then get the appropriate allen head bolt, Bob's your uncle.

[anonymous-user]

ndg said:

Get the 50mm and cut it down. The cut end is under no stress/strain so it won't have an effect. Can't remember the tensile strength of SS in comparison to 12.9 etc though, so check that.

N.

Yeah cutting down isn't the problem Stainless is pretty weak in comparison to 10.9 let alone 12.9 in this application.

[anonymous-user]

CoolC said:

Can you not just convert it to a usual metric thread. Measure the nut part and search for an M6 or M8 threaded version. They are called a cross dowel and come in many sizes.

This type of thing - http://www.woodfit.com/product_info.php?name=M6%20...

Then get the appropriate allen head bolt, Bob's your uncle.

Good idea, I'll see if I can get an 11mm diameter/30mm length M6 version