Seatpost Bolt

[NinjaManiak]

What are the options for replacing the bolt's on the bike (in this case, specifically the one from the seatpost clamp ?

Obviously there are different materials, but are there different grades within each of these ( ie. does a steel bolt always = a steel bolt)

I broke ( read: bottomed out & then overtorqued and snapped off the head) my last one, and replaced it with the equvalent (I think) steel one, which cost R0.80 at the local nut & bolt shop.

Any thoughts, any knowledge, anything ?

[Johan Bornman]

Bolts are not bolts.

 

In steel, readily available are mild steel and high tensile steel. The latter you'll only get at a specialised bolt place and is much stronger than standard hardware shop bolts.

 

The finish on these is generally black and if you live at the coast, rusty.

 

 

You can also get stainless steel bolts. Stainless is a bit stronger than mild steel and should be strong enough for your application. However, find out waht the torque on that bolt should be and stick to it. A broken seat clamp bolt is potentially lethal since a ruptured anus is one of the more dreaded forms of surgery.

 

The one you bought was probably mild steel, plated in either zinc or perhaps even chrome. Even that should be strong enough if properly torqued.

 

BTW, if it has an internal hex head (allen key) then it is usually referred to as a cap screw. With a spanner head it becomes a bolt. Don't ask me why.