matt-richardson Posted April 3, 2009 Report Share Posted April 3, 2009 (edited) Why are there specific rotor bolts used for attaching discs to hubs? Reason I ask is that I'm converting to front disc and at the moment I have attached the disc using two rotor bolts and four allen key bolts as that is all I could find. Is this ok or should I go out and buy some rotor bolts? Edited April 3, 2009 by matt-richardson Quote Link to comment Share on other sites More sharing options...
Luke_zoo Posted April 3, 2009 Report Share Posted April 3, 2009 Why are there specific rotor bolts used for attaching discs to hubs? Reason I ask is that I'm converting to front disc and at the moment I have attached the disc using two rotor bolts and four allen key bolts as that is all I could find. Is this ok or should I go out and buy some rotor bolts?Rotor bolts would be best. Quote Link to comment Share on other sites More sharing options...
monkeyseemonkeydo Posted April 3, 2009 Report Share Posted April 3, 2009 Bolts is bolts. So long as they're not aluminium they'll be fine. Quote Link to comment Share on other sites More sharing options...
Muel Posted April 3, 2009 Report Share Posted April 3, 2009 Torx bolts are shite if you ask me, the head strip out really easily, and they they're flat on top so you can't get the out easily.I use Stainless allen key bolts, not sure what grade, but they're strong enough to pull all the threads out of the hub before they snap! Quote Link to comment Share on other sites More sharing options...
Skilled trials Posted April 3, 2009 Report Share Posted April 3, 2009 Torx bolts are shite if you ask me, the head strip out really easily, and they they're flat on top so you can't get the out easily.I use Stainless allen key bolts, not sure what grade, but they're strong enough to pull all the threads out of the hub before they snap!Yes i agree, Im a cycle mechanic and there is not alot of differnce from rotor bolts than normal allan key bolts, If i was you i would just got for a normal allan key bolt which is not aluminium as you said . Quote Link to comment Share on other sites More sharing options...
forteh Posted April 3, 2009 Report Share Posted April 3, 2009 (edited) All hope brakes used to come supplied with allen screws (screws not bolts ), they were low profile cap heads so they would clear the caliper on smaller rotors. Im not entirely sure why they all use torx screws now as there is no really high torque requirement on them and its just a pain in the arse to have a torx driver aswell. I use allen screws on all of my disk brakes. Edited April 3, 2009 by forteh Quote Link to comment Share on other sites More sharing options...
Mr Motivator Posted April 3, 2009 Report Share Posted April 3, 2009 Why are there specific rotor bolts used for attaching discs to hubs?The propper jobs will have been tested to cope with the high shear stresses.Normal bolts will do, but get some good quality stainless steel ones. Try a chandlery for quality bolts, not B&Q. Quote Link to comment Share on other sites More sharing options...
forteh Posted April 3, 2009 Report Share Posted April 3, 2009 The propper jobs will have been tested to cope with the high shear stresses.Normal bolts will do, but get some good quality stainless steel ones. Try a chandlery for quality bolts, not B&Q.Stainless steel is weaker than normal steel Most 'blacked' allen screws will be grade 12.9, more than plenty strong enough For more info see here Quote Link to comment Share on other sites More sharing options...
Mr Motivator Posted April 3, 2009 Report Share Posted April 3, 2009 All depends on grades. Quote Link to comment Share on other sites More sharing options...
forteh Posted April 3, 2009 Report Share Posted April 3, 2009 All depends on grades.Typically the strongest stainless fastener you can buy is an A4-80 which has a uts of 800 MPa, now compare that to the 1200 MPa of a standard black allen screw. Also bear in mind that 90% of the stainless fasteners you buy (especially in the sizes common to bikes) will be A2-70, weaker still. Quote Link to comment Share on other sites More sharing options...
neonneon Posted April 3, 2009 Report Share Posted April 3, 2009 Torx bolts are shite if you ask me, the head strip out really easily, and they they're flat on top so you can't get the out easily.I use Stainless allen key bolts, not sure what grade, but they're strong enough to pull all the threads out of the hub before they snap!Muel, you probably ground them down to make them lighter.My torx bolts are fine, they came with my disc. Quote Link to comment Share on other sites More sharing options...
Muel Posted April 4, 2009 Report Share Posted April 4, 2009 Errm, no? I'm clearly bothered about weight these days, using stainless steel bolts over TI/aluminium ones...My bike weighs over 10kg, I'm not bothered by numbers any more as long as it isn't a tank. The only modification to mine was I drilled the sidewalls because it was too heavy towards the front and I wanted to find out how much I could save.The torx ones would be lighter anyway? I just really hate them, I had so much trouble getting one out for my mate once after he stripped the head. An allen bolt wouldn't have stripped anyway, and if it had they have a square head instead of a dome, so you can easily file a flat on either side and get it off with a pair of mole grips. Quote Link to comment Share on other sites More sharing options...
neonneon Posted April 4, 2009 Report Share Posted April 4, 2009 Errm, no? I'm clearly bothered about weight these days, using stainless steel bolts over TI/aluminium ones...My bike weighs over 10kg, I'm not bothered by numbers any more as long as it isn't a tank. The only modification to mine was I drilled the sidewalls because it was too heavy towards the front and I wanted to find out how much I could save.The torx ones would be lighter anyway? I just really hate them, I had so much trouble getting one out for my mate once after he stripped the head. An allen bolt wouldn't have stripped anyway, and if it had they have a square head instead of a dome, so you can easily file a flat on either side and get it off with a pair of mole grips.I was joking.. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.