drunkn munky Posted February 19, 2012 Report Share Posted February 19, 2012 Ive got a Honda RS250 front wheel that looks as if the disc bolt holes have been drilled and had a thread inserted, problem being is that the insert is recessed and looks to only be 4 maybe 5mm of thread in there. What would be the best thing to do in this situation? With the disc on a normal disc bolt only just reaches the thread and although goes tight im not confident its safe, the fact thats theres also atleast 5mm of recessed area before it reaches the thread where the bolt will be unsuported also worries me. Suggestions please Link to comment Share on other sites More sharing options...
Benji Posted February 19, 2012 Report Share Posted February 19, 2012 What do the original bolts look like? Link to comment Share on other sites More sharing options...
paul8899 Posted February 19, 2012 Report Share Posted February 19, 2012 It looks to me that the inserts are there so that the thread doesn't pull out , can you make/get some disc bolts with a longer thread and shoulder ? Link to comment Share on other sites More sharing options...
paul8899 Posted February 19, 2012 Report Share Posted February 19, 2012 Thinking about it I might know someone who could make some disc bolts to suit your wheel and disc Link to comment Share on other sites More sharing options...
drunkn munky Posted February 19, 2012 Author Report Share Posted February 19, 2012 I didnt get bolts with it, the bolts i used to trial fit were standard NC30 ones. I did think at first that it would use a shouldered bolt but every hole isnt identical so id say its been drilled at some point. If i go for a shouldered bolt then that means drilling the holes on the disc bigger, doesnt bother me if thats the best option but would the 4-5mm of thread thats in each hole be enough? Paul, would you need the wheel and disc to make said bolts? Link to comment Share on other sites More sharing options...
paul8899 Posted February 19, 2012 Report Share Posted February 19, 2012 I'll send you a pm Link to comment Share on other sites More sharing options...
sonic Posted February 19, 2012 Report Share Posted February 19, 2012 I wouldn't worry.My TZ came with only 3 of the 6 disc bolts fitted.Yamaha supply them this way,they race GP's this way ,but the ACU make me fit all 6.Therefore fit a bolt and you will be fine. Link to comment Share on other sites More sharing options...
drunkn munky Posted February 19, 2012 Author Report Share Posted February 19, 2012 Ive used just 3 bolts before its not that thats bothering me its the fact that the most of the bolt will have nothing to support it. Paul has come up trumps with a solution tho, gota love the PB massive Link to comment Share on other sites More sharing options...
Superdunc Posted February 19, 2012 Report Share Posted February 19, 2012 Glad You've got it sorted. For future reference, it looks like you have enough material to remove the helicoi inserts and replace them with timeserts or keenserts, which would give you thread all the way to the mating face. As for thread depth,as a rule of thumb you want a minimum of 1.5 d in aluminimum and 1d in steel. Link to comment Share on other sites More sharing options...
drunkn munky Posted February 19, 2012 Author Report Share Posted February 19, 2012 Thanks for the input superdunc i'll look into the inserts. When you mention thread depth what do you mean by "d" as in a minimum of 1.5 d? And with it being a magtek what would the minimum depth be of magnesium? The holes are nearly 8mm dia, would the kit fill that hole for use with a normal disc bolt? Link to comment Share on other sites More sharing options...
paul8899 Posted February 19, 2012 Report Share Posted February 19, 2012 Looking at the pictures I would say that they aren't helicoils , I would guess that they are steel headed bushes which are pushed in from the inside of the hub Link to comment Share on other sites More sharing options...
Superdunc Posted February 19, 2012 Report Share Posted February 19, 2012 Sorry my post wasn't very clear on reflection. 1.5d means 1.5x the diameter of the thread, so an M6 bolt would need 9mm of thread. I would try for 2d with Mag. I can't remember the tapping size for an M6 Keensert but it would be bigger than that of the equivilant helicoil. If you're really in trouble is there enough material to drill and tap 6 new holes between the existing ones? Edit Paul I'm pretty sure there Helicoils, that's not to say you couldn't make some inserts like you suggest. Link to comment Share on other sites More sharing options...
drunkn munky Posted February 19, 2012 Author Report Share Posted February 19, 2012 Ah i see so an M6 bolt would need 12mm of thread, ive got nowhere need that, that worries me slightly. Id say theres plenty of room to drill a new set of holes, not something id trust myself to do tho. Now im really wishing id sorted this before having the wheel powder coated Link to comment Share on other sites More sharing options...
tanuki Posted February 20, 2012 Report Share Posted February 20, 2012 do what Honda did for their road Magteks and use long bolts. you can see them in this pic between the discs and calipers Link to comment Share on other sites More sharing options...
bezzer Posted February 20, 2012 Report Share Posted February 20, 2012 Ah i see so an M6 bolt would need 12mm of thread, ive got nowhere need that, that worries me slightly. Id say theres plenty of room to drill a new set of holes, not something id trust myself to do tho. Now im really wishing id sorted this before having the wheel powder coated An M6 doesn't need 12mm or even 9mm (1.5 x diameter) You don't go by the diameter you go by the pitch and 5 full turns of thread is quoted to achieve maximum strength..... so it's 5mm on a standard M6x1, 6.25mm on standard M8x1.25 etc. Check the thickness of a standard nut and you'll see it's very close to the 5 turns of it's thread pitch. If you can have more thread depth then great but it isn't critical once you've got the 5 turns. Link to comment Share on other sites More sharing options...
Superdunc Posted February 20, 2012 Report Share Posted February 20, 2012 Nuts aren't made out of Aluminium or Magnesium though. Link to comment Share on other sites More sharing options...
bezzer Posted February 20, 2012 Report Share Posted February 20, 2012 Nuts aren't made out of Aluminium or Magnesium though. But we're also talking about inserts which are steel anyway. Doesn't matter what the material is 5 threads is still what is required, the torque required to strip 5 threads would also strip anything deeper, but as I said if you can get more then fine. Link to comment Share on other sites More sharing options...
drunkn munky Posted February 20, 2012 Author Report Share Posted February 20, 2012 Is there a way i can measure the amount of turns are left on the inserts? Link to comment Share on other sites More sharing options...
bezzer Posted February 21, 2012 Report Share Posted February 21, 2012 It's as simple as putting a bolt down the hole turn it until you can feel it start to thread then count the number of turns before it bottoms out. That's if the insert goes to the bottom of the hole, if it doesn't then it's guesswork. Link to comment Share on other sites More sharing options...
drunkn munky Posted February 21, 2012 Author Report Share Posted February 21, 2012 Theres no bottom to them Link to comment Share on other sites More sharing options...
bezzer Posted February 21, 2012 Report Share Posted February 21, 2012 Theres no bottom to them Your guess is as good as mine then unless you can get a depth gauge/vernier to measure the start and end of the insert to work it out that way. Link to comment Share on other sites More sharing options...
tanuki Posted February 25, 2012 Report Share Posted February 25, 2012 Or do what I suggested.....or not. Link to comment Share on other sites More sharing options...
drunkn munky Posted March 3, 2012 Author Report Share Posted March 3, 2012 Or do what I suggested.....or not. Longer bolts will be needed regardless mate but longer bolts alone wont solve the problem, they need to be shouldered to add support or maybe some small spacers inserted in the hole to take up the slack. Link to comment Share on other sites More sharing options...
eddie Posted March 5, 2012 Report Share Posted March 5, 2012 Suzuki and Kawasaki disc bolts are shouldered, the shoulder fits through the disc and fits part way into the wheel. I'm guessing this is what you're after? Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.