Thread Inserts
 

Removing a disc mounting bolt,its removed the thread with it.Is the answer a Helicoil,are they easy to do.Looks like the mounting holes have threaded inserts as original rather than the casting being tapped,dont suppose a new insert will screw straight in.Any advice please.

Don't know how easy it is to do, but it cost me around £20 to have a radial master cylinder helicoiled by a local hydraulic engineering company, so I'd guess it'd be even cheaper for a wheel.

Its very easy to do yourself AKA, you can get a full kit or just a kit in the thread size you actually need.

Where are you, someone might be able to help you out.

If you are anywhere near Towcester Paul James could do this for you.
Otherwise any decent bike shop with a workshop should have the gear-St.Neots Motorcycles have done some for me in the past, and Paul sorted the clutch centre on my TZ.

John

Yup, doddle. Got M5 and M6 kits myself if you're anywhere close.

Rgds, Rob

what is the difference between a helicoil and justv re tapping a thread??

My guess is that helicoiling will allow you to use the original sized bolt, re tapping will need a larger bolt unless the thread is only slight damaged and a tap of the right size will restore it.

Re-tapping cuts into the existing metal... if the thread has stripped out then there is nothing left for the item bolted in to locate to.
A helicoil is a threaded insert... think along the lines of drilling out to the next drill size & inserting a new bit of metal with a thread on it which matches the original hole......

Thanks for the offers.Picked a helicoil kit up,job done in no time,brilliant tool.

As I understand it ( I'm sure some one will tell me if I'm wrong) Thread inserts ie Helicoils were developed for RollsRoyce in WW2 so they could strip Merlin engines time and time again.
A helicoil is made of hardend coil wound steel and can be used to restore a tapped hole to it former self.when you buy a kit you get a tap and thread inserts.
The down side to them is they can come out and will

Unlikey to come out on a disk or caliper bolt though as its only restraining a rotational force, not a pulling one. Now a spark plug, well i can see that is likely to come out in time.

Give Marko a toffee apple, he`s right.

The Helicoil will only come out when we take the part apart, the screw binds on the insert and out it comes.

It doesn't matter what the bolt, screw is holding when it is done up the force is a pulling one (tension) and the force is tensile.(pulling it apart)

Wots a Thrapston........................is it a surgical or sexual device?:D