Remove stuck Allen bolt

i had this happen on a dome head allen head bolt on my Bandit, i used a centre punch and hammer to undo it. Hit the dome head off-centre to rotate it undone, worked a treat on the mashed up hex bolt.

If its got a large protuding head, you can normally saw in a verticle line (go quite deep), and then unscrew it with a screw driver. If not then the above is your best bet.

[Mark_h]

Interestingly (or perhaps not) the mudguard bolts with hex button heads are M6x1 thread when tested with my die set. The phillips headed fairing bolts are much coarser, probably m6x1.5 but as I don't have an m6x1.5 die I can not absolutely confirm this.

Master plan after reviewing the thread is:-
1. Try the imperial set to see if I can get enough grip on it.
2. Try the hammer and punch method
3. Try the drill the head off them mole the thread out approach
If 1-3 fail then live with sloppy front forks and accept that the mudguard aint ever coming off.

Screwfix still sell packs of 50xM6 dome headed socket bolts for a couple of quid so hopefully can replace all the iffy bolts as I go. <Link>

[Sid Squid]

Originally Posted by Mark_h

If 1-3 fail then live with sloppy front forks and accept that the mudguard aint ever coming off.

I've worked on a set of forks not long ago - one of them had the mudguard attached all the way through the process, (not an SV).

No it isn't ideal - but you could do it.

[Mark_h]

Originally Posted by Sid Squid

I've worked on a set of forks not long ago - one of them had the mudguard attached all the way through the process, (not an SV).

No it isn't ideal - but you could do it.

But the law of sod has come into play. four fixings. Two released, 2 seized and rounded. Guess what, one on each side free and one on each side stuck.

May be a bit tricky doing it with both forks fixed to the same mudguard.

Also still need to try to get some info on oil weight and airgaps as there is no technical data available on the web for the scooter.

Just seen this thread, removed the mudguard on my son's curvy, the trick is to get an impact driver, less than a tenner, Loosen the bolts with a sharp tap on the impact driver before damaging them. If damaged you can as mentioned use a torq or spline or anything else to fit the damaged head, again use the impact driver and you should be Ok.
This was considered an essential too for working on the Japanese bike back in the early seventies, especially as their crankcase bolts had "phillips" (before pozidrive) style screws with different angles to those use in Europe, and they just rounded off.

For those who have not used them this is the item I mean, not the electrical or pneumatic ones, Most market tool stalls have them.

http://www.ebay.co.uk/itm/SILVERLINE...item2a12726642

Originally Posted by warmshed

the trick is to get an impact driver, less than a tenner, Loosen the bolts with a sharp tap on the impact driver before damaging them.

How does it work? - is it just a screwdriver that you can smack the end?

Every time you hit the impact driver it rotates a little. Great if u can use one on the bolt. Also m6x1.5 is almost non existant. Most likely if a coarse thread that its 1/4 unc. That equates to a pitch of 1.27mm.

Originally Posted by HoL

How does it work? - is it just a screwdriver that you can smack the end?

The driven piece has a bevel inside the handle that mates with a corresponding bevel on the handle, When you strike the end it travels down the bevel thus transmitting the hammer blow downwards but also clockwise or anti clockwise depending how you set up the wrench. This shocks the screw/bolt and turns it at the same time. It prevents the end from "camming" out and thereby prevents damage to the head, it is a most useful tool.
It has a Hex and 1/2" square drive, normally comes with a set of impact cross and straight drive bits. Ordinary 1/2" sockets are OK at a pinch too but serious heavy work will need matching impact sockets to take the force but these will rarely be needed on the bike.

metric 6 is normally available with two pitches, M6x1 is known as M6 coarse, and M6x 0.75 is known as metric fine. Metric coarse is a more used size. The old 1/4" threads can be used if you damage the thread 1/4" is 6.35 mm and can be just that bit bigger to enable you to thread it BSF and be strong enough to use.

1.5 thread pitch is only normally used on M10 and bigger sizes, but non preferred sized do crop up.