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Disc Bolts.

PostPosted: Sat Feb 06, 2010 3:10 pm
by GEOFF587
Could someone please confirm the size and type of bolts required for the front / rear brake discs and the rear sprocket for an 03 Baggie. And where to get them from , stainless preferred.

Thanks in advance

Geoff

Re: Disc Bolts.

PostPosted: Sun Feb 07, 2010 11:38 am
by Bill Jurgenson
standard rotor bolts are M8 x 20m or 25mm.

Re: Disc Bolts.

PostPosted: Sun Feb 07, 2010 1:22 pm
by GEOFF587
I thought they were standard but reading through some of the threads M8 X 15 and M6 x 16 are mentioned, just trying to get some clarification before buying some stainless.

Re: Disc Bolts.

PostPosted: Mon Feb 08, 2010 2:18 am
by Bill Jurgenson
why don't you just remove one and measure it? Seems to me to be the easiest and surest way to find out!

Re: Disc Bolts.

PostPosted: Mon Feb 08, 2010 3:32 pm
by samandkimberly
GEOFF587 wrote:I thought they were standard but reading through some of the threads M8 X 15 and M6 x 16 are mentioned, just trying to get some clarification before buying some stainless.


Typically disc bolts are hi tensile steel, even the best stainless alloys used in bolts aren't. You're probably not taking your life in your own hands by changing them to stainless, but still, it doesn't fall at the top of my "smart things to do" list.

Sam

Re: Disc Bolts.

PostPosted: Tue Feb 09, 2010 1:09 am
by Bill Jurgenson
I agree with Sam here.
In my onw bikes, I have the Poggipolini (but no others!) titanium bolts that are available for Ducatis.
Otherwise, I have Allen-head 12.8 steel bolts I had zinc plated and heat treated myself.
After plating the steel needs to be anealed again.
In your case, I would just use standard Allenhead machine screws of at least 10.9 rating.

There are no hi-tensile plated bolts on the market; that is not a regular product. The OEM bolts with most manufacturers are not hi-tensile at all. MZ's are soft as butter so careful when attempting to remove them or you'll end up with a very round hole instead of a hex.
Yamaha's are only slightly better in Quality but they are 5mm wrenchsized instead of the usual 6mm and have shallow hole. Both use Loctite. Best to heat the bolt with a blowtorch first, then a sharp smack on the head with an impact hammer.

Do NOT use Loctite. Use Schnorr saftey washers and the proper torque for the M8 bolts.
Screen shot 2010-02-09 at 6.55.27 AM.jpg

obviously in meter/kilogram, not in foot/pounds.
Also use a correct thread grease or the torque wrench is just stage prop.
The Loctite used in industrial assembly is pre-applied and dry. It functions both as a torqueing lubricant and after setting again as an adhesive.
http://65.213.72.112/tds5/docs/2050-EN.PDF
There is a lot more to correct assembly, even of such seemingly mundane things, than meets the eye. You might take the time to have a look at my blog.

Re: Disc Bolts.

PostPosted: Wed Feb 10, 2010 12:14 pm
by GEOFF587
Belated thanks to all the above posts. All advice noted and taken on board.