Which speedo drive for this front wheel on an R1150GS?

[mr_magicfingers]

I have a set of alloys to put on the GS so I can have knobblies on the wire wheels and road tyres on the alloys. I'm not sure what machine the alloy wheels have come off, but they are from another BMW. There's pictures below and numbers on the wheels, can anyone help with identifying them please.

Once I know which model it's from, I need to know which speedo drive to put on the front wheel so that it'll display the speed correctly on the speedo.

I seem to remember that you need a different length set of bolts for the rear wheel compared to the wires, is that the case? The brake disk seems to just attach with the wheel using the same bolts, does it just sit in place between the drive and the wheel with no other attachment. (I've not taken the rear wheel off my bike yet, so not sure.

Are the front disk bolts of any particular spec? I'm short 2 of the 12 and need to pick them up from somewhere. Do they need to be BMW specific or can I just get a pair of suitable size bolts from the hardware store?

Thanks for the help,

Justin.

 

[Speedy]

Hi, I'm not able to identify the wheels for you but I do know the rear one should have disc attachment lugs, which are part of the casting, to mount the rear disc. I can't see how the rear wheel will fit otherwise.

 

[Paul Young]

Hi Justin,

The front is a 3-spoke from an older model K or R1100, You need a 2.6:1 speedo drive for it. Those brake discs will also be much better than the newer semi floating ones.

The Rear is from a model which uses a disc mounting plate, such as a K1 or K1100 model, but the good news is that these plates cost peanuts from Motorworks/Sherlocks/etc, & will take the disc from your spoked wheels. This gives you a very handy advantage as the disc mounting plate is screwed into the output flange of the final drive & stays in place when you remove the rear wheel. This means that you don't have to undo & move the rear brake caliper, etc... Take a look at the output flange & you will see not only the 4 holes for the wheel bolts, but also 2 smaller holes for the disc mount.

You got a good pair of wheels there, well done

Edit: Just found a photo which might help picture the rear brake disc carrier...

 

[Superhypo]

I suppose the rear wheel is from a k1200rs and yes you will need the brake disc with adapter and abs ring if you have abs brakes. The bolts are different as well since they are shorter than the ones from the gs wheel. The front wheel you got I suppose is from a r1100rs/rt/r and the needed speedo hub is a 2.6 ratio one if I recall right.
Check this and you will find a lot of useful information http://www.ukgser.com/forums/showthread.php?t=15702&highlight=cast+rims

 

[mr_magicfingers]

Hi Paul, thanks for the great advice. Would you happen to know which models I should ask for at breakers yards for a speedo drive like that, or is it best to just get one new?

Rear disc mounting plate, do you mean one of these?

It came with the rear wheel and I was having trouble figuring out how to get it to fit. I take it the two extra bolt holes have matching threaded holes in the output flange? If that's the case I just need the appropriate size pair of bolts to bolt the carrier to the flange, hopefully a bmw dealer will know which these are.

Do I also need longer wheel bolts then as there's now the extra thickness of the carrier between the wheel and the flange.

Thanks again for the help,

Justin.

 

[Paul Young]

For the speedo drive, just tell the dealer/breaker that you need a 2.6 ratio or one from an R1100R/RS/RT. They aren't very expensive new, but they are cheaper s/h... Ask them for a couple of the screws that mount the rear disc carrier at the same time as they cost pennies. Depending on your spoked rims, you might need a cast abs ring to mount on the rear carrier, where the other 5 holes are. These are stupidly expensive new (£80+ ISTR).

 

[mr_magicfingers]

Thanks for that Paul, I'll get on to the breakers tomorrow. Won't need an ABS ring as don't have ABS on my bike.

Hopefully have something done on the conversion next week.

Cheers,

Justin.

 

[Packer]

Speedo drive under £34 last year, new from Motorworks.

The internals are pretty fragile on these drives, I'm talking about the original BMW ones, so I wouldn't bother using a secondhand one.