The large crown wheel ball race. Is that a BMW only part or readily available from a bearing supplier? If so, anyone have the bearing manufacture part number/code for it? I'm guessing it would be cheaper to buy that way than a 'genuine' BMW bagged part. John

k100virgin wrote:The large crown wheel ball race. Is that a BMW only part or readily available from a bearing supplier? If so, anyone have the bearing manufacture part number/code for it? I'm guessing it would be cheaper to buy that way than a 'genuine' BMW bagged part. John

I just did mine, recommendation from someone with nothing to gain and huge experience of doing them was to buy the BMW part, you also need the seal to go with it and it's a separate part. Its the same bearing on the R bikes and on the paralevers.

Never actually checked if there was one from a bearing supplier but the same person who recommended that one to be a BMW bearing quite happily uses bearing suppliers for the other bearings.

Motobins was a good source but check Motorworks too.

Don't let that bearing go long if it's on the way out.

"Don't let that bearing go long if it's on the way out."

That's good to know. Sometimes you think "It'll be all right for a while".

Thanks for info. Bike passed its MOT last week but the tester found the very slightest of movement in the rear wheel, felt more than seen. Are we saying a new race would eliminate that completely or is there still a running clearance and movement? Bike has done 85,000 miles.

Mine was on 80,000 miles so same lifespan. If you leave it then it ruins the final drive with the race moving around and can [will] eventually break up unexpectedly. I had no apparent play, what alerted me to it was the feel of a bearing on the way out and I had worked out it was related to road speed and not engine speed.

Final drive doesn't even have to come off to do it. Done from the wheel side. Getting the clearances right is important, needs to be tight enough to remove play but still rotate freely.

That bearing is the only thing on the back end that's keeping it all together.

Looks like a trip to Motobins, there only 35 miles away.

That bearing (85X120X18) fits Airheads from 1981, all K bikes whether Monolever or Paralever, R850/1100/1150/1200C Oilheads, and the later K1200RS/GT & LT series. The current BMW p/n is 33121242211. An aftermarket bearing number is 61917/C3 by SKF. When it goes it goes. 'Bins has 'em for £39.00 inc VAT.

Two Wheels Better wrote:That bearing (85X120X18) fits Airheads from 1981, all K bikes whether Monolever or Paralever, R850/1100/1150/1200C Oilheads, and the later K1200RS/GT & LT series. The current BMW p/n is 33121242211. An aftermarket bearing number is 61917/C3 by SKF. When it goes it goes. 'Bins has 'em for £39.00 inc VAT.

Will check price from my local UK bearing supplier out of interest but have to say not a bad price from Motobins and of course they have the seal and 'O' ring.

Price from my local bearing supplier as a special order a staggering £106.04!!!!!!!!!!!!?????????

I think that's full MRP as I've seen that price (or very close to it) quoted by a lot of different suppliers. The big bearing in my Guzzi bevel drives is in the same ballpark.

K100virgin, what year K100 are you riding? If it has a paralever rear it could also be the pivot bearings causing the play. The FD bearing will not 'fail' overnight but gradually wear over thousands of miles/kilometers. A new bearing will totally illuminate any movement. You can check the FD bearing for wear by using a screwdriver as a stethoscope, placing the tip on the FD and the handle to your ear and spinning the rear wheel. If the FD bearing is worn you will pick up a rumbling sound. Alternatively, if you have a paralever place the screwdriver tip on the pivot bearing lock nut and get a second person to rock the rear wheel at 9.00/3.00 o'clock. If the pivots are worn or in need of re torquing, you will pick this up as a noticeable ticking sound through the screwdriver. Often when it is thought the pivots are worn, sometimes a re torque is all they need. BMW suggest 8Nm from memory, but 10 is better. When torquing mine I torque them a couple of times to 12Nm to expel excess grease before a final torque to 10Nm

Its a 87 K75s so standard back end. Picked up the parts from Motobins the other day so will wait until weather a bit cooler. 28C today, Its the humidity that's killing me. John