For this tutorial, we'll do both wheels at the same time, starting with the front wheel. I've tried it two ways: first loosening the front axle and rear lug-nuts while the bike is on the side stand, and doing the same thing after first putting the bike on the centerstand and sliding a small jack under the skid plate so as to get both wheels off the ground at the same time. I prefer the latter scheme, so that's what I'll describe. Starting with the tools you'll need — basically it can all be done with three Torx bits and something to remove the front axle. The photo below shows what I used, which included:
- T-30, T-45 and T-50 sockets.
- A speed handle (for the rear wheel bolts).
- Two torque wrenches (the big one is for the axle).
- A big socket wrench to remove the front axle.
- A short 1/2" extension, and a 1/2" to 3/8" adapter.
- A short 3/8" socket wrench.
- My custom tool to adapt the front axle to a 3/8" socket drive.
I try to use my custom toolkit whenever I work on the bike. That helps me make sure I've got everything in it I'll need on the road. In this case, to make it easier, I added the speed handle and the big wrench. On the road, I don't worry about exact torque settings (I recheck them when I get back to the garage).
Front Wheel
First, loosen the two T-45 bolts holding the brake calipers to the forks. The arrow above shows one of the bolts partially removed. A good trick is to use a small container to hold the bolts and parts as you remove them, so as not to lose any of them. The two bolts are identical, but I try to remember which is which so I can put them back in the same holes nevertheless.
This step is necessary because the rim/tire won't fit through the space between the mounted calipers. Be particularly careful of the left caliper, as it has a small black line which runs to the ABS sensor and which will remain connected to the caliper after you loosen it. There's a RECALL concerning this line, see below.
Note that a T-40 socket wrench almost fits. I hate that about Torx, the smaller sizes sometimes fool you into thinking they are the right ones. Make sure you've got the T-45 or you'll bung up the head of the bolts.
Next step is to loosen the T-45 axle pinch-bolt at the lower leading edge of the right fork tube. You don't have to remove it all the way, just get it nice and loose. Then use whatever tool you have to remove the axle. It is installed fairly tightly, so you will likely need a large wrench. I built a special tool for removing the axle which I carry in my toolkit. The earlier stock toolkits (assuming you got one) have a tool, one end of which fits the front axle. The 17mm wrench fits the other end, but is probably too short to get enough leverage to loosen the axle. In 2006 (or possibly earlier) BMW stopped putting this tool in the toolkit, so you'll have to come up with your own tool for the front axle.
If you have the small jack configured so as to have the front wheel just barely touching the ground, you should be able to slide the axle out without the wheel dropping. There are a lot of threads on the axle, so don't get anxious, just keep turning until you feel it come loose. Just roll the wheel forward to remove it.
There is a spacer on the left side of the axle (all my rights/lefts are relative to an observer sitting on the bike), remove it and put it with the caliper bolts. It will fall out if you don't, and likely fall out somewhere where you don't notice. Then you'll be stuck waiting for your BMW shop to order you another one.
Carefully remove the wheel, and you're almost done. If you're going to take your wheels to a shop to have new tires mounted, it is wise to mark the direction of travel so the tire guy will put the new tires on correctly (motorcycle tires are directional, meaning they are built to be mounted only one way). The R12GS cast front wheel has a small arrow cast into it, but it's kinda hard to see. I stick a piece of duct tape (or masking tape) on the rim and draw a big arrow with a magic marker. On the cast wheels, the convex side of the spokes is on the left (both wheels) and the concave side is the right (both wheels). With the wire-wheels, the proper orientation is much less obvious.
To remount the front wheel, just reverse the above procedure. Be particularly careful of the ABS sensor line on the left brake caliper (see red arrow above). There is an NHTSA Safety Recall on this line which involves some clips to keep the line from contacting the disk itself and wearing through. Mine has some clips and a cable tie, seen above. I'm always careful to twist the lower cable tie to move the line as far from the disk as I can.
The proper torque values at the front wheel are:
- Axle pinch bolt: 19 Nm (14 ft-lbs)
- Brake caliper bolts: 30 Nm (22 ft-lbs)
- Axle: 50 Nm (37 ft-lbs)
Rear Wheel
The rear wheel is much easier than the front. Simply remove the five M10 x 1.25 bolts with the T-50 Torx bit, and then remove the wheel. This will be much easier if you raise the jack so as to lower the rear wheel so it contacts the floor. That way the tire won't be as likely to turn when you try to remove the bolts.
Reinstallation is the reverse. Hand tighten the five wheel bolts, then tighten them in a diagonally opposite sequence. Torque them to 60 Nm (44 ft-lbs). Do not use any oil or grease on the wheel bolts!
Proper torque value for the rear wheel bolts is:
- Wheel lug bolts: 60 Nm (44 ft-lbs)
Using the floor-jack trick in combination with the bike's center stand, you can easily remove both wheels and leave the bike sitting safely in your garage. It's relatively stable, but if you want to be extra cautious, find a way to use some tie-downs to secure it. I don't bother, and so far I've been lucky!
Things to Watch Out For...
- The front axle spacer goes on the LEFT side. I believe it's symmetrical, but it should be easy to see which side fit into the dust seal on the wheel. Make sure you don't leave it in the wheel when you take it to the shop for the tire swap -- the tire guy will have to remove it, and may forget it (or lose it).
- Make sure your new tires got mounted with their directional arrows going the same way the wheel normally rotates.
- After remounting the wheels, pump the front and rear brakes a few times before you ride, and check the brakes as soon as you start rolling.
A Shameless Plug...
My friend Marc Parnes makes a spiffy tool for balancing your wheels yourself. He offers a version (shown in the photos below) for the R1200 models which has an adapter for the rear wheel. This makes it super easy to get your wheels in balance after you've changed them yourself. Highly recommended.
Left side
Right side
(showing the cones used for the front wheel and the plate used for the rear wheel)
Copyright © 2006, by H. Marc Lewis. All rights reserved.