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1991 K100RS front wheel removal

littledog

Member
I just ordered new tires front and back for my 1991 K100RS as per a previous post. To expedite matters I decided to remove both wheels so when the tires arrived all I needed to do was take the wheels and tires to my local shop for mounting. I've removed the front wheel on my 1985 K100RS several times so I figured it was no big deal.WRONG The front wheel is a 17" three spoke and there is not enough clearance between the disc and wheel to get the calipers off. Clymer doesn't mention this quirk. Am I missing something or do I have to take the discs off the wheel to get the wheel off? Thanks again for all the help offered on this forum.
 
On my K75, after the front calipers are removed from the fork, I just flex the connecting brake line a little to slip the brakes backwards and away from the wheel.

I usually hang the calipers with a bungee cord from the fork tube tops.
 
After unbolting the calipers from the fork legs, rocking them back-and-forth a bit (while they are still straddling the disk) will push the pistons back in the bores. This will create more clearance to finesse the calipers off the disk without being blocked by the rim.

It is not difficult to damage the brake lines. Make sure you hang the calipers on a piece of wire or bungee or something else; do not let the calipers hang on the brake line.
 
After unbolting the calipers from the fork legs, rocking them back-and-forth a bit (while they are still straddling the disk) will push the pistons back in the bores. This will create more clearance to finesse the calipers off the disk without being blocked by the rim.

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That is the trick! The pistons have to be pushed back. It also helps if you remove the pads. But be careful not to push the pistons out.
 
I have pushed the pistons back to no avail. Still need about 1/2" more to clear the wheel. I will try removing pads and see if that works. Let you all know later today.
 
Wow, I never had such a problem, and I have never removed the pads prior to pulling them off the rotors. Leads me to ask if, after you rock the calipers back and forth, are you then tipping them one at a time, outward to get past the rim? They definitely will never go straight back. As noted, I have never had such an issue with any of my K-Bikes. The calipers always have tipped out and then slid back past the rim.
 
I've not had this problem either. As I mentioned in my original post, I have had the front wheel off my 1984 K100RS and didn't encounter this problem. In comparing the two bikes, the 1985 has an 18' front wheel and the rotor is about 11" in diameter. The 1991 has a 17"front wheel and the rotor appears to be at least 11.5". That adds up to somewhere around 1.5" less space to get the caliper out. I'm sure I'm not the only one who has encountered this problem. I'm going to try removing the pads and see if that solves the problem.I'll keep you "posted". Another difference. I believe, is the 1985 has a single piston front caliper while the 1991 has a dual piston caliper.
 
Success! After driving the retaining pins out and removing the brake pads the calipers came off easily. Not the most convenient way to change pads, but I know I learned something. Hope others will benefit from this discussion also. I would like to note that the Clymer manual says to drive the retaining pins out front to back. After a few taps with a drift and hammer with no success, I looked at the pins close up and realized the "big end "was on the outside. A few taps on the inside, driving the pins outboard, and out they came. Don't know if the pins were installed incorrectly at an earlier time or if Clymer is wrong. Interesting
 
I've pulled many a K100/1100 front wheel; never removed the brake pads first. I do wiggle/press the calipers to retract the pistons. That gives enough angle to get the calipers over the disks and around the rims. Maybe my pads are more worn than yours.
 
I was the one who suggested to take the pads out. I said it would make it easier. Didn't say it was necessary. And I have to admit, I have a 1990 K1 with a 17" front wheel and I have not taken the pads out to remove the calipers.
 
I just ran into this same issue on my new-to-me R1100RT with 17" cast rim. I did have to press the pads/pistons just about fully back into the caliper to have room to tilt the caliper back and out. The other thing I had to do was make sure I had the wheel rotated such that there was an open space, not a spoke, next to the caliper. By the spoke, I couldn't tilt the caliper far enough. This may be obvious to most people, but some of us are spatially challenged. :)
 
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