Friday, July 8, 2011

Tires and Snowflakes

Yesterday evening, after getting an email from Shawn at Adventure Cycleworks notifying me that my tires were in, I pulled off the wheels from the bike to take them over. While I was at it, I took a good look at the drive splines, brake pads and the bearings and all looked pretty good. You may notice that the brake calipers are all hanging by wires from the forks and frame as they need to be removed to get the wheels off. And, yes, there is a ratchet strap between the front axle and the center stand to keep it from folding.

While I was waiting at the shop, I was talking to an R12GS owner who was getting his TKCs removed and street tires put back on. He was describing some of his favorite features of the bike and, while sounding very convenient, all of the electronics and motors to accomplish these things seemed to add a lot of complexity. It was obvious that he loved the bike and I must admit that I think that they look great and are probably very capable. Dan Armstrong, one of the co-owners of the shop, kept telling me that I needed to get a new bike as the 18" rear tires and tubes were getting increasingly rare in this country. He was also was having a heck of a time getting the tires to seat on the rim and kept mumbling something about no more airheads. After messing with the front for easily an hour and a half, he decided to wait until his son came in this morning to take care of it. After all, he was the one who sold me the tires. The Heidenau K60 tires are tubeless and have a very stiff sidewall. The BMW snowflake cast rims are designed for tube type tires and need to be very clean with no trace of rubber and need a lot of tire lube for the tires to seat. I suspect that more air pressure would have helped the tire to seat but Dan was very careful not to exceed the maximum pressure (only 35 psi) for the tire. So, I had to drive the truck in today (and it was a nice day too!)


Friday Evening - Shawn from advcycleworks.com managed to get the tires mounted. I picked them up, got the bike back together and took it for a short ride. Handling is definitely different. These tires feel soft and turns feel slower, i.e. push the right hand grip, you feel the bike lean to the right followed a moment later with the bike starting to turn. The original tires were inch sizes with an aspect ratio of 100 where the new ones are 80 in the rear and 90 in the front. I suspect that also has an effect on handling. The rear tire is also about ½" smaller in diameter. I'll post a more in depth review once I get some miles on them.

3 comments:

redlegsrides said...

Richard

I look forward to your feedback re those K60s!

dom


Redleg's Rides

Colorado Motorcycle Travel Examiner

Troubadour said...

I too am interested in your review of the Heidenau. I've heard good things including high mileage and with the stiff sidewalls the ability to nearly run flat. I put Shinko 705 on my Tiger and it took a while to get used to going from a street tire to a tractor tire and trusting them in the corners.

Jack Riepe said...

Dear Richard:

I read this with great interest... The tire size for the K75 is also getting tough to find, with the primary source of replacements coming from Metzler, a fine name in motorcycle tires, but from a plant in Brazil.

Do the brake calipers on your "R" bike have to really come off to remove the wheels? I watched legendary K75 guru Brian Curry remove my tires and he only loosed the calipers, which gave him enough play to remove the wheel.

It rrequired three different tools to revove the front tire, which I thought were two tools too many.

Fondest regards,
Jack/reep
Twisted Roads