Michelin Power Pure SC for the Yager

[az_slynch]

After two punctures in ten miles and noticing that I had less than 2mm of tread left until I hit the treadwear indicators on the rear tire, I decided to pony up for new rubber for the Yager. After hearing great things about the Michelins, I picked up a set for the Yager. There are tread designs for front and rear tire; Michelin makes a 120/70-13 tire for front and rear. The front style was a bit harder to find. I had to obtain the tires from two different vendors.

I had the tires mounted Friday and bolted them back on today. All I can say at this point is that tire profile contributes to sharper handling. Turn-in feels more positive and steeper lean angles are easier to achieve thanks to the dual compound tread (stickier on the edges) and the more rounded sidewall (doesn't have the sharp step between the tread and sidewall). Wet-weather traction is improved as well. The only potential downside I see for fitting these is that the water channels on the tread would probably be susceptible to tracking on grooved road surfaces or steel-decked bridges.

With the rear tread restored, it's time to go out and test top speed again. With a new front tire, I should probably check the speedometer calibration as well. I'll provide more feedback after putting some miles on them.

[az_slynch]

One of the rear as well.

[Yager200i]

I'll have to do that soon, as well. I bought a couple Avon AM63 Viper Stryke tires, though.

What's the procedure for taking the wheels off? Is it complicated?

[az_slynch]

Front wheel is a piece of cake. One 14mm wrench for the axle bolt and one 19mm wrench for the locknut. Spin off the nut, pull the axle bolt out. Speedometer drive can be swung free once the wheel drops out of the forks. I put an old ammo can under the bike's belly to hold it up while the wheel was removed.

Rear wheel is a bit trickier. Disconnect the O2 sensor and fish it free of the cable holders. Drape it out through the near-side bodywork hole. Remove the two 12mm long cap-nuts that hold the exhaust to the cylinder head. Remove the 10mm nut that holds the rear fender to the muffler. Loosen the three nuts that hold the muffler to the swingarm, take the top one out last (easier to handle the muffler). Pull the muffler away from the bike slowly and pivot it counterclockwise from the headpipe end to facilitate getting the O2 sensor and header flange out through the frame. Remove the 24mm axle nut with an impact gun or breaker bar; remove the nut and the spacer below it. Note that the spacer flange faces the nut on removal. Remove the 12mm lower shock bolt and swing the shock back. Fish the brake line free of the three line holders on the swingarm, you might need to unbolt the center one (8mm). Remove the two 12mm grey bolts that hold the brake caliper. swing the caliper free and set it forward of the powertrain (put it on the floorboard?). Remove the two 12mm bolts that hold the swingarm to the engine case. Wiggle the swingarm off of the axle; note that the shaft may stick to the swingarm bearing and some penetrant or percussion may be required. Remove the inner axle spacer from the axle shaft. Remove the wheel; the shock and inner fender will impede you some so some finesse will be required.

Prior to reassembly of the rear wheel, clean the splines of the rear axle with a brass brush to remove any rust.  If there's any rust or discoloration on the axle where the swingarm bearing rides, polish this with a Scotchbrite pad or #000 steel wool until shiny. Take a packet of the cheap anti-seize that they sell at your local auto parts shop and lightly coat the axle splines and the bit of the axle where the swingarm bearing rides; you'll thank me the next time you need to take the wheel off. Note which bolts had blue threadlocker on them; put a dab of Loctite 242 before re-installing them.

[az_slynch]

Update: I put 700 miles on the Yager this weekend riding from Tucson to Yuma and back via the scenic route. The bike handled the trip well, though heavy-duty headwinds on the trip home made for a bit of a grind. The Power Pures worked like a champ; rode smooth on the interstate segments and gripped well on the crumbly old backroads or southwestern Arizona.  Never felt uncomfortable throwing the bike around.


Bonus!
New Top Speed: 74mph at 9000 rpm. I'm missing a little top end due to drivebelt wear (measured .5mm wear at 5200 miles, has 7300 miles now), though probably not 3mph worth. The 18gr weights might be a touch too heavy, but I was still killing carbureted 250cc scooters in 0-40 acceleration.

[CapnJ]

I had a set of the Power Pure SC's installed on my Yager last fall at the end of the season. 9000 miles of fairly hard riding had worn out the rear tire. I went ahead and replaced both. So far I love these tires. The ride is smooth and they corner like crazy.

[az_slynch]

Update on the Power Pures!

First note, do not inflate the rear tire beyond 33psi cold. The tire pressure comes up at least 2 psi as the tires warm up and inflating beyond that can be detrimental to the tire. I replaced the rear tire after less than 1000 miles due to some worrisome tears in the compound. It is a dual-compound tire, with stickier edges and a firmer center tread. I was having a weird pressure loss where I'd lose about 7-10 psi on a 20 mile ride. I checked for a puncture and found none. I did find radial tears where the compound bands were delaminating. Replaced the tire and all is well.

In general, tire pressures are critical on these tires. It's very easy to cause cold tears or warm tears in the tread by running under inflated or over inflated.

I've also noticed a more pronounced bar shake at certain speeds if the tires aren't inflated properly.

Finally, did a speed run on the interstate with the new belt and tire: I managed to hit a verified 77mph for five miles on I-10! I backed off after tripping the CELP twice, but didn't trip the cutoff. If you're quick on the throttle, it's possible to avoid the stuttering slowdown; the throttle can be opened back up as soon as the light winks off. I still think that 18 gram sliders might be a bit too much, but it makes it easier to keep off the rev limiter at max speed. Thinking that a mix of 17 and 18 gram sliders might be better for performance and that a 130/80 rear tire might make up for the loss of weight, if it can be fitted. Heidenau has an M-rated K61 in that size and SIP Scootershop lists it as a fit for the Yager. Might be worth experimenting in the neverending quest to keep up with Yager200i!