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Old 03-13-2011, 07:18 PM   #21
Brtp4 OP
Yea, its a friggin L
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Joined: Sep 2006
Location: Bend, OR
Oddometer: 1,894
Tires, Tubes, Gearing

I do not get too concerned with rear tire selection, I worry much more about the front. The rear can slide around and I don't get freaked out, front is a different story. Generally I am a Michelin guy, so I just picked out some M12 XC tires based on a recommendation from a friend. I got a 130/80x18 rear, and it is a little smaller than other tires with the same numerical size. Seems perfect for this, not too much tire, so it should be east to break loose. I am a little curious about the knob spacing, Michelin calls it an intermediate tire, but there is a lotta space between knobs. Front looks fine. We'll see.

On thing I did do was to put both tires in with Bib Mousses. I can tackle most work on a motorcycle excluding bottom ends, but I can barely change a tire. The idea of doing it out in the desert with 5 guys bitching at me to HURRY UP is not appealing. Since I will not be doing extended slab on this, I decided to sidestep the whole thing (which means I still can't do it) and use the Mousses.

Let's get something out in the sunlight: they are intangible to the point of being bizarre. First, the though of never. getting. a flat. is fricking awesome. But installing them, their short service life, susceptibility to heat, is odd. How you seat the tire beads, I have no idea. So I sidestepped installation too. As my friend Phil says, "that's what money is for". I paid M-Tech to put them on.

On gearing, I am looking at it like a work in progress. I have never met a bike I did not want to gear down, but in the case of the little XR, some people say that you should gear them up. I looked at trans and final drive ratios, and sprocket gearing, and this seems to be true.

I initially figured I would both gear up, and try to slow chain speed also. Stock gearing is 13/48, or 3.69. I looked at various application charts, and decided to go with 14/49, or 3.5, a mild difference. Ordered up a popular branded front sprocket and a Renthal Alu carrier / steel ring rear. These are great for saving weight, yet still fairly strong:

Once again, I am not an arteest builder like Colebatch, Wattner, or my newest inspiration, DisTech. But I am a shrewd parts changer, and good at prep and heading off problems. My bikes rarely break. Anyway, when I went to put the CS sprocket on, I found two things: first, a few folks have complained that the brand I chose has a soft spline area, and can walk back/forth on the shaft. I do not know this for certain, but there were enough anecdotes from people, I did not want to find out.

Second, these XRs will accept a 14T front, but fit is so tight, you have to modify the stock case guard. The stocker is so flimsy, it seems useless as it is, and grinding it can't help. Throwing chains through the cases is far, far too common, and where I live it can strand you and cause a serious pain in the ass. Additionally. I had decided to use an XRs only guard, but they do not make one for a 14T.

I do not want to have any chain, meet transmission issues, and had to have a good case protector more than 14/49 gearing. Reliability is key, and in the hands of the guy choosing and installing the parts. So basically, I set my 14/49 gearing on the shelf, and ordered a 13/45 (3.46) set from Supersprox:

Everything gets blue Loctitite, especially sprocket bolts:

Sprocket w/XRs Only Guard:

Looking at this, I decided two more things: first, ANYTHING I can do to strengthen the guard and minimize the possibility of case damage, the better; and I don't want to suck the cuff of my over-the-boot pants into the chain. The stock guard would not fit, but I did some Dremeling on it:

cleaned it up with a wire wheel:

And got it to fit. I now have a stronger case protector, and it looks like stock:

Continuing on the theme of heading off issues before they happen, I added an IMS shifter. It does not function any better than the stocker, but the shape places it differently, and the thicker material makes it less likely to punch through the cases in a fall. You can see the PO already gouged the cases with the stock shift level, BTW. I will eventually make a reinforcement and attach it to the side cases somehow.



Bend, OR

Brtp4 screwed with this post 03-13-2011 at 07:27 PM
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