CM91 tire size

Discussion in 'General' started by OldGuy, Apr 4, 2017.

  1. OldGuy

    OldGuy New Member

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    I'm resurrecting a '66 CM91 that was outdoor stored for 40 yrs. I have posted engine question in another section & progress is being made. Now I'm looking at tires & wheels. Doing this on a budget to begin. If all goes well I might re-visit some restoration items to improve the cosmetics. Cheap tires (approx $20) are 2.50 x 17, 290 pound 74 mph ratings. That matches the bike's oem ratings just barely, but I'm not going to ride this 2-up on the freeway anyhow! I could go with 2.75 x 17 on the rear to gain a bit more capacity for occasional 2-up riding or better traction at about the same price. Will this bike handle 2.75 on the rear??? Then there is the rust question. Rims cleaned up (chrome) pretty well with steel wool. But there is some rust on the inside (spoke ends area) of the rim. How clean must I get this area to be serviceable?? Should I paint this area with rustoleum or what ??? Thanks for your comments.
     
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  3. OldGuy

    OldGuy New Member

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    Update...
    I got the cheap tires, new tubes and new protective band that goes on the rim first to cover the spoke ends to protect the tube. I painted the inside of the rim with rustoleum paint. I chose 2.50 x 17 for the front. It meets OEM specs & keeps the speedometer in calibration. But I chose 2.75 x 17 for the rear. This gives me more wight capacity. It fits OK and looks good. The bike is now roadworthy, but I don't have insurance yet, so I only have about 5 miles of 'test rides' to tune the carb, etc. All looks good so far. Well 'looks good' is a relative statement. This is a "Rat-Bike" style of restoration. Many missing parts are now replaced with home made substitutes, so it actually looks like crap... but everything works and should be reliable and roadworthy.
     
    kirrbby likes this.
  4. Fastestgrass

    Fastestgrass New Member

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    I love rat bikes. Please post some pictures.
     

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