Front brake squeek and grind
Posted May 07, 2000 - 02:00 PM
Posted May 07, 2000 - 03:23 PM
Truing a wheel: Put a screwdriver or socket extension (or dial indicator if you are really loaded with tools) resting against the fork/swingarm with the tip next to the rim, then rotate the wheel. A dial indicator is preferred. (You can pick up a decent dial indicator with a magnetic base from mail order tool supply houses for about $35.) If the wheel is true, the tip of the tool/indicator will show nearly constant lateral and vertical position of the rim during the full rotation. If not, then you will see the variation. The wheel runout spec is .080" or 2mm lateral and vertical. If it is way out of true, it is best to loosen all spokes and start gradually tightening all of them while checking how true it is. If the wheel has a deviation to the left, slightly loosen the spoke that attaches to the left side of the hub and slightly tighten the spokes that attached on the right side of the hub. This will pull the rim to the right. A note the truer the wheel the less vibration and less rotor warp. Get it as true as you can. I trued mine within about .020” or 0.5mm.
Step2: Rotor Truing (CAUTION: ROTOR TRUING IS NOT YAMAHA AUTHORIZED) The brake still squealed a bit, so I went after the rotor. You will need a dial indicator to check/true a rotor. The runout spec on the front rotor is 0.006”. Mine measured 0.009”. Yamaha recommends replacing the rotor if out of spec (assuming the wheel is true). I placed a small piece of hardwood (3”x1”x1/4”) on either side of the rotor and placed a crescent / adjustable wrench over the pieces of wood and tweaked / bent the rotor to correct the warp condition. Start by bending very slightly and measuring runout each time. I got the runout to 0.005”. This saved me from having to buy a new rotor.
Result: much better brake performance and no dealer / parts hassle.
Eric in WA
’99 WR400, YZ timing, IMS Tank, YZ Seat, Acerbis Handguards, Scotts Steering Damper, Renthal Bars, Yamaha Full Skidplate, Devol Rad Guards, Dunlop 755F & 756R Tires
’99 Polaris 400 Scrambler –“Trail Couch, Toolbox and Lunchwagon”
’99 Honda Z50R, ’97 Honda XR70R, Kubota L275DT and an assortment of farm equipment.
Posted May 07, 2000 - 04:07 PM
Posted May 07, 2000 - 04:47 PM
Posted May 08, 2000 - 04:27 PM
I use to never check my spokes. Now I do it every other ride at least.
Dougie, '99 WR400
Mods: YZ timing, Race Tech Suspension, FMF PC IV, FMF Hi FLo Moto, YZ seat, IMS 3.3 tank, One Industries Graphics, Renthal bars, 14/52 gearing.
Posted July 20, 2007 - 07:54 AM