On a trip to Laughlin earlier this year I noticed that I was getting a lot of brake pulsing. The pulsing was present no matter how I braked. I tried tightening up the triple clamps to no avail. I found that I was missing the axle pinch bolt on the right fork. Replacing the pinch bolt didn’t change anything. I went online and checked the GSX forums and found that pulsing is not a unique problem and was usually due to warped rotors. I went out and bought a cheap dial indicator. My father left me a lot of tools, but no micrometers, calipers, or dial indicators. The no name dial indicator worked well enough and I found that I had 0.025” of runout on one side and 0.015” on the other sidle. I think that exceeds the manufacturer’s recommendations.
I found a company online that grinds motorcycle rotors, but I decided not to go that way. The GSX was meant to be a price point bike, and I was afraid that the rotors might have been one of the places Suzuki skimped to get the price down. If the basic metallurgy isn’t right, regrinding the rotors might not improve things. I just hoped that they hadn’t taken similar shortcuts with the calipers. I’d already replaced the brake lines so I’m safe there. The only aftermarket rotors I found were EBCs which were the same price as stock Suzuki replacements. The EBCs are supposed to be spring loaded on their carriers, so brake pulsing they claim won’t be a problem. Although I had recently replaced the brake pad since I didn’t like the stock ones, I decided to replace the EBC pads with sintered DP brake pads from Bike Bandit. While I was at it, I didn’t want to take any chances so I also replaced the front tire with a Michelin Pilot 3. I never liked the stock front tire anyway.
In stalling the rotors was pretty easy. I used my Makita electric impact wrench to remore the rotors, after going out to Sears to get some allen bits for a 3/8” drive (I had the 3/8” to 1/2” adapter. I tightened the new rotors down in my approximation of a pattern (Thanks, Dad, for all the bolt patterns I tightened in your shop) and finished off with my torque wrench set to the values from the Suzuki shop manual. The GSX brake pads are really easy to change, easier even than on my DL. Nothing like the misery of changing and aligning brake pads on my BMW R90/6 and R100S. I took the front wheel over to Temple City to have the tire changed. They’re always friendly and take walk-ins on Saturdays. Price is also good.
After all that effort and money, I’m glad to say that the pulsing problem is gone, and the bike does handle better with the Michelin and after tightening all the fork bolts. Next project will be changing to iridium spark plugs and getting longer throttle cables. The latter will not be cheap, I found out, since I have to get custom ones made.
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