speedysdad

My son competed in his first trials competition last weekend. He bought a 2005 280 txt pro to ride at Endurocross events to get more track time, but as all of you know he fell in love with it and wanted to see what trials was all about. He rode almost two complete loops when he noticed a flat front tire. The tire was the least of our problems as the front rim was broke and spread out pretty good at one point. There are several small cracks around the rim so I am going to replace the rim. Can I buy any MC rim or is the Trials bike rim different? I have not seen the rim listed separately on any of the aftermarket sites. Do I need to go back to Gas Gas? Looking for options. Thanks.

Well here is what I have learned after 2weeks of brake frustration. The rear mc was bad and not pushing fluid even with a new piston. The corrosion had damaged the interior of the mc more than I could tell. With all the advice on bleeding, it bleed up very quickly after the mc was replaced. After days of initially being frustrated, I finally broke off the bleeder screw. Then I broke off the carbide extractor in the broken bleeder. So then I ordered a new caliper. I was in a hurry to get the bike running, so I paid overnight shipping twice. I now have rear brakes. I also have the most expensive rear brakes ever. Thanks everyone for the help.

This sounds promising. Thanks everyone for all the suggestions.

Hey thanks, that gives me hope

Kind of, I used an allen wrench

The inlet port is clear and I have good flow to the mc. I can't get fluid to pump out of the mc to the caliper. I can't get any push from the mc, It won't pump up or push enough fluid to push out the air in the line. I am using the clear hose. I discovered the lack of movement at the caliper while attempting to change the pads. I adjusted the pedal to have a little free play when I installed the new mc kit. When I said the plunger was tight I just meant snug like it was fitting correctly, not with any resistance. I have already tried the back bleed as you described when hours of standard bleeding didn't work. Thats why I came here for advice. I am not new to brake rebuilding, but I have hit a wall with this one. Never seen a system that won't build pressure at all. After pumping the pedal 50 times, from fully up to fully down, I might get the bleeder to spit out a single tiny bubble. The mc hasn't built the slightest bit of resistance since I started. Now very frustrated.

Hello gentleman, I am new to trials bikes as my son races woods on a KTM. He decided to get a trials bike for cross training for Endurocross. The bikes seem simple enough, I have read every post in this forum while working on an 05 TXT Pro (The clutch is much better now). Enough intro. Since we got it the rear brakes quit working. So last night I rebuilt the rear master cylinder. I bleed brakes, back bleed brakes, vaccum siphon, and bleed brakes again for three hours, nothing happens. It won't pull or push fluid. This morining I start again. I take the rear MC apart again and see inside the barrel that there is some discoloration, maybe corrosion. It seems smooth. Then I inspect the old plunger and seals and notice some discoloration on it also. The new plunger seems tight, but it will not pump up or push any significant amount of fluid. Does this means I need a new MC?