bcmcrider

We'd like to welcome everyone to the PNTA coming up in Victoria on June 28th/29th. A lot of work is being done to make sure this is an interesting and fun event. Also, many of the sections are near the parking area, making it an ideal event for spectators. Please follow the link here to view the poster.

Not just to dig up an old thread but in response to the age of the event, the VMC recently held the 43rd annual Terra Nova.

I went through this with mine and the problem turned out to be a slightly tweaked rear caliper hanger. The bent hanger results in the caliper being slightly out of alignment with the rotor so when the brake is released, the flex causes the pistons to be pushed slightly further back in the bores than otherwise. The result is that when you step on the brake, part of the very limited motion of the pistons is used just to reset the pads against the disk. If this doesn't make any sense, hold a wooden ruler lightly in your hand, put it in your mouth and bite down. Now relax your jaw slightly and then bite again. How much motion did your jaw require to put a large force on the ruler. Very little. Now when you relax your jaw, place a twisting force on the ruler with your hand so that your teeth are forced apart slightly and then bite again. This time, the motion required is a lot more than the previous time. The essence of the problem is that the minimalist design of the braking system only allows for a tiny amount of motion in the slave cylinder with full excursion of the master cylinder. If for any reason, ie air bubbles, or misalignment, this motion is wasted, there won't be enough left over to do the job of creating the force on the pads. I fought with this issue for a couple of days before I figured out I needed a new hanger. I even tried to straighten mine but couldn't do it accurately enough. A soon as I replaced the hanger, the problem vanished.

You may also want to check for clearance between the upper triple clamp and the steering shaft as mine had. Added a shim and took out this play as the nut being tight wouldn't seem to hold for long prior to shimming. Also, the sound you're describing could be play in fork bushings. Slide up your dust cap, remove wheel, and try to move fork back and forth and watch for movement at the stanchion / seal interface. May need new bushings or other method to remove excess clearance. Ian

Talk to Beta. I sent them an email asking where I could get a manual for my 02 Rev3 and they sent me one from Italy completely free of charge or shipping cost. Thanks again to Marco Mannucci at info@betamotor.com Now that's service! Ian

An update for those interested. I wasn't able to obtain new bushings quickly and wanted to ride so I used a chisel point punch and "peened" or maybe more correctly, "splined" the outside of the upper bushings and filed the end gap, then shimmed the inside of the lower bushings, thereby removing a large amount of clearance. Five rides later, the forks don't make a smack sound when coming out of a wheelie now, they don't leak any more, and best of all, didn't cost a cent. Ian

Just a side note here that this site (www.vmc.bc.ca) doesn't display all the content properly when using Firefox. IE (unfortunately) must be used to view the site if you want to see the link to the event poster.

Yes, I had a good look and don't see any damage of any kind (surprisingly). With the motion that I could see due to bushing clearance, I'm pretty sure that's the cause of the leakage, especially since one seal started leaking within hours (riding) of replacement. I just wanted specs for the bushing thickness so I could see how much they're worn, but like I said, the dogleg motion of the assembly is considerable. I've decided to replace the bushings regardless so I'll post the thicknesses of new and old when I receive the new ones in case anyone else is interested.

Bump. Anyone know what the thickness of new bushings is?

I repacked mine with bulk packing material and it was a nasty messy job. If you can, I'd advise the preformed packing. Mine did work fine however.

2002 BETA Rev3 Fork seals were leaking before and after seal replacement so I started looking into other options. It was suggested to me that fork bushing wear could cause this and upon checking, I've got what appears to be a fair amount of play between the stanchion and tube at the top bushing. I can see the stanchion moving inside the tube bushing when rocking the tube back and forth (wheel and brace off obviously). Upon removal of the bushings, I notice that they don't look worn at all, in fact the teflon shows no visible wear inside the upper bushings. How do I tell how much wear is on the bushings? Are there specs somewhere for diameter or thickness? How will I know if new bushings will fix this prior to purchase and install? Any suggestions appreciated.