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1/3rd race sag works too. It will help tighten turning ability at the cost of straight-line stability. The reason I like a little more preload on the front is that the rider can affect a greater load shift on the front through the bars than just through the pegs like the rear (butt not on seat, which would change the angle of force). You have to be careful when measuring race sag. The rider must, of course, have riding gear on, but the rider must be in the position that reflects how the bike is ridden in a section and that means the appropriate pressure on the bars and upper body placement. Total weight of the rider/gear, how tall the rider is and upper body mass have an influence on how the front end is set up. Jon

That large, cone-shaped washer is the spring that exerts pressure on the plates. Another trick for taking out the screws is to use a good quality T-15 Torx bit tapped into the top and used as an "eazyout". Get the 10 replacement screws from your dealer and you will need a 7mm 12-point socket to install them. Don't overtighten them as the star shape acts as a kind of lockwasher. I wouldn't use any other screw than the GasGas ones as this is a critical area and clearance is an issue. Jon

My experience is that static sag is generally only useful as a starting point to measure race sag. Race sag is the "operating mode" of your suspension, and as such, sets the conditions under which your damping system works. The reason for my advice being different for forks and shocks is they are different systems with different variables. The shock usually works well at 1/3rd and not 1/6th is because you need to factor in the "rising rate' spring loading caused by the linkage. The ratio of the shock shaft travel to the rear axle travel is not linear, but exponential i.e. the shock shaft speeds up with a constant rise in the axle level. The shock operates in a relatively constant set of vertical forces but the fork has a lot of stuff going on that affects it's operation like weight transfer/bar pressure, steering geometry-rake/trail/offset etc., side forces, shock preload, blah, blah, blah. Given the choice of correcting the forks or the shock settings, I'd say get the rear set first. A lot of riders spend a lot of time fiddling with the forks and tend to forget about the shock. In my experience, the main reason I'm wiggling the bejezez out of those handlebars is to make the rear tire go where I want it, not just try to steer through the section. The back tire gives you traction and drive. Shock preload also (affecting race sag) has a lot of influence on how a bike steers as it affects the "trail" measurement. Before you jump for a new spring, try setting up what you have first. Recommended suspension settings are just advice as to where to start and are not carved tablets handed down from some mountain, so don't be afraid to experiment a little to see what suits your riding style. I don't think that 65 kg. would be totally outside the spring range you have. Poke around with your settings and see what you find, but try to change only one thing at a time as it takes a bunch of experience to accurately evaluate the effect of multiple variables. I wouldn't worry too much about making a mistake, your bike will tell you when you've gone too far with a setting. Jon

Jeff, If you need to split the cases, I'll give you some pointers as to what to look for. Cheers. Jon

Hi Jeff! Hey, no problem, I know it's tough being accurate when describing sysmptoms on a forum (like what constitutes a "knock"). What is "clacking" is the pins (called "dogs") on the shifting collar rubbing against the milled shots in the gear body itself. Motorcycle transmissions are what's called a "constant mesh" transmission and the gears are always in the same position relative to each other and do not move, contrary to what most riders believe. Power transmission is done by splined, sliding collars with pins that engage/disengage with slots in the gear bodies. If the edges of the dogs and/or the edges of the slots are worn, the dog may not slide into the slot easily but bounce back as the two radiused edges meet. The problem can be exacerbated by worn/bent shift forks. The "cure" is to replace the parts but that is expensive, and focused, deliberate shifting will help avoid the problem in most cases. Another thing that might help is to replace the tension spring on the roller detent that drops into the cutouts in the "star" on the end of the shift drum. You can get at the spring by taking off the sidecover. Look for a short arm with a roller on the end that engages the shift drum. There is a good possibility that replacing the detent spring may fix the problem completely and your tranny parts are o.k.. While you are in there, carefully inspect all the exposed shift parts. I'm not positive, but the earlier models had a rivit on the shift arm (that arm attached to the shift shaft that has a "claw" looking attachment) that acted as a built-in "breakaway device" to protect the transmission components if the shift lever got hit by a rock. If that rivit is loose, it could also create your symptoms. Jon

Neil on your Dad's "Bitzer", now that combination might be hard to beat! Jon

Clive? You out there? Inquiring minds want to know the Geritol results. The Geritol is one of my absolute favorites and on my bucket list to ride again. Jon

Jeff, When I wrote that answer years ago, it was for a different set of symptoms/circumstances, so I doubt it applies to your problem. I know from answering about 4000+ questions since those first 84 on the website that a lot depends on the nature of the "knock". If it's a heavy, deep metallic sound, it's probably a major component like a crank, with a lot of mass. If it's a light, short click, it's probably something like a kickstart idler gear. I've found diagnosing engine sounds by e-mail is an "interesting" process.... I'd start by a process of elimination, with the easy-to-get-at, less expensive components first. That means taking off the clutch sidecover and carefully inspecting all the various things in there. The 321 is a very stout engine and unless abused, rarely has any major component problems. We have a bunch of them running around here and all have never even had the head off. Jon ps. And try pulling in the clutch lever, it may just be the primary/clutch hub gears normal clacking while not under load. Cranks do not rotate at a uniform rate but speed up and slow down slightly each revolution and the gear tooth faces engage and disengage when not under load (more so with straight-cut gears as helical gears have slightly more than one tooth engaged at a time) which causes the rattle/knock in some engines.

That's always worked for me! I get more traction than anybody. Jon

Slight clutch drag is normal and the wheel spin test on the stand bears little relevance to how the bike operates in a section so I would not worry about that. Adjusting the "pin" (I'm assuming you mean the one on the lever) in and out to fix clutch drag will only cause problems and in most cases, more drag/slippage. First adjust the lever throw (how far out the lever is to start with) by holding on to the grip and use your extended "clutch finger" at a comfortable spot where you would normally modulate the clutch engagement, then add a few mm's to that for maximum throw. Due to hand size and finger length, it is different for each rider (which is why it is adjustable). Now you want to adjust the pin on the lever by turning it in/out to just barely contact the plunger that goes through the rubber boot on the master cylinder assembly. Turning it in from that will cause clutch slippage and out from that will cause more drag. From maximum throw setting, the lever should travel a mm or two before it starts to put pressure on the plunger. Jon

We used to do that with the old Bultacos at times. Engine valve springs work well. Any engine repair shop will usually have a bunch you can have for free. Jon

Beautiful area. I've been to Germany three times the last 5 years and stayed in Weisbaden twice so went through your town several times on the way down to Mannheim. Tried to hook up with a Trials event while visiting but wasn't able to, so that is still on my bucket list for next visit. Welcome to the Forum! Jon

The holes are for oil circulation within the case. Jon

Unfortunately, it was. Fuel droplets have washed the grit in the throat of the carb into the engine. Jon

http://www.trialspartsusa.com/tech.html has a bunch of GasGas info, including a downloadable 2004 owner's manual that should answer your questions. Jon

Good for you! It gets more fun as time goes on. Pretty soon you'll be like the rest of us and when you're taking the wife for a drive in the country, you'll also be scanning the sides of the road for ravines, creeks and rocks and thinking "Cool! That would make a neat section....". Trials is addictive. Cheers. Jon

Matt, The "JT" is a 1994 model and the "JTX" is the 1997 model, so there is only a couple of years between them. I havent heard of a 94-97 swap, but I would imagine there is a good possibility the mounts are the same. I doubt the guy will sell the frame fast, why not take the JT engine out and see if it fits in the JTX frame before you buy it? Jon

Excellent! Jon

If you are going to work on your forks in the future you may want to make a plate to fit under the lower jam nut. The spanner will work but suspension work is messy and oil will make your hands slip a lot. I think I still have a few scars from the spanner technique... Jon

Over-tightening can compress the spacer and lead to side loading. Jon

With that type of angle, I'd check that also. If the swingarm axle has snapped, the pieces still would be held in place by the rear clamps on the engine, unlike most engines that do not use the clamp design which would make the snapped axle fairly obvious. Jon

Provided it's not too far gone, you could possibly straighten it. Front floating discs will self-compensate to a certain degree as to a bent area. You'll want to get it a stright as you can or you may start to gouge the sides of the caliper. Use duct tape on any area you are working on to avoid damaging the surface of the disk (including on the jaws of the tool. Aluminum vice jaw inserts are very handy for this type of work). Carefully find the "center" of the bend to force back, otherwise you'll have a "wave" rather than a bend when you are finished. You'll also want to check where the disc got hit so you can smooth off any cuts or raised areas. Take your time and check your work often, this is like tightening spokes. The disk condition should not have any affect on the master cylinder. Jon

Andy, you can use either one. They will give slightly different clutch engagement, with the ATF maybe slightly quicker engagement. Try both and see which one you like. 650cc's is a good volume and change it maybe every 10-15 hours of use max and your engine and clutch will be happier. Most of use a 50/50 mix of distilled water and auto anti-freeze with good results. You don't need to bleed the system but it's good to check it after running a short time just to be sure you don't need to top it off. Fill the coolant to the bottom of the filler neck and if you over fill it a little expect a little to dribble out the overflow tube at first (not a problem). Jon