binnes Posted February 16, 2009 Report Share Posted February 16, 2009 MY 2002 Sherco 290 seems to suffer from the front end pushing on/washing out in tight turns. I'm a beginner at trials and thought at first it is my technique, but a friend of mine rode the bike at the weekend and said he had the same problem. I'm 6'2" so I have the bars fairly far forward to make it comfier. Could this be making it worse? Any thoughts? Quote Link to comment Share on other sites More sharing options...
grahamjayzee Posted February 16, 2009 Report Share Posted February 16, 2009 Welcome! Short answer, yes! My mate (Nicks_TR34) is having a similar problem and watching him yesterday, his weight is too far forward. Get your weight back and try to ride the bike 'from the rear tyre'. Rocking the bars back will certainly help things. Check that the front brake isn't binding though. Any binding will cause understeer. I suspect that the bars being forward is the biggest factor though. Graham Quote Link to comment Share on other sites More sharing options...
motofire Posted February 17, 2009 Report Share Posted February 17, 2009 Also make sure your forks are not set too high in the triple clamps. Quote Link to comment Share on other sites More sharing options...
dan williams Posted February 17, 2009 Report Share Posted February 17, 2009 Compared to other brands Shercos are light in the front end but there are a whole host of things that will make the front end push. So yes check the fork height in the triple clamps and make sure there isn't too much air pressure in your tires and make sure the suspension is balanced and you don't have much more preload on one suspension then the other but the best advice is get used to steering with those big connecting rods that make you 6' 2". Bar position is usually not one of the biggies as there is a wide range of bar positions used by the top riders and they can make them all work. If your bars are vertical to slightly forward of vertical that's a fairly common position. Contrary to intuition having the bars further forward doesn't necessarily put more pressure on the front end. The opposite is true because you will be sticking your rear counter weight out and unless you look like Popeye (in which case a thyroid exam is a good idea) your butt weighs more then your arms. If anything beginners tend to wash out the front end by not turning with their feet. The bike will go where you tell it with your feet. I take it you are coming to trials from another type of riding. You are used to leaning into a turn with your whole body. That ain't gonna work with trials bucky. Here's the easy exercise to help illustrate. Find an off camber and go stand on it facing along the direction of the camber so one foot is higher then the other. Carefully observe how your body is positioned. Your torso and shoulders are level. The difference in height between your feet is taken up by your knees. Your weight is centered over your center of gravity and you can be pushed and still resist falling over. That is exactly the position you should take when the bike is leaning for a turn. The torso and shoulders are straight and level and the inside knee for the turn is straighter then the outside knee which is bent to allow the footpeg to come up. Same with the arms, the inside arm straightens and the outside arm bends to allow the handlebar to come up. This is how you see the good riders picking their way through a section able to stop at any time still in balance. What most beginners do is keep their legs too straight leaning the whole body into the turn as you would turning a bike at speed. After not being able to turn at a slow speed for a while they learn to compensate for the difference in peg height by twisting their bodies and sticking their tails over to the side of the bike to counter weight their twisted torsos. Try this standing on the off camber. Go from your normal balanced leg bent position to one where you try to keep both legs the same length. All you can do is twist to compensate and that is extremely limited. It's a very weak position and a passing squirrel could knock you over. The ability to compensate in this position is marginal at best and in a section where everything is designed to knock you off balance you are at a serious disadvantage. So what does this have to do with pushing? Well extend the logic here. When you turn the front wheel and don't allow the bike to lean because your legs are straight and usually tucked into the frame you are forcing the bike to go straight. No matter how much you turn the front wheel the driving wheel at the back is going to dominate. This whole problem can be fixed with some driveway practice. Get out and try to do slow figure eights being consious of the lean of the bike and your center of gravity over a center line between the two contact patches of the wheels. Think pressure rather then weight. Pressure one side of the bike then the other as you transition from left to right to left turn. You'll know when you've got it wrong because you'll dab to the inside. That's a sign that you're not bending your knees to make the bike turn. When you have it right you'll know that too because you'll be able to stop at any point in the turn in balance. Like those fancy turning wheelies you see the pros do? Ever wonder how they steer around on just one wheel? Hate shooting through the bushes in the corner at the top of a climb? Me too. Once you get the centering and steering with your feet as a natural part of your riding having the front wheel come off the ground is no big whoop as the bike will continue to turn and be controllable simply with peg pressure. You actually have an advantage. Since you're new to trials you don't have years of bad habit to unlearn. 1 Quote Link to comment Share on other sites More sharing options...
copemech Posted February 17, 2009 Report Share Posted February 17, 2009 Dan offers many good insights here, but as a Sherco rider for many years now, I can tell you things can be a bit baffeling as it does seem they like to push the front a bit more than some. On the '05 and prior Sherco Paioli fork there are the blue caps that are there to vent pressure and such. The o-rings are bad about leaking both air and small amounts of oil. I routinely replace the originals with a bit thicker section o-ring so they do not leak air. Thiss actually allows you to do a bit of adjustment for tight off camber sections by loading the fork and venting them, actually creating a vacume in them upon extension, and thusly a lower ride height which tightens the steering geometry. I will be the first to admit that for me this has been something of a baffling issue, as in some downhill off cambers, and yet prior to the certain transition point where you can use the rear wheel, there seems to be a point where the front would push and not bite at about the 1/2 point through the downhill turn. As we were in practice at the time of this specific time I used as example, my instructor(Ryan Young) suggested to apply even more weight toward the front so as to get more bite with the tire and turn untill the uphill and transition to the rear wheel power could be made. This actually worked under the circumstance, yet I still find it baffling. Seems one can use this initial loading of the front to then unload and drive from the rear during this transition. Difficult to explain and I have not perfected it at all! Yet may yield some insight Quote Link to comment Share on other sites More sharing options...
micm Posted February 17, 2009 Report Share Posted February 17, 2009 Dan, a good and thorough explanation, ever thought of writing a book on trials training? Also Sherco have altered the frame geometry on the more recent bikes. Quote Link to comment Share on other sites More sharing options...
dschigoda Posted February 17, 2009 Report Share Posted February 17, 2009 Great comments. I agree with all of them. After several years of Trials riding, I finally got Dan's turning concepts last summer. Even though I knew what to do mentally, I still struggled with turns, until... 1) I was lucky enough to have an expert rider/trainer yell at me while I was riding in a section in an event, to get my outside elbow and knee OUT while I was turning, and 2) I practiced more tight figure 8's in the backyard, on the side of a gentle slope. These two things made a huge difference in my trials performance. Dave Quote Link to comment Share on other sites More sharing options...
bigwig Posted February 18, 2009 Report Share Posted February 18, 2009 Agree with most of what has been said, but the biggest improvment to counter your problem is to drag the rear brake when clutchiing on tight turns. This approach calms the aggression of the clutch and stop front end from pushing away. Most top riders do this without even knowing that they are doing it.Watch the top lads. Quote Link to comment Share on other sites More sharing options...
dan williams Posted February 19, 2009 Report Share Posted February 19, 2009 Agreed a choppy clutch makes it much harder on two fronts. First the grabby clutch applies too much power to the rear wheel which lifts the front wheel. Second the rapid acceleration causes the rider to get "behind" the bike by a fraction of a second. Not only is your weight back but the effect is amplified by the need to pull on the bars to regain centering causing the front to be even lighter. If you compound this with the natural tendancy to clamp the legs in to hold on to the bike when it starts to get ahead of you it's the perfect recipe for going straight. Quote Link to comment Share on other sites More sharing options...
lselph Posted February 20, 2009 Report Share Posted February 20, 2009 Possible real simple question. Are your front brakes hanging up? Get the front wheel in the air and spin it. If it binds the tire will wash out easily. I have an old motocross bike that binds up and I can always tell because it wants to wash out all the time. Quote Link to comment Share on other sites More sharing options...
copemech Posted February 21, 2009 Report Share Posted February 21, 2009 And then you see we do still have a handful of the Older Class around to give us lessons in basic trials, as some of the ones I know that have been riding for decades now will just KILL you in the tight off cambers and such. And where a modern rider would want to hop, they never do. They can usually ride with much better feel for the course, as their experience has led them, and "the feel" for traction is a big deal! It does not come easily, but by experience! Everything is critical in these maneuvers, just takes practice! Which I sorely lack! Quote Link to comment Share on other sites More sharing options...
dan williams Posted February 23, 2009 Report Share Posted February 23, 2009 Heh heh they kill me too. I'm one of those oddballs who is a lousy rider but a good teacher/minder because I've studied the mechanics of riding. I also had the advantage of spending a lot of time with Ron Commo Jr. who I still regard as one of the best trials teachers I've ever seen. Quote Link to comment Share on other sites More sharing options...
binnes Posted February 25, 2009 Author Report Share Posted February 25, 2009 Cheers for all the advice guys, not had time to ride the bike for over a week, but am competing on Sunday so I'll try and put sime of your ideas into practice... Quote Link to comment Share on other sites More sharing options...
steve Posted July 20, 2009 Report Share Posted July 20, 2009 Agree with most of what has been said, but the biggest improvment to counter your problem is to drag the rear brake when clutchiing on tight turns. This approach calms the aggression of the clutch and stop front end from pushing away. Most top riders do this without even knowing that they are doing it.Watch the top lads. Great point. Sometimes when people ask how to do certain moves I simply can't tell them as I'd never really thought about it! It's only when someone watches you close up that you realise what you're actually doing. Quote Link to comment Share on other sites More sharing options...
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