huffysgas Posted February 6, 2010 Report Share Posted February 6, 2010 HI ALL AFTER REBUILDING MY OSSA 350 TR80 GRIPPER AND AFTER COMPLETING 3 TRIALS I JUST CAN,T SEEM TO GET ANY GRIP AT ALL ON THE REAR .SPEC IS AS FOLLOWS NEW ROCK SHOCKS WITH 80 POUND SPRINGS ( LAID DOWN SHOCKS ) NEW REAR MICHELIN TYRE 5PSI ( HAVE TRIED VARIOUS PRESSURES ) IAM 6,3 AND 17ST AND RIDE EXPERT ROUTE IAM WATCHING OTHERS DO SLIPPY BITS AND I SIT THERE PADDLING IT IS BRILLIANT IN THE DRY JUST NOT WET ANY IDEAS ? IAM LOOKING AT SPRINGS NEXT ( LIGHTER ) ALTHOUGH THE SUSPENSION FEELS GREAT THANKS JIM . Quote Link to comment Share on other sites More sharing options...
mattlloyd50 Posted February 6, 2010 Report Share Posted February 6, 2010 Try the white route! Quote Link to comment Share on other sites More sharing options...
woody Posted February 7, 2010 Report Share Posted February 7, 2010 80lbs springs is a very high rate for a trials bike. I'm about the same size/weight as you and I used 90lbs springs on a Pursang when I raced one a few years ago. Angled shocks usually require a stronger spring rate than upright but I used 60lbs springs on my Majesty (Falcons) which are angled and they worked fine. I think the recommended rate for the Gripper for Falcons is 60lbs. Try dropping to those, 80lbs may be giving too much rebound and not allowing the rear to sink down and bite in. I'm assuming it is mud/wet grassy banks your struggling for grip in. If you're running with a tubed rear still there is only one choice really and that is an IRC, the Michelin tubed is useless in mud as it is no longer an X11, that was discontinued. Pirelli is a waste of money, it is way off a modern tyre for grip level. The IRC is brilliant in mud, but, some have really soft sidewalls and they roll all over the place at our weight at under 5psi. Increase the pressure to stop the roll and they don't grip. If you aren't using one and think of getting one, if you can actually see it before you buy it (ie; from a dealer rather than on line shopping) you can see if it has a really soft sidewall by flexing it with your hand. The 'duff' ones bend all over the place whilst a 'normal' one has limited flex, say, like the Michelin. Ideal pressure if it is only mud and roots in the trial is 4psi, if there are rocks go to 5 as the IRC can puncture easily. It will lessen the chances of compression punctures. If you're using tubelss tyres on the original tubed rim, the Michelin X11 should grip fine but an IRC is better. I'd go for the IRC again, the tubeless version shouldn't have the same sidewall issues as the tubed version and is the best mud tyre. Also, the 350 Gripper can be really sharpe off the throttle which can induce wheelspin. If yours is, think about a 3mm head gasket if it only has the 1mm or 0.5mm fitted and retarding the ignition to soften it off. Quote Link to comment Share on other sites More sharing options...
huffysgas Posted February 7, 2010 Author Report Share Posted February 7, 2010 Mat i can,t do the white route my uni cycle has a flat tyre ! thanks woody for a comprehensive answer we are on the same wave length been out this morning with a set of shocks off a friends gripper there njb , more grip but bottoming problems the head gasket was my next step i do have a 3mm one . with regard to ignition i will have a play thanks again jim Quote Link to comment Share on other sites More sharing options...
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