jokerr Posted December 13, 2009 Report Share Posted December 13, 2009 can anyone tell me what influence rear suspension has on improving grip if any? ie . to increase grip do i harden or soften the rear end? (flywheel is going back in and black throttle on order) cheers. Quote Link to comment Share on other sites More sharing options...
godzilla Posted December 13, 2009 Report Share Posted December 13, 2009 (edited) I prefer hard with a little more damping. Edited December 13, 2009 by godzilla Quote Link to comment Share on other sites More sharing options...
1sherco1 Posted December 13, 2009 Report Share Posted December 13, 2009 ive never noticed altering the shock i just say ``stick yerr a*** over back`` Quote Link to comment Share on other sites More sharing options...
baldilocks Posted December 13, 2009 Report Share Posted December 13, 2009 Softer rear suspension generally grips better as your changing the weight bias of the bike, also at slow speed the tyre will not leave the ground as much. However if you go too far your bike wont steer very well and the suspension will be running on the bump stop a lot of the time, this may damage the shock if your doing big stuff or riding fast between sections. Measure the spring length before you start, just wind off one full turn at a time and see how it goes. Quote Link to comment Share on other sites More sharing options...
jokerr Posted December 13, 2009 Author Report Share Posted December 13, 2009 Softer rear suspension generally grips better as your changing the weight bias of the bike, also at slow speed the tyre will not leave the ground as much. However if you go too far your bike wont steer very well and the suspension will be running on the bump stop a lot of the time, this may damage the shock if your doing big stuff or riding fast between sections.Measure the spring length before you start, just wind off one full turn at a time and see how it goes. thanks baldi. that was my initial thoughts. softer = more grip. my bikes suspesion is stock unaltered evo 250( soft with my 13 stone on it) i had removed the flywheel wich i loved in the dry. (now going back in) and i will also reduce tyre pressure even more . will also try black slow throttle. my bike was spinning out big time today when i could climb using my mates bike with no probs. the gulf in grip difference was huge and i was wondering if the suspension could be an issue. many thanks Quote Link to comment Share on other sites More sharing options...
nzralphy Posted December 14, 2009 Report Share Posted December 14, 2009 Nope. He is wrong.....ish. Some blokes will say that their soft rear springing gives them more traction and feels better. Well that's BS, other wise the factory would send them out like that. More likely is the spring has sagged and the rider is preferring to slow shock feeling cos the shock is working in a more dampened part of it's action. Mostly it is Rebound Damping gives the bike traction. Reset the spring and slow the damping down. Springing resists some compressing force, makes your bike ride at the correct height, and forces the shock back out ready for the next impact. BOTH need to be set for your body weight. The rear spring settles over time and is not adjusted up. Reset it! Stand on the bike and make sure it ONLY sags 1/3 of it's travel (on front and back). Have someone help you measure this. It is important. Note that bikes are sent from the factory for 70-95kg (ish) riders - if you are outside this range you'll need appropriate new springs. Resetting this will correct your bikes geometry. Shocks wear. Shocks need servicing. Shocks need to have their damping tweaked at regular intervals to take account for wear or a re-tensioned spring. Your bike has a small rebound damping adjuster screw near the top of the shock. Give it a little turn inwards to slow the damping down. If you turn it in (go on, turn it all the way in) and there is no difference to slow the shock down then you are due a shock service. Try different settings. Remember DAMPING gives you traction. Quote Link to comment Share on other sites More sharing options...
godzilla Posted December 14, 2009 Report Share Posted December 14, 2009 Totaly with Ralphy on this one.. Quote Link to comment Share on other sites More sharing options...
jokerr Posted December 14, 2009 Author Report Share Posted December 14, 2009 ah ha! this seems to make perfect sense lads. you see the bike is new and the suspension has lately softened right up and feels springy. i did not have any dramatic grip issues before infact i thought i had plenty. the only change i had made in the interim was to remove the flywheel weight. (much prefer the response with it out )but if it has to go back in then so be it. when riding the bike it feels fine and does not bottom out on drop ins and rides great other than very poor grip. will check the travel with me on bike as you suggest. do you think at 83kgs i need the uprated spring or do you think more dampening should do it? thanks Quote Link to comment Share on other sites More sharing options...
chewy Posted December 14, 2009 Report Share Posted December 14, 2009 Still got an edge on your tyre? I too have recently bought new EVO gripped like sH*T to a blanket with OEM tyre (Michelin) but as soon as the edge went so did that feeling of confidence. A while back wew were talking about relative merits of various tyres. For me (riding on mud and roots mostly) the Michelin looses its grip along with its edge pretty quickly although this isn't nearly so noticable on rocky going. IRC is best tyre for trials down this way at this time of year takes longer to loose its edges and even then remains more predictable. Ralphs advice is pretty sound he's been around a bit! only additional comment re suspension is to make sure front and back end are balanced..its no good having a pogo stick on the back and rock solid on the front etc. Quote Link to comment Share on other sites More sharing options...
vgstef Posted December 14, 2009 Report Share Posted December 14, 2009 thanks baldi. that was my initial thoughts. softer = more grip. my bikes suspesion is stock unaltered evo 250( soft with my 13 stone on it) i had removed the flywheel wich i loved in the dry. (now going back in) and i will also reduce tyre pressure even more . will also try black slow throttle. my bike was spinning out big time today when i could climb using my mates bike with no probs. the gulf in grip difference was huge and i was wondering if the suspension could be an issue. many thanks can you explain to me how to remove the flywheel weight ? i like to try this. thank you Quote Link to comment Share on other sites More sharing options...
jokerr Posted December 14, 2009 Author Report Share Posted December 14, 2009 Still got an edge on your tyre? I too have recently bought new EVO gripped like sH*T to a blanket with OEM tyre (Michelin) but as soon as the edge went so did that feeling of confidence. A while back wew were talking about relative merits of various tyres. For me (riding on mud and roots mostly) the Michelin looses its grip along with its edge pretty quickly although this isn't nearly so noticable on rocky going. IRC is best tyre for trials down this way at this time of year takes longer to loose its edges and even then remains more predictable. Ralphs advice is pretty sound he's been around a bit! only additional comment re suspension is to make sure front and back end are balanced..its no good having a pogo stick on the back and rock solid on the front etc. i dont think its a tyre issue chewy. still pretty good edge. defo think its suspension related. Ralphs advise makes a lot of sense. my mate has recently replaced his rear shock because it was dead. he now gets a lot less grip with his brandnew soft shock than he did with his old dead one! we could not understand it untill we read Ralphs post .so he is now looking at the damping to sort his out. cheers. Quote Link to comment Share on other sites More sharing options...
jokerr Posted December 14, 2009 Author Report Share Posted December 14, 2009 can you explain to me how to remove the flywheel weight ? i like to try this.thank you they dont all have them fitted but if it does. remove right hand side casing and plastic spacer ( 3 allen bolts ) flywheel weight will be visible remove 2 large countersunk screws and weight. replace side casing but not the spacer. 10 mins. Quote Link to comment Share on other sites More sharing options...
garyc Posted December 14, 2009 Report Share Posted December 14, 2009 Raphly is not entirely right. Too much damping and you'll lose grip. Too little damping and you'll also loose grip. To get the most grip as the wheel goes over a bump, it has to stay stuck to the ground and the force from your weigth needs to stay as constant as possible. If the damping is too high (or too slow) the shock won't contract fast enough and you'll unweight after the bump and loose grip. The shock won't rebound fast enough either so this will make the effect worse. If the damping is too low or the shock is knackered it will feel springy and when you hit a bump the shock will shorten too fast and rebound too fast and make the bike unstable which will loose you grip as well becuase the force on the tyre is changing. I'm not sure it's all down to the suspension though, chewey is right about michelins in the mud, they are mediocre when new and absolutley awful once the edge is worn compared to a reasonably used IRC. Your mate might have had a lot less pressure too, you can get away with very low pressures in mud. The flywheel weight would definitely make a difference, if your struggling to bring in the throttle without the wheel spinning then it could be that. The slow action throttle might help, but I don't like them because it's hard to wind it on fully and it doesn't really change anything, just means your throttle control can be sloppier. If you want actual engine mods then you can look into carb inlet spacers or longer front pipes to shift the torque curve down the rev range, but don't go too far or it will be hard to bring in the throttle off tick over without it spinning. Lastly it could also be the ride front/back heights. If your mates bike was set up with a lower rear and higher front it will grip better as more of your weight will naturally be over the rear. you can adjust the spring preloads or slide the forks in the clamps to set this. Hope this helps and dispells some of the myths! Quote Link to comment Share on other sites More sharing options...
jokerr Posted December 14, 2009 Author Report Share Posted December 14, 2009 cheers gary, i will try an IRC next change. regarding his bike my bike, we were both running simmilar aged tyres at approx 3.5psi. i got more grip on his and he got less than me on mine. (hope that makes sense) he is approx 3 stone heavier than me. the most noticable difference in the feel of the bikes was that mine now feels springy and his feels planted. this is what has lead me down the suspension trail. just to confuse things slightly, i just had a look at my rear shock to look at the damper adjustment. the manual shows the adjustment screw on the airbox side (easily accessable) . on my bike it is on the carb side (totaly unaccessable) whilst i dont think this will affect the performance of the shock, it appears to have been fitted the wrong way round from new. or does anyone know different? Quote Link to comment Share on other sites More sharing options...
b40rt Posted December 14, 2009 Report Share Posted December 14, 2009 If your mates big Stu, the fact that he's 17 stone probably has some baring on how quickly the engine revs, and 4psi in the back tyre is equivalent to 2psi for "others" Quote Link to comment Share on other sites More sharing options...
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