Over the last couple of years I've heard, many times, how one bike has better traction (grip), on a steep or slippery climb, than another bike. A lot of this, I know, is to do with smooth power delivery to the rear wheel, but by no means all of it.

The Sherco 250/290 is well know for having poor traction if you don

I don't know anything about the geometry of traction, but will be more than happy to discuss the physics of my finger hitting the ban button if you spam the same thing into multiple forums again...

I see you are judging your opinions on the 02 sherco (lack of grip that is).

It's funny but that year model had the longest swing-arm and didn't grip as well as previous or later models.

I had an 03 model and from what I remember it didn't matter where your weight was placed the back end gripped very well..I think the 03 had a shorter swing-arm.

Just my opinion.

Is that the sort of answer you were looking for?

Edited November 13, 200619 yr by HAM2

Over the last couple of years I've heard, many times, how one bike has better traction (grip), on a steep or slippery climb, than another bike. A lot of this, I know, is to do with smooth power delivery to the rear wheel, but by no means all of it.

The Sherco 250/290 is well know for having poor traction if you don

Edited November 13, 200619 yr by Slapshot 3

Just because something has a longer swing arm. does not Necessarily mean it will have more grip. For example you could have a swing arm seven foot long, but if all your weight was at the front , would it grip, er, no it wouldn't. If you have a short swing arm it takes smaller differnces in movment backwards and forwards to make a difference in grip, flip or no traction . Its all down to weight distribution.

Over the last couple of years I've heard, many times, how one bike has better traction (grip), on a steep or slippery climb, than another bike. A lot of this, I know, is to do with smooth power delivery to the rear wheel, but by no means all of it.

The Sherco 250/290 is well know for having poor traction if you don

Will the calculator i got with my AXA Sunlife quote work this out

might be pushing it a bit... don't those ones just calculate the bonuses the underwriters will fiddle you out of???

I could be wrong, but seems like I remember seeing some sort of traction diagram in Bernies book "Observed Trials"

All right leave him alone

how about distance between gearbox sprocket and end of swinging arm is one issue (effect of engine weight)

stroke of the engine is another issue ( a longer stroke engine will be less likely to break traction due to the number of times the piston goes past TDC per rotation of the wheel )

flywheel weight ( once you have the rear spinning you should be able to leave the throttle closed for longer to regain traction if the flywheel is heavier)

back pressure through exhaust ( that popping noise when your engine is slowing down after being revved, similar to flywheel effect ) just two stroke ???

actual power ouput and also how smooth the power curve is .

effect of rear suspension units ability to keep the wheel on the ground

disregard tyre because in a back to back test you would have the same tyre on all the bikes.

some combination of the above determines how a bike grips

in my rather humble opinion............

And it total contrast a GG Rookie will climb a hill as if it

i personally think that its nothing to do with the tyre or anything like that and is to do with weight over the back end and how much torque the bike puts out, the little rookie 80 has alot of torque for a little engine and i have seen it go up hills better than the bigger bikes alot of times which is torque of the engine and the bigger bikes seeem not to have as much torque but more "revvy". in any case if you rev the bike it will find grip from somewhere its to do with the physics of the spinning rear wheel and tyre etc but am not going to go into that!

when i saw the title 'geometry of traction' my heart missed a beat, in anticipation that at last, some real input into what all trials riders want to find...GRIP, but after reading the thread...same old story, ALL talk and no action. I've been trying to master the intricacies of steering angles, fork lead, wheel base, swinging arm length for 30 years, not to mention 2 stroke tuning and guess what...i'm still learning, and i think i know less now than when i started. So a 80cc Gas Gas, has more torque than a 500 Ariel. I would suggest that if that thing that you wrap your right hand around, the throttle is used in the correct manor, rather than being an on/off switch, and you took the time to study a true trials rider, you would notice that they find grip, where others fail. If you spent more time riding your bike than walking, in the end you'd be a better rider than walker, The better riders use a taller gears, converting the power, and superior clutch control, to allow the maximum amount of power to the rear wheel, without loosing traction. Ok get yourself the lastest blinged trials bike, you can't buy success in trials, time spent over many many years off practice is the only way.

I would suggest that if that thing that you wrap your right hand around, the throttle is used in the correct manor, rather than being an on/off switch, and you took the time to study a true trials rider, you would notice that they find grip, where others fail.

If you spent more time riding your bike .

The better riders use a taller gears, converting the power, and superior clutch control, to allow the maximum amount of power to the rear wheel, without loosing traction.

time spent over many many years off practice is the only way.

Good post greeves

Traction is obtained primarly on how one arranges the letters in the alphabet.

To date the best order or combination of these letters has been Scorpa SY250F.....

BillyT S4RT

There seems to be an obvious solution to a complex problem here. There are many variables that may all result in the same solution, RIDE WHAT YOU BRUNG AND RIDE IT WELL, IT WILL WORK! (if you know how to use it)

Well said Mark...........