Easier to highside an IL4 than a twin. True or false?

[flymo]

The more torque applied to the rear wheel, the more chance of it losing traction under the right circumstances. So yeah I would say that it would be easier to lose the rear on a V twin if you have poor throttle control, assuming that both types of bike were on the same corner and the Vtwin in question happened to be applying more torque than the IL4 at the point in the corner were the rear broke loose

For a given corner though, if both types of bike have excessive torque available then really makes no difference. It would be more relevant which type of engine configuration was being used and how the power is applied.

Powerful 2 strokes break loose very very easily mainly due to the narrow power band, its much more difficult to apply power gently on one of those.

[STRAMASHER]

Originally Posted by flymo

Powerful 2 strokes break loose very very easily mainly due to the narrow power band, its much more difficult to apply power gently on one of those.

I concur, as witnessed by myself for my 1st look at what a "highside" really was ,at a mate going over right infront of where I was stood.

One of the funniest things I have seen. Still see the look in his face now.



Powerful 2 stroke Honda MT-5 , gravel carpark ........hey,but its the same dynamic maybe not quite so much pain at the end!

Please refrain from bypassing the swear filter. Thanks

Originally Posted by Holdup

I just used it as an example for the low down torque as thats when id expect the v twin to lose traction, but as i said i may be wrong

Id say perhaps. I know V2 are supposed to be good for grip not bad. So id expect it to be a case of how often the power pulse comes...

Originally Posted by flymo

The more torque applied to the rear wheel, the more chance of it losing traction under the right circumstances. So yeah I would say that it would be easier to lose the rear on a V twin if you have poor throttle control, assuming that both types of bike were on the same corner and the Vtwin in question happened to be applying more torque than the IL4 at the point in the corner were the rear broke loose

For a given corner though, if both types of bike have excessive torque available then really makes no difference. It would be more relevant which type of engine configuration was being used and how the power is applied.

Powerful 2 strokes break loose very very easily mainly due to the narrow power band, its much more difficult to apply power gently on one of those.

Id be willing to bet its more down to the amount of power pulses, hence a 2 stroke being bad, on top of that the power band and oh dear! A lot of smaller pulses are more likely to lose traction than fewer bigger ones. We need to find some facts tbh. I just know that the whole Idea of big bang was to make a 4 cylinder more like a twin cylinder (all except the Yamaha... but thats more like a V4.).

[flymo]

Originally Posted by ThEGr33k

Id be willing to bet its more down to the amount of power pulses

Thats what I meant really when I said "It would be more relevant which type of engine configuration was being used and how the power is applied."

Originally Posted by flymo

Thats what I meant really when I said "It would be more relevant which type of engine configuration was being used and how the power is applied."

Fair enough

Originally Posted by flymo

The more torque applied to the rear wheel, the more chance of it losing traction under the right circumstances. So yeah I would say that it would be easier to lose the rear on a V twin if you have poor throttle control, assuming that both types of bike were on the same corner and the Vtwin in question happened to be applying more torque than the IL4 at the point in the corner were the rear broke loose

For a given corner though, if both types of bike have excessive torque available then really makes no difference. It would be more relevant which type of engine configuration was being used and how the power is applied.

Powerful 2 strokes break loose very very easily mainly due to the narrow power band, its much more difficult to apply power gently on one of those.

Mr Flymo is pretty much spot on.

Taking this on further, it really depends how the particular 4 stroke engine is fuelled/ECU'd regardless of whether its an inline 4 or a V twin. If they are fuelled to behave like a two stroke with the power higher up the rev range and in a narrower rev range then they'll be more likely to high side if you're ham fisted with them.

I'm thinking here about the Ducati 1198 which is deliberately fuelled/ECUd so the power comes in with a much steeper power curve if viewed on a dyno print out to give the feeling of "rush". Conversely the KTM RC8 is fuelled/ECUd so it gives a very smooth linear power curve on a dyno and doesn't feel "quite as exciting".

So the 1198 is easier to highside than an RC8 despite them being V twins.


A highside is caused by the rear breaking away suddenly due to too much power. If you happen to be in a steep part of the power curve when it breaks free then the chances of catching it and preventing the slide developing into a full highside is much greater due to the engine being more "committed" to producing power. Its producing more in a shorter rev range so is much harder to reign in.

So to answer the question originally posed. The answer is neither. Its the way each particular engine is tuned that makes it more or less prone to it.

A flat torque curve is the ideal solution to an engine having good and even drive throughout the rev range.

C

I would have said it all comes down to the right wrist.

[Sid Squid]

Originally Posted by fatneck

Easier to highside an IL4 than a twin. True or false?

Neither true nor false.

Originally Posted by fatneck

Any ideas people? Someone told me this but didn't explain why. Total b*ll*cks or hard fact?

It isn't about losing traction, it's about getting it back.

An actual highside is a very rare thing, it occurs when the rear wheel loses traction whilst the bike is leant over and turning, the rear end of the bike slides outwards and most commonly when in this circumstance the rider shuts the throttle.
Think about it, when the throttle is still on and the traction is lost the wheel speed will rise from that which the road speed is, now when the tyre is spinning it doesn't grip much in any direction, which allows it easily to slide sideways across the road surface, if you shut throttle the wheel speed will reduce, the tyre will grip again but now it's not going in the direction the bike is travelling, the wheel will stop sliding across the road but the bike's momentum will cause it the mass of the bike to continue, using the tyre's contact point as the pivot it will rotate, sometimes quite violently, in the direction of travel.
In extreme circumstances this can cause the rider to be thrown from the machine, as the bike is rotating from leaning one way, through upright and over the other way the rider can be ejected upwards.

Good throttle control is a key part of this not occuring, there are many variables and engine configuration isn't anywhere near the top of that list.

Originally Posted by Sid Squid

............
Good throttle control is a key part of this not occuring, .............

and not cornering over slippy stuff...