Has Speedway Reached/over-reached Its Top Speed?

[Vince]

I'd bet that there are far more accidents caused by engines that have been 'softened' picking up too much grip than there ever are by outright engine power. Very noticeable in the NL when you sometimes see inexperienced riders trying to use the same set up as top riders and struggling to even get the bike turned. Strange as it may seem a novice is generally safer with more power rather than less (too much wheelspin is safer than too much grip).

 

Where I think modern bikes are more difficult is that they are very sensitive to set up because of their lighter flywheels and higher revs and the difference between a fast well set up bike and a complete pig to ride is narrower than ever before. My opinion is that the rev limiter could be the best thing ever by not only making service intervals longer but by making super light flywheels a bit less effective. A minimum stroke would help as well.

[*JJ]

I believe that to be so - yes.

I don't know ... no-one at Perry Barr has got near Jason Lyons' track record (56.4 sec.), set with the pre-2010 silencer; the later ones have slowed the bikes down a bit. This includes the top EL riders.

[oldace]

I'd bet that there are far more accidents caused by engines that have been 'softened' picking up too much grip than there ever are by outright engine power. Very noticeable in the NL when you sometimes see inexperienced riders trying to use the same set up as top riders and struggling to even get the bike turned. Strange as it may seem a novice is generally safer with more power rather than less (too much wheelspin is safer than too much grip).

 

Where I think modern bikes are more difficult is that they are very sensitive to set up because of their lighter flywheels and higher revs and the difference between a fast well set up bike and a complete pig to ride is narrower than ever before. My opinion is that the rev limiter could be the best thing ever by not only making service intervals longer but by making super light flywheels a bit less effective. A minimum stroke would help as well.

 

 

Spot on Vince, virtually mirrors a post I made on another thread back in March

 

 

Up to and including the JAP engine a speedway bike revved at possibly half the revs of a modern engine. The JAP, in particular was good at generating straight line speed but it didn't want to go round corners, the lack of revs gave it a tendency to want to drag you out near the fence, especially on the deeper tracks of the day. It had to be laid very low to get round bends

The advent of the 4 valvers gave riders massively more rpm (not necessarily mph) and were a totally different beast to ride and in the hands of inexperienced riders could cause more accidents.

Those extra revs though make the bike much easier (and therefore safer) to ride.

As times have gone on new short stroke motors with super lightweight flywheels mean the bikes have a very limited power band, it will only work right at the top of its revs and it takes very little in the way of dirt on the track to kill the motor and therefore point the rider the wrong way.

[Bream]

Are bikes any easier to control with new exhausts versus last few years? Havent had a chance to try these new ones.

 

With longer stroke piston speed/velocity becomes a problem. In short stroke engine mean piston speed is lower than in long stroke. Something to do with piston durability and valve timing. Cant remember but I remember a tuner cursing about the topic few years ago.