Technical question

[Robert Taylor]

When I see a silly thread I don't even bother to post on it. Perhaps you could explain why you feel compelled to do the opposite?

Please feel free "not to post" as its not compulsory !

So youre not posting on your own threads.....there have been some reasonable threads youve posted and frankly some downright silly ones.

[Benk]

Dunno about everyone else, but isnt the 'Racing' forum for 'racing' related info?

Shoulndt mooting these useless points be relagated to General Ravings, or basically anywhere other than the Racing forum?

[GSVR]

So youre not posting on your own threads.....there have been some reasonable threads youve posted and frankly some downright silly ones.

And many of your posts seem like either a Kiwibiker sponsored advertisement for CKT or a party political broadcast (Thank fark the elections over).

[GSVR]

Dunno about everyone else, but isnt the 'Racing' forum for 'racing' related info?

Shoulndt mooting these useless points be relagated to General Ravings, or basically anywhere other than the Racing forum?

I'd just send it to PD its already been sabotaged by God. Judas!

[Robert Taylor]

Dunno about everyone else, but isnt the 'Racing' forum for 'racing' related info?

Shoulndt mooting these useless points be relagated to General Ravings, or basically anywhere other than the Racing forum?

I agree, its always a shame when there seems to be either an agenda or a petty vendetta, for what perverse reasons god only knows.
My own personal record stands in having helped a lot of people over the decades in racing circles and a more recent expression of that has been here in print. I make no apology for responding appropriately to anyone who has a smart alec demeanour.
My own vocation has given me a lot of experience and any relevant information is passed on in good spirit, I just dont get why there have to be such people that relish in winding others up.

[Mishy]

A racetrack is built that is flat.............................................. .........
To look at this another way does the forward and rearward pitching of a bike help it to go any faster? How does the level of grip effect things in this case?

many people have written substantial books on the subject of suspension, and dedicated immense amounts of time in trying to understand EXACTLY what goes on with suspension behaviour, and how to use it to progress laptimes. It is TOTALLY fair to say that you will not get a complete definitive answer via a forum, nor by many publications, so i have to say - good on you for wondering, but the answers will require a LOT more thought, effort and investigation.

I started making an effort to get an understanding of what makes it all tick a few years ago, and am STILL discovering how little I really do know about why/how, and how much, despite the fact that i have learnt quite a bit (Robert will testify to the volume of "silly questions" and "crazy ideas")

It's complicated, and once you start it will comsume you
If you are still keen, seek psycological help my friend

[t3mp0r4ry nzr]

am I crazy to wonder of the merit of a "speedway" type bike set-up for the circuit. it would need plenty of torque to break traction at will to "steer with the rear" at high speed? I probabley am, cos circuits are'nt perfectly smooth so its wasted thought. mind you drift cars usually have rudementary suspention to stop weight transfer to ultimately reduce traction (?) to create slip. with the inherent instability of a 2 wheeled machine, this probabley isnt the best or fastest way around a circuit even if perfectly smooth.

[MSTRS:Me]

am I crazy to wonder of the merit of a "speedway" type bike set-up for the circuit. it would need plenty of torque to break traction at will to "steer with the rear" at high speed? I probabley am, cos circuits are'nt perfectly smooth so its wasted thought. mind you drift cars usually have rudementary suspention to stop weight transfer to ultimately reduce traction (?) to create slip. with the inherent instability of a 2 wheeled machine, this probabley isnt the best or fastest way around a circuit even if perfectly smooth.

This would tend to illustrate the reason why suspension is important. It's primary function is to keep the tyres in contact with the road/track/whatever. Without it, the tyres will deform slightly (would anyway?) providing a tiny bit of 'suspension', but not possible to provide enough. With a rigid rear, it would be hard (sic!) to keep the front down under hard acceleration, and heavy braking would definitely be interesting. Cornering without drifting would be almost impossible. Both would slow you down.

[GSVR]

many people have written substantial books on the subject of suspension, and dedicated immense amounts of time in trying to understand EXACTLY what goes on with suspension behaviour, and how to use it to progress laptimes. It is TOTALLY fair to say that you will not get a complete definitive answer via a forum, nor by many publications, so i have to say - good on you for wondering, but the answers will require a LOT more thought, effort and investigation.

I started making an effort to get an understanding of what makes it all tick a few years ago, and am STILL discovering how little I really do know about why/how, and how much, despite the fact that i have learnt quite a bit (Robert will testify to the volume of "silly questions" and "crazy ideas")

It's complicated, and once you start it will comsume you
If you are still keen, seek psycological help my friend

Thanks for your reply. I spend way too much time thinking about many aspects of what makes a racebike tick. Weather it be suspension, engines, weight distribution, electronic aids, rider psycology, fitness and diet, tyres, support crews, aerodymanics, etc. the list is endless.

One method I use to make decisions on what are major factors or not is to break a problem down into easy to understand parts. Hence the dead flat track in this case.

I can see that when hard on the brakes if the front end dives by any amount this will lower the bikes center of gravity and make it possible to brake harder before the rear wheel lifts. And of course all bikes do this the trick is for the suspension not to bottom out!
I can also see the same effect under hard acceleration but if the front is sprung then its going to raise unless its already topped out.

The changes in rake and trail when the bike pitches I see as being a negative effect. If the pitching of the bike is minimal or doesn't happen when the bike is trying to be steered then its not a problem. The trail being the biggest issue because as soon as it becomes negative the bike is unstable.

The level of grip and power of the the engines and brakes are possibly the most important factors in deciding if the non suspended bike could be faster than a suspended one.

Say that the bikes do not have enough power to pull a wheelstand and cannot achieve hard enough braking to lift the rear wheel. This would then isolate the grip factor somewhat.
Lets say that the grip is 100 percent (ie. not loss of traction whatsoever) Then possibly both bikes may even lap at exactly the same pace or some other aspect of the problem I have overlooked become apparent!

One thing I do know is the rake and trail of the rigid bike would be able to be set very accurately.

Anyway when you stop about thinking how to go faster your've either given up or your paying/getting someone else to think for you!

[GSVR]

This would tend to illustrate the reason why suspension is important. It's primary function is to keep the tyres in contact with the road/track/whatever. Without it, the tyres will deform slightly (would anyway?) providing a tiny bit of 'suspension', but not possible to provide enough. With a rigid rear, it would be hard (sic!) to keep the front down under hard acceleration, and heavy braking would definitely be interesting. Cornering without drifting would be almost impossible. Both would slow you down.

Example of rigid rear end may be Top Fuel Dragsters again its all about levels of grip/traction

[Robert Taylor]

This would tend to illustrate the reason why suspension is important. It's primary function is to keep the tyres in contact with the road/track/whatever. Without it, the tyres will deform slightly (would anyway?) providing a tiny bit of 'suspension', but not possible to provide enough. With a rigid rear, it would be hard (sic!) to keep the front down under hard acceleration, and heavy braking would definitely be interesting. Cornering without drifting would be almost impossible. Both would slow you down.

Yes, controlled pitch and weight transfer is neccessary to initiate turn in and to assist exit grip. Theres obviously a lot more to it than that but thats the important bits. Also when relating to speedway the surface is obviously loose and chops up. I dont know what the construction of speedway tyres is with respect to sidewall stiffness and carcass construction.

[Robert Taylor]

Thanks for your reply. I spend way too much time thinking about many aspects of what makes a racebike tick. Weather it be suspension, engines, weight distribution, electronic aids, rider psycology, fitness and diet, tyres, support crews, aerodymanics, etc. the list is endless.

One method I use to make decisions on what are major factors or not is to break a problem down into easy to understand parts. Hence the dead flat track in this case.

I can see that when hard on the brakes if the front end dives by any amount this will lower the bikes center of gravity and make it possible to brake harder before the rear wheel lifts. And of course all bikes do this the trick is for the suspension not to bottom out!
I can also see the same effect under hard acceleration but if the front is sprung then its going to raise unless its already topped out.

The changes in rake and trail when the bike pitches I see as being a negative effect. If the pitching of the bike is minimal or doesn't happen when the bike is trying to be steered then its not a problem. The trail being the biggest issue because as soon as it becomes negative the bike is unstable.

The level of grip and power of the the engines and brakes are possibly the most important factors in deciding if the non suspended bike could be faster than a suspended one.

Say that the bikes do not have enough power to pull a wheelstand and cannot achieve hard enough braking to lift the rear wheel. This would then isolate the grip factor somewhat.
Lets say that the grip is 100 percent (ie. not loss of traction whatsoever) Then possibly both bikes may even lap at exactly the same pace or some other aspect of the problem I have overlooked become apparent!

One thing I do know is the rake and trail of the rigid bike would be able to be set very accurately.

Anyway when you stop about thinking how to go faster your've either given up or your paying/getting someone else to think for you!

We have dvds available for sale that explain some of that. You should also look at purchasing a copy of Tony Foales book, it will answer all of your questions and some.

[MSTRS:Me]

Example of rigid rear end may be Top Fuel Dragsters again its all about levels of grip/traction

Yeah, but aren't we talking about bikes? You know...those unstable 2 wheeled death machines?
Anyway, even Rails can wheelstand if the driver gets it wrong.

[GSVR]

I'm still talking about the perfectly flat track here.

So we have established that the people in the know believe that the bike with suspension will be faster because it can pitch back and forth to provide better steering and corner exit amounst other things.

Now lets say just so things don't get too radical that the bike is based on the latest GSXR1000.

How much suspension travel would you need for the perfectly flat track?
How far would you setup the bike to pitch?
How does the level of grip effect this?

Be careful as I don't want to be accused of having leading questions!

[Benk]

*Loads gun, blows own brains out*