Higher corner speed, less engine braking, or both? 250/2-stroker love less engine braking, they can rail through turns. What does the higher corner speed come from?
MAinly out of neccessity. Have to keep the revs up on 2 strokes since they dont make squat for power down low. Plust they are soo much lighter than the 4 stroke bikes.
I guess I should have been more specific.
what is the benefit on a 4-stroker?
I think it helped me go faster, but I want to understand where it might have aided me.
I have mine about 3500 on the F2. Keeps the rpms up in corners.
I run a higher idle because it makes the throttle less abrupt and I can be smoother through the turns.
same. it reduces the effect of engine braking on turn entry. sort of the poor man's slipper clutch.
That's what I was thinking. 3,500 rpm. Isn't that really higher if you are just sitting around the paddock waiting to go out?
QuoteThat's what I was thinking. 3,500 rpm. Isn't that really higher if you are just sitting around the paddock waiting to go out?
My idle spped knob is right by my leg. Easy to adjust on teh bike.:D
Ultimately, you are affecting the chassis with some chain torque induced anti-squat.
The reality is that your chassis is not as good as it could be, but the addition of some "preloaded" throttle opening cleans up the chassis snafu.
Hmmm!
QuoteUltimately, you are affecting the chassis with some chain torque induced anti-squat.
The reality is that your chassis is not as good as it could be, but the addition of some "preloaded" throttle opening cleans up the chassis snafu.
So translated....Good or bad? Is it just a quick fix for a chassis or suspension problem?
I think there were two benefits:
- I was setup better going into turns (speed)
- I had better down shifts before I even initiated my turn (suspension was settled)
I think the higher idle reduced the problem I was having with wheel hop, which resulted from poor clutch habits left over from the TZ (no engine braking). The higher idle reduced the engine braking by reducing the engine's pumping losses. The lower the engine braking effect, the more settled the suspension was for me. The additional benefit was that the engine rpm's haven't dropped too much, so I can get back into the power a little faster (what I like about the TZ)?
Hopefully staying on topic...Super Dave I was watching you going into T4 at BHF on May 8th and I was amazed how smooth your downshifts were. Not trying to kiss as$ but it was a huge difference between you and the other fast guys. Are you running a slipper clutch/ is your idle rpm higher/ or are you that effictive matching rpms'? Or is this a secret of the trade?
QuoteHopefully staying on topic...Super Dave I was watching you going into T4 at BHF on May 8th and I was amazed how smooth your downshifts were. Not trying to kiss as$ but it was a huge difference between you and the other fast guys. Are you running a slipper clutch/ is your idle rpm higher/ or are you that effictive matching rpms'? Or is this a secret of the trade?
Um, downshifting into T4?
Depending upon what kind of traffic I'm in, I down shift for the carousel, T3 and leave it in the same gear until I exit T5, then I go up to fourth, then back down to third for T6.
When I've got to do something that requires me to do some different stuff, I might downshift to second going into T3D, the bus stop or whatever, but I keep it there until I exit T4 then.
I could never afford a slipper clutch...
I do brake pretty hard going into T4...
MJ...yeah, it can be a "fix" for either a chassis or rider issue. Really, rider issues are usually related to the chassis.
Remember all the work that we did on Thursday? Feel, feel, feel. We got it feeling better, then we needed the whole chassis to go up, I think. That would really make it feel even better. No way that I could have made any real magic with your bike, but I have enough experience that I recognize some of the "bad feel" and I should understand a little more about the limit. You don't have so much experience in that, so you just don't go as fast.
That's a good thing 'cause really "trying" to ride past it can just cause you to fall down...takes away from the budget for the slipper clutches...LOL!
Sean...ultimately, any kind of input from the engine (acceleration) or the rear wheel (deacceleration) will produce an output of an amount of anti-squat which will alter the location of the swingarm pivot. That, in turn, changes wheel base, steering head angle, and trail....
You still get some on a two stroke on deacceleration, but not as much.
Regardless, a false neutral will always produce a lack of input into the chassis...no anti-squat...
Even going into a corner at the same speed but in a different gear, which will have a different RPM for the same speed, will produce a different amount of anti-squat...and a completely different feel.
QuoteUm, downshifting into T4?
Depending upon what kind of traffic I'm in, I down shift for the carousel, T3 and leave it in the same gear until I exit T5, then I go up to fourth, then back down to third for T6.
When I've got to do something that requires me to do some different stuff, I might downshift to second going into T3D, the bus stop or whatever, but I keep it there until I exit T4 then.
I could never afford a slipper clutch...
I do brake pretty hard going into T4...
MJ...yeah, it can be a "fix" for either a chassis or rider issue. Really, rider issues are usually related to the chassis.
Remember all the work that we did on Thursday? Feel, feel, feel. We got it feeling better, then we needed the whole chassis to go up, I think. That would really make it feel even better. No way that I could have made any real magic with your bike, but I have enough experience that I recognize some of the "bad feel" and I should understand a little more about the limit. You don't have so much experience in that, so you just don't go as fast.
That's a good thing 'cause really "trying" to ride past it can just cause you to fall down...takes away from the budget for the slipper clutches...LOL!
Sean...ultimately, any kind of input from the engine (acceleration) or the rear wheel (deacceleration) will produce an output of an amount of anti-squat which will alter the location of the swingarm pivot. That, in turn, changes wheel base, steering head angle, and trail....
You still get some on a two stroke on deacceleration, but not as much.
Regardless, a false neutral will always produce a lack of input into the chassis...no anti-squat...
Even going into a corner at the same speed but in a different gear, which will have a different RPM for the same speed, will produce a different amount of anti-squat...and a completely different feel.
SD,
you really brake in 4?
I don't.... I engine brake that is it. Slower traffic is the exception...but I am also in 2nd gear from 3d-
exit of 4. Robbie does the same thing as you. WHen
we went out together on monday, I watched his everymove.... smooth. He also ran a 15/48 on his 01GSXR600. most corners in 3rd gear, like the R6. We ran/run a 15/45 . So my 2nd gear was about the same, right? What is the rpm difference between
2nd and 3rd? it couldn't be more than 300 or so
going from 3.0 to 3.2 gearing? I have been pondering the gearing issue for a while now.
QuoteSD,
you really brake in 4?
Yes.
QuoteWhat is the rpm difference between
2nd and 3rd? it couldn't be more than 300 or so
going from 3.0 to 3.2 gearing? I have been pondering the gearing issue for a while now.
Difference between gears? I don't know, but I'm sure that it's probably 1500 RPM's or something...would be closer as you went up.
Each tooth is probably 180 to 300 RPM's at the same gear and speed.
That help?
Then we're back to how the anti-squat makes the chassis wound up...
Dammit, know im supposed to brake for 4, i finnaly can get through there without brakes !!!
Yea, im trying to figure out the gearing thingy too.
I got a spread sheet that has all the gear ratios, and sproket ratios, and speed for each gear based on rpm,tire size.
It takes a big chunk of gearing to make 3rd the same rpm as 2nd
QuoteHe also ran a 15/48 on his 01GSXR600. Êmost corners in 3rd gear, like the R6. We ran/run a 15/45 . So my 2nd gear was about the same, right? What is the rpm difference between
2nd and 3rd? it couldn't be more than 300 or so
going from 3.0 to 3.2 gearing? I have been pondering the gearing issue for a while now. Ê
You would need to know the ratios for each gear, final gearing, and the primary gear ratio (crank to clutch) to calculate the changes in rpm. Spread sheets work great for calculating gearing (especially if you can change transmission gears).
QuoteIt takes a big chunk of gearing to make 3rd the same rpm as 2nd
No, it doesn't necessarily... Don't follow the lines laid out in front of you...
I was using the same gearing when I was running second through fifth as I was when I was running third through fifth...just I was down to a flat 12 using only third, forth and fifth...but I did have to tweak the chassis just a bit to get it to have the right bias.
I'm on a 600...low RPM's are well below 8500...with a rev top of 15000.
That's it, I'm going bigger on the back and running 3rd gear more next BHF. Trying to smooth things out..some more.
.
That help?
yes
Then we're back to how the anti-squat makes the chassis wound up...
[/quote]
my squat,as you know, is a suspension issue...wrong needle in the shock so says mr fitzgerald. I'm all the way out on the rebound, and had to add pre-load...funny how things changed so rapidly this year ;)
I have to get different internalls front and rear then we'll start from there.
QuoteThat's it, I'm going bigger on the back and running 3rd gear more next BHF. Trying to smooth things out..some more.
Try it. It might not work the first time, but it will get your mind going in a direction.
The Yamaha seems to have more RPM on top to overrev with, and the internal ratios are different... So, it may not be the end all, but it should give you ideas... See you in July!
QuoteTry it. It might not work the first time, but it will get your mind going in a direction.
The Yamaha seems to have more RPM on top to overrev with, and the internal ratios are different... So, it may not be the end all, but it should give you ideas... See you in July!
yes sensai you will, and I will, and you will, hopefully
the back of my cute little bottom as I girate through
the bus stop. You make me feel so good.....about myself.
Quoteyes sensai you will, and I will, and you will, hopefully
the back of my cute little bottom as I girate through
the bus stop. You make me feel so good.....about myself.
:D ;D
Super Dave, I misspoke...it was your transition into the busstop. I was watching several guys downshifting into the busstop and their bikes were wallowing back and forth and the blipping and the chattering was going on. Your bike was very smooth and now I understand why. I wanted to know the secret of smooth downshifting wthout getting tennis elbow.
QuoteS bikes were wallowing back and forth and the blipping and the chattering was going on
Hmm, those might be Suzuki's? They seem to have a weight bias problem so they tend to have those kind of issues.
yea, i was doing everything perfect, its just my bike that wasnt listnening to me !!!
In addition to what's been mentioned, the simpler reason a lot of racers use a high idle setting is for bikes that have a rough or abrupt transition from idle speed to rolling on the throttle, regardless of the riders' smoothness, helping to eliminate the resultant upsetting of the chasis. Some bikes, no matter what you do with the jetting or EFI, there's just no smoothing out the transition from off to on throttle.
FYI for those unfamiliar with two-stroke GP bikes: why are they always blipping the throttle or holding the throttle when warming up and waiting to go on the track? The throttles don't have an idle position and the engine would otherwise die, leading to frantic attempts to push start the bike NOW! Well, at least a few years ago. Now, with all of the extra electronics, who knows? Maybe they do have an electronic idle circuit on the newest GP bikes.
Even some carbed 4 stoke race bikes didn't have idle circuits.
The blipping on two strokes is usually related to the plugs loading up. Old four stroke race bikes, we're talking 60's here, apparently used some different kind of valve seat material, so I'm told, that needed more loading to keep the valves loaded into the seats.
Electronics has evolved to the point where the "box" can do the blipping.