low siding under power??

[t3mp0r4ry nzr]

I have crashed twice now lowsiding under power, both at minefield. 1st time exiting turn 1 during a summer session, leading up to it I did feel the back moving around alot in the preceeding laps. This was on the CBR250 with a rubbish tyre on the back. 2nd time was at the hairpin the other week. It was 12degrees with light,cooling breeze. Had warmers on and was 3 laps into the session with no movement from rear in preceeding laps, on the SV650 running metzler sportec m3's with 29psi at the back.

The turn went like this. gentle rolloff to eleviate massive forkdive from standard forks, brake/set turn speed, turn high and fast onto knee, dive down banking towards ripples, starting roll on throttle gently just at the ripples (very light roll on at when leant, building more roll on as I straighten). As I was straightening up the rear somehow lost grip and next thing I know I was lowsiding up and over the ripples. Inspecting the tyres, the look as they they were on the "meaty" part of the shoulder when let go judging by the claw marks down the rear tyre. It happened so fast I didnt adjust throttle position.

At round 5 of the winter series on my very first ride on the SV, I almost low sided under power coming out of turn 1 again. The rear stepped out so far that the peg and brake pedal touched down but regripped and threw me back onto seat.

question is, why am I low sideing under power?
Im not too fazed by the rear moving under power, I tell myself not to roll off, let it slide and tighten the line to exit turn faster, in better track position.
Am I using too much throttle at too much lean? do I need to carry more entry speed so Im not trying to make to much distance up on exit.Am I fighting the bike from opposite locking and therefor spinning put. Or am I just running rubbish tyres? am I just a muppet? do I think too much?

thoughts and advice welcome

[twinshock750]

I think you have mostly answered with the admisison to crap tyres.

Like beer, tyres don't like heat, light and age, plus the usual wear aspects.

So an old tyre that has sat around in the sun, been used abused, done a lot of miles and been warmed, cooled, warmed, cooled a lot won't be the most effective thing. Especially on top of a coolish day where the track temp won't be great

I'd also be looking a little at suspension set up - not enough compliance Ie too much rear preload, and damping won't allow the tyre to follow the surface or can just overload it on dodgier seurfaces.

You did call it "Minefield"....

At least a low side is the best way to get off...far better than a highside!

[codgyoleracer]

Order of Concern:
Condition of rear tyre, Suspension, Ride Height at both ends, Body Position & Throttle control.

Tap me on the shoulder if I am at the track next time your there & we can go over these things.
Glen Williams

[Leong]

Interesting thread..... both my crashes have been lowsides under power, once coming out of turn 1 at Taupo and and the other coming out of the hairpin at Puke. Both happened very quickly and after much discussion we "blamed" the dusty inside line at Taupo, and oil at Puke. Of course the blame really lies with me - to much throttle for the conditions.

[Cr1MiNaL]

My first high speed off came under throttle and at the puke hairpin too. I was running 30 - 30 on brand new Pilot Powers so cant blame the tires... could possibly blame oil from the drifters who were racing between sessions, but at the end of the day I think it was me... way too much throttle for that degree of lean. It happened so fast I didnt realise what was happenng till I stopped. bike didn't even drag across the tarmac 10 feet and got written off. Live and learn I supppose.

[Sully60]

Have you thought about the way you turn in at the entrance of the corner?
When I first started on my carb'd mini tractor I had problems with the exit of coke, running wide on the exit so backing out of the throttle to avoid this situation(no crasehes but f'n slow) my problem was not getting enough turning done before the apex ( a combination of having the thing set up like a chopper and me being tentative about turning the thing hard).

I have helped a few people out at customer track days I helped run in a past life and this type of crash (apart from outbraking oneself and running off the track) was the most common. These guys were road riders and never really had to muscle a bike hard like you do on the race track, consequently they get into the corner with ok pace but the haven't got the thing pointing down the track enough on the exit, so they end up carrying heaps of lean at the exit (where you should have the bike relatively upright and driving hard) and grab more throttle that they should at that lean angle an presto? Titanium sparks galore and dented ego (if they're lucky).
I had the simplist method of teaching them to avoid this (beacuse they weren't racers):
If you are leaning over further you must be rolling off the throttle.
If you are rolling on the throttle you must be standing the bike up.
This is really elementry stuff and not applicable to all situations but does apply to most slow corners like coke or the hairpin.

What I'm trying too say is the enrty to the corner dictates everything there after, not enough turning at the point of the corner where you're able to get it done leads to messy exits and poor drive off the turn. Talk to Codgy next time out at the track and get him to see if the geometry is close to where it needs to be. Get that right and concentrate on getting the bike to turn enough so you can be standing it up and driving off the turns safer and even earlier than you did when you crashed.

My two cents, hope it helps, but please talk to someone like Codgy (Glen) at the track the people on the spot always no so much more.
Good luck!

[t3mp0r4ry nzr]

Cheers Sully for thought put into your reply, it is appreciated. I try to turn hard and fast, at the apex of this turn im almost starting to straighten up, trying to get the best drive onto the straight (I was on the meaty part of the shoulder when I slid).

Cheers codgy, will hit you up next time you have a free moment at the track. I just want to know what Im doing wrong so Im not doing it again (especially at the Cemetry Circuit cos there aint no run off there!)

Cheers for the replies from all