Grip! - how much?

[johnnyrod]

I think this might be asking how long is a piece of string, but here goes anyway... I think there are some pretty switched on people here who might shed some light.

In short, how do racers manage to do faster laps when they have more grip, i.e. the tyres haven't gone off, or it's dried out a bit more than earlier? Maybe this is what the top ones get paid so much for, but how do you feel for the outer limits of grip? This sometimes isn't that far away on the road, with crappy surfaces and smoothed off bits where the lorries have been going, and all that. I'm trying not to develop paranoia, having lowsided a few times in my biking life (once with the bike ending upside down in a hedge about 3 feet off the ground, and my nose is still bent, the Motoliner could only fix the taco'd frame). The closest I had to a gentle slide without either falling off or over-reacting was laying a big black stripe out of Barn at Cadwell.... a few hours before I fell off at Park. I don't think it helped me though.

But anyway, I watch them zipping around on the telly and wonder how they "know" how much grip they have, i.e. how does it feel? Is there a boing as the suspension starts to unload? Is having my knee on the deck really going to make any difference? Do I just need bigger nuts and less of a compulsion to go in too fast and/or shut off/stand up the minute it twitches?

[G]

Personally I can feel exactly when the tyre is starting to loose grip, its something I have developed through driving cars and riding my bike. Cant explain it but theres just THAT point, where you know.

I also have (upto now - running to touch wood) a strange knack at being able to control slides, whether it be in a car or a bike......sooner or later I will push my luck but then I will have learnt another lesson and another boundary.

[Blue_SV650S]

Its harder to judge grip levels on the road than on the track as there are so many variables on the road. However on track, not only can you get the tyres up to full/optimum/consistent working temp, but the track is the same every lap, coupled with the fact you have been round it so many times before - you KNOW how fast/hard you normally go into, round or out of a turn, you also know the amount of ‘slippage’ you normally get at that speed. If you don’t get this slippage (new/different tyre), then you feel you can push a bit harder - so go faster - simple as that?

[Smudge]

the pro's have done many track laps and can judge it by the tyres response like if you power out of a corner too early and the back wheel slips and grips again, IMO its the front thats less forgiving once it slips theres less chance to regain control, i think its just down to practice but i would save the, wheres the limit tests for the track theres less chance of ending up under a car

[kwak zzr]

when i went down on the wales rideout it was the front that let go and down she went:( ive been round corners quicker than that with my knee on the ground and to this day i still dont know why it happen'd?

[riktherider]

i tend to find a good stomp on the ground helps with front wheel grip loss. hurts your foot a bit but save the bike and yourself. worked a couple of times with me.
thing is with on the road, there are so many different types of tarmac out there its hard to know exactly where the limit is. but you will find the point of "no return" as it were. where you know if you pass that point you are going down.

[Smudge]

i tend to find a good stomp on the ground helps with front wheel grip loss. hurts your foot a bit but save the bike and yourself. worked a couple of times with me.
thing is with on the road, there are so many different types of tarmac out there its hard to know exactly where the limit is. but you will find the point of "no return" as it were. where you know if you pass that point you are going down.
that comes natural if your used to riding off road i had to do it on the same rideout on a gravel patch round a corner, didn't think about it it just went down like a reflex

[rob13]

Aye i had the same on a switchback once where the front started to give and instinctively put my foot down to save the bike, which I think I learnt from my mountain biking days

[John 675]

Personally I can feel exactly when the tyre is starting to loose grip, its something I have developed through driving cars and riding my bike. Cant explain it but theres just THAT point, where you know.

I also have (upto now - running to touch wood) a strange knack at being able to control slides, whether it be in a car or a bike......sooner or later I will push my luck but then I will have learnt another lesson and another boundary.


Its that feeling in the pit of your bum, lol, i developed it from a year ir two of falling off lol, seems to be the best way to learn imho.... maybe not the cheapest tho :p

[johnnyrod]

Quite timely this, this was posted yesterday:
http://forums.superbikeschool.com/index.php?showtopic=877

I do struggle with consistency on the track (spend 3/4 of the day getting up to speed), and as you all rightly say, on the road things change too much to be able to get much repetition in riding it. I never really expected a magic answer, but perhaps a few hints on what this means to you. What does Greame feel? Is it Lyle's sphincter creaking? Am I being ham-fisted and charging from grip to falling off zone in one hit? I think this may be the case, also maybe the Keith Code article is right in that I've put a lot of effort into beefing up the suspension and tyres for maximum grip that it's all beyond what I can ride properly with what skills I have (hmm).

Any more? Sarah? Rob?

[rob13]

I think its just a case of finding the limit for yourself, I know i have reached a bit of a watershed in my road riding as I seem to have an angle of lean where I cant go any quicker round the corners because my brain is telling me to keep the bike from leaning any further over. Its the mortality issue and the fact that if i binned it I would be very annoyed! Maybe I should buy a rat bike and throw it into corners to see what happens- most likely i'll fall off and end up breaking something on me. On the track I guess its different. The ideal scenario would be to use a hired bike where you dont mind so much if it goes down. Only then will you be able to see how much grip you can acheive. I think the Conti RA tyres say that they can hit a limit of 50deg lean angle, which for me is a lot further than I'm prepared to lean it. Think it may be time for some tuition for me.....

[Smudge]

on some tyres you wont get rid of the chicken strips on an SV

[Berlin]

This is an interesting thread and thanks for the link to the race shool info too.

Tonight I came back from the local town on a road I've not used before and the weather was intermittent showers with some dry roads and some damp stretches.

deliberately taking it easy because I'm on (race scubbed) Supercorsa Pro Sc's that were almost warm never mind up to temperature, I came to a very tight (dry) left hand corner that was masked by a blind summit. As I crested the sumit (at the speed limit surprisingly) it took me a little by surprise but with cars coming the other way I just leant over.. and over, and over. :)

I got round without going over the double whites.

When I got home I checked the tyres and I'd actually managed to clear off the "race scrubbing" from the front and back tyre.

That means I've been over as far, it not a little farther than the guy who sold me them. And that's a long way, I can tell you!

I would *never* have believed that this was possible with 1) the temperature of the tyres, 2) The dirt on the road versus the track, 3) the speed I was riding.
They didn't even hint at letting go either.

There was a very interesting article in Bike magazine earlier this year on Grip and it was basically confirmed that (as long as the road is dry and clean) a road rider will never be able to find the limit of grip and that crashing is due to rider error and not tyre grip. You will either hit something (gravel, mud, horse crap, fence etc) or run out of road before the tyres let go.

Tonight, I belive them.

I also followed a BMW K1200 this morning in the rain and I couldn't keep up with him through the bendy bits. My tyres were slipping all over the place whist he seemed to be effortlessly carving through wet twisties. I finally caught him up at some traffic lights and he was using Conti Road attacks. He must have had an extra 5-8 degrees of lean more than my SC Pro's with them. Very impressive. The new PR2's should be even better.

The problem, now tyres are so good, is that if it *does* go wrong, you are so far commited at the point where it does that there's very little chance of saving it. Collecting a slide when you are leant over more than 45 degrees is going to be impossible. There are now fewer crashes due to better tryes but the ones that do happen are usually much worse because of the level that things went wrong.

I've found a good way of gauging your lean level and comfort is to use your toe. Boots with Toe sliders can be used as a measure of how far you are actually over quite accurately and it is quite repeatable. If you don't have toe sliders it's fairly easy to knock some up.

When coming into a corner, stick your toe out and when it grounds out you know the angle. Next time on that corner, try a little further etc. If it starts to go a bit squirrely at a particular angle of lean, you know quite accurately where that was from your toe.

So when out and about, if you place your toe on the "comfort" side of where it was when things got a little pear shaped, you'll always be fine.

Unless Jemima, riding Snowdrop, happens to leave a big steamy one right on the line through the next corner. Take heed of horse signs :)

I've not used super sticky tyres on the road before (but I have used slicks on the track a long time ago) and I'm used to taking road tyres to the limit. But when you've got all of that extra grip in reserve it takes a lot of self belief to actually use it on the road :) It's a matter of just chipping away at it ride after ride and seeing if the tyres can handle it... or borrow your mates bike to try it so it's his you end up bending when you do find how far is too far! :D


Cheers,
Carl

[johnnyrod]

Dunno if I said before, but last time at Cadwell I saw a guy on a CBR600 ride off the outside of the entry to the Gooseneck (basically a right-hander with a banked-over braking area) at a serisouly soft-**** lean angle because he thought the bike wouldn't go round the bend, just like you. I was behind him and had been thinking that if he carried on like this he'd fall off it.

I used to toeslide on older bikes where the ground clearance was less, but only on the left (right sides are my problem, I have plenty of homework to do!) and now I'm getting into kneesliding properly they do both help, a bit to judge the angle but also a bit to take away some of the fear of leaning over too far, not sure why though.

Re the BMW, I don't know how smooth you are, but on old bits of crap i could lean them over enough to make the pegs deck out up to about 55mph as long as it was dry and you were smooth, if you weren't smooth then forget it. Even in the damp I could still toeslide at those speeds, I have the ground down wellies to prove it. Being smooth is, to me, one of the most important things on the road when its' slippery.

Anyway perhaps digressing a bit!

[G]

Being smooth is, to me, one of the most important things on the road when its' slippery.


I 100% agree, there is nothing worse than bouncing and wallowing around a corner to knock your confidence and make you feel uncomfortable.

I was asked in this thread http://forums.sv650.org/showthread.php?t=96442 why my hand was so far off the throttle and onto the bar end. My answer was for smoothness. Gripping the bar end slightly whilst cornering means at speed your much less likely to jolt the throttle more or less if you hit a bump and accelerating out of the corner can be controlled more progressively. I find it helps anyway. The smoother you are the more you can feel when something like grip is going.

[Blue_SV650S]

...

Supercorsas are great tyres. You can’t expect massive lean in the wet as they are slicks after a point ;) … but they are surprisingly effective/confidence inspiring if kept in the treaded area, even in pretty heavy rain!!

And sure if you had a perfect surface you struggle to exceed grip, but the whole point is that there are very few places where you don’t encounter stones/mud/horse dung at some point in a turn so it is a bit pointless saying in perfect conditions!!! ;)

As for your toe slider tip ... that is the same/exact function that kneesliders should be used for ...

[G]

As for your toe slider tip ... that is the same/exact function that kneesliders should be used for ...

I Marshall at Classic Racing Motorcycle Club races and its funny watching the techniques, bearing in mind these guys are racing on square oldschool tyres on 25+ year old bikes.

Young kids on the old bikes are scrapping knees, and the old guys (some are 50/60+) are just just toesliding getting the same lean, faster cornering speeds and are normally infront of the young guys.

[rob13]

I think i find that the bike tends to feel a bit unstable at the front when leant over. Im attributing that to the fairly soft suspension lifting and diving over the uneven surface, I actually think that I should maybe push the preload up on the rear shock slightly. I need to find out what setting its at.

[John 675]

I 100% agree, there is nothing worse than bouncing and wallowing around a corner to knock your confidence and make you feel uncomfortable.

.

+1 smooth throttle control is essential for safe fast riding, you can snap and yank your throttle all you like but the weight transfer is all over the place and mid corner can land you into trouble with the Grip and low side you ( or highside if your really unlucky )
IMHO its all about smooth progressive control, you will probably find your faster too,

[G]

I think i find that the bike tends to feel a bit unstable at the front when leant over. Im attributing that to the fairly soft suspension lifting and diving over the uneven surface, I actually think that I should maybe push the preload up on the rear shock slightly. I need to find out what setting its at.

Because of my weight 13.6st Mine is on the maximum setting front and rear, felt amazingly different, doesn’t make playing about on particularly bumpy roads much fun though unless your concentrating 120%.

[johnnyrod]

Yeah the front in stock form is too soft on the springs and also underdamped, which makes it feel vague expecially on the gas. Cranking up the rear might help but it'll also make the front feel even softer. Better to stiffen the front, balance it out properly than make it even more unbalanced.

[Smudge]

i found just a thicker fork oil did wonders but the springs seem fine to me, i suppose Suzuki was going for comfort as its not a race bike but a sports tourer

[stuartyboy]

on some tyres you wont get rid of the chicken strips on an SV

Yep - corsa III's for example. been through 2 sets on track and still left with a 6mm strip. Same bike using power 2cts and virtually no hoops at all.

[Berlin]

Because of my weight 13.6st Mine is on the maximum setting front and rear, felt amazingly different, doesn’t make playing about on particularly bumpy roads much fun though unless your concentrating 120%.

Graeme,

I'm surprised at this because in full leathers I weight just over 20 stone and on my curvy, I'm nowhere near the top of the preload at the rear.

I've converted to Maxton 0.95 springs up front with 15 weight oil and 12mm of preload and they are excellent. But at the rear I'm 4 clicks off maximum on the rear and it suits the front perfectly. If I jack it up any more without a pillion it puts the weight back on the front and upsets the forks.

This is why I was having problems keeping up with the guy on the BMW in the wet in my post on the first page of this thread. the back was skipping out on small bumps in the wet. I'd left the rear set up for a light pillion from the day before (three clicks up, one off max) and it was terrible.

This would be a good set up for the track though. Round here it's all country roads that are usually quite bumpy so anything firmer that 4 clicks off on the rear and the bike's all over the place.

I ride quite hard and I'm very hard on the brakes. The back doesn't quirm at all coming out of a bend under power until I take two clicks off the back. (7 from top)

I presume that the springs for the Pointy must be quite different to the curvy because if you're on max at 13 stones, I'd not be able to ride a Pointy! :)

Cheers,
Carl

[johnnyrod]

Yep agree with Carl, excessive preload will make the back very springy and reduce damping (because of the linkage), not the way to go. The adjustment on the back shock is pretty crude, it does go from okay to hard in a click or two.