Cornering at speed with full tank of petrol.

[pete h]

Originally Posted by jarl

Mine does this every now and then, pretty scary, feels just like the rear is shuffling sideways. No play in the rear wheel assembly at all, so it must be the tyre (tourance), which is correctly inflated. Ergh!

I used to get that on mine Jarl, it's not shuffling sideways though, if you find this happening after you've been out for a while, it's just the large blocks on the tread squirming because of the heat they've generated on the road.

It stopped happening as soon as I put purely road tyres on.

[Grendel]

Thanks for all the replies folks

I have Tourance fitted as well so that probably didn’t help. So basically if I go too fast into a corner do almost the opposite to a sports bike rider and lean the bike over but sit up right while counter steering rather than lean in and hang off.

I must admit it was really my fault for going too fast around the corner. Sometimes I forget it’s not a little 125 sports bike that you can throw into corners.

[twistgrip]

Very interesting discussion. When we set out on our biking voyage of life we think it's just sitting there and working our hands and feet in the right order but after 40 odd years of riding I heard about negative/counter steering, weighting the footrest, vanishing points etc. Some of us do all this naturally and we are called 'gifted' and become world champions but you can also be taught as PeteH clearly has. I still see riders, mainly on scooters I might add trying to go around corners bolt upright, did CBT teach them anything I wonder. But the thing is that these techniques can be mastered and they do make riding better and safer. Regards riding after filling up, just make sure you don't ride through diesel spilt at the pumps. Better still try to use a petrol only pump.

[jarl]

Originally Posted by pete h

I used to get that on mine Jarl, it's not shuffling sideways though, if you find this happening after you've been out for a while, it's just the large blocks on the tread squirming because of the heat they've generated on the road.

It stopped happening as soon as I put purely road tyres on.

Can I push the tyre harder when it's squirming? I mean, it's all very well saying tyres have more grip than you think but when the rear is moving sideways exactly as if it's breaking free more countersteering is the last thing on your mind!! (just as Grendel has also found out!)

p.s: Got a peg down for the first time in months earlier today. Dry roads

[Dee Duble Yuh]

While the tyre might have more grip even when squirming, in general consider that the absolute maximum the tyres can take; it's certainly not safe on public roads to corner that way deliberately. However, if you accidentally begin to run wide and there are vehicles coming the other way, you have the choice between counter-steering (and probably exiting the bend safely) or not counter-steering (and certainly having a head-on collision). Not a difficult decision, methinks.

[Paul-S]

Originally Posted by jarl

Can I push the tyre harder when it's squirming? I mean, it's all very well saying tyres have more grip than you think but when the rear is moving sideways exactly as if it's breaking free more countersteering is the last thing on your mind!! (just as Grendel has also found out!)

p.s: Got a peg down for the first time in months earlier today. Dry roads

You need to have / create the grip before increasing countersteering.

In my first post on this thread I have broken down the component parts to cornering and correcting a wrong line and they are in an order that they happen or should be used to correct an incorrect line.

A lot of this will become natural with practice but locking in the grip with the outside peg will give you much more confidence and may be enough to get you round the corner. If that's not working then you have more grip to put in more countersteering to change direction mid corner.

As Pete-H stated earlier the speed may have been inappropriate for the road conditions but not impossible to recover or overcome.

As you become more accustomed to getting it right or dealing with a line correction you will reduce the possibility of future instances like this but you will have them, we all do no matter how good we get and having the training or the skill to get you out of that situation is invaluable.

Advanced training such as "California Superbike School" provide this type of training using their bikes and also with outriggers so you can experience when it goes wrong without hurting yourself or the bike.

[thetimkirby]

A bit of advice I got was to put more weight on the inside handgrip: it was said to make the front wheel tuck in a bit and tighten the line in the corner. I've tried it in the dry a few times and can convince myself it works: don't know why and I've not had cause (or bottle) to try it in the wet. Anybody else tried it and did it work?

[AlanH]

Originally Posted by thetimkirby

A bit of advice I got was to put more weight on the inside handgrip: it was said to make the front wheel tuck in a bit and tighten the line in the corner. I've tried it in the dry a few times and can convince myself it works: don't know why and I've not had cause (or bottle) to try it in the wet. Anybody else tried it and did it work?

That's countersteering. Yes, it works - but not by making the front wheel 'tuck in'.

[Yeti]

In answer to the question! 'trust your rubber dude!' it is generally better than you are at keeping you right side up!

and ....

Sorry off topic'ish: but.....

......Pick up a physics book or get on't tinterweb if you have the inclination and patience. It helps anyones understanding of the real world around them. A lot of what you thought was complicated in life is rudimentary stuff if you can read it without falling asleep.

Never even really thought that hard about the whole knee down thing, but from a push pull reaction thingy type affair the rules are set by the laws of angular motion so thats that! slinging something around a corner has a few ins and outs but basically it is a balance between the forces of good and evil! just kidding. Would have to do homework to be sure but I think all the rider is doing by hanging off the bike in any fashion is: (firstly not really getting more grip) trying to achieve the tightest radius for a velocity, or fastest velocity at a given radius. The outcome of lean angle is 'simplistically' set, all you can do, again simplistically, is fiddle the numbers to achieve what you are after.

Draw a straight line through the centre of mass of the combined rider and bike to where the tyre is in contact with the ground. This is the real lean angle that satisfies the physics. In real terms on say a big 250+kg lump, even a 100kg guy hanging off the side is going to have nominal effect, hence in racing a lighter bike not only accelerates quicker but the dynamics of its combined rider/bike mass can be changed a lot more readily by moving the rider around.

On the track a bike will only go so far before it is on the edge of manufacturable tyres and touching the ground somewhere, so the real lean angle can be fiddled by lobbing some weight (body) out the side.

The difference between motoX and MotoGP body position is mostly, without semantics, born out of neccessity and dictated by situation. Both could ride like each other in theory but for example a motoX rider would, with rapidly varying surface, condition, and vicious second by second direction changes, be unceremoniously dumped on his arse hanging off the side of his saddle as he simply would not be able to make the large centre of mass adjustments required quick enough and not to mention being able to 'stamp' the bike back up and getting buckaroo'd off his seat. Vice versa for many of the more obvious benefits of not riding a motoGP bike like a motoX.


Anyway bored myself now! Sorry if that sounds like gibberish! I've been awake faaaaar too long now!

(Lookups if it really interests you: just follow a few links around Normal Reaction, Kinetic Friction-independant of surface area, gyroscopic effect are the tip of an iceberg)

zzzzzzzz zzzzzzzz zzzzzzzz

Suppose you could just at least spare a chuckle for the poor bypass billy who lobs his knee out at every opportunity rather than just to keep his bike from touching down, as without the reassurance of actually knowing what and why he is doing it he is probably increasing his chances of coming off and letting the guy on an everyday bike round or up the inside of him plonked firmly in his seat, (although possibly lighting up the centre stand occasionally )

I would say that by enlarge most of the people I have seen riding with their knee out in the summer months have never actually come close to exploring their limits of ground clearance or tyre edge, and still fail to realise that you have to shift your bum over the saddle too and not just poke your knee out . My knee doesn't weight that much?? anyone else got an 80kg kneecap?

Only a few thoughts so sure someone will be along to explain it proppa like!

[jarl]

Good post. Will a street tyre grip more or less with the bike leant over further?

(i.e, if I'm in no danger of touching hard bits but grip is iffy (wet corner, for example), should I stay vertical and lean the bike more or should I hang off the bike to try and keep the bike vertical?)