Know your limits - clues?

[TheInternet]

I always like to have an idea of the limits of any vehicle I am in control of. Finding and exceeding that limit in a four-wheeled machine is easy and relatively safe to do, not so on a bike.

In an effort to avoid pointless crashes whilst exploring two-wheeled behaviours can anybody answer the following (assuming sensible tyres and rider inputs):

What sorts of clues can be expected when near cornering limits?

Are they the same wet/dry?

Is there typically much of a window between starting to lose grip and binning it?

Front brake - is the risk of lockup most often greater than the risk of lifting the rear end? In the wet I'd imagine the only issue is locking the front.

Are there any exercises which can help with the learning process? Riding in decreasing circles has been suggested.

Thanks in advance.

[Hong Kong Phooey]

Different bikes, or even same bike on different suspension settings or tyres are all going to behave differently. Same as cars, some you get a courtesy phone call before it lets go (skinny wheel fwd), others chuck you off backwards without even a text message (911 turbo from 80's).

Bikes depend so much more on correct tyre pressure, tread condition and temperature and rider positioning and smooth inputs, so it's an impossible answer to give accurately without having the experience to feel for it. Therefore exploring the limits of grip should be left for the track only.

Rear end can be lifted if you're progressive and don't snatch at the lever.
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'81 CG125, '97 FZS600 : '99 CBR600F4, '09 KTM RC8

[struan80]

Best place to even think about getting to a bikes limits is on the track.

You'll know when you've reached the limit on the road when your bike ejaculates you into the nearest tree.

In my opinion avoid trying to the get to the limit because if you do you have already gone too far.

Edit jeez I'm dull.

[stinkwheel]

Because you put progressively more and more weight onto the front tyre as you brake, the grip increases proportional to braking. You'll tend not to lock the front until you bottom out the suspension providing you brake progressively and don't snatch at the lever.

Locking the front isn't instadeath as many seem to think. If you're upright and going in a straight line, squealing the front is eminently recoverable by letting off the brake.

Try it somewhere safe and quiet, it's handy to know what it feels like.

Yes there is less grip in the wet so a loss of grip will tend to happen earlier.

I find in most cases a bike will warn you as you're approaching loss of grip by squirming about and making your bumhole tweak. It's when this is coupled with something that makes the suspension suddenly load/unload that the loss of grip becomes abrupt and you're flying through the air/sliding on your arse. This can be either due to rider input (snatchy brake/throttle action, pulling the clutch mid corner etc) or a road feature like a bump in the road or overbanding.

My most recent super squeaky bum moment was on an overtake abort. Braked hard to pull back in and hit a compression in the road that bottomed the forks, locking the front and snapping the bars round. Took a foot dab and a lot of swearing to get it back under control. Ordered new springs as soon as I got home.

I landed up with an oddball rear tyre at one point last year (had to, I'd hit canvas on my old one and it's the only thing they had in stock). It was fine in the dry but first time out in the wet I could feel it squirming under me as I exityed corners so I backed off a bit. At one point I went for an "overtake with extreme prejudice" only to find it spinning the rear wheel up instead of accelerating. Not good. Again, changed the tyre as soon as I got home. The bike did however let me know I was pushing the limits of grip. As a general rule, if you're in a straight line, you get away with it.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[TheInternet]

Thanks for the replies, helpful.

Just to be clear this is not so I can be on the ragged edge every ride, it's to have a clue where I am on the scale. At the moment it's not obvious if I'm at one, four, or nine tenths of the limit; it's more this:

[M.C]

Go watch Moto GP and you'll see that going over the limit results in sliding down the road on your face Therefore I tend to stay under it. Bikes are pretty good at giving you an indication of grip levels anyway, hey give you a lot more feedback than cars IMO.

With the front brake as long as you're not grabbing fist fulls straight away you're fine.

[CaNsA]

[mentalboy]

[TheInternet]

[mentalboy]

[Teflon-Mike]

[TheInternet]

[gingercat]

[Azoth]

To do this safely, you need a track, the right gear and a trainer to make sure your technique is OK. And you need to be happy to bin the bike. If you don't have those things, you can try it on the road but you're going to be pushing your luck.

The limits change a lot depending on road and machine conditions. It's important to know your bike's maximum braking performance at various speeds, if you want to overtake safely. That's something you can practise on an empty stretch of road without too many problems arising.

If you're talking about cornering, it's more difficult. First, you have to be sure your technique is spot-on, otherwise your cornering ability will be well short of the bike's capability. Once you're sure your technique is absolutely right in the corners, that you're doing all the right things, smooth and not panicking, you can try to find out where the limits lie. However, there's always a high risk of binning the bike or ending up in a hospital or both when doing this. If you really want to, try to find a corner where there's no other traffic or pedestrians, where your bike can crash into something green, and preferably without kerbs. Then take it slowly a few times until you learn the absolute maximum speed you can take that corner in those conditions.

There's a double bend I use for practice from time to time in Berkshire which meets nearly all those conditions. Feel free to PM me for the coordinates.

NB: not recommended to find the limits of your machine on the road.
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Safety in numbers

[Holdawayt]

Interesting topic and it's something that I've never really thought about whilst riding. It's more intuitive.

I was at Rockingham last year in the wet, and coming on to the start / finish straight I opened the throttle far too aggressively and the back wheel tried to overtake the front. Obviously from then on I knew to be more progressive with my inputs and I was fine. It wasn't a conscious thought process though, more of a "I've scared myself, don't do that again" thing.

Same with cornering, I know that if I've come back from a ride and I don't have any chickenstrips I've done alright. If I come back and see that the tyres are blistered I know I've probably been pushing it a bit too much for the road.
Mid corner you need to relax and feel what's going on with the bike. If it starts to feel unsettled or if you can feel the bike start to act strangely - back off and make subtle changes.



TL:DR - You'll know the limit when your bike tries to kill you, your bike is probably far more capable than you are. Track is the safest place to push it. Enjoy.

[Teflon-Mike]

[Holdawayt]

Sorry mate but I didn't read a word of that.

[onlyJaz]

[Holdawayt]

Do I get a badge? "I've been Teffed!" or similar?

[mentalboy]

[Hong Kong Phooey]

What should worry you though, is that even pro racers with years of practice on top quality bikes will high or lowside on perfect tarmac. They are pushing it all the time, and know how to react.
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'81 CG125, '97 FZS600 : '99 CBR600F4, '09 KTM RC8

[Monkeywrenche...]

[Monkeywrenche...]

[Teflon-Mike]

Take what you wish from it.
"The Point" was, and remains, there is a direct conflict between safety and speed.
Doesn't matter how you try and wrap up the wordage; if you are trying to go fast enough that 'The Limits' are in question, you are NOT doing anything to make things any 'safer'.
If you want to explore "The Limits", go ahead... just DON'T try and kid me, yourself or any-one else, that it is in ANY WAY in the interests of 'safety'... or come crying when the plot goes to pot and you learn the lesson the hard way.
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My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'

[TheInternet]

It doesn't matter HOW many times you write the same thing WITH random words in capitals, you'RE still wrong. SOZ.

And what SORT of reply is that? 100 words? Pathetic. You'll be ON Twitter next.