Back end wobble

[Ivor]

Technique question... what does it mean when my back wheel steps out when I'm cornering on a descent?
(other than a slippy road or going too fast)
I've been nervous of cornering downhill quickly after a nasty fall last year, but thought I'd up the pace on my long ride in this morning.
Predictably as I was descending I felt the back wheel kick out, it gripped again and straightened up and all was ok. but wondered if this pointed to a problem in my technique.
am I putting too much power down cornering? am I not putting enough? do I need to try and shift my weight backwards onto the rear wheel? or is this just something random that happens that you have to learn to handle?
freaks me out every time.

[Ivor]

You know her too! gosh. small world.

[huw williams]

You leave my sister out of this

[Sylv]

Maybe the road is bumpy with an uneven surface, and your are locking your legs (typically in the 6/12 o'clock position) and tensing them up which accentuates the vibrations in the frame?

[George]

I felt exactly the same thing last year at the palace.

I looked down and my tub had just rolled off

[Andrew G]

Try to keep your weight back a bit more, you may find you naturally slip forwards a touch descending either due to gravity or lowering your body when on the drops (descending on the drops is better as you lower your centre of gravity). Maybe make an effort to shunk back towards the rear of the saddle at the top of the hill.

On your outside leg (on the bend when you've raised the inner pedal to avoid grounding out) push down on the pedal as this helps keep the bike planted more, but remember to keep your knees and elbows "soft" to absorb any bumps.

You can counter steer round a bend if it tightens which means you are less likely to have to think of feathering a brake which is a bit dodgy when banked over. For a test find a flat and empty bit of road and build up a bit of speed. Now riding on the drops stop pedalling and with your right hand push down and out (at about 45 degrees). Do this gradually and smoothly and you'll find you start to move across to the right of the road without turning the bars or banking the bike at all. Try with the left as well and see how you find it. Next you can try the same thing on a fairly gradual descent to assist in cornering without banking the bike as far.

Once you get the hang of it you don't have to think about it and you can corner tighter and faster. You can actually turn a bike in an amazingly small space, but it can get a bit frightening when you get leant over too far and counter steer at the same time as it sort of whiplashes you round really quickly and you're out the other side quicker than you expected.

If you're trying to build up your confidence again then I'd freewheel down the hills rather than pedalling to moderate the speed a bit until you are happy with your technique again. Also make sure your tyres are correctly inflated and that you have confidence in their grip. I had some that I just wasn't happy with and never felt happy leaning the bike over on them as they always seemed to skip a bit once you got to a certain point.

[Sylv]

[quote="Andrew G"] Now riding on the drops stop pedalling and with your right hand push down and out (at about 45 degrees). Do this gradually and smoothly and you'll find you start to move across to the right of the road without turning the bars or banking the bike at all.

[Ivor]

Sounds like motorbike steering technique, although you push with the hand in the direction you want to go. i.e. if you want to turn right, you apply pressure to the handbars with your right hand. This is slightly counter-intuitive because you think that means you are turning the bars to the left.
Sylv is that what you mean or do you mean that by flicking the bar really hard and quickly you are effectively turning the bars in that direction really quickly?

[Andrew G]

I think I know what you mean Sylv, push directly down hard and sharp on one side and the bike would "pop" to the opposite side. Sounds logical but never tried it, my reflex is always to bunny-hop thanks to a mis-spent youth on a bmx. With clipless pedals it's even easier. I think it's probably more controllable(sp?) too.

[Ivor]

Used that as my technique for clearing speedbumps this morning. very effective.

[Snoop Doug]

Don't go down hills, that's my advice.

[Tony]

Have you got your weight distributed correctly? The pedal on the 'inside' will obviously be raised to the top of the pedal stroke when you are cornering fast with the pedal on the 'outside' lowered. When I corner fast (and stop pedaling) I have no weight on the inside pedal (even though you are very shortly going to press it down again) and as much weight as feels sensible on the outside pedal. Effectively you are rotating your pelvis slightly from one side to the other to reduce weight on the inside pedal and transfer it to the outside one. In my experience, the bike should feel more secure in the corner if your spread the weight in this manner.

Alternatively, if your cornering technique is good, maybe you've got some hard winter tyres with no grip!

[mrP(Boonen)VT]

[quote]I felt exactly the same thing last year at the palace.

I looked down and my tub had just rolled off

[mrP(Boonen)VT]

Sylv,
The bit you quote about the opposite flick is a bit like the technique rally drivers employ, and a few years ago, Chris Colford was explaining the technique to me that he had read somewhere and I thought it was a load of bull**** but he told me that when he was riding behind me, he watched me do it and when I analysed it, I realised that I kinda did it automatically without thinking about it. IT WORKS.

I don't analyse what I do to the extent that Mr Green does, just go for it, although I have had some "moments" descending in the alps, but only because I was carrying too much speed/braking too late or oncoming vehicles (but that's another story).

Perhaps it is a confidence thing and that you are being too tense and rigid on the bike

[Andrew G]

[quote="Sylv"]
Talking about this has anyone ever read of the opposite method, which is more meant to help you avoid an obstacle that suddenly appears in your path (say a pothole or debris on the road)- basically you are supposed to push down on the opposite side of which way you want to be turning your wheel - ie quickly press with the left hand if you want to go right of the pothole - the reaction of the bike will take care of the rest, and quicker than if you had actually initiated a turn.