Locking up rear wheel.

Over the last week or so I see to be continuously locking up the rear on my commute.

1st time the road was greasy and I was probably going a little too fast but nothing excessive. This knocked my confidence a little and so reverted to riding the local station in Colchester and cramming onto a train to London.

The lockups persisted however. I noticed that my standard rubber was still pretty much stone cold. So today I decided to travel the 70ish miles into Docklands and it locks up again. I had been filtering down the A13 for a good 20 minutes, this was a controlled stop and I was being pretty gentle given how aware of this issue I have become.

My question is, is this purely down to the rubber or should I be looking at up rating my fork springs to stop the bike diving under breaking?

There's a few things I could think of that *may* cause this to happen (and I'm relatively new to all this myself so ... I'm sure one of the technical-types will be along soon enough) ...

Are these lock-ups happening under braking? or on down-changes?

1. Have you tried "blipping the throttle" on down-changes? Makes quite a difference.
2. How are you braking? Front only? Rear only? what percentage of both? (e.g. 75% front, 25% rear)
3. What's the rubber like on the rear tyre?
4. Have you checked chain tension recently? My chain was REALLY loose yesterday and I could almost feel it jumping about the rear sprocket and I'm sure at one point it snapped back into place and almost wrenched me out of the seat ... I'm sure I've heard it said that it could cause the rear wheel to lock also?!

In the current weather conditions think you have to make your riding a LOT smoother ... everything you do should be SMOOOOOTH. No sudden movements. Not too heavy handed with the right hand ... not too quickly/sharply/heavy on the brakes.

Also, give your tyres a little more time to warm up (especially these days)
There's a smallish roundabout not far from home for me, and I've felt the back wheel drift a little on it on really cold mornings (just not enough heat in the tyre to grip), so I always take it easy around that one. However I would have thought on a 70mile commute your tyres would be well and truly warmed up by then.

HTH,
Pete

[Biker Biggles]

Sounds like you are using too much rear brake.You get very little stopping power from the rear,so I tend to use it very lightly,more as a steadying brake than for serious stopping.The front is what stops the bike.Some people hardly use the rear at all,but I think that is OTT for road use.Get used to a very light right foot.

[fizzwheel]

Originally Posted by Pedro68

In the current weather conditions think you have to make your riding a LOT smoother ... everything you do should be SMOOOOOTH. No sudden movements. Not too heavy handed with the right hand ... not too quickly/sharply/heavy on the brakes.

I'd say that applies at all times not just when the roads wet / greasy etc.

Could use a little more info on your bike and how long you've been riding etc etc.

its easy to lock the rear on the SV, normal cause of lockage is the the speed of the engine isnt matched to the speed of the back wheel and at low speeds and low RPM you can lock the back wheel up.

The fork dive on the SV is quite alot, but thats not the cause of your rear wheel locking, from what you have described it sounds like you are being to heavy with the brakes and throttle, try and be a bit more gentle and give yourself more time when changing gear.

Originally Posted by Pedro68

In the current weather conditions think you have to make your riding a LOT smoother ... everything you do should be SMOOOOOTH. No sudden movements. Not too heavy handed with the right hand ... not too quickly/sharply/heavy on the brakes.

Originally Posted by fizzwheel

I'd say that applies at all times not just when the roads wet / greasy etc.

Well yeah very true

But what I suppose I should have said is ...
"Sudden operations/actions, such as throttle, braking, and turning, you can get away with in good (dry) conditions. MUCH LESS SO in poor conditions"

Well as i feel comfortable gettin Brian outta line on the anchors, know how to and how not to, rear brake down two gear clutch out you get a bit of a slide, all depends on how much rear brake you wanna give it, obviously the more you give the more you get. Now if your blipping the throttle on downshifts this all changes and seems to stop it and still you get the decent engine braking. If you arent too keen on blipping your throttle theres also the let the clutch out slower. Different ways you see, i use them all.

By the sounds of it you are maybe heavy footed on your rear brake a bit. Try the blipping throttle technique it does work. Blip it and as you return the throttle release the clutch out normally. Shouldnt lock up unless you are severely heavy footed.

What everyone has said so far is what I was going to suggest, but I just wanted to go a ltitle further on the downshift technique, where you as the rider "blip" the throttle. No doubt someone wil correct me, so everyone else feel free to scrutinise my method and amend it as neccasery.

Anyway, the idea is that you pull the clutch in, poke the lever down and then before you re-engage the clutch (let the lever out fully) you give the throtle a quick blip, as to rev the engine. When the clutch re-engages, the engine speed will be more suited to the rear-wheel speed, and therefore reduce the chances of a lock-up. Go out and try this, going from 3rd gear to second gear.

At first, do it while just using the engine braking; as you get used to this method, then start to do it while using the front brake.

Here you might find that when you blip the throttle, you may accidently pull on the brake lever a bit harder making everyhting a bit pogo! Dont worry, as you get used to the method of blipping while downshifting this will go away.

I tend to use two fingers on the brake lever while downshifting and blipping, sometimes three but never four.

It is fine to use the bake brake, but best to use it when you have scrubbed off alot of speed with the front, to reduce the likely hood of the rear end locking up.

Matt

[EDIT] Just as a disclaimer, take my advice with a bit of thought...I'm not a great rider ye know

For normal road riding I don't use the back brake at all. Seems to me that the engine gives about as much safe back wheel braking as you need. The only times I use it is if it's an emergency and even then I am very wary about putting any real pressure on it. I do use it on loose ground and when pulling away uphill from a standstill.

Just to say, I use the back brake alot when filtering. Keep my foot over it incase I need to brake suddenly (hands not covering lever so i get extra control). I havnt had a lock up yet doing this, and I have used it pretty hard. Experiment, and see where the line is

My back brake is a bit spongy, i admit

Matt

If i see gravel etc in road i use it(if I am carrying too much speed), sorry but if i use my front brake, whats gonna happen if i catch it, slide mama sliiiiiiide, and it's not quite often a sliding front end can be saved(awaits for all the stories that people have saved the front end). The peanut butter and jelly of it is, what would you feel more comfortable with a sliding front or a sliding rear????