Going down a steep slope

jeannot18

The specific slope I am talking about there is no clear exit as such, just a 90 degree turn at the bottom, quite tricky for a novice like me.

Do you keep control of your speed all the way, or do you try to go a bit faster and apply brakes a bit heavier to slow down the bike. First time I took it, it was dry and managed ok, this week after the rain it was quite soft and chickened out.

THanks
JC

supersonic

Always control the speed of your bike.

jeannot18

supersonic wrote:

Always control the speed of your bike.

Thanks, hard when it is wet to apply the right pressure on the brakes, but I guess it only a matter of experience.

JC

Anonymous

Remember that your front brake is your friend, learn to control it properly.
There's a few descents round here that you simply cannot just let go of the brakes and let rip - you'd never get your speed back under control, so descending whilst dragging the front brake to control your descent is the inly option.

If it's REALLY steep, you'll want to shift your weight waaaaaaaaay back off the rear of the bike too, and drop your heels.

jeannot18

Thanks guys, I am working on dropping my heels did not realise that it had an impact until I have read about it.
JC

Anonymous

It's a great way of eplaining a few small things at once. It's not the actual dropping of the heels that helps in and of itself, so to speak, but the other small adjustments your body has to make in order to drop your heels.

nozzac

http://www.imbikemag.com has lots of articles relating to "under rotation" by dropping heels and wrists etc. It's a useful way of looking at things I think.

ian220476

recommend the IMBike Mag read and I have had a few lessons with Richard who writes the technique section in here as well. pedals level; drop the heels and get your bum way off the back and down. Practice on a fire road and you'll be amazed by employing this technique how hard you can stamp on the brakes without locking up.

As a principle it works on loads of stuff as well (drops; descents etc). Practice to make it natural

jeannot18

Cheers guys, went back reading some of the article from imbikemag.com (very good), ian, thanks for that, I know it is down to practice, shame I don't have as much time as I would like. Hopefully, I should get there one day...
JC

Shocker_33

ian220476 wrote:

Practice on a fire road and you'll be amazed by employing this technique how hard you can stamp on the brakes without locking up.

I wouldn't stamp on the brakes too hard on a fire road, as you will lock the front wheel up easily. The technique mentioned will only work at it's best down a steep decent.

On a fire road, because they tend to be pretty flat, using the technique will cause a lack of weight on the front wheel and the very small moments about it (Moments about the wheel = When you brake hard enough, you will feel the front suspension compress and the rear wheel wanting to lift. This is your bike wanting to rotate around the front wheel, ie. a moment about the front wheel.) In turn this will have cause the wheel to have a low tyre-ground adhesion and a super fast rate of deceleration will be too great and the wheel will lock.........knowledge from my engineering background.

So if you do choose to practice on a fire road, i would start off at either a low speed and work your way up to get a feel for when it's about to lock.
Or i would start at the speed you desire and initially apply your brakes gently and work your way up to stamping on them.
Either and preferably both is good because you learn how your bike handles

KitsuneAndy

Shocker_33 wrote:

ian220476 wrote:

Practice on a fire road and you'll be amazed by employing this technique how hard you can stamp on the brakes without locking up.

On a fire road, because they tend to be pretty flat, using the technique will cause a lack of weight on the front wheel

I was always under the impression that your weight shifted forwards during braking, so it's your back wheel that un-weights and locks?

kentos1978

Shocker_33 wrote:

[quote="ian220476" This is your bike wanting to rotate around the front wheel, ie. a moment about the front wheel.) In turn this will have cause the wheel to have a low tyre-ground adhesion and a super fast rate of deceleration will be too great and the wheel will lock.........knowledge from my engineering background.

Not sure where you studied but surely if the tyre had a low ground adhesion it would just skid, and it's almost impossible to skid the front wheel if you lock the brake, much easier to skid the rear as your weight goes over the front.

Anonymous

KitsuneAndy wrote:

Shocker_33 wrote:

ian220476 wrote:

Practice on a fire road and you'll be amazed by employing this technique how hard you can stamp on the brakes without locking up.

On a fire road, because they tend to be pretty flat, using the technique will cause a lack of weight on the front wheel

I was always under the impression that your weight shifted forwards during braking, so it's your back wheel that un-weights and locks?

Your weight transfers away form the rear wheel, towards the front wheel when braking.
Because of this shift of weight AWAY from the rear, the rear wheel has less traction, and skids much easier.
Conversely, the weight shift TOWARDS the front causes increased traction on the front wheel, and allows it to brake very effectively.

I think what Shocker is trying to explain is that by shifting your weight WAY over the rear, as if you were going down a very very steep slope (BUT, still riding on the flat) you can actually unweight the front so much that it becomes far less effective at stopping you, and very prone to locking up and skidding - it will lose traction before it decelerates the bike enough to shift your weight over it effectively.

Anonymous

kentos1978 wrote:

it's almost impossible to skid the front wheel if you lock the brake

I have photographic evidence to the contrary (which sadly I can't post, as it's one of the kids that came on a training day).
Locking the front wheel on loose terrain is easily done, without going over the bars. As long as you brace yourself, so your weight doesn't get flung forwards. It's one of those sily things I do sometimes just to muck around, like manualling through puddles, or leaning way over the bars and doing gigantic rear wheel skids.

Shocker_33

On a flat track, If your arse is over the back tyre. Most of your weight is pressing down on the rear wheel and depending on how far your arse is over the rear wheel, one could say that your slightly lifting the front wheel upwards as there is a moment about the rear wheel as you cling on to the handlebars. Therefore......the front wheel has a lower tyre-ground adhesion than in a normal riding position because the static force is lower and the moment about the front wheel is lower because your arse over the back wheel is counter acting it to some extent. With the front wheel having a lower tyre-ground adhesion makes it easier to lock up (ie. it doesn't follow the rough standard of 70/30 brake ratio).........come on guys this is basic physics !!


The technique works at its best whilst going down a steep-ish decent......do i need to explain the basic physics behind this too? I'll stop as i don't want to patronise anyone but if anyone wants me to, i'll continue?


Before anyone else questions my knowledge, i've just studied this stuff at university with an average of 84% at one of the best engineering universities in the country (Took my final exam lesson than a couple of months ago). I studied this stuff looking at motorbikes, car's, car's with trailers and lorries. They all follow the same basic principles.

getonyourbike

yeehaamcgee wrote:

kentos1978 wrote:

it's almost impossible to skid the front wheel if you lock the brake

I have photographic evidence to the contrary (which sadly I can't post, as it's one of the kids that came on a training day).
Locking the front wheel on loose terrain is easily done, without going over the bars. As long as you brace yourself, so your weight doesn't get flung forwards. It's one of those sily things I do sometimes just to muck around, like manualling through puddles, or leaning way over the bars and doing gigantic rear wheel skids.

I agree, it is easily possible, get over the back and jam on the front brake and the front wheel will lose traction and skid providin you're not on tarmac or similair

Anonymous

Shocker_33 wrote:

come on guys this is basic physics !!

It is yes, but you're not explaining it very well to anyone who has no idea what moments or static forces are. You're dealing with a lot of people here who haven't just done the same course as you, remember. Plain English helps

Before anyone else questions my knowledge, i've just studied this stuff at university with an average of 84% at one of the best engineering universities in the country

YAAAAAAWN

Nobody seems to be questioning your knowledge, But I suspect they were misunderstanding, or not comprehending your terrible explanation of it.

nicklouse

getonyourbike wrote:

yeehaamcgee wrote:

kentos1978 wrote:

it's almost impossible to skid the front wheel if you lock the brake

I have photographic evidence to the contrary (which sadly I can't post, as it's one of the kids that came on a training day).
Locking the front wheel on loose terrain is easily done, without going over the bars. As long as you brace yourself, so your weight doesn't get flung forwards. It's one of those sily things I do sometimes just to muck around, like manualling through puddles, or leaning way over the bars and doing gigantic rear wheel skids.

I agree, it is easily possible, get over the back and jam on the front brake and the front wheel will lose traction and skid providin you're not on tarmac or similair

done it on Tarmac.

Shocker_33

KitsuneAndy wrote:

Shocker_33 wrote:

ian220476 wrote:

Practice on a fire road and you'll be amazed by employing this technique how hard you can stamp on the brakes without locking up.

On a fire road, because they tend to be pretty flat, using the technique will cause a lack of weight on the front wheel

I was always under the impression that your weight shifted forwards during braking, so it's your back wheel that un-weights and locks?

This is correct if in a normal riding position.

Anonymous

getonyourbike wrote:

yeehaamcgee wrote:

kentos1978 wrote:

it's almost impossible to skid the front wheel if you lock the brake

I have photographic evidence to the contrary (which sadly I can't post, as it's one of the kids that came on a training day).
Locking the front wheel on loose terrain is easily done, without going over the bars. As long as you brace yourself, so your weight doesn't get flung forwards. It's one of those sily things I do sometimes just to muck around, like manualling through puddles, or leaning way over the bars and doing gigantic rear wheel skids.

I agree, it is easily possible, get over the back and jam on the front brake and the front wheel will lose traction and skid providin you're not on tarmac or similair

Quite, it should do it on tarmac too at some point, even. It's definitely possible on wet tarmac.

bentes

Last time my front wheel skided, it ended up with me lying in an un-natural position over some rocks. But it's quite possible, yes. Wouldn't recomended it if you're as clumbsy in a bike as me tough.... :oops:

KitsuneAndy

yeehaamcgee wrote:

KitsuneAndy wrote:

Shocker_33 wrote:

ian220476 wrote:

Practice on a fire road and you'll be amazed by employing this technique how hard you can stamp on the brakes without locking up.

On a fire road, because they tend to be pretty flat, using the technique will cause a lack of weight on the front wheel

I think what Shocker is trying to explain is that by shifting your weight WAY over the rear, as if you were going down a very very steep slope (BUT, still riding on the flat) you can actually unweight the front so much that it becomes far less effective at stopping you, and very prone to locking up and skidding - it will lose traction before it decelerates the bike enough to shift your weight over it effectively.

Ah yeah, that makes sense. I think you're right with the "trying to explain"

Shocker_33

yeehaamcgee wrote:

Shocker_33 wrote:

come on guys this is basic physics !!

It is yes, but you're not explaining it very well to anyone who has no idea what moments or static forces are. You're dealing with a lot of people here who haven't just done the same course as you, remember. Plain English helps

Before anyone else questions my knowledge, i've just studied this stuff at university with an average of 84% at one of the best engineering universities in the country

YAAAAAAWN

Nobody seems to be questioning your knowledge, But I suspect they were misunderstanding, or not comprehending your terrible explanation of it.

In my original post i explained what a moment was in basic terms. I didn't even mention a static force, i just said weight.
In the second post i talked about the way the weight was pressing down on the rear tyre and possibly lifting on the front and then moving on to the term static force, i thought it was pretty clear. Also static as in still. Force as in something exerting an energy on something. Since the only force on the bike whilst stationary is the person's weight x gravity................static force = persons weight x gravity.


I'm 1000% certain i read a post about someone questioning my understanding of this topic, its not there any more, the person must have edited it out. I only wrote the second post to prove them wrong because of the comment i had read, otherwise i wouldn't have bothered writing it at all.
EDIT: And i've just altered this post because i realised i repeated a word twice. After i finished editing it, it didn't show that i had altered it..


I actually think my original post is pretty good at a basic level of explaining it without going in to technical terms or the use of maths. The only thing i didn't explain is tyre-ground adhesion but i thought that was pretty self explanatory.

Shocker_33

bentes wrote:

Last time my front wheel skided, it ended up with me lying in an un-natural position over some rocks. But it's quite possible, yes. Wouldn't recomended it if you're as clumbsy in a bike as me tough.... :oops:

And this is the reason why i explained at a basic level what happens when braking with your arse over the rear wheel. And why i advised the person to be careful when slamming on the brakes.

Deputy Dawg

Shocker_33 wrote:

yeehaamcgee wrote:

Shocker_33 wrote:

come on guys this is basic physics !!

It is yes, but you're not explaining it very well to anyone who has no idea what moments or static forces are. You're dealing with a lot of people here who haven't just done the same course as you, remember. Plain English helps

Before anyone else questions my knowledge, i've just studied this stuff at university with an average of 84% at one of the best engineering universities in the country

YAAAAAAWN

Nobody seems to be questioning your knowledge, But I suspect they were misunderstanding, or not comprehending your terrible explanation of it.

In my original post i explained what a moment was in basic terms. I didn't even mention a static force, i just said weight.
In the second post i talked about the way the weight was pressing down on the rear tyre and possibly lifting on the front and then moving on to the term static force, i thought it was pretty clear. Also static as in still. Force as in something exerting an energy on something. Since the only force on the bike whilst stationary is the person's weight x gravity................static force = persons weight x gravity.


I'm 1000% certain i read a post about someone questioning my understanding of this topic, its not there any more, the person must have edited it out. I only wrote the second post to prove them wrong because of the comment i had read, otherwise i wouldn't have bothered writing it at all.
EDIT: And i've just altered this post because i realised i repeated a word twice. After i finished editing it, it didn't show that i had altered it..


I actually think my original post is pretty good at a basic level of explaining it without going in to technical terms or the use of maths. The only thing i didn't explain is tyre-ground adhesion but i thought that was pretty self explanatory.

Really? 1000%? Thats equal to 10 & very bad maths fractionally speaking.

nozzac

I think you make yourself look a bit of a idiot when you go down the "don't challenge me - I got A's in this" like. I did Physics at Uni but I don't claim to be an expert at bike riding. I can't say it helps much at all unforunately. You don't need any knowledge of physics to ride a bike. You just need to learn from experience. I dare say the Athertons and Macaskills of this world didn't ace applied maths.

Fact of the matter is, if you drop your weight and take other actions to try to prevent over rotation, like dropping heels etc then you can apply the front brake a lot harder because you don't get thrown over the bars. Obviously this needs to be balanced by the amount of grip available - no point in worrying about going endo if you have no traction at all. You can also improve your traction a lot by dynamically weighting the bike at the moment of braking and effectively increasing your weight at least twofold. I like doing this because I'm always amazed how much grip you can generate and how fast you can stop.

Valy

Jesus christ

this and the thread yesterday about landing on rear or both wheels... what the fuck guys...

Deepunder

Valy wrote:

Jesus christ

this and the thread yesterday about landing on rear or both wheels... what the fark guys...

Just as one fruit falls and gets eaten, another ripens in its place !

Anonymous

Deputy Dawg wrote:

Really? 1000%? Thats equal to 10 & very bad maths fractionally speaking.

Does that make it "bad maths^10"? Or potato*bad maths?

Come on, this is semantics, and turns of phrases es eseses.

He was right in waht he said, it just wasn't very clear - especially considering most of the readers here just don't get technical terms. More plain Engrish , please.

bennett_346

Ah, bikeradar maths. One day i'll learn it fully.

Shocker_33

NozzaC wrote:

I think you make yourself look a bit of a idiot when you go down the "don't challenge me - I got A's in this" like..

It was the comment that i read that got the reaction.......

Maybe i was in a bit of a mood earlier that didn't allow me to shrug it off. Oh well....life goes on, i don't really care what impression i made with it. All i was originally trying to do in the first comment was to make sure the lad didn't wipe out practising because he was given advice that wasn't too clever.