Braking down hill /engine braking

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lemmy
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Braking down hill /engine braking

Post by lemmy »

I know that it isn't good to engine brake on a 2-stroke for very long, but how long is it before it really starts to be a problem? I enjoy every part of riding except for steep descents. The rear brake just locks up if I even think about using it, the front brake can rarely be used and only lightly. The only other option is engine braking. I let it engine brake then pull in the clutch and rev it a little to get some oil in the engine, but I really start to get too fast quickly. I really feel out of control on descents.
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Post by ArkansasXC »

2 strokes dont really have engine braking, to speak of. Thats a 4T trait.

For downhills, shift your weight back as far as you can, with your weight back, you have far more control over a high side due to front brake grabbing. Tap your front brakes, dont lock them, to control descent. Use the rear brake for direction change.
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Post by lemmy »

Yeah, I have always heard that. But if I am in 2nd gear going down a steep hill with no brakes, there is a big difference between clutch in and clutch out.
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skythrasher
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Post by skythrasher »

I know it doesn't sound right, and can feel even more foriegn at first , but "MORE FRONT BRAKE".

Once you get the hang of using the front brakes you will forget yu even have the back. (until they're gone) :cry:
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lemmy
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Post by lemmy »

I use the front brake almost 100% on my street and road racing motorcycle and I use it tons on my mountain bike. I guess it would make sense to use it more on the dirt bike. I do on flat an mild descents, but just not on the steep loose/muddy descents.
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Post by skythrasher »

The whole trick is proper modulation of the brakes. A skidding tire does you little good. You'd be suprised at how much you can get on those front binders and remain in control. So what if the rear tire comes up every now and then, as long as the front still has traction no big deal. If you get a chance watch the Dirtwise video from Shane Watts. He has some really good braking exercises in his videos. If you practice like he says it won't be long you'll be doing stoppies that really impress the neighbor kids.
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Post by Colorado Mike »

I used to avoid the front brake on downhills until one day when I was going down a very long grade from about 13,500' to 10,000'. Maybe the altitude contributed, but my rear brake fluid boiled, which made the brake fail completely. That forced me to get good with the front brake real fast. Now I rely on it almost totally.
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Post by zz3gmc »

I try to stand up (where possible) with my weight back and modulate both brakes on most downhills. By standing, you are less likely to get pitched over the bars if you encounter something, such as a rock, root, log etc. Where possible, I carry a good amount of speed and use the momentum to help get over obstacles. I also use the throttle to help clear stuff, that way you can lighten up the front end and not just plow into obstacles.
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Post by lemmy »

I can't modulate the rear at all with boots on. It is either locked up or not on at all.
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Post by kawagumby »

If the traction is poor your back brake is worse than worthless on any kind of steep downhill. Even when traction isn't that bad, you really need to be easy on the rear brake. My experience is that you want to always be in a gear that will allow you to accelerate, so you can straighten the bike as needed (I keep the clutch in), and your body position should not be way back, but back just enough to provide some neutral control of the bike with fore and aft weight shifts, knees and elbows bent, ass slightly off the seat, knees grabbing the bike also - you still want to be able to control the front end, and you can't if you're too far back. If you sit on the seat, you probably eventually slide forward and lose the whole thing. This is where proper suspension setup is key- a firm but responsive front end - and plenty of front end braking when the bike is straightened out and traction presents itself. I always look far enough ahead for safer braking areas and try to hit them as I go down long steep and rough hills.

If you can't feel the brake pedal, you can feel (and often hear) the rear wheel losing traction - and let off before things get tense.
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Post by canyncarvr »

Opines differ I'm sure....

Compression braking isn't a lot on a 2T for sure...but, as said..it's a whole lot better'n a free wheeling rear, imo. Weight transfer indeed makes a rear brake largely useless on any half fast steep downhill..it's going to skid at a touch 'cuz it's pretty much floating over the surface to start with. I use a brake-steer approach quite a bit on downhills anyway. A free-wheeling rear isn't likely to track where I want it to go.

But...the question in regard to harm to a 2T: KawaG said: 'My experience is that you want to always be in a gear that will allow you to accelerate...' Seems to me that precludes the situation that incurs harm to a 2T through the use of compression braking, namely some screaming rpm in a too low gear with the throttle shut down.

A 120mph straight followed by a down-shifted 8000rpm throttle chopped corner approach isn't something you have to worry about.

Keep the revs in a 'decent' range..upshift if they're not. That will get you in shape for KawaG's acceleration mode and not hurt anything in the process.


A btw...but I've heard a number of advices saying to move back on the seat on descents/downhills.

From a dirtbikeschool post (the link is a 3MB pdf file):

COACHING TIPS FOR DESCENDING
• To go downhill, shift your weight back. On steeper
downhills, extend your knees and elbows and bend
forward sharply at the waist so that your posterior is
over the back of the seat.
• Use both brakes to slow you down as you descend
the hill and descend in a gear that will utilize the
engine compression to slow the descent.
__________________________________________

Maybe if you have to try to unload the front end 'cuz you think it's going to stick..but generally speaking I prefer to be in the saddle of the seat..not adding to the pressure already on the front that comes from leaning off a rearward seat position.

To be fair (and clear) the above excerpt is referring to standing..not sitting. The old saw, 'If you're standing you're racing..if you're sitting you're riding' has its merits. I don't stand a lot on the KDX..it's a tad too wide to be comfortable for my broken knees. Standing seemed as natural to me as sunlight on a 200exc I rode for awhile.

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Post by skythrasher »

I agree with CC on the standing. I stand most of the time, my CR is much easier to get comfortable standing than the KDX. The Kdx is just not shaped right for really aggressive riding positions, but that the type of riding it was designed to do.
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