Tips For Downhill Cornering

Discussion in 'The Perfect Line and Other Riding Myths' started by jnclem, Apr 27, 2013.

  1. jnclem

    jnclem True Airhead

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    I started riding motorized two wheelers again last fall, after about 30 years of on and off road bicycling. Let me say that I'm 55 years old, and not at all interested in setting any speed records. My interest in riding is doing a lot of dual sport miles here in western Colorado, enjoying myself, and becoming a smooth, safe rider, and doing some longer cross-country tours.

    I guess I have put on about 3500 miles since I got my GS last September. It has been a blast, and I learn a lot every time I get it out. Today was the first time this year that I had enough confidence in the weather to take a longer ride outside of our valley, which always requires crossing some high passes. It was a beautiful day and a great ride.

    But, what I'm noticing is that I am much more confident going up passes than descending. The roads are in good shape, but being Spring, you always have the possibility of sandy patches, snowmelt running across the road and carrying debris, and rocks coming down, just around any corner, not to mention the yahoos that don't seem to realize there are two lanes on road.

    I know the physics of why downhill cornering robs us of more front wheel traction, but I am looking for any techniques that you all use for better downhill cornering on pavement or dirt. I find myself tightening up, going slower, and having to consciously relax and concentrate much more on technique when descending. I am better on right handers than left too. Granted, the consequences for mistakes on our bigger passes can be pretty severe, but I know i can improve a lot. Again, Speed is not realy my goal, smoothness and confidence are, and I don't want to be an obstacle either.

    Sorry for the long post - any advise?
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  2. PeterW

    PeterW Long timer

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    Different bike ?

    Sorry, I know exactly what you mean and most of the bikes I've owned have felt the same. The one I own now - just doesn't.
    It's perfectly happy cornering and braking downhill on sealed roads even in really crappy conditions. Well, at least, the rider feels comfortable.

    Even there, steep dirt downhills are nasty

    I'd guess it's mostly a seating position/geometry thing, so you might be able to make it less bad by fiddling with the ergomics - but other than 'not all bikes are like that' I don't have anything specific.

    Pete
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  3. guitarhack

    guitarhack Long timer

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    It sounds to me like you are just exhibiting good common sense.
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  4. joef

    joef Been here awhile

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    My Multi corners differently down hill as opposed to up hill, braking force's change, geometry changes, front end compresses more and the rear has less weight on it while braking down hill. I feel the difference and my approach to up hill and down hill turns changes
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  5. jnclem

    jnclem True Airhead

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    I don't think the bike is having any problems, I think I am just not as comfortable with the feel of downhill cornering as uphill. The feel is dramatically different on any kind of two wheel vehicle I have ever ridden. It has to do with so much more weight on the front as opposed to the back.

    I just thought maybe my positioning should be different or something, but I probably just need more time and experience.
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  6. joexr

    joexr Banned

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    If you're not , you should be against the tank , more weight on front , not sitting back. Been riding for 43 years.
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  7. anotherguy

    anotherguy Long timer

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    The beggest problem I see riders doing is coasting through the corners on the brakes overloading the front wheel's traction. Turn up the loud switch,even just a little and gear down to use compression braking. There's usually more traction than you think there is. Technique (or the lack of) robs you of traction. When you have to brake do so with force appropriate to the situation.

    Have you tuned/set up the suspension yet? That is the key to just about everything. If the bike works well it frees the mind to do what it needs to do.

    Start slow but using correct cornering technique and the speed/confidence will come.
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  8. Madrox

    Madrox Like a bat out of hell

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    Loosen up, get your weight on the back of the bike and make sure you're not carrying any weight on the handlebars. Enter the corners slower than usual and accelerate harder through them; this will transfer more weight to the back (larger contact patch) and make the bike much more stable. When you're going down hill there's more weight on the front tire (smaller contact patch, much easier to overload) than on the back which introduces instability. Rear grip is also reduced substantially because of this. If you're tight on the bars all imperfections the front tire encounters will be amplified through your body and sent through the entirety of the bike. With the front tire beyond ideal 40/60 loading already the bike will feel very unsettled. Your natural reaction will be to back off the throttle which transfers even more weight to the front causing the bike to stand up and run wide.

    Short answer: Consciously relax, loosen up, slow in, fast out.

    Edit: Also make sure you're in the right gear, it will help a lot.

    And a demonstrative youtube video

    http://www.youtube.com/watch?v=0ncgT008MxI
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  9. joexr

    joexr Banned

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    Is that a BMW GS in that video?:rofl
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  10. Madrox

    Madrox Like a bat out of hell

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    The physics are the same whether it's a MotoGP bike or a giant bagger. I couldn't think of a better corner than the corkscrew.
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  11. joexr

    joexr Banned

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    The weight bias is much different. Best handling is front weight bias. Sorry , don't have a video to show.:lol3
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  12. Madrox

    Madrox Like a bat out of hell

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    The Motogp bike has more weight up front so it can turn in much more quickly and is more stable under hard acceleration. The fact still stands that the bike is most stable with a weight distribution of roughly 40/60. When going downhill more of the weight will shift to the front putting more load on the smaller contact patch making it much easier to overload both tires. You have to counteract this as a rider by getting more weight back onto the rear tire to keep it stable.
    #12
  13. joexr

    joexr Banned

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    :huhYou really don't know what you're talking about.
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  14. benzbaron

    benzbaron Adventurer

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    I was going to hold back a bit but I have run fast downhill before and find that trail braking with just the rear brake can help set the bike through the curve. Trail braking might not be a good way to control speed but if you come into a downhill curve a bit too fast trailing the rear brake through the beginning of the corner and you won't get the imbalance associated with applying the front brake while turning. I chewed through a set of pads trail braking down the east side of Palomar mountain in san diego area.

    I'm still figuring out riding techniques so don't know if this is the best way. I figure if the traction circle remains the same between cars and bikes the fastest line through a curve involves overlapping braking/turning, pure turning, and turning/acceleration.
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  15. Madrox

    Madrox Like a bat out of hell

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    Enlighten me then if you feel my understandings of physics and motorcycle dynamics are that wrong.
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  16. ongrade

    ongrade Been here awhile

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    Treat a downhill curve just like you would flat ground. Get your entry speed right before you lean the bike over, meaning get off the brakes. Smooth throttle, either steady or accelerating out of the turn. Chopping the throttle will cause the front suspension to load and change your steering geometry. Body position should be exactly what it is on flat ground. Trying to sit back on the bike to change the weight bias will lead to a stiff body position as you try to fight gravity and the decel of the bike entering the turn. Downhill turns really are no different than flat ground except that gravity does some of the accelerating for the engine and you need to brake a bit more aggressively before corner entry.
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  17. jnclem

    jnclem True Airhead

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    My usual routine is to slow with engine and brake before the turn, then let everything loose ( no brakes, throttle probably about neutral) as I initiate, then add throttle through the turn. And yes, I have lived in the mountains most of my life, so I am big on engine braking.

    Interesting about moving forward. My habit from bicycling is to get weight back downhill, although it is much more noticeable on a 20 pound road bike than a 450 pound motorcycle. Can't quite figure that ounce out since the weight is already forward. Maybe by "does being against the tank just put you more in the center, or move your weight forward of center? I'll have to give that one some thought.

    As to suspension, I recently replaced the rear shock with a Wilber's, and got that set up right. I haven't done anything with the front. I know it was serviced right before I got the bike. The PO is bigger than I am though. This is stock R100 GS, so I don't know how much adjustment it has. That is something I should look into.

    I really am not blaming the bike here. It's not like it feels bad, off, out of control or anything. I just think I am a novice and trying to get used to taking a lot more weight than I am used to through a corner. Add to that having power, rather than only gravity, and it is a different animal.

    I just want to be sure that by the time summer rolls around and there is a lot more traffic up there, I can by handling the corners well.

    Thanks for all the input. I will see how the weight forward, weight back debate goes.
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  18. joexr

    joexr Banned

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    Look at racers , road or dirt , forward on the seat. This isn't to keep the front wheel down , it's for traction for turning. And if you don't know countersteering well , try riding a moderately curvy road with your left hand on the gas-cap , you'll start to understand.:deal
    #18
  19. fredN4

    fredN4 Adventurer

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    And learn to trust your tyres. they have a lot more tread on the sides than you might believe. picked that up a couple of weekends ago at Simon Pavey's offroad skills training in Wales.:1drink
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  20. Madrox

    Madrox Like a bat out of hell

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    The extra front traction you're describing is really only beneficial when you turn in. Once you're leaned over and are rolling on the throttle the weight transfers to the rear and the bike stabilizes. It takes more effort to get the bike to the optimum weight distribution to maximize available grip when traveling downhill due to there being excess weight on the front tire. You're simply asking too much of the front tire mid corner.
    #20