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SA Advanced Ridersafe - U-turns

Discussion in 'New Riders and Riding Tips' started by Glekichi, Oct 13, 2011.

  1. Ive been down the old Oaklands range to practice on my Hornet and everything is a breeze except the damn double u-turn. Ive been a few times now and only on my most recent visit have started to actually get a couple (maybe 40-50%) through, but its not consistent.

    So, I got off and pushed my bike around the course and found out that if the bike is upright at full steering lock it does not make it around the first right hander, by about 10cm. If I lean it over considerably I can get it around with 5cm to spare. Not a lot of leeway for a new rider!!

    Then at the other end the follow-on left hander gets through without any lean at all with about 20cm to spare.. So thats probably why I have no problems with that one! I still dont know if my bike has more lock on a left turn than a right or if the box is designed like that to make the 2nd turn a little more forgiving. I guess next time I go for a practice I should try pushing my bike through the course in the opposite direction.

    Gives me the shits because at the basic ridersafe course on their bikes (the trail bike provided) I could do the u-turns without a problem on the first attempt!

    Id really prefer to do the course on my bike and learn some more relevant skills, but the uturns are starting to seem just too bloody difficult in the given space on my bike.

    Im contemplating borrowing a mates scooter, (No restricted licences in SA that I know of?) or using theirs (if thats possible?).

    Also open to other suggestions too.

  2. might get flamed for this...but, bikes turn sharper at low speed with counter balancing?

    case in point?

    or do a search on this site for tips...

    shit if people can do it on a Yamaha 650 cruiser, a Hornet should be fine...
  3. My hornet has brilliant steering lock.. But yes, it will turn sharper with a bit of lean.
  4. You guys need to be a little more explanatory for the sake of other noobs.
    With the way you said the above, it sounds like you are saying you go faster so that you have to lean the bike over more, and THAT tightens the turn (decreases the radius)

    However, i think you are meaning that you just tilt the bike over and counter-balance it by keeping your body upright, or even leaning out away from the turn. Also it's important to note, that this mothod is only used for low speed manouvering.
  5. mmm. well yes you said it all for me...
  6. I've been reading plenty of tips but to be honest haven't given the counter balancing a decent go on the course yet.
    So, it is normal to have to do a turn in a smaller radius than what the bike could physically achieve when upright? If so I guess it's simply a matter of me needing a lot more practice then!!
  7. If you don't feel that you are going to comfortably be able to do the turn on your bike, then i would suggest using theirs bikes on the day.

    However if you want to use yours, they will go through practices on all the test through the day and will give you tips on how to get through the turn on your bike. If you can't do it then thats all good. You will only lose a couple of points on the whole test.
  8. All quite right haha.
    1. The more a bike leans the sharper it turns.
    2. Under about thirty K's an hour the bike does not have much righting motion form the wheels and is hard to lean far.
    So we use the artificial righting motions we have at our disposal.
    We ride the rear brake against the throttle to use the righting motion of the rear brake and crank shaft. And we bend at the hips to stay upright or lean out a bit to use our own body as a counter balance. And we look up at where we want to go well before we are going that way.

    I have no idea what you ride so using you as counterbalance might be counterproductive as you might be on a cruiser and ground clearance might be an issue.
    If it is a cruiser I would suggest more rear brake and throttle action and not leaning out. I would actually move my ass over to the inside of the cruiser to help it turn sharper.
    But if you are having trouble already this maneuver might be a little bit scary at first.
  9. Thanks everyone for the replies.

    I tried counter balancing after work tonight and although I will need some more practice on it I think it will work. Still bloody tight though! I was sitting with my arse right off the seat on the outside of the turn and with the bike leaned over into the turn at full lock, with the clutch slipping, engine revving, and dragging the rear, and still only just getting around.

    Doing the advanced course on my own bike would be the best option, because I do actually want to learn something there, but I was worried that the u-turn was an instant fail type of maneuver and with the trouble I was having it was starting to seem near impossible.

    Will be calling up tomorrow to book, so I hope the waiting list isn't too long.
  10. When i did my Ridersafe test at the same course, i struggled to get around aswell. It was a confidence thing. On the turn that i thought would go outside the lines, i ended up putting my foot down. You lose points, but i still passed. The instant fail is the emergency stop test. You get up to 20 or 30 (it was a while ago) they put up a hand and you have to stop in a certain distance, in 1st gear then place your left foot on the ground.

    You practice it all on the day so no issues.
  11. Clutch slipping ???? No no no. I know some schools let you use it.
    But if you think about it. Using the clutch will take away any righting motion you have from the bike. It will feel like it wants to fall over.
    Ride along and get the bike to U turn speed using the rear brake, while still holding the throttle on.
    Use something as an eye marker. Look at it and don't look away till your riding by it the other way.
    You shouldn't need to move out on the seat unless your a big fella with a few extra pound. Bending at the waist should be enough. Think about keeping your body upright and nicely balanced.
    Let the bike tip all the way over but bend at the hips to keep your upper half erect.
    If the bike feels like it wants to fall you are not using enough throttle against the rear brake. Ride in a strait line and add more of both again till you are comfy with it and then try the U turn.
  12. Thanks Bretto. Will give that a try at the next opportunity! I was thinking that the crank had to be turning to be getting the righting motion, and the more the better, but obviously I had that bit wrong (for some reason was getting mixed up with gyroscopic rigidity). Think I need to read a bit more on motorcycle physics! Not that I'm thinking of that while riding.
  13. My advice is don't worry so much about getting it done in the box right now. Just practice in a car park until you can do nice, tight, low-speed, full lock figure eights. Do it over and over again. Use a bit of rear brake and friction zone and shift your weight to the outside of the seat. Look where you want to go (over shoulder).

    Then, on the day use their 225cc bikes. You will get around easy. Good luck.
  14. :/ yeah, nothing wrong with rear brake + clutch slip on really tight corners IMHO. Both of those things help remove driveline lash and the use of the clutch allows higher revs to be used = greater gyroscopic effect (or whatever you'd wanna call it) = more stability.

    Also much more forgiving way to adjust speed than with your right wrist directly affecting the speed, especially with a snappy-throttled EFI bike.
  15. It comes back to two different styles.
    One way of teaching is to use the steering lock. Keep the bike upright and feather the clutch to get the bike around tightly.
    I would say this is HARTS way.

    I prefer to drive the bike around and decrease the turning radius by lean and not lock.
    You achieve a tighter turning radius.
    Simple way to test it is to walk a bike around you upright on full lock or spin one around you with it leaning right over. It will always turn tighter in a lean.
    Yup it's scarier ha ha.
    But eventually in riding you are going to have to bank and crank to get out of trouble or though a corner you have fallen on too fast.
    I would rather find out if I can do it at a low speed than a high one.
    The theory is the same to get a bike right over at speed as it is to slow. We just don't have that gyroscopic effect at a low speed so we improvise.
  16. Brettos could you sum up where the righting force comes from when you do apply the engine torque hard agains the rear brake?

    I've done a little research on the net but it seems even the experts don't agree I much when it comes to certain bits of cycle dynamics.

    I understand gyroscopic rigidity from the crank revving but that is stability only not a righting force, and I'm quite interested in why power against brake works.

    A link would suffice if it's too long winded!

  17. Quite simply the brakes.
    They have a huge righting affect. The front dangerously.
    The rear not so much as it is only one and a small single or two piston caliper to boot.
    So the righting affect is not as strong.
    You don't choose a rear brake for strength, but for feel. You only want enough strength from it to hold the bike on its intended lean angle.
    For me the cranks affect is more slow speed strait line work where you have the availability of feathering the clutch.
    When I do a U turn I want to be pushing that bar down. Not trying to hold the whole bike up while sitting on it. The physics there are mind boggling.
  18. I have no idea how that brake/righting effect could possibly work the way you are describing it. The righting affect of applying the brakes is a different animal to some affect that is meant to happen from driving the engine against a braked rear wheel.

    But the idea of clutch feathering is entirely independent of whatever method you want to use to make a tight u-turn, be it upright or counter-leaning or whatever.
  19. I wish I could explain the physics of it.
    The crank has as much righting movement as it's own weight and work rate. RPM.
    So while it does have a certain amount of righting motion. It's not that much.
    What's the circumference of a rear brake? 100 150 mm.
    Ever try a 100mm grinder? Imagine something holding resistance against that.
    You can feel the effect when you hold one. They will work at an angle. But don't like to be waved around. And that's just with a light wheel on it.
    Add resistance and it would sit right up. Unless it was only a little resistance. A little bit of help.
  20. Oh okay, yes I understand what you are saying. Right so yes it is a different mechanism to the righting action that occurs due to the geometry of the wheels when braking.

    Don't understand enough physics to know whether it's correct or not but I certainly see what you're saying, ta.