|
|
| Author |
Message |
| eifion |
This post is not being displayed .
|
eifion
Nova Slayer
Joined: 13 Sep 2006
Karma :  
|
 Posted: 18:35 - 26 Oct 2014  Post subject: How to deal with tightening bends? |
 |
|
Reason I ask is this:
I was joining the A34 today from the B430 to head south on the A34:
https://goo.gl/maps/A8Moi
Now as you can see the slip road curls round in a nice constant curve, then suddenly snaps round on you right at the last minute before the acceleration lane.
The mantra from instructors is you do not brake / close the throttle on a corner - you should enter the bend at such a speed that you don't need to slow down, constant speed through bend and accelerate out.
Thing is if I go round the entire slip road at a speed I'm comfortable with for the last tight bit I'll have a tail of annoyed cars behind me, who are trying to get round that bit as fast as possible due to the short acceleration lane. So it's always a bit of a compromise. Went round there today, got to the tightening bit, increased lean angle and still ran a little wide into the white hatched area. And this is a junction I know very well - though today was the first time on a bike - and it still caught me out. How do you deal with something like this unexpected?
Could I have leant over even more? Probably, but I'd be interested in getting some thoughts. |
|
| Back to top |
   |
You must be logged in to rate posts |
|
 |
| Val |
This post is not being displayed .
|
Val
World Chat Champion
Joined: 03 Nov 2012
Karma :  
|
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| weasley |
This post is not being displayed .
|
weasley
World Chat Champion
Joined: 16 Oct 2010
Karma : 
|
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| Rogerborg |
This post is not being displayed .
|
Rogerborg
nimbA
Joined: 26 Oct 2010
Karma :
|
| Posted: 22:23 - 26 Oct 2014 Post subject: Re: How to deal with tightening bends? |
|
|
| eifion wrote: | The mantra from instructors is you do not brake / close the throttle on a corner - you should enter the bend at such a speed that you don't need to slow down, constant speed through bend and accelerate out. |
Why do they say that? Bunch of know-nothing old geezers. 
| eifion wrote: | Went round there today, got to the tightening bit, increased lean angle and still ran a little wide into the white hatched area. |
Oh, right, because that.
Don't be a pussy, ride according to what's in front of you, not what's behind.
____________________
Biking is 1/20th as dangerous as horse riding.
GONE: HN125-8, LF-250B, GPz 305, GPZ 500S, Burgman 400 // RIDING: F650GS (800 twin), Royal Enfield Bullet Electra 500 AVL, Ninja 250R because racebike |
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| matto |
This post is not being displayed .
|
matto
Crazy Courier
Joined: 18 Apr 2012
Karma : 
|
| Posted: 22:25 - 26 Oct 2014 Post subject: |
|
|
As above, if you need to brake in a corner you need to brake, it's way better than running into something 
As for the slip road; apply some more pressure downwards on the inside bar, make sure your outside leg is right up to the side of the tank; stick your inside knee out and look where you want the bike to go. You will be surprised what the bike is capable of. |
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| arry |
This post is not being displayed .
|
arry
Super Spammer
Joined: 03 Jan 2009
Karma : 
|
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| Pigeon |
This post is not being displayed .
|
Pigeon
World Chat Champion
Joined: 27 Sep 2012
Karma :
|
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| Val |
This post is not being displayed .
|
Val
World Chat Champion
Joined: 03 Nov 2012
Karma :
|
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| FlightRisk |
This post is not being displayed .
|
FlightRisk
Spanner Monkey
Joined: 08 Jul 2014
Karma : 
|
| Posted: 00:03 - 27 Oct 2014 Post subject: |
|
|
Check out the links advice and links in this thread especially the links down the bottom of the page:
https://www.bikechatforums.com/viewtopic.php?t=295963&postdays=0&postorder=asc&start=25
These ones:
Very educational. 
Snapping the throttle closed abruptly could be bad but that doesn't mean you shouldn't use it to help adjust your trajectory. Braking makes the bike stand up (and run wide), but accelerating makes the bike run wide. Mental, huh? You should generally be rolling on through a turn so what you can do is ease off the roll on, countersteer/lean more to the inside, look where you want to go and the bike WILL come round.
That though is two bends really isn't it? It would probably help to chop it up in your mind and say 'Right that's wide turn 1 done, now set up for turn 2.'. And fuck the cars behind.
____________________
Honda CB500S |
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| wr6133 |
This post is not being displayed .
|
wr6133
World Chat Champion
Joined: 31 Dec 2013
Karma : 
|
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| barrkel |
This post is not being displayed .
|
barrkel
World Chat Champion
Joined: 30 Jul 2012
Karma : 
|
Posted: 11:01 - 27 Oct 2014  Post subject: |
|
|
| Celt500 wrote: | Snapping the throttle closed abruptly could be bad but that doesn't mean you shouldn't use it to help adjust your trajectory. Braking makes the bike stand up (and run wide), but accelerating makes the bike run wide. |
Braking with the front makes the bike stand up because front braking force causes the front wheel to steer into the ground, whichever way "into" means for whichever way you're leaned. And steering into the ground when leaned over will countersteer the bike upright.
Braking with the rear will mostly just make you go slower. All things equal, you can turn tighter when going slower. Getting off the throttle will do the same thing.
But too much of either brake and you'll run out of grip, since a bunch of grip is already used by cornering forces. And it's easy to lose grip with the rear, especially on a sportsbike. Slowing will shift weight to the front, meaning less grip on the rear. And sportsbike weight is front loaded to begin with.
Best thing is to not go in so fast. Don't ride at your limit, especially through a corner you don't know and can't see through, so you have some comfortable extra lean left, and hold off accelerating through the bend until you can see through the bend.
After that it's a matter of experience. Experience will let you read bends better so that you can see through them earlier, looking at hedgerows / telegraph poles etc. Better positioning will let you see through the bend sooner (and knowing when not to position wider will keep you safe). And experience will increase the amount of comfortable lean angle you've got left.
One point of caution about looking further ahead, e.g. for treelines and telegraph poles; don't do this until you're happy with what's immediately in front of you. A couple of times in the past I've zipped up to an immediate corner slightly faster than anticipated because I was consciously looking for clues further down the road.
____________________
Bikes: S1000R, SH350; Exes: Vity 125, PS125, YBR125, ER6f, VFR800, Brutale 920, CB600F, SH300x4
Best road ever ridden: www.youtube.com/watch?v=s2MhNxUEYtQ |
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| eifion |
This post is not being displayed .
|
eifion
Nova Slayer
Joined: 13 Sep 2006
Karma :
|
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| Taught2BCauti... |
This post is not being displayed .
|
Taught2BCauti...
World Chat Champion
Joined: 12 Jan 2012
Karma :
|
| Posted: 11:21 - 27 Oct 2014 Post subject: |
|
|
You are out of the first bend by the time you get to the T junction on the right - treat the next bend as a separate bend.
Watch the Keith Code video as suggested above.
____________________
Honda Varadero XL125(V8)
www.TheFutureIsHere.eu |
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| stinkwheel |
This post is not being displayed .
|
stinkwheel
Bovine Proctologist
Joined: 12 Jul 2004
Karma :
|
| Posted: 13:07 - 27 Oct 2014 Post subject: |
|
|
| barrkel wrote: |
Braking with the front makes the bike stand up because front braking force causes the front wheel to steer into the ground, whichever way "into" means for whichever way you're leaned. And steering into the ground when leaned over will countersteer the bike upright. |
More that people lean their weight on the bars as they brake. It's surprising how much braking you can do in a corner if you make sure you keep the bars for steering with. The level of grip you'll have at this time of year over two axis is another matter entirely.
@ OP. The way you deal with something unexpected is to expect it. You have to read the road. Look ahead more, the vanishing point of the corner will give you a lot of warning that it is going to tighten up on you. Fence/tree/hedge lines will also tend to follow the road (although not always). Position yourself to the outside of corners to get a bettrer view through them. You should know if a corner is tightening before it is likely to become an issue. If you didn't, you were eithergoing too fast or were positioned in the wrong place.
The fact is though, this was not unexpected, you already knew this was a decreasing radius corner. Your problem was the mechanics of geting round it.
Your throttle is your primary means of controlling your speed, it works both ways and is entirely analogue, smoothness and accurate varying of your throttle position will see you progressing smoothly and rapidly through corners. Being in a lower gear will help with the throttle responsiveness.
Constant speed through a bend is nonsense so I don't know where you got that. For constant radius curves the mantra was always "In like a lamb, out like a lion.". So decellerate into the corner then accelerate smoothly and progressively through the corner until the exit. If a corner is varying in its radius, of course your speed is going to have to vary with it and it should vary smoothly and progressively. Ideally, by using the throttle, not the brakes. If you're pushing the limits of your machine, the revs are up and that throttle hand is never still.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles. |
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| barrkel |
This post is not being displayed .
|
barrkel
World Chat Champion
Joined: 30 Jul 2012
Karma :
|
| Posted: 15:01 - 27 Oct 2014 Post subject: |
|
|
| stinkwheel wrote: | | barrkel wrote: | Braking with the front makes the bike stand up because front braking force causes the front wheel to steer into the ground, whichever way "into" means for whichever way you're leaned. And steering into the ground when leaned over will countersteer the bike upright. |
More that people lean their weight on the bars as they brake. |
The effect of straightening up when braking with the front in a corner is mostly caused by the width of the front wheel, holding lean angle constant. The wider the front wheel, the more pronounced the effect, because the edge of the tyre - the bit in contact with the road - has more leverage over the steering axis.
| Quote: | It's surprising how much braking you can do in a corner if you make sure you keep the bars for steering with. |
You'll need to actively steer against the countersteer effect of the braking force. It is much easier with narrow wheels.
But in a panic, it's easy to brake too hard and straighten up. I think it's better to learn to bleed off more speed before the corner, and simply not use the front in a corner.
____________________
Bikes: S1000R, SH350; Exes: Vity 125, PS125, YBR125, ER6f, VFR800, Brutale 920, CB600F, SH300x4
Best road ever ridden: www.youtube.com/watch?v=s2MhNxUEYtQ |
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| Pete. |
This post is not being displayed .
|
Pete.
Super Spammer
Joined: 22 Aug 2006
Karma :
|
| Posted: 15:25 - 27 Oct 2014 Post subject: |
|
|
If you're leaned and slightly turned then braking will try to articulate the bike at the headstock pivot. The more you brake, the more you're turned or the more you weigh - the more the effect of braking will be.
____________________
a.k.a 'Geri'
132.9mph off and walked away. Gear is good, gear is good, gear is very very good  |
|
| Back to top |
 |
You must be logged in to rate posts |
|
|
| RhynoCZ |
This post is not being displayed .
|
RhynoCZ
Super Spammer
Joined: 09 Mar 2012
Karma : 
|
| Posted: 16:16 - 27 Oct 2014 Post subject: |
|
|
When I do not know the road, I do one simple thing. Do not accelerate if you can not see the end of the bend.
If for some reason I went way too fast into the corner, where's no place for more lean angle, then I shut the throttle and gently apply brakes. If the bend gets too sharp, I straighten the bike and give it as much brake power as I can, then let go of the brakes and finish the turn.
The last variable, if we don't count in tyres, weather, traffic, dirt on the tar and so on, is the pure luck. But in 90% of cases you will be able to increase the lean angle and survive. Tyres outperform the rider nearly every time. You can ask me, my front brake gave up right in front of a corner, my first peg down on the ZXR.
Side info: I mostly ride on my favourite routes I know so well, I know how fast can I actually go where. So, I get into trouble only because of a technical failure or a hazard/weather/traffic situation. Keep it safe and don't speed everywhere.
____________________
'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor |
|
| Back to top |
| |
You must be logged in to rate posts |
|
 |
Old Thread Alert!
The last post was made 11 years, 250 days ago. Instead of replying here, would creating a new thread be more useful? |
 |
|
|
Help & FAQs
Search BCF
Members
Groups
Events Calendar
rating
rating