UK Karting - Notice Board (General Karting) : Re: Is wheel lift only from turn-in till apex?

Notice Board (General Karting)

Re: Is wheel lift only from turn-in till apex?
Posted by 'itpro' on 21 Aug 2012 @ 16:42

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itproJoined: August 2001
Total Posts: 6
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Again, you are getting it!

Strictly, you don't NEED to 'lift' a wheel. All you need to do is REDUCE the downward pressure on that tyre enough to let it slide.

I don't know if anyone else has covered this ..... so:-

Try a trick. Place the kart on the ground and PUSH it with one finger. On a flat surface, that should be easy! Now, turn the steering wheel through a few degrees and try to push it...... One finger will NOT be enough!

This is caused by an effect you will have seen in your school days on the running track. You'll note that the INSIDE lane has a shorter distance to trave;l then the one nhext to it and the one with the LONGEST distance of travel is the OUTSIDE line. (note at end on Ackerman steering)

This is the same for the kart. Your INSIDE wheel has a shorter distance to travel than the outside wheel! However, your rear axle is LOCKED and both tyres MUST rotate at the same speed! In a car, we have a differential gear system that lets the two sides rotate at different speeds. On a kart, that's illegal!

Therefore, when we turn the steering wheel, our two tyres are ALWAYS 'arguing' and that has two effects:-

1) when EVER the steering wheel is turned, the kart is SLOWING becasue of that 'drag' you felt trying to push the kart!

2) if your rear tyres manage to stay solidly in contact with the track, they will overwhelm the front tyres and simkly IGNORE your steering...... and force the kart STRAIGHT ON (understeer)

Number 2) is why we have HIGH caster angles compared to cars..... this lets the kart 'rotate' over the outer front tyre, reducing the grip of the INNER rear tyre. It can then rotate FASTER than it needs to (for the track surface) which allows the kart to TURN IN to the corner. This is the phase which gives us 'Turn In Understeer'. If the caster angle is too low or there's too MUCH weight over the rear (and other causes) the kart can develop 'turn-in-understeer'..... and simply 'scrub' wide on the corner

That implies there is ANOTHER phase...... AFTER the initial turn in...... and there IS!!!!!

The second twist is harder to understand and LOADS of people will tell you I am WRONG about this..... I am NOT!

Karts can corner FASTEST if all four wheels are being used at once. That's so obvious as to sound daft..... However, we know that, the kart will 'drag' if there is ANY steering lock applied (and 4 wheels are on the ground).

That's a dichotomy! How can we keep all four tyres in contact with the track WITHOUT getting 'drag' because of our lack of diff.....?

That's easy...... we simply let the REAR of the kart slide enough....... but not TOO much!

In a kart, after the turn in phase and before the exit phase... the IDEAL 'angle' for the kart is so that the kart is EXACTLY at a tangent to the corner.... i.e., the FRONT wheel should be ON the 'ideal line' but the REAR wheels should be sliding. The PERFECT angle is when the steering remains EXACTLY in the 'dead ahead' position.....

Now...... if the driver is going too slowly (for that corner), the rear end will grip and he'll have to apply more steering which will cause DRAG. If he's going too FAST for that corner, the rear of the kart will go WELL past 'dead ahead' with the driver needing to apply opposite lock to AVOID a spin! That TOO will cause DRAG!

Basically, :-

1) The turn in phase is done using the steering
2) once the turn has started, he should REDUCE the lock until the steering is DEAD AHEAD and he should maintain that position by use of throttle, weight shift, brakes etc... but NOT using the steering!

Now..... I am FULLY aware that sounds impossible.......however..... just WATCH the QUICK GUYS...... you will note that MID corner..... they have ZERO lock applied!

Here's a video of Schumacher, et al. Watch them ALL in the middle of a LONG corners...... no lock WHATSOVER!

http://www.youtube.com/watch?v=f7Hoqw0oHdg

That's TWO of the corner phases covered. I think there are are 5 phases...... Jackie Stewart says there are are Seven! He'll be right and I'll be wrong!

Ian

************************

Ackerman steering. People will tell you a LOAD OF TRIPE about this. ALL karts have 'Ackerman Steering' no matter WHAT anyone tells you. What it describes is the effect that the inside FRONT wheel needs to 'point' more sharply than the OUTSIDE front wheel for the reasons given in the 'running track example'. If you had two bikes on a running track, the one of the INSIDE would need to turn the handlebars further to stay in lane than the one on the OUTSIDE lane. That's why your inner wheel turns more sharply than the outside wheel. The 'Ackerman Angle' describes that effect and ALL karts have it to a greater or lesser effect. It's the AMOUNT by which the inner turn more or less that can be adjusted!

Message Thread:

Lifting inside wheel - beginner's guide by 'RedDragonRacing' (15 Aug 2012 @ 10:17)

Re: Lifting inside wheel - beginner's guide by 'd-i-y71' (15 Aug 2012 @ 14:35)

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Re: Lifting inside wheel - beginner's guide by 'Brasic' (15 Aug 2012 @ 22:43)

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Re: Lifting inside wheel - beginner's guide by 'RedDragonRacing' (16 Aug 2012 @ 12:37)

Re: Lifting inside wheel - beginner's guide by 'Chris34' (16 Aug 2012 @ 15:38)

Re: Lifting inside wheel - beginner's guide by 'BFD' (16 Aug 2012 @ 17:46)

Re: Lifting inside wheel - beginner's guide by 'michaelg36' (16 Aug 2012 @ 23:34)

Re: Lifting inside wheel - beginner's guide by 'BFD' (17 Aug 2012 @ 6:51)

Re: Lifting inside wheel - beginner's guide by 'RedDragonRacing' (17 Aug 2012 @ 7:59)

Re: Lifting inside wheel - beginner's guide by 'PoppaAl' (17 Aug 2012 @ 9:09)

Re: Lifting inside wheel - beginner's guide by 'Thebrick' (17 Aug 2012 @ 10:26)

Re: Lifting inside wheel - beginner's guide by 'Danlee' (17 Aug 2012 @ 11:31)

Re: Lifting inside wheel - beginner's guide by 'Chris34' (17 Aug 2012 @ 12:32)

Re: Lifting inside wheel - beginner's guide by 'Traxtar' (17 Aug 2012 @ 12:53)

Re: Lifting inside wheel - beginner's guide by 'd-i-y71' (17 Aug 2012 @ 13:02)

Re: Lifting inside wheel - beginner's guide by 'RedDragonRacing' (17 Aug 2012 @ 13:10)

Re: Lifting inside wheel - beginner's guide by 'RedDragonRacing' (17 Aug 2012 @ 13:35)

Re: Lifting inside wheel - beginner's guide by 'd-i-y71' (17 Aug 2012 @ 13:53)

Errrr...... well...... by 'itpro' (17 Aug 2012 @ 13:04)

Re: Errrr...... well...... by 'RedDragonRacing' (17 Aug 2012 @ 13:25)

Re: Errrr...... well...... by 'michaelg36' (17 Aug 2012 @ 13:53)

Re: Errrr...... well...... by 'BFD' (17 Aug 2012 @ 14:24)

Re: Errrr...... well...... by 'itpro' (17 Aug 2012 @ 14:41)

Re: Errrr...... well...... by 'itpro' (17 Aug 2012 @ 14:52)

Re: Errrr...... well...... by 'RedDragonRacing' (17 Aug 2012 @ 20:35)

Re: Errrr...... well...... by 'BFD' (17 Aug 2012 @ 21:05)

Red... by 'itpro' (18 Aug 2012 @ 0:57)

Re: Errrr...... well...... by 'RedDragonRacing' (20 Aug 2012 @ 9:50)

Re: BFD by 'Attack2001' (18 Aug 2012 @ 2:11)

Re: BFD by 'BFD' (18 Aug 2012 @ 18:55)

Re: BFD by 'Aquila' (19 Aug 2012 @ 22:01)

Re: BFD by 'BFD' (19 Aug 2012 @ 22:38)

Re: BFD by 'BFD' (19 Aug 2012 @ 23:27)

Come on BFD.......... by 'itpro' (21 Aug 2012 @ 0:05)

Re: BFD by 'Aquila' (20 Aug 2012 @ 10:30)

Red.... by 'itpro' (17 Aug 2012 @ 14:36)

Re: Red.... by 'RedDragonRacing' (17 Aug 2012 @ 20:11)

re: itpro. wrong wrong wrong wrong wrong by 'BFD' (17 Aug 2012 @ 21:18)

re: itpro. wrong wrong wrong wrong wrong by 'itpro' (18 Aug 2012 @ 0:40)

re: itpro. wrong wrong wrong wrong wrong by 'richpudd2003' (19 Aug 2012 @ 23:51)

OK Red... I apologise for the idiots, though! by 'itpro' (18 Aug 2012 @ 0:34)

Re: Classic! by 'PoppaAl' (18 Aug 2012 @ 10:09)

Re: OK Red... I apologise for the idiots, though! by 'markmorton' (18 Aug 2012 @ 17:38)

Re: OK Red... I apologise for the idiots, though! by 'RedDragonRacing' (20 Aug 2012 @ 9:57)

Re: Red.... by 'RedDragonRacing' (27 Aug 2012 @ 9:58)

Re: Red.... by 'John' (28 Aug 2012 @ 8:14)

Re: Red.... by 'itpro' (30 Aug 2012 @ 1:46)

Re: Red.... by 'BFD' (30 Aug 2012 @ 6:48)

Re: Red.... by 'itpro' (30 Aug 2012 @ 17:42)

Re: Red.... by 'BFD' (30 Aug 2012 @ 20:57)

Re: Red.... by 'BFD' (30 Aug 2012 @ 21:04)

Re: Red.... by 'itpro' (31 Aug 2012 @ 0:48)

Re: Red.... by 'BFD' (31 Aug 2012 @ 7:15)

Re: Red.... by 'itpro' (31 Aug 2012 @ 11:37)

Re: Red.... by 'BFD' (31 Aug 2012 @ 18:24)

Re: Red.... by 'Aquila' (31 Aug 2012 @ 18:28)

Re: Red.... by 'itpro' (02 Sep 2012 @ 1:14)

Re: Red.... by 'Traxtar' (02 Sep 2012 @ 20:19)

Re: Red.... by 'BFD' (02 Sep 2012 @ 22:14)

Re: Red.... by 'Traxtar' (02 Sep 2012 @ 22:24)

Traxtar..... by 'itpro' (03 Sep 2012 @ 1:36)

Re: Traxtar..... by 'BFD' (03 Sep 2012 @ 7:51)

Re: Traxtar..... by 'sawf' (03 Sep 2012 @ 10:28)

Re: Red.... by 'PaulMRotax' (31 Aug 2012 @ 7:58)

Re: Red.... by 'John' (31 Aug 2012 @ 8:37)

Re: Red.... by 'PaulMRotax' (31 Aug 2012 @ 11:19)

Re: Red.... by 'itpro' (31 Aug 2012 @ 11:31)

Re: Red.... by 'PaulMRotax' (31 Aug 2012 @ 11:35)

Re: Red.... by 'itpro' (31 Aug 2012 @ 11:39)

Re: Red.... by 'PaulMRotax' (31 Aug 2012 @ 11:51)

Re: Red.... by 'itpro' (31 Aug 2012 @ 12:27)

Re: Red.... by 'PaulMRotax' (31 Aug 2012 @ 12:30)

Re: Errrr...... well...... by 'NJB' (23 Aug 2012 @ 17:11)

Re: Errrr...... well...... by 'RedDragonRacing' (27 Aug 2012 @ 9:47)

Re: Errrr...... well...... by 'Andy99' (30 Aug 2012 @ 9:56)

Re: Errrr...... well...... by 'RedDragonRacing' (30 Aug 2012 @ 10:26)

Re: Errrr...... well...... by 'Liam' (21 Aug 2012 @ 14:18)

Re: Errrr...... well...... by 'itpro' (21 Aug 2012 @ 15:57)

Re: Errrr...... well...... by 'Liam' (21 Aug 2012 @ 20:54)

Re: Lifting inside wheel - beginner's guide by 'SimonS' (18 Aug 2012 @ 12:13)

Re: Lifting inside wheel - beginner's guide by 'RedDragonRacing' (20 Aug 2012 @ 9:36)

Re: Lifting inside wheel - beginner's guide by 'itpro' (20 Aug 2012 @ 10:43)

Re: Lifting inside wheel - beginner's guide by 'SimonS' (21 Aug 2012 @ 1:49)

Re: Lifting inside wheel - beginner's guide by 'itpro' (21 Aug 2012 @ 2:20)

Re: Lifting inside wheel - beginner's guide by 'd-i-y71' (21 Aug 2012 @ 12:53)

Is wheel lift only from turn-in till apex? by 'RedDragonRacing' (21 Aug 2012 @ 13:18)

Re: Is wheel lift only from turn-in till apex? by 'itpro' << You are here!

Re: Is wheel lift only from turn-in till apex? by 'Liam' (21 Aug 2012 @ 20:43)

Re: Is wheel lift only from turn-in till apex? by 'itpro' (21 Aug 2012 @ 20:51)

Re: Is wheel lift only from turn-in till apex? by 'Liam' (21 Aug 2012 @ 21:08)

Re: Is wheel lift only from turn-in till apex? by 'Traxtar' (21 Aug 2012 @ 22:49)

Re: Is wheel lift only from turn-in till apex? by 'Liam' (21 Aug 2012 @ 23:56)

Re: Is wheel lift only from turn-in till apex? by 'richpudd2003' (22 Aug 2012 @ 0:36)

Re: Is wheel lift only from turn-in till apex? by 'Liam' (22 Aug 2012 @ 2:09)

Re: Is wheel lift only from turn-in till apex? by 'itpro' (22 Aug 2012 @ 10:34)

Re: Is wheel lift only from turn-in till apex? by 'richpudd2003' (22 Aug 2012 @ 11:47)

Re: Is wheel lift only from turn-in till apex? by 'Traxtar' (22 Aug 2012 @ 12:20)

Re: Is wheel lift only from turn-in till apex? by 'RedDragonRacing' (22 Aug 2012 @ 10:37)

Re: Possibly better video to highlight steer angle by 'NikG' (22 Aug 2012 @ 15:16)

Re: Possibly better video to highlight steer angle by 'Traxtar' (22 Aug 2012 @ 15:23)

Re: Possibly better video to highlight steer angle by 'NikG' (22 Aug 2012 @ 15:38)

Re: Lifting inside wheel - beginner's guide by 'd-i-y71' (20 Aug 2012 @ 12:40)

Perfect weigth distribution? by 'RedDragonRacing' (20 Aug 2012 @ 10:03)

Re: Perfect weigth distribution? by 'itpro' (20 Aug 2012 @ 11:10)

Re: Perfect weigth distribution? by 'RedDragonRacing' (21 Aug 2012 @ 12:27)

Re: Perfect weigth distribution? by 'itpro' (21 Aug 2012 @ 16:02)

Re: Perfect weigth distribution? by 'Traxtar' (21 Aug 2012 @ 17:21)

Re: Perfect weigth distribution? by 'BFD' (21 Aug 2012 @ 18:53)

Re: Perfect weigth distribution? by 'Farrang' (21 Aug 2012 @ 19:16)

Re: Perfect weigth distribution? by 'RedDragonRacing' (22 Aug 2012 @ 10:51)

Re: Perfect weigth distribution? by 'Aquila' (21 Aug 2012 @ 22:09)

good to see a lively debate.... by 'NJB' (22 Aug 2012 @ 8:07)

Re: good to see a lively debate.... by 'itpro' (22 Aug 2012 @ 10:37)

Re: good to see a lively debate.... by 'BFD' (22 Aug 2012 @ 18:01)

Re: good to see a lively debate.... by 'EtheT' (24 Aug 2012 @ 15:55)

Re: good to see a lively debate.... by 'BFD' (24 Aug 2012 @ 17:28)

Re: good to see a lively debate.... by 'richpudd2003' (24 Aug 2012 @ 18:03)

Re: good to see a lively debate.... by 'BFD' (24 Aug 2012 @ 23:08)

Re: good to see a lively debate.... by 'Traxtar' (25 Aug 2012 @ 0:46)

Re: Lifting inside wheel - beginner's guide by 'RedDragonRacing' (01 Oct 2012 @ 15:49)

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