stu999 Posted December 13, 2006 Posted December 13, 2006 QUOTE Remember that most bike boxes are constant mesh, so you can change without the clutch provided that you are not accelerating or braking hard at the time. Most car boxes are constant mesh too. And you can aslo change gear without the clutch. It just takes a little more 'balance'... QUOTE Locking the rears on a downshift is due to not getting the revs to match the layshaft/roadspeed and has nothing to do with heel and toe or double declutching. A bit of heel and toe will prevent this happening - if applied correctly... QUOTE You can double declutch without heel and toeing if you drive like the IAM tell you and get all your braking over with before you decide what gear you need to accelerate away from the hazard. The only real reason to use the 'double declutch' techinque is if you are driving something without any form of syncromesh. Pointless otherwise... QUOTE On a track and being the last of the late brakers, you need to stay on the brake pedal whilst you blip the throttle. IMHO this is useless if you do not bring the clutch up at the same time so that you spin the layshaft (CECs only for this bit) to save the synchro from having to match the speed of the two cogs that are about to engage. Point missed completely The idea of the 'blip' of the throttle is to bring the engine speed up. This is because when you are braking on the limit, the rear wheels have very little grip. It is possible (read likely) that lifting the clutch would actually cause the low revving engine to 'slow' the rear wheels, rather than the rear wheels overcome the inertia of the engine. The affect for the driver would be similar to yanking up the handbrake - not nice. The increase in engine revs helps to overcome the inertia, thus hopefully preventing the problem. The speed of the gearbox layshaft is of little concern! The bigger the motor, the greater the problem. V8's will do this on a damp day *just* by lifting the throttle sharply on occasion... Quote
JulianS Posted December 13, 2006 Posted December 13, 2006 Most car boxes are constant mesh too. And you can aslo change gear without the clutch. It just takes a little more 'balance'... I cracked the bone in my left leg in the 2001 Great North Run, and drove back to Manchester doing just this - a bit scary when I stopped to fill-up with fuel and had to hop to the counter past the plod! Quote
Morbius Posted December 14, 2006 Posted December 14, 2006 On a track and being the last of the late brakers, you need to stay on the brake pedal whilst you blip the throttle. IMHO this is useless if you do not bring the clutch up at the same time so that you spin the layshaft (CECs only for this bit) to save the synchro from having to match the speed of the two cogs that are about to engage. Point missed completely The idea of the 'blip' of the throttle is to bring the engine speed up. This is because when you are braking on the limit, the rear wheels have very little grip. It is possible (read likely) that lifting the clutch would actually cause the low revving engine to 'slow' the rear wheels, rather than the rear wheels overcome the inertia of the engine. The affect for the driver would be similar to yanking up the handbrake - not nice. The increase in engine revs helps to overcome the inertia, thus hopefully preventing the problem. The speed of the gearbox layshaft is of little concern! The bigger the motor, the greater the problem. V8's will do this on a damp day *just* by lifting the throttle sharply on occasion... The end result is the same, we just get there via different routes. Life is too short to waste shooting holes in the detail of your argument.. ...actually it isnt, I just deleted my original riposte because it would only show me up as a nit-picking tw@t (no change there, I hear from the back). Quote
V 8 Posted December 14, 2006 Posted December 14, 2006 Well Stu, I think you are spot on m8. Can't see the point in ddc as the inertia held in the input/layshaft is insignificant, not withstanding both legs going like bees wings at the same time DDC really useful in the old "crash" gearboxes, and when vehicle weight and gearbox/engine inertia was considerable. Lorries. buses, tractors etc. First time I drove the Flymo, Tom still owned it and the throttle was all wrong for me. H & T was almost impossible the way I do it. Needless to say, with the clutch it had in it, the first down change, braking hard into the hairpin at the club circuit at Cadwell.........boom tish...spun it completely round To be honest, I don't know how Tom drove it. The pedal was so sloppy, it was rubbing on the panelling in the footwell, so when rolling your foot over to it, you just forced it to bind more, and it wouldn't move. That bloke's a good driver!! With all the mods I've done to the car over the last 2 years....I still haven't managed to beat him anywhere Quote
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