• Welcome to the forum website of the Vincent H.R.D. Owners Club.

    Should you have any questions relating to the Vincent H.R.D. Owners Club, or Vincent H.R.D. motorcycles in general, please contact Graham Smith, Online Forum Webmaster by calling 07977 001 025 or please CLICK HERE.

    You are unrecognised, and therefore, only have VERY restricted access to the many features of this forum website.

    If you have previously registered to use this forum website, you should log in now. CLICK HERE.

    If you have never registered to use this forum website before, please CLICK HERE.

Cadwell Park Jump

roy the mechanic

Well Known and Active Forum Website User
VOC Member
It's great entertainment, but it's not the quickest way. while the rear wheel is airborne it is not driving. Also ,it's difficult to line up for hall bends which follows.
 

Bill Thomas

Well Known and Active Forum Website User
VOC Member
I agree Roy, And I could not even lift the Front wheel !! Did you see that Josh Brookes, Take out one of our top blokes, Can't remember his name, Rats ! He was out of control a year or two ago, Cheers Bill
 

david bowen

Well Known and Active Forum Website User
Non-VOC Member
Cliff Brown, Georges brother use to tell us when the Cadwell special was on the start line before push start, he had a oil can with Ethylbenzene in it, and gave a few squirts into the Carb
 

davidd

Well Known and Active Forum Website User
VOC Member
It's great entertainment, but it's not the quickest way. while the rear wheel is airborne it is not driving. Also ,it's difficult to line up for hall bends which follows.

You are no doubt correct. I think it is interesting that when I was downhill racing on skis we were told the same thing. It was quite exciting to get airborne for 100 feet at 70 mph, but we were taught to "pre-jump" the lip in order to keep the skis on the snow as it was faster. So it seems it works for gravity propelled racing also. Pre-jumping simply required a quick snap to attention from a full tuck and then pulling your feet up to meet your torso in a full tuck. With luck, you jumped high enough that as you hit the lip or bump your legs would be at full compression and you would only be airborne for a few yards. Having missed the lip your skis would alight gently on the back side of the jump and remain in contact with the snow. It always worked well in theory.

David
 

BigEd

Well Known and Active Forum Website User
VOC Member
VOC Forum Website Moderator
It is a fact that while your rear wheel is in the air it can not be driving but I suspect that as these are some of the top Superbike riders in the world they would not be airborne if it gave them even a few thousandths of a second advantage over their rivals. The higher speed of approach up the hill probably gains more in time than is lost by shutting off a little to prevent a jump.
 

Bill Thomas

Well Known and Active Forum Website User
VOC Member
David B, I knew a Vin' racer who had a "NIP" , Sip, For his own tank !! Befor a race, It worked for him, He was always at the front !!, Cheers Bill.
 

davidd

Well Known and Active Forum Website User
VOC Member
It is a fact that while your rear wheel is in the air it can not be driving but I suspect that as these are some of the top Superbike riders in the world they would not be airborne if it gave them even a few thousandths of a second advantage over their rivals. The higher speed of approach up the hill probably gains more in time than is lost by shutting off a little to prevent a jump.

I always assumed this was not related to power, but at least in the gravity based racing it was due to aerodynamics. Once in the air it is difficult not to double or triple the frontal area that the racer is presenting. The tuck is always the most efficient position. I would be inclined to say the same thing about racing motorbikes. The tuck is the most efficient and when you tip the bike in the air you have increased the frontal area to include the bottom of the bike as well. So, I would suspect there is an aerodynamic penalty to the jump. It could be offset by an increase in entry speed, but it seems to me that there is always someone who can figure out how to enter faster and stay closer to the ground, which should provide an advantage. To add to the aerodynamic advantage, if the rider can stay close to the ground, he can then apply the throttle and get a benefit much longer, as Roy says.

I think you would have to examine lots of lap times to find the answer, but it would be interesting to know if the track record lap time was made with the bike in the air or closer to the ground. That would give a quick clue.
 

vibrac

Well Known and Active Forum Website User
VOC Member
Yes but anyone who looked at the background of the membership renewal sheet this year with Ben on it has to admit:
A Vincent looks good when its imitating a backwards wheelbarrow:D
 
Warning! This thread is more than 9yrs ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Top