stevie_350z Posted November 23, 2006 Share Posted November 23, 2006 I followed the link to the Ride Drive people and was browsing through their tips when I spotted this: “I have had wider wheels and tyres fitted to my car to give me more grip.†Quote Link to comment Share on other sites More sharing options...
rickya Posted November 23, 2006 Share Posted November 23, 2006 IMO: I think that chap is getting pressure & grip mixed up. Yes your pounds per sq inch presseure is increasing with narrower tyres but that does not mean grip. Whereas with wider tyres the surface area in contact with the ground is greater & hence more friction & more grip. Quote Link to comment Share on other sites More sharing options...
stevie_350z Posted November 23, 2006 Author Share Posted November 23, 2006 I thought I'd post it to see what reaction it got... it seems to make sense that bigger tyres = more grip, esp when you look at the back of a 911 with those fat tyres they have, but... is there anyway to prove it? Quote Link to comment Share on other sites More sharing options...
monkfish Posted November 23, 2006 Share Posted November 23, 2006 I thought I'd post it to see what reaction it got... it seems to make sense that bigger tyres = more grip, esp when you look at the back of a 911 with those fat tyres they have, but... is there anyway to prove it? Put a set of wheels from a Fiat Panda on an F1 car? Quote Link to comment Share on other sites More sharing options...
Removed Posted November 23, 2006 Share Posted November 23, 2006 don't let me post on this issue again... I'll have a word with my instructor about this and argue the case my Italian race engineer friend sustains (which you can find on this forum, somewhere) here's your scientific proof http://www.350z-uk.com/forum/viewtopic ... t=miraglio Quote Link to comment Share on other sites More sharing options...
Chesterfield Posted November 23, 2006 Share Posted November 23, 2006 As I am very curious of any physics type questions (the plane on a runway one keeps popping up every now and then).. I did some digging. It seems there is a whole world of debate out there about this very issue - even physics forums have had debates on the subject.. Ive found the follwoing which are quite informative: http://www.madsci.org/posts/archives/no ... .Ph.r.html http://www.physicsforums.com/archive/in ... 31381.html http://www.pistonheads.com/gassing/topi ... h=&t=78848 I havent read all of the stuf, but they seem informative for anyone wanting to read further on the subject. Now if only someone could tell me if the plane actually could take off, that would be great. Quote Link to comment Share on other sites More sharing options...
Sarnie Posted November 23, 2006 Share Posted November 23, 2006 Now if only someone could tell me if the plane actually could take off, that would be great. Explain. What conundrum are you thinking of? Quote Link to comment Share on other sites More sharing options...
Removed Posted November 23, 2006 Share Posted November 23, 2006 the explanation posted on the first post doesn't take into any consideration, object in motion, which cars are, and friction! Cars just don't stand there, do they? they move! and a whole host of new forces come into play then Quote Link to comment Share on other sites More sharing options...
stevie_350z Posted November 23, 2006 Author Share Posted November 23, 2006 Further down the article ( http://www.ridedrive.co.uk/tipoffs03b.htm ) more about his thinking: The heavier the vehicle the more momentum it has, but the heavier the vehicle the greater the down-force there is transmitted through the tyres to the road giving a better braking effect. The extra weight is pushing down on the road more, but it is also pushing forward by more. Put extra wheels on to make more surface area touch the ground and the weight is spread over a larger area and becomes less at any given pin-point cancelling out any advantage that you think you would have had. Take a 28-tonne 4-wheeled vehicle and a 28-tonne solid block of tyre rubber and each will slide for the same distance from the same speed on the same coefficient of friction road surface. Quote Link to comment Share on other sites More sharing options...
Pingu2 Posted November 23, 2006 Share Posted November 23, 2006 original article = bollocks.. vertical load on tyres not linearly related to horizontal force required to overcome friction (specially given uneven surface of road!).. Quote Link to comment Share on other sites More sharing options...
monkfish Posted November 23, 2006 Share Posted November 23, 2006 What's the plane on the runway question????? Quote Link to comment Share on other sites More sharing options...
Chesterfield Posted November 23, 2006 Share Posted November 23, 2006 Its here: http://www.350z-uk.com/forum/viewtopic.php?t=1080 Still cant make my mind up. But best to post about that one on there... Quote Link to comment Share on other sites More sharing options...
ir_fuel Posted November 23, 2006 Share Posted November 23, 2006 The thing to consider too is that rubber heats up and deforms when accelerating. Quote Link to comment Share on other sites More sharing options...
ir_fuel Posted November 23, 2006 Share Posted November 23, 2006 original article = bollocks.. vertical load on tyres not linearly related to horizontal force required to overcome friction (specially given uneven surface of road!).. And how is it related then? Thing is, if we simplify (which we shouldnt) that friction is independent of surface, as long the weight stays the same. Overcoming the friction of something on a table by applying force until it slides ( == wheelspin) is independent of the contact surface of the object. It is dependent on the material the object is made of and its weight. Quote Link to comment Share on other sites More sharing options...
monkfish Posted November 23, 2006 Share Posted November 23, 2006 Its here: http://www.350z-uk.com/forum/viewtopic.php?t=1080 Still cant make my mind up. But best to post about that one on there... Nick U is absolutely correct. If, as the question states, the conveyor belt maps and matches the speed of the wheels in the opposite direction, then the aircraft will be going nowhere. It will be sitting stationary with the wheels turning. Zero airspeed over the wings = zero lift. An aircraft gets up to takeoff speed by using engine thrust and rolling on the wheels until it has enough airspeed to not require contact with the earth. You'll notice that sometimes when you're flying, a pilot will advance his engines to full power or damn near it before the take-off roll, then sit on the brakes for a while. The aircraft goes nowhere. (I used to do the same when I did engine runs for the aircraft company I worked for) This is exactly the same effect that you have with the conveyor belt working in the opposite direction. It's all about stopping the aircraft accelerating on the wheels and getting sufficient airspeed to generate the lift required for takeoff. Even with aircraft as powerful as fighter jets that cannot be held on the brakes at full power, if the first tiny bit of acceleration (rotation of the wheels) is cancelled out by and then matched by a conveyor belt running in the opposite direction, the aircraft will not move forward, will not accelerate, will remain stationary and will not generate airspeed and lift. Actually, I'd love to see a conveyor belt that could match the wheel speed that a fighter jet on reheat would generate. Or indeed landing gear that could take it!! Quote Link to comment Share on other sites More sharing options...
stevie_350z Posted November 23, 2006 Author Share Posted November 23, 2006 So when did a plane ever move because of its wheels? What are those big engines stuck to the wing for - show? It would take off, and its wheels would be spinning twice as fast. Quote Link to comment Share on other sites More sharing options...
Removed Posted November 23, 2006 Share Posted November 23, 2006 NO LIFT! Quote Link to comment Share on other sites More sharing options...
stevie_350z Posted November 23, 2006 Author Share Posted November 23, 2006 hehehehhe! stay calm, Val! LOL! I bet you're shouting at the screen! Quote Link to comment Share on other sites More sharing options...
Removed Posted November 23, 2006 Share Posted November 23, 2006 nearly Quote Link to comment Share on other sites More sharing options...
monkfish Posted November 23, 2006 Share Posted November 23, 2006 Stevie, if it was anyone other than you (or maybe Sarnie too) I'd be not only shouting at the screen, but I'd be giving it Chuck Norris style roundhouse kicks. ........................you are joking, right? Quote Link to comment Share on other sites More sharing options...
stevie_350z Posted November 23, 2006 Author Share Posted November 23, 2006 Yeah baby! I'm in a trouble-causing mood today... I'll be back to my normal self tomorrow... whatever that is... Quote Link to comment Share on other sites More sharing options...
Emperor Ming Posted November 23, 2006 Share Posted November 23, 2006 So when did a plane ever move because of its wheels? What are those big engines stuck to the wing for - show? It would take off, and its wheels would be spinning twice as fast. Stevie Ming here AGREEING with you. Wheels on a fighter just turn. There is no drive. They in theory actually SLOW an aircrafts take off as they generate both heat and friction there by initially slowing forward motion. Rotating wheels have no effect on lift. As you rightly say the plane would still move forwards and the wheels would just turn twice as fast!! The thrust of an engine is on the air behind it not the ground below it! If the theory of conveyor belt and aircraft held true then a Harrier jump jet would never fly!! It goes up. Stops, and then goes forwards with no contact with the floor! Ming the Thoughtful Quote Link to comment Share on other sites More sharing options...
stevie_350z Posted November 23, 2006 Author Share Posted November 23, 2006 I've always loved you, Ming, you know that don't you... BTW - did you post pics of your polished plenum? (good job I've got my teeth in) Quote Link to comment Share on other sites More sharing options...
Emperor Ming Posted November 23, 2006 Share Posted November 23, 2006 I've always loved you, Ming, you know that don't you... BTW - did you post pics of your polished plenum? (good job I've got my teeth in) ?????????????????Polished plenum ... poop. Purple plenum Pic Posting Person pleeeaaase!! Ming the Muddled Quote Link to comment Share on other sites More sharing options...
stevie_350z Posted November 23, 2006 Author Share Posted November 23, 2006 I've always loved you, Ming, you know that don't you... BTW - did you post pics of your polished plenum? (good job I've got my teeth in) ?????????????????Polished plenum ... poop. Purple plenum Pic Posting Person pleeeaaase!! Ming the Muddled Where's the pics then? I feel uncomfortable searching for a "purple plenum" Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.