richsimpson Posted April 30, 2007 Report Share Posted April 30, 2007 Did any one else notice a strange looking device on Crumpys forks in the GP. I thought at one stage it may be a camera but no shots were recorded from it on the night, and the 'device' was on both bikes when he changed them in his early race. Quote Link to comment Share on other sites More sharing options...
pirate paul Posted April 30, 2007 Report Share Posted April 30, 2007 I think its just the shock absorber, or whatever the technical term is. I noticed Bjarne is using them as well this year. Quote Link to comment Share on other sites More sharing options...
richsimpson Posted April 30, 2007 Author Report Share Posted April 30, 2007 I think its just the shock absorber, or whatever the technical term is. I noticed Bjarne is using them as well this year. <{POST_SNAPBACK}> Here is the only image I can find that shows the device, seems to have some sort of wire going to it? crumps bike click here Quote Link to comment Share on other sites More sharing options...
The Know Posted April 30, 2007 Report Share Posted April 30, 2007 Here is the only image I can find that shows the device, seems to have some sort of wire going to it? crumps bike click here <{POST_SNAPBACK}> Oh dear ! Quote Link to comment Share on other sites More sharing options...
Shalewhale Posted April 30, 2007 Report Share Posted April 30, 2007 Here is the only image I can find that shows the device, seems to have some sort of wire going to it? crumps bike click here <{POST_SNAPBACK}> If you're talking about the thing on the right hand leg of the forks, then its just part of the damping system I think. Can't see any wires, only the bottom of the fork covers????? Quote Link to comment Share on other sites More sharing options...
SCB Posted April 30, 2007 Report Share Posted April 30, 2007 It was there last year too. He's not the only rider with one either. Quote Link to comment Share on other sites More sharing options...
richsimpson Posted April 30, 2007 Author Report Share Posted April 30, 2007 Yeah, on the inside fork, the one with the orange gaiter on. Just below the frame covers. seems to have a wire going down the centre of it, but perhaps just the picture. The one below shows it from the wrong side but its just above and in front of the gaiter on that one. SCB you may well be right as th first image I think was from the 2006 season, didnt Jason have the yellow race jacket on Saturday? This may be clearer Quote Link to comment Share on other sites More sharing options...
Rob B Posted April 30, 2007 Report Share Posted April 30, 2007 Yes it is the shock absorber, Jason was the first person to start using them in the middle of 2005, had a conversation with him about it. It has a dial on the top of it which can be set to one of 50 damping settings. Sure he said they were about £800 each. Noticed most of the top riders have them now, they must think thats why he was so good last year, but it wasn't. Quote Link to comment Share on other sites More sharing options...
rusky Posted April 30, 2007 Report Share Posted April 30, 2007 Yes it is the shock absorber, Jason was the first person to start using them in the middle of 2005, had a conversation with him about it. It has a dial on the top of it which can be set to one of 50 damping settings. Sure he said they were about £800 each. Noticed most of the top riders have them now, they must think thats why he was so good last year, but it wasn't. <{POST_SNAPBACK}> Not sure Jason was the first, maybe the first for that particular brand ? I'm sure that Tony Rickardsson had been using similar devices by one of his sponsors, Ohlins for sevaral years now. Whether they were as complex as Jason's I'm not sure Quote Link to comment Share on other sites More sharing options...
f-s-p Posted April 30, 2007 Report Share Posted April 30, 2007 For what I know, it keeps the pressure in the absorber. So when the front lifts, it's pushes the fork down, so that the front wheel stays on the track longer. So for giving more/longer steering as the bike would otherwise lose control regarding the front wheel. Excatcly the same that AJ was after with his black carbon fork. Only cheaper... Quote Link to comment Share on other sites More sharing options...
SCB Posted May 2, 2007 Report Share Posted May 2, 2007 Just noticed Scott Nicholls was using the same device at Swindon. No idea if he has used it elsewhere. Quote Link to comment Share on other sites More sharing options...
Guest Donsking Posted May 3, 2007 Report Share Posted May 3, 2007 It was there last year too. He's not the only rider with one either. <{POST_SNAPBACK}> I shouldn't think there are any riders without one! Today's speedway bikes use what is known as a leading link fork, where the fork length itself remains fixed, but a pivoting link allows the front wheel to move up and down. Uncontrolled, the front wheel would just flop up and down at will, so a spring is added to force the wheel onto the track; leaving just a spring would mean that, at the slightest jolt, the spring would just keep bouncing up and down like a pogo stick, even on a flat surface, so a damper (shock absorber) is added, to control the amount of bounce in the spring. What the riders use today is an adjustable damper that can be altered to change the amount of control the damper has over the spring, which needs to be varied depending on track conditions. There were some pictures of AJ testing a bike with telescopic forks floating around; in this case, the damper and spring are inside the fork, and the fork moves up and down. So, the suspension effect is the same, but the fork length changes and with it, the steering geometry, which will change the way the bike handles. Hope that helps. Quote Link to comment Share on other sites More sharing options...
The Know Posted May 3, 2007 Report Share Posted May 3, 2007 I shouldn't think there are any riders without one! Today's speedway bikes use what is known as a leading link fork, where the fork length itself remains fixed, but a pivoting link allows the front wheel to move up and down. Uncontrolled, the front wheel would just flop up and down at will, so a spring is added to force the wheel onto the track; leaving just a spring would mean that, at the slightest jolt, the spring would just keep bouncing up and down like a pogo stick, even on a flat surface, so a damper (shock absorber) is added, to control the amount of bounce in the spring. What the riders use today is an adjustable damper that can be altered to change the amount of control the damper has over the spring, which needs to be varied depending on track conditions. There were some pictures of AJ testing a bike with telescopic forks floating around; in this case, the damper and spring are inside the fork, and the fork moves up and down. So, the suspension effect is the same, but the fork length changes and with it, the steering geometry, which will change the way the bike handles. Hope that helps. <{POST_SNAPBACK}> a good answer compared to some but not quite right as a speedway bike uses 2 rubber bands, one on either side instead of a spring like a normal bike has. due to the very limited travel of the fork and the race being very short the damper makes very little differance to the handling of the bike and the piggyback is not required as the race is to short to heat the oil/nitrogen to cause fade. in short a stock cheap hagon shock is as good as one 4x the cost and is mearly for show. Quote Link to comment Share on other sites More sharing options...
Odds On Posted May 3, 2007 Report Share Posted May 3, 2007 it's a lap counter!! Quote Link to comment Share on other sites More sharing options...
Guest Donsking Posted May 3, 2007 Report Share Posted May 3, 2007 a good answer compared to some but not quite right as a speedway bike uses 2 rubber bands, one on either side instead of a spring like a normal bike has. due to the very limited travel of the fork and the race being very short the damper makes very little differance to the handling of the bike and the piggyback is not required as the race is to short to heat the oil/nitrogen to cause fade. in short a stock cheap hagon shock is as good as one 4x the cost and is mearly for show. <{POST_SNAPBACK}> If you're really telling me that speedway bikes use an elastic band instead of a spring, then I need to get my pencil out and apply to the patent office immediately! Quote Link to comment Share on other sites More sharing options...
rickmiller Posted May 4, 2007 Report Share Posted May 4, 2007 You lot dont half get carried away!!! Using rubber as the springing element in suspension has been around for years as have leading link forks. Greeves produced thousands of bikes between 1955 and 1970 for moto-x, trials and road with basically the same fork as our hero's use now. See www.greeves-riders.org.uk for more info. As for a patent, well, you are approx 75 years or more too late!!! More info on the 'device' can be found here: www.bitubo.com In answer to the comment that 'a stock cheap hagon shock is as good as one 4x the cost' - thats not strictly true. The expensive ones are adjustable and can be tuned for different tracks and changing conditions where the cheap ones are not. But you have to know what you are doing or its easy to make the handling worse! Its also down to the quality of materials used which affects how durable they are in service etc, etc. There are lots of reasons why leading link forks are better than telescopics for speedway but be very aware that the phrase 'a little knowledge is a dangerous thing' was invented for people who think they know it all about suspension!!!!!!!!! Quote Link to comment Share on other sites More sharing options...
The Know Posted May 4, 2007 Report Share Posted May 4, 2007 If you're really telling me that speedway bikes use an elastic band instead of a spring, then I need to get my pencil out and apply to the patent office immediately! <{POST_SNAPBACK}> Have you ever looked at a speedway bike Quote Link to comment Share on other sites More sharing options...
The Know Posted May 4, 2007 Report Share Posted May 4, 2007 You lot dont half get carried away!!! Using rubber as the springing element in suspension has been around for years as have leading link forks. Greeves produced thousands of bikes between 1955 and 1970 for moto-x, trials and road with basically the same fork as our hero's use now. See www.greeves-riders.org.uk for more info. As for a patent, well, you are approx 75 years or more too late!!! More info on the 'device' can be found here: www.bitubo.com In answer to the comment that 'a stock cheap hagon shock is as good as one 4x the cost' - thats not strictly true. The expensive ones are adjustable and can be tuned for different tracks and changing conditions where the cheap ones are not. But you have to know what you are doing or its easy to make the handling worse! Its also down to the quality of materials used which affects how durable they are in service etc, etc. There are lots of reasons why leading link forks are better than telescopics for speedway but be very aware that the phrase 'a little knowledge is a dangerous thing' was invented for people who think they know it all about suspension!!!!!!!!! <{POST_SNAPBACK}> ya totally wrong about the shocks making any differance. i have been involved in motocross for 30yrs and have worked with many top riders and recently speedway riders. due to the very small amout of travel on a speedway bike and the track being quite flat the damping makes very little differance. for a shock to work correctly you need,adjustable, spring preload, rebound damping, compression damping with both low and high speed settings and this is just the start. in road racing, motocross and most forms of bike sport the suspension is just as important as power, in speedway it is not due to the reasons i have stated. Quote Link to comment Share on other sites More sharing options...
daveyracing Posted May 4, 2007 Report Share Posted May 4, 2007 its simply an extra gased up canister taht allows different pressur for the actually absorber Quote Link to comment Share on other sites More sharing options...
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