Roger Ford Posted September 10, 2013 Share Posted September 10, 2013 At Cadwell last weekend, a friend's mechanic had put lines on the wheels and new tyres to show any slippage. We sniggered at this display of over-zealousness. We didn't snigger when he came back in after quali, and the lines were out by some inches on the rears. Subsequently I put similar marks on mine, and found my rears had rotated significantly during the first race - as had his. Is this normal? It would seem like it should put the wheel balance out, though when we discussed this with George Polley he reckoned the balance was mostly down to the wheels rather than the tyres, so it shouldn't make much difference. These are 13 inch Yoko 48s on Caterham 8-spoke anthracite wheels. Link to comment Share on other sites More sharing options...
AntonyH Posted September 10, 2013 Share Posted September 10, 2013 It happens with bicycle tyres, so it's not unreasonable to imagine it happening on a car too. Link to comment Share on other sites More sharing options...
ruff seven Posted September 10, 2013 Share Posted September 10, 2013 I had this a couple of times on old MB wheels, they now put a knurling on the rims Link to comment Share on other sites More sharing options...
Mavic82 Posted September 10, 2013 Share Posted September 10, 2013 Yes common issue with performacne vehicles driven hard. Link to comment Share on other sites More sharing options...
prangerman Posted September 10, 2013 Share Posted September 10, 2013 Slightly OT but I was reading an article recently about landing a WWII B24 Liberator which apparently had rather binary but effective brakes on the main wheels. It was said that the brakes could easily stop the wheels turning but not the tyres if one applied them too hard Peter Link to comment Share on other sites More sharing options...
Phil B Posted September 10, 2013 Share Posted September 10, 2013 This is a common problem when tyres run at the lower pressures we use on light cars. In my early motorsport days doing car trials, where pressures as low as 12-15psi were normal, we used to drill the steel rim in several places on inner and outer edges and screw self-tappers into the tyre bead! Crude but effective. Phil B Link to comment Share on other sites More sharing options...
2GBR Posted September 10, 2013 Share Posted September 10, 2013 One of the many reasons we changed over to tube less tyres to stop the tyre turning then ripping the valve from the tube. Forty years back i spot welded tractor rims to snag the bead to reduce this when ploughing. Have also done it to my BSA scramble bike and also had security bolts to nip the tyre beads to the rim which helped Link to comment Share on other sites More sharing options...
colindavies56 Posted September 10, 2013 Share Posted September 10, 2013 as a big barry sheene fan,i can remember his suzuki team doing this on his works bikes Link to comment Share on other sites More sharing options...
wild bill Posted September 10, 2013 Share Posted September 10, 2013 Is this why the bike shop glued the tyres to the rims on my colnago? never worked out why they did that Link to comment Share on other sites More sharing options...
elie boone Posted September 10, 2013 Share Posted September 10, 2013 Too much fairy liqiud when you put the tyres on ? the special "gease " for mounting tyres dry's rather quickly just to avoid this, alternativly mount the tyres dry on the rim. Link to comment Share on other sites More sharing options...
Z3MCJez Posted September 10, 2013 Share Posted September 10, 2013 Interesting. I will have to test this now too. I wonder if Cadwell is particularly bad for this, as every time you go over the mountain the rear wheels unload and then reload, and if anything is going to move the tyre it's that sort of thing ... Was there any movement on the fronts? That would be braking driven (I would guess). Jez Link to comment Share on other sites More sharing options...
Roger Ford Posted September 10, 2013 Author Share Posted September 10, 2013 No, the fronts didn't move at all. Elie, the tyres were fitted by George Polley personally. He's had very many years of tyre fitting (as well as a spell as Stock Car World Champion) so I doubt that he used the wrong lube, or too much of it. Link to comment Share on other sites More sharing options...
RS2000 Posted September 10, 2013 Share Posted September 10, 2013 Wild Bill - it may be that you have 'Tubs' (Tubulars) rather then 'clinchers'. Tubs are glued to the wheel rims (or with special double sided tape) and basically have the inner tube sealed within the tyre. Lot of pro teams will use tubs and majority of track (velodrome) riders will use them (can inflate to higher pressures, tend to be lighter and offer the rider more control if punctured) This shows the difference: here Link to comment Share on other sites More sharing options...
Birkin S3 ZA. Posted September 10, 2013 Share Posted September 10, 2013 From fitting hundreds of motorcycle off road tyres I always use washing liquid mixed with water on the rims and tyres, it gets absorbed by the tyre in a short time. You need it to get the tyre bead on to the rim, and its a sod to get the bead off again a week later. All the rims use bead locks to lock the tyres in place, one for the front two for the back. If it moves it rips the valve out of the tube, its also a good idea to elongate the valve hole in the rim and never tighten the locking nut allowing the valve to move to about 45 deg without ripping it out. When its at a angle to straighten it up again let out the air and loosen the rim lock, put the bike on the stand and rev the bike in forth gear and jam the brake on and the tyre will move a bit Repeat until its straight again. I was doing a race once when my rim lock broke and I ripped my valve out, there was no point in stopping. It was like riding a automatic the rim was spinning in the tube and smoking, then all the wire came out of the tyre and got caught in the chain and sprocket and rapped around the hub. More power and snapped the wires so I finished with not much tyre left on the wheel. Chris. Link to comment Share on other sites More sharing options...
Guy Lowe Posted September 10, 2013 Share Posted September 10, 2013 On dragsters they screw the tyres to the rims with Drag Slick Mounting Screws They look like self tappers to me Guy Link to comment Share on other sites More sharing options...
myothercarsa2cv Posted September 11, 2013 Share Posted September 11, 2013 Quoting Guy Lowe: On dragsters they screw the tyres to the rims with Drag Slick Mounting Screws They look like self tappers to me GuyAnd this is why Link to comment Share on other sites More sharing options...
Birkin S3 ZA. Posted September 11, 2013 Share Posted September 11, 2013 I always wondered why my steering goes light when I accelerate 😬 😬 Link to comment Share on other sites More sharing options...
Guy Lowe Posted September 11, 2013 Share Posted September 11, 2013 Quoting myothercarsa2cv: And this is why Perhaps Roger should take a video of his rear tyres as he leaves the line and we could compare 😬 Guy Edited by - Guy Lowe on 11 Sep 2013 14:47:29 Link to comment Share on other sites More sharing options...
Roger Ford Posted September 11, 2013 Author Share Posted September 11, 2013 I think even Charles' car has rather a lot less power than one of those. Link to comment Share on other sites More sharing options...
Z3MCJez Posted September 11, 2013 Share Posted September 11, 2013 Top end refresh coming then Roger? Jez Link to comment Share on other sites More sharing options...
CharlesElliott Posted September 11, 2013 Share Posted September 11, 2013 Corner exit speed Roger 😬 Link to comment Share on other sites More sharing options...
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