eric Posted October 9, 2002 Share Posted October 9, 2002 Track days and 15" Wheels As the famous R300 and R400 use 15" Wheels with avon CR500 Tyres 195 / 45 x 15, do you think they are better than 032 with 13" minator for circuit use The 7 is a sprint Caterham (1600 110 HP) de dion, 5 speeds gearbox Thanks for your advices Link to comment Share on other sites More sharing options...
F355GTS Posted October 9, 2002 Share Posted October 9, 2002 eric general view is that 13" are better for track use. CR500's are very grippy but are tend to overheat on track work, 32's are better from this point of view however 32's are much heavier than CR500's adding unsprung weight. Mark Link to comment Share on other sites More sharing options...
murph7355 Posted October 9, 2002 Share Posted October 9, 2002 I'm guessing, but I honestly believe that Caterham have done this for perceived aesthetics and so are obviously trying to appeal to a "wider" audience. Your 32s on 13" rims are a much better option. There's also more variety of good rubber available in 13", it's a lot cheaper and it's lighter. Link to comment Share on other sites More sharing options...
fordy Posted October 10, 2002 Share Posted October 10, 2002 Yeah but the new 15" jobbies do look a bit nice! Apparently they are quite light too. The R300 review in low flying last month seemed surprised how good they were. Not on the track though. Link to comment Share on other sites More sharing options...
NoLimits Posted October 10, 2002 Share Posted October 10, 2002 I have both setups and can confirm 15" look great. Are much better than other 15" tyres however they are not a patch on 13" rubber particularly the 13" CR500's. 15" Cr's feel to hard. I'm sure this is less to do with the compound and more to do with the height of the sidewall. MY 51VEN - SLR Give it some WELLY! Link to comment Share on other sites More sharing options...
murph7355 Posted October 10, 2002 Share Posted October 10, 2002 Looks are subjective. I used to love 14" minilites but the car looks soooooo much meaner on black 13" wheels. Drives better too. Big wheels are for the top shelf at WHS. Especially when you know they give zero advantages (+ disadvantages) elsewhere. Link to comment Share on other sites More sharing options...
DonkeyDave Posted October 11, 2002 Share Posted October 11, 2002 there are advantages to having large diameter wheels, you can run larger discs - you can run lower profile tyres reducing tyre wall deformation - this applies more to larger/heavier cars Link to comment Share on other sites More sharing options...
eric Posted October 11, 2002 Author Share Posted October 11, 2002 R300 and R400 are typical 7 for trackdays It is very strange that Caterham uses 15' for that purpose if it is not the better choice. All the customers of R300/R400 will order their car with 13" wheels Any point of view, on the hidden benefits of the 15" are welcome regards eric Link to comment Share on other sites More sharing options...
SteveP Posted October 11, 2002 Share Posted October 11, 2002 "All the customers of R300/R400 will order their car with 13" wheels" Not when the 13" wheels available are 1k's worth of magnesium ones they won't I personally think the 15" rims are great, very light having picked one up, certainly as light (IMO) as my 13" Minator's with Bridgestones SteveP Edited by - SteveP on 11 Oct 2002 13:23:40 Link to comment Share on other sites More sharing options...
murph7355 Posted October 11, 2002 Share Posted October 11, 2002 But did you compare the wheels with tyres attached Steve? 13" wheels give enough space for big enough discs on a 7, but I do get your point DD. On a massive, heavy tin top that needs huge stoppers etc etc then go large. On a 7, small is good. It's aesthetics alone on Caterham's part. And they're probably hoping that they'll get new customers back soon afterwards slapping another wad on their desk for mag wheels too. Link to comment Share on other sites More sharing options...
NoLimits Posted October 11, 2002 Share Posted October 11, 2002 I would have splashed for another set of Mag's but just could not get hold of them. Mike Barnby did not reply and Caterham have a 6 mth back order. MY 51VEN - SLR Give it some WELLY! Link to comment Share on other sites More sharing options...
eric Posted October 12, 2002 Author Share Posted October 12, 2002 I have generally read in low flying or here that CR 500 melted after some dry hard laps on circuit Will they recover their qualities after ? What about A032 in 13" or other tyres in 15" brigestone, yoko A032,A539, 038 pirelli PO etc... Yours ideas welcome Link to comment Share on other sites More sharing options...
NoLimits Posted October 12, 2002 Share Posted October 12, 2002 32's are i find the most economical particularly for track use in 13". Not as good as the CR500's though. So i keep the cr's for the road. MY 51VEN - SLR Give it some WELLY! Link to comment Share on other sites More sharing options...
murph7355 Posted October 12, 2002 Share Posted October 12, 2002 Goes to how how subjective tyres can be. I really do not like CR500s and think that even 21Rs are a better tyre for general use and on the track. Link to comment Share on other sites More sharing options...
Red SLR Posted October 13, 2002 Share Posted October 13, 2002 I got the R300 items and have a spear set of 13s for track days with either ACB10s or A032Rs. See X777CAT here Link to comment Share on other sites More sharing options...
JP Posted October 13, 2002 Share Posted October 13, 2002 Has anyone got any experience on the track with 15" wheels as opposed to 13"? Are they so bad? In addition to Caterham offering their new cars with 15", IIRC doesn't the SR3 Radical come with 15" - (the other models, I think come with 13") do they know something... Link to comment Share on other sites More sharing options...
Slipper man Posted October 13, 2002 Share Posted October 13, 2002 I have never tried 15" CR500's on the track, but there was a set at Llandow which got very good reviews. Allegedly, the compound is now harder for CR500's, so that they don't cook themselves on track. I have never tried them though. General advice is if you primarily want track performance then go for the 13" option. The 15" option is there because it looks better for a road car, and involves comparatively little compromise. If you are going 13", then the question is which tyre. The best by far is the ACB10 option (in the dry), but they cost more (I believe twice as much as Yoko 32R's) Link to comment Share on other sites More sharing options...
Red SLR Posted October 14, 2002 Share Posted October 14, 2002 Will be by the end of the year.. See X777CAT here Link to comment Share on other sites More sharing options...
NoLimits Posted October 14, 2002 Share Posted October 14, 2002 Well as Keith has just said i ran the 15" CR500's at Llandow. It was'nt just wet we were driving on a totally saturated surface. I would sugest that there is less of a difference between the 15" and 13" CR500 on track than on the road. As previously stated i had found the 15's to be "skittery" on the road. But on a smooth track surface this was not the case. I know the track was saturated but there was very little sign of wear on the tyre. The comments regarding compounds would add up to my comments regarding the differences. I had hopped to try the 15/13 back to back but the weather was so bad there was no way i was changing tyres from wets to wets. MY 51VEN - SLR Give it some WELLY! Link to comment Share on other sites More sharing options...
eric Posted October 14, 2002 Author Share Posted October 14, 2002 News from Caterham : new 15" wheels + CR 500 very low weight A032R + 13" not much different What are your theory about unsprung weight How do you feel it ? Link to comment Share on other sites More sharing options...
Mark H Posted October 14, 2002 Share Posted October 14, 2002 If the 13s don,t work as well acording to caterham why do they continue to sell them as aftermaket fitment, if they thought that they did,nt work would,nt they be trying to sell us 15s instead. still fast in flares 😬 Link to comment Share on other sites More sharing options...
DaveK Posted October 14, 2002 Share Posted October 14, 2002 A 15" dia tyre of a larger dia will give a greater contact patch on the road for a given section width. So a 195 15" dia cr500 will have more surface area than a 195 13" cr 500. Therefore mechanical grip will be greater on the 15" given the same compound rubber. The perceived grip level could be greater due to the larger sidewall on the 13" tyre giving more progressive breakaway charecteristics Dave Link to comment Share on other sites More sharing options...
JP Posted October 14, 2002 Share Posted October 14, 2002 DaveK, Won't the contact patch area vary with the aspect ratio of the tyre? Link to comment Share on other sites More sharing options...
murph7355 Posted October 15, 2002 Share Posted October 15, 2002 I've tried the 2 Yoko types (not 48Rs yet) and CR500s in wet and dry conditions, track and road. The CR500s are harder to get up to temp. and nowhere near as confidence inspiring. But others have felt the opposite. The *only* way to tell is to try both yourself and make your mind up that way. Yokos are half the price of ACBs and CR500s, possibly even a good bit less. I've not tried ACBs but am not prepared to risk brown trousers in the wet. Especially at 100+ quid a corner. I'd like to see all weights (wheel and tyre) on proper scales before I believed anything Link to comment Share on other sites More sharing options...
Mike Bees Posted October 15, 2002 Share Posted October 15, 2002 JP - what Dave is saying is that the contact patch is proportional to the overall diameter of the tyre (which is a function of the wheel diameter and tyre aspect ratio) as well as the width of the tyre. Mike Link to comment Share on other sites More sharing options...
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