frankyknuckles Posted October 3, 2003 Share Posted October 3, 2003 what are the benefits of the 13" Magnesium wheels? I know they are alot lighter than the 15" alloys, but how does this transpose itself to performance / handling? I also presume the ride will be slightly better with bigger side walls? Are the rear tyres wider or anything like that? Link to comment Share on other sites More sharing options...
scooby dooby doo Posted October 3, 2003 Share Posted October 3, 2003 advantages of 13" wheels: you can fit 13" tyres which are much cheaper (better than half the price of 15" tyres) and have a much better range for the likes of us. advantages of magnesium wheels: they're lighter - like half the weight of a normal 13" alloy this means: less static mass so you corner and accelerate a bit better (8kg in a 500-600 kg car) less rotational inertia: so you can accelerate a bit quicker still less unsprung weight: this is the big one - the springs and dampers have to control the wheel and tyre - the lighter it is the better they can do this. halving the weight therefore helps a LOT. so better control over bumps etc. HOOPY R706KGU Hoopylight R Link to comment Share on other sites More sharing options...
frankyknuckles Posted October 3, 2003 Author Share Posted October 3, 2003 I presume if I buy these as an upgrade after the build, I will not get them at the option price of £725? Link to comment Share on other sites More sharing options...
SteveP Posted October 3, 2003 Share Posted October 3, 2003 You won't get them at that price (think that they are on the Caterham site for £260 front and £270 rear, rims only), although they are cheaper if bought direct from Mike Barmby I believe. The 15" wheels that come with the R400 as standard are also pretty light (although not quite as light as the mag wheels), look better (IMO) and work well - I have them on my R300 Don't know of exact difference in weight, 1kg a corner ?? Link to comment Share on other sites More sharing options...
Jason Plato Posted October 3, 2003 Share Posted October 3, 2003 I know some of you will think all the following is bull**** - Its not I had 6" minators all round runing 185/60 and 205/60 F/R 32R's , when cornering realy hard I could feel the back tyres wallowing and bouncing , trying to get traction . Turn in bite on the fronts was Ok , but still a little wallowy .The tyre pressures were as a result of temperature tests , so they were fine . Then I fitted R500 wheels with the same tyres - I wasnt expecting any change other than a lighter wallet and a pretty set of wheels . The difference was incredible , the rear tyres are now slightly streched on the rims (8") which has made the fell of the suspension a lot tighter , traction was improved dramatically with the rear now realy biting into the track . Also in long fast corners , the rear is far more stable allowing you to get the power down earlier . Plus the tyre wear has reduced by about 1/3 , possibly as a result of the tyre no longer wallowing ?? . The front end bite is pretty much the same , but the feel through the steering is lighter at low / medium speed . Ridding kerbs also results in less bump steer or jaring through the steering . The weight saving was about 9 Kg I wasnt expecting any of the above when fitting the wheels , and I doubt many realise the difference they make unless you have tried testing with the same tyres . dave Edited by - Dave Jackson on 3 Oct 2003 11:22:07 Link to comment Share on other sites More sharing options...
frankyknuckles Posted October 3, 2003 Author Share Posted October 3, 2003 Steve, the R300 and R400 come as standard with the 15" wheels Link to comment Share on other sites More sharing options...
scooby dooby doo Posted October 3, 2003 Share Posted October 3, 2003 you can get them from MB direct for well under 200. i think they were 170 each last i got some. poss pluys VAT. I know i got a set of 4 with yoko 32Rs delivered for under 1000. HOOPY R706KGU Hoopylight R Link to comment Share on other sites More sharing options...
Rob Walker Posted October 3, 2003 Share Posted October 3, 2003 Go on HOOPY keep shouting about getting them cheaper direct and you will stop it for everyone. Really use some common sense. Link to comment Share on other sites More sharing options...
DanB Posted October 3, 2003 Share Posted October 3, 2003 Given that Mike Barnby advertises his 13" wheels for sale in various magazines (and they're identical to the ones which Caterham happen to use on the R500) I don't see what's supposed to be such a secret. They're Mike Barnby wheels, not Caterham wheels. Mike Barnby sells these wheels to historic formula ford racers, stock hatch racers and other kit car builders. I can't see why he would object to selling a few more to some Caterham owners. Dan A Louis XV chair on rollers has heritage, but it's bo11ox at trackdays... Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted October 3, 2003 Leadership Team Share Posted October 3, 2003 On the subject of tyres - some cars with the R500 / SLR wheels are shod with ACB10s, and some with the CR500 radials - is there a necesity to set up the dedion ears to accomodate either the cross plys OR the radials, or in the real world does it not really matter? Stu. Link to comment Share on other sites More sharing options...
scooby dooby doo Posted October 3, 2003 Share Posted October 3, 2003 Rob Walker - so should I just keep quiet so me and you can profit from it and to hell with all out seven owning friends on here 🤔 And DanB is quite right - they're for sale on the open market anyway. HOOPY R706KGU Hoopylight R Link to comment Share on other sites More sharing options...
bertie Posted October 3, 2003 Share Posted October 3, 2003 As I understand it, it's not a case of setup as such, they use different ears with dirrerent camber and yes it does need doing. Link to comment Share on other sites More sharing options...
Felix E Posted October 3, 2003 Share Posted October 3, 2003 Franky, if you want to change and are looking for a buyer for your 15" wheels, do get in touch. Best Regards, Felix. Link to comment Share on other sites More sharing options...
robmar Posted October 3, 2003 Share Posted October 3, 2003 i run acb's (plus slicks) and cr500's on the same setup and everything seems ok so far. The setup is optimised for the acb/slick xply tyre 1/4 degree rear ears etc. From my understanding the cr500 although a radial tyre is of such a construction that it can cope with the different camber setting that the acb10 needs. I am not sure if this was by design or just a side effect of the tyre design rob Link to comment Share on other sites More sharing options...
tom7 Posted October 3, 2003 Share Posted October 3, 2003 Dave, I'd be interested in your opinion as to whether the improvement you experienced was due more to the wheel size, and a lower tyre profile (by stretching the 205's) than the weight of the wheels 🤔 I am going to buy some new wheels before next season and have considered an 8" rather than a 7" rear wheel. - I wonder if other 205/60x13 tyres would cope with a 8" wheel. Tom Link to comment Share on other sites More sharing options...
Jason Plato Posted October 3, 2003 Share Posted October 3, 2003 Tom , I do think the improvements in traction were as a result of streching the tyre onto a 8" rim . Thus reducing sidewall flex . The reduced weight certaining helps reduce inertia in the steering and allows the dampers to do a better job . I would expect heavy cast 8" rims to have other effects - steering inertia & damper control would be comprimised I imagine . I have also seen 32R 205 tyres work well on 8.5" rims . I cant say about list 1a tyres though . Dave Link to comment Share on other sites More sharing options...
Rob Walker Posted October 3, 2003 Share Posted October 3, 2003 Yeh shut up HOOPY. Edited by - Rob Walker on 3 Oct 2003 16:47:54 Link to comment Share on other sites More sharing options...
Gasmaninaseven Posted October 3, 2003 Share Posted October 3, 2003 Do the CR500s fitted to the magnesium wheels have the same rolling circumference front and rear?? Does the fact that you have "more rubber" at the back c/w front alter the handling of the car?? eg. more understeer necessitating altering setup. I'm interested too in these wheels but are they cost effective in the go-faster stakes?? anyone have any comparative lap times? Orange SUPERLIGHT R300 Link to comment Share on other sites More sharing options...
edmandsd Posted October 4, 2003 Share Posted October 4, 2003 The little step in each wheel nut hole is also handy for locating the wheel on the MBR mag splits. Home of BDR700 Link to comment Share on other sites More sharing options...
edmandsd Posted October 4, 2003 Share Posted October 4, 2003 Oh I almost forgot - Mike also prides himself on the fact that his rims are perfectly round and the right size...I kid you not ❗ He says that when the competition get close to his wheel weights he'll start thinking about areas on the wheel other than the centres for saving additional weight. Home of BDR700 Link to comment Share on other sites More sharing options...
mav Posted October 4, 2003 Share Posted October 4, 2003 Neil, Can't give you lap times but can say that I trid Darren balls aCB10's on a std KN / minilight wheel last saturady at Anglesey and was cionsiderably quicker over the whole track - This compared to my 16" rims with P zero's - I can't give any more information that that at present, as I have something in the pipeline wrt to wheel / tyre tests............. Link to comment Share on other sites More sharing options...
Bare Posted October 4, 2003 Share Posted October 4, 2003 I would think carefully about 'Genuine' Magnesium Alloy wheels. My Saabs have Ronal Magnesium wheels came OEM...V light.. surprisingly so.. But also V soft.. have Bent a couple on pot holes.. and if you do scrape a curb, however lightly, the damage is significant. Think Fragile, then think about how they will survive in your World.. Link to comment Share on other sites More sharing options...
mav Posted October 4, 2003 Share Posted October 4, 2003 I am led to believe it is only the Centres that are MAg alloy, and that the rims are not made of this material....... Please will someone confirm this? Link to comment Share on other sites More sharing options...
Marius Posted October 4, 2003 Share Posted October 4, 2003 Confirmed. Link to comment Share on other sites More sharing options...
mav Posted October 4, 2003 Share Posted October 4, 2003 Thank you Link to comment Share on other sites More sharing options...
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