Anyone run 70 profile tyres on R13's?

Anyone run 70 profile tyres on R13's?

Author
Discussion

Scotty996T

Original Poster:

433 posts

208 months

Tuesday 4th May 2010
quotequote all
Our Supersport runs on A021 R's 185/60 R13. (Minilites)

Really seems to suit the car. Good in wet and dry and progressive. Customers drive enthusiastically (!) so we only get about 3k out the rears.

Was buying another set and the guys at George Polley mentioned they can do 70 Profile much cheaper as they're control tyres for a race type and they go through loads of them.

Happy with the set up we have but wondered if anyone had run 70's??

Have stuck to 60's for now. Plenty of space on rear arch but will check front cycle wings tonight - might be a little tight.

Thanks, Scott.

allen l

443 posts

183 months

Tuesday 4th May 2010
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If anyone has other options for the standard Caterham 8 spoke wheels (6j and 8j) I'm also interested.

Eugene7

741 posts

199 months

Tuesday 4th May 2010
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I run 70 profile 021Rs on 13 rims - works fantastic.

I find the extra side wall height helps a lot.

cambuscat

153 posts

176 months

Tuesday 4th May 2010
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I also run 70's which help with gearing as I have a 6 speed with 3.9 diff.

David

Aeroscreens

457 posts

231 months

Tuesday 4th May 2010
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Another vote for the 70 profile.

I've used them on 13" rims for the last 50,000+ miles for the following reasons:

1. Price: cheap as chips, I think my last ones cost £46 per corner inc. VAT
2. Extra ground clearance helps protect the sump just that little bit more.
3. A more compliant ride on the road

It seems to be a matter of personal taste on looks, some people just don't like the higher profile. I, often in jest, refer to them as 'balloon tyres'.

My are on the caterham anthracite 8-spoke wheels


Dave J

891 posts

271 months

Tuesday 4th May 2010
quotequote all
anyone happen to know what the rolling radius of 70 profile 021R 185/70/13 is compared to a R888 in 205/60/13 ?

ta

david

Scotty996T

Original Poster:

433 posts

208 months

Tuesday 4th May 2010
quotequote all
Thanks Chaps

Think I'll grab a set and see how we get on.

Cheers

Scott.

Murph7355

38,647 posts

261 months

Tuesday 4th May 2010
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Aeroscreens said:
Another vote for the 70 profile....
Did your car used to be green and yellow?

Aeroscreens

457 posts

231 months

Tuesday 4th May 2010
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Certainly did! Full story here

Eugene7

741 posts

199 months

Tuesday 4th May 2010
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And here's Eugene on 70's...


Edited by Eugene7 on Tuesday 4th May 19:57

S47

1,325 posts

185 months

Tuesday 4th May 2010
quotequote all
I use the yoko Ao21's they're a great tyre in 70 section if you need a tall tyre to give the desired amount of sump clearance. In fact they're the only 'sticky' tyre I know of in 70 series for 13" wheels.
One thing I noticed when I tried 60 section yoko's on 14" rims [to give the same rolling radius as 70 section on 13" rims] on my car was that the tyre walls were stiffer, and the car certainly feels tighter through the bends when using 60 section, I'm sure the same would be true of 60 series tyres on 13" rims. The 60 series tyres lasted slightly less 3Kmiles instead of 3.5-4K on the front of my car though that could be due to other factors. On the rear they both lasted about 800-1000miles Onlyfrown
Hope this helps
Mal

gedG

97 posts

233 months

Wednesday 5th May 2010
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Dave J said:
anyone happen to know what the rolling radius of 70 profile 021R 185/70/13 is compared to a R888 in 205/60/13 ?

ta

david
The rolling circumference for the AO21R's is 1790mm, haven't a clue for the Toyo's but shouldn't be a million miles away.

ETA
The R888's should have a rolling circumference of 1747mm, based on Toyo's published data of 921 revs per mile.

Edited by gedG on Wednesday 5th May 10:57


Edited by gedG on Wednesday 5th May 11:11

Scotty996T

Original Poster:

433 posts

208 months

Thursday 6th May 2010
quotequote all
The circumference thing is interesting.

I'm in conversation with the guys at Caterham as I'm sure that when they upgraded our SV to the R300 style 15" wheels when I bought it, the originals must have been larger as the speedo is showing too fast (10mph at 70ish. Not good. Awaiting their response on how to resolve. Also the spare was sitting a tad high on the rack. Will see what they say but any advice appreciated.


gedG

97 posts

233 months

Thursday 6th May 2010
quotequote all
If it was fitted with 185/60x14 the unloaded circumference would be about 50mm greater than 195/45x15 CR500's, which I think are the R300 tyre. Once you put the car back on the ground I would suspect the difference would decrease as I would expect a 60 series sidewall to deflect more than a 45 series.
ETA
It seems that Caterham speedo's are notoriously inaccurate, mines about spot on up to roughly 50mph then gradually reads slow. At a true 70mph it's about 10% out. Heard of others that are wildly optomistic.
A cost effective solution is to fit a push bike speedo. Mines spot on (GPS checked) to well above the legal limit. And it will tell you your customers max speed, unless they know how to reset it.

Edited by gedG on Thursday 6th May 22:25


Edited by gedG on Thursday 6th May 22:27

sjmmarsh

551 posts

225 months

Friday 7th May 2010
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Scott

BC has some advice on how to set the speedo - see here: http://www.blatchat.com/t.asp?id=83462

Steve

Scotty996T

Original Poster:

433 posts

208 months

Sunday 9th May 2010
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Thanks Steve, worth a punt. Went to Cars in The park in the SV today and it is quite a bit out. Cheers s

Scotty996T

Original Poster:

433 posts

208 months

Tuesday 18th May 2010
quotequote all
BIG thank you to Kev at Caterham who sent me a new speedo gratis when it was clear the micro switch on the old one was stuffed and therefore I couldn't re-calibrate. I was out of warranty so thanks for the decent gesture. Ta

Scott

benjy10

2 posts

169 months

Monday 16th August 2010
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Anybody need a set of Yokohama A021R 185 60 13's?????

Recently sold my pride and joy with a different set on, and had these in the garage (used once before changing to a different size and never got round to doing anything with them.


benjy10

2 posts

169 months

Tuesday 17th August 2010
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nb these there are wheels and tyres together, although I am willing to sell you them, and you can do what you like with the parts you don't want