Motorsport tyres sizes 20x61/16 confused

[SM]

Anybody understand slick sizes? or know of any good links.

What equates to
205*50*16
215*50*16
or similar, ie for S14 standard size rims.

Whats
20x61/16 ??

and how different is that from 18/62-16 which are the size of my current knackered slicks. They seem to be written differently :confused:


:confused: :confused: :confused:

[SteveCarter200]

I think its width (cm) x circumference (cm or mm) x wheel diameter (inch).

[SteveCarter200]

Hmm, maybe not. Some size comparisons:

http://www.longstonetyres.co.uk/michelintb15.php

Another tyre article, no help but interesting anyway.

http://www.eng-tips.com/viewthread.cfm?qid=56923&page=1

Damn, cant find anything on google.:annoyed:

[200sxct]

I think it’s the width in cm, total diameter of the tyre in cm, plus the size of the rim in Inches, nice mixture of imperial and metric as usual.

So at a guess they would be 2cm wider and 1cm smaller on the diameter.
Circumference:
Old slicks = 194.78 cm
20.61/16 = 191.64 cm
205/55/16 (63.24 cm diameter) = 198.67 cm

So as you can see, the current slicks are smaller rolling circumference than the original fitment tyre, and the slicks your are looking at there are even smaller so SHOULD give better acceleration at the cost of a bit of top speed. Could give you the predicted speeds per gear if i was at home and had access to my handy excel spreadsheet but instead I’m in work bored stiff doing a 24hr shift :( damn NHS.

Those tyres should be ok, A little wider as well :) Get a second opinion first though.

Chris.

[Jon]

http://www.dunloptyres.co.uk/ourTyres/motorsport/

[SM]

18/60-15, 18 = tread width in centimetres, 60 = overall diameter in centimetres and 15 = rim diameter in inches.

Found some in the size I have now now :D at a OK price, some sizes and wets are only £35 :(

18x62/16 Michelin slick
Available in two compounds soft and medium
Price: £75.00 (Excluding: VAT at 17.5%)

[200sxct]

Still Quite pricey arnt they, Where is that from? Wonder how much they would be in a 230.60.17 ish?? Shame you havent got a set of 18" rims
http://cgi.ebay.co.uk/220-645R18-DUNLOP-CR311-X08-SLICK-TYRES-x2-18_W0QQitemZ8008366327QQcategoryZ9891QQrdZ1QQcmdZV iewItem

Just out of interest how much use did you get out of your last set and which compound were they?

[kev1nc]

I must have this wrong cos i thought the standard tyres are 20.5 cetimetres wide which would mean 18cm is small :confused:

[SM]

Last set were second-hand and already hard and worn when I got them :( I havent yet used them but dont have much confidence in them.

Kev, yeah, I'm confused too, they look the right size :confused: