8" Rear wheel - Advantages & Disadvantages

[The Boy]

I have a 150 Sigma with Caterham 13" wheels and CR500 tyres all round.

 

I was looking to replace the rear for 8" wheels with CR500. What are the advantages and disadvantages of doing this? Fitment, handeling etc.

 

Many thanks for help in advance, sorry if sill question.

 

Learning new skills all the time, 7800 miles completed.

[Jason Plato]

fatter tyre = more grip

 

fatter tyre on wider rim = more stable tyre wall = less wobbly back end

 

 

here is C7 TOP

Taffia rear gunner

 

[Shaun_E]

You could also say fatter rear tyre = better traction = understeer. You may need to adjust the suspension set up to eliminate this - first stop could be to increase the rake slightly.

 

Yellow SL #32 - member of Drowned Rat Racing

[Simon Owen]

I couldn't work out why to go for 8" when 7" would do the job, I was fitting R888's, 205 60 13's. This clearly depends on what size tyres you are upgrading to ❗

 

Also Toyo did not recommend fitting the 205 R888's to anything above 7.5"

 

 

 

 

[Shaun_E]

Caterham 8 spokes only come in 6" or 8" so if that is the wheel you want you have no choice. Putting a 205 tyre on them is fine. I've run 205/60R13 A048R, R888 and CR500 on Caterham 8" rims with no problem.

 

Yellow SL #32 - member of Drowned Rat Racing

[Jason Plato]

8.5 " is also fine on 205 section tyre

 

here is C7 TOP

Taffia rear gunner

 

[akakubi]

Sorry to hijack the thread, but speaking of the tyre widths. I have A048 and CR500. Yokos at the back are 205 (13") and CR500 are 195 (15"), but I could swear the contact patch on the CR500 is wider than the A048... Also, the CR500 look almost square from surface to sidewall.

[Jason Plato]

stated width vs actual contact patch needs a big pinch of salt

 

here is C7 TOP

Taffia rear gunner

 

[akakubi]

So I guess it is similar to the traction and treadwear abbreviations (e.g. A 220 on the BMW rubber, or C 50 on the A048). 😬

[Simon Owen]

Are we saying that the performance of say a 205 60 13 R888 is better on 8” rims than 7”, or is it just different, or would the average driver ( me 😳 ) not really notice much difference anyway 🤔

 

I couldn’t get my head round buying 8” rears when I knew that 7’s would do the job I wanted ( no intention of going above 205’s ) and were within the manufactures recommendations for the tyre I was intending to use.

 

Just because Caterham didn’t do a 7” didn’t seem a good enough reason for me to buy a heavier 8” rim, obviously this would be different if you were only buying the rears and you needed a matching set.

 

Why do Toyo say the 205’s are not suitable for anything over 7.5” when we all know that lot’s here use them without any problems whatsoever on 8” & 8.5”, possibly with better results

 

This one has always confused me a bit, no doubt I will soon be educated on this matter in more detail 😬

 

[Simon.Rogers1]

Toyo and others are not generally dealing with a 500kg car!

 

Probably refering to a car nearly 3 times as much!