R400 Wheel and Tyre Choices

[Blackmamba]

Hello

Apologies if this has been covered before but I searched the forum and couldn't find a specific answer. I have a (new to me) 2003 R400 currently on 15" Superlight wheels with 195/45/R15 CR500s. The wheels look to be in good shape but there is some paint bubbling so they could do with a refurb. The tyres have 5mm tread, no signs of damage etc but are over 10 years old so I want to change them in the Spring when I start to use the car. Plan is to do mainly road miles and a few trackdays.

I've been told these cars work well on 6x13" front and 8x13" rear wheels so have been keeping an eye out for a set as I am thinking if I have to refurb the wheels and am buying new tyres, it might be an opportune time to make the switch. I would expect some improvement in ride and handling due to lower weight and taller sidewalls. Interested to hear from anyone who has switched from 15" to 13" wheels (or vice versa) and if you noticed any improvement or changes? I would think the wider rear rubber would help on track but maybe less so on road.

Avon ZZS seems to be the default choice on Caterhams but they no longer do the 195/45/R15 size. If I stick with the 15" wheels, what are the alternatives? I see Toyo Proxes TR1 come in this size and might be an option, what else do people use? Are the ZZSs really that much better than everything else on these cars?

Thanks

 

 

[David_Long]

I also bought my R400 with 15 inch wheels and ran them for about a year before swapping to 13 inch. The 13 in are quicker on track by some margin -  not so noticable on the road. The 15 inch has a lower profile and tend to repsond positively and feel good, but grip breaks away earlier. The 13 inch is just more tolerant of being pushed harder, albeit you may think they feel worse at first. Unspung weight also helps - you find it just feels a little more nimble.

Tyres - I used ZZR, ZZS, R888, for road use and V70 Kumho's for the track. I'm not a fan of Avon but there is plenty of choice these days.

[Dave Hardcastle]

I have ZZS on a R400D and they're great. I put Toyo TR1's on my previous Caterham, 156bhp, and REALLY regretted it. I had no confidence whatsoever in the amount of grip I had.

Lots of people on here run ZZS/ZZR, there's a reason for that 

Hope that helps

[Nigel B]

When I bought my 420R, it was fitted with 15 inch Orcus wheels. 

I swapped them for 13 inch wheels, with the wider, 8 inch rears & the balance of grip front to rear doesn’t feel as good as it did with the equal width 15 inch wheels. The car now has a tendency to under steer. You can get it to over steer with a mild lift & a jab of throttle, but if you do that the transition to over steer is quite sudden. 

With the previous set up (& with my previous 7!) I found you could simply squeeze the throttle & find the point where the car starts to gently rotate into a subtly over steering stance. You felt as though you could drive through a corner with the rear axle sliding out by an inch or so, whereas, with my current set up it’s almost impossible to find that point of balance. 

I’m assuming the reason for this is the car was originally set up for the equal width 15 inch wheels & I have it booked in for a set up & flat floor session in the spring, which I’m hoping will restore the balance of grip. 

I think the point I’m trying to make here, in a somewhat long winded fashion, is that you may have to have your set up adjusted & optimised to suit the new wheels. 

I’ve been running Avon ZZS with both the 15 & 13 inch wheels & I’m very pleased with them. Grippy & progressive in the dry & confidence inspiring in the wet.

[ScottR400D]

I have 8/6” 13s on my R400 with ZZRs. They are fine on road in the summer, you need to be careful in the wet, which I try to avoid. 

I have two sets of rims and both have ZZRs on at the moment, one set quite worn. When they’re changed I’ll probably fit ZZS to that set and keep the R set for track and hot summer days. 

[W2TKY]

I've got the same set up on my R400. Seems to be working well, but I'm really tempted to change for an aftermarket set of wheels, you never see many 7's on non Caterham wheels.

[7 wonders of the world]

6" / 8" here to shod with R888R on Revolution race rims   

[Blackmamba]

Really good feedback, thank you all. Sounds like 13s are better on track but not so clear cut on the road if both set up well.

If sticking with 15s, tyre choice seems limited. I'll avoid the Toyo TR1s but there doesn't seem to be much choice in the correct size with a 45 profile. The wheels are a snug fit under the arches as they are and I wonder if switching to 50 profile tyres will cause them to foul?

For those on 15s, do you go for 195/50/R15 ZZS or R888Rs and any issues with clearance?

Thanks

[aerobod - near CYYC]

195/50-15s are definitely a snug fit, I use Bridgestone RE-71Rs in that size at the moment and they fit without any contact, but the wheel studs have to be rotated until they are level when removing or fitting the wheel, to allow the wheel to be tilted out at the bottom before moving it vertically slightly to clear the front mudguard.

[Golf Juliet Tango]

Is the car a slimline S3 or an SV? I would expect this to make a difference. Or is that mistaken? I wouldn't put 14", let alone 13" on my 21. Another owner tried this and reverted to 15" or 16".

[7 wonders of the world]

If you hunt you can still get 195/50/15 Toyo R1R's a great tyre !

 

[John Vine]

Re #8:

The wheels are a snug fit under the arches as they are and I wonder if switching to 50 profile tyres will cause them to foul?

Discussion here.

(ETA: It looks as though you've seen that thread already!)

JV

[Blackmamba]

It's the standard S3 chassis and I would prefer not to have any issues with the arches fouling.

I did see the other thread JV, thank you. Looked very close in that picture!

[John Vine]

Looked very close in that picture!

It is, but I've had no problems at all.

JV

[Geoff Brown]

I have learnt from some members that the ZZ series can be a tight fit under the cycle wing. Due to the 'odd' profile sizes.

This year for me will be an all round change to ZZS when my - wait for it -  13" CR500s finally wear out. I am on my last set as I purchased three complete sets before the end of manufacture. With tyres having a recommended on shelf life of about five years I thought that I was not going to use the whole stock but managed the problem. 

Pity the CR500 went out of 'fashion' as the tyre was offered in sensible profile sizes, had a decent compound & the carcass weight was significantly less than the ZZS series. That is progress for you?

[John Vine]

...an all round change to ZZS...

What width and profile will you go for on 13", Geoff?

JV

[Geoff Brown]

JV - CR 500s are 175/55 6J & 205/55 8J.

So ZZS will be 185/55 & 215/55.  They are the only 13" sizes that pair up with the same aspect ratio of 55.  

 

[John Vine]

Thanks, Geoff. 

Of course, I'm on 15" so my ZZS are 195/50 all round (previously CR500 195/45 all round).

JV

[Bob Shelley]

John,

How much clearance have got in the wheel arches with ZZS 195/50 on 15" rims? They will be my next choice on my R400D after my CR500's expire.

[John Vine]

Hi Bob,

I've just ventured out to the garage to measure the gaps:

• Tyre to wing (top edge) = 4mm both sides
• Tyre to front wingstay (at the narrowest point where the stay curves round under the wing) =  3mm
• Tyre to rear wingstay (ditto) =  2mm

The tyres are indeed a tight fit, but there are no witness marks to suggest contact, and my friendly MOT chap made no comment.  

There's plenty of room between the centre-line of the tyre and the wingstays.

Hope that helps.

JV

[7 wonders of the world]

If you drive very hard you may find they kiss the stays - you can ease the stay to give a little more clearance

PS I'm not inferring you drive like Miss Daisy JV    

 

[Bob Shelley]

Thanks a lot John for doing that. Hope you and yours are OK. I'm getting jabbed on Saturday.

[Blackmamba]

Very helpful feedback. All this talk of 15" being a tight fit makes me think 13" would be better!

[7 wonders of the world]

The R888R are made in 60 series and offer a little more ground clearance over the Avons in 55 series too 

If you go for an asymetric set up F185 / R205 etc you will need to reset your rake and ride heights, corner weights, and check castor camber and toe to.

[StevehS3]

I have have used 13, 14 and 15" over the years. I prefer 13" and the higher sidewall makes for a much improved ride over rough road surfaces. I have never liked lower profile tyres on any car I've had.