Wheel advice/sizes

[ICJason]

Just wondering if anyone can help me out, my Caterham is coming with the standard 14" wheels and i'm really not keen! Sadly my kit is due in November so I can't change the wheels now. I would have preferred the 15" Orcus Anthracites but the nearest I can find online for looks would be the Team Dynamics Pro Race 1.2...

Has anyone got these wheels or any opinion on them?

Also, what size would I need? Offset etc? Tyre Size? I really don't want the speedo reading incorrectly so need something that matches the factory spec ideally!

Thanks in advance!

Jason 

[martyn]

I doubt it is too late to change the order.  Especially for something like wheels which they will throw in a box the day before it is delivered.

People generally have a hard time finding a good range of tyres in the 14" size so 13" or 15" is definitely the way to go.  Wheel size is of course a matter of personal preference, but 13" is generally considered the upgrade option, giving a more compliant ride and progressive handling near the limit.

You can buy the 15" Orcus wheels direct from Caterham but you may possibly need to change your wing stays:  http://caterhamparts.co.uk/product.php?id_product=5257

[JNC]

I would think you have plenty of time to change your order with CC .  what have you got to loose give them a call. Nice wheels better in silver

[ICJason]

I'll try again... Got a categorical no before!

We shall see...

[DJ.]

Seems strange they would refuse. It isn't a 160 is it?

[PinotNoir]

Hi Jason

Whatever the outcome regarding your last point the speedo calibration is ultimately affected by the rolling circumference of the tyre. A speedo should be calibrated for specific wheel diameter, tyre tread width and tyre aspect ratio, therefore change to any of these specifications would impact upon speedo accuracy.
I could only find US sites to offer comparisons with a quick search, but these may prove to be of interest:

https://www.tacomaworld.com/tirecalc
https://tiresize.com/comparison/

 

[Jonathan Kay]

Also, what size would I need? Offset etc? Tyre Size? I really don't want the speedo reading incorrectly so need something that matches the factory spec ideally!

The accuracy of the speedometer would come a long way down my list of priorities. After you've fitted the wheels and tyres you want you can:

1. Recalibrate
2. Add a GPS speedometer (options include a smart 'phone)
3. Add new lines or ticks to the display with Letraset at the values of interest .

Any of those would also let you make sure that the displayed values are actually correct.

Jonathan
 

[ChrisC]

Calibration is very simple on the current electronic speedo.   Just hold the reset button when switching on the ignition, a 5 digit number will appear.  This is the number of pulses per mile, if your speedo is reading under by 10%, reduce the number of pulses by 10%.

 

[Garth]

Hi Jason

Caterham changed my wheels during my build (6 years ago now!) so cannot see why they would not change them for you ages before delivery? Do make sure you get the correct sized cycle wing stays as already mentioned. 

I started on 15" rims (thought they looked better?) but am now on 13". More tyre choice and easier to get hold of cheap tyres and rims for smoking up whilst giving joy rides (officially allowed at the Super Car event - honest). I do prefer the feel of the 13" compared to the 15" on track too.

Good luck.

Garth

 

 

[ICJason]

Thanks everyone for the advice! Didn't know there were different stays for different wheels - glad I found out as I was planning to attach the wings with adhesive as Caterham seem to do now! Would use the Big Heads but heard of Caterham removing them at the PBC and bonding them on for some reason... presumably an IVA test issue.

Great info on how to calibrate the speedo so thanks to Chris for that!

[ballisticsupersport]

Hi Chris,

Hope you're well.

I've just changed from 185 55 to 215 55 rear tyres, this has increased the circumference significantly, you say how to find out how many pulses per mile but how do you adjust it?

cheers

Tom

[ChrisC]

Hi Tom

Building my first Caterham, and enjoying it ;-) Thanks.  Hope your well.

i have a image from Caterham with the calibration settings they use, which I can send you tomorrow it you send me a message with your email address.  

But this was still a bit out (over) compared to sat nav.   So I just added 9% to the number, because it's was about 10% over.  This left my speedo 1 mph over sat nav, all the way up to 70 which was just about perfect.   Basically you need a good way to calibrate it, either a sat nav or another reading from a proper car while you follow it.

You can't go wrong, it's just a number, so take a note of it before you start and put that number back in if you don't like the adjustment you have made.

Chris.

[Toughie]

Garth

What width rims have you changed to?

 

Regards

Alan

[Garth]

Hi Alan
Standard Caterham 8 spoke anthracite rims - 6” on the front 8” on the rear. Running Avon ZZS’s with 185 x 55’s on the front and 215 x 55’s at the back. I am much more comfortable with this combination compared to the 15” 195’s I used to have and feels much more planted! Do probably not need 215’s at the rear, but they look so much more purposeful!
Had to adjust the ride height accordingly.
Cheers
Garth

[John Vine]

This PDF explains how to work out the pulses per mile, and then how to input this value into your speedo.

There's a chart here that gives the calibration code ("input pulses") for a selection of wheels and tyres.  If yours isn't listed, use the method above, and then recalibrate as needed after you've taken some speed/tripmeter measurements on the road.

JV

[Toughie]

Thanks, Garth.  That's useful info.

Regards

A