Replacing 15” orcas for 13” apollos

[sjl1]

My 310r is currently running on 15” orca’s and cr500’s 6” and 8” which whilst very grippy aren't very progressive. One avenue if thought is to change to 13” wheels and zzs tyres and i have some questions

current front cr500’s are very tight (less than and inch clearance) under front cycle wings, how much of a gap can expect with 13’s and will i need shorter stays?

How much can i expect to sell 4 apollos and cr500’s, one year old and good tyres? (Anywhere where i could part-ex them)

Should i go for 6” or 8”’width on the rears? 

 

many thanks

[JNC]

I think Orcas are only in 6.5" I don't think they come in 8".  You will have quite a big gap under the front mudguards if you change to 13" also you will need to recalibrate your speedo .

[simon_h]

If you get 8inch rears I think the overall rolling circumference is the same almost so probably won't need to do anything with the speedo. At least yours will just be a pulse setting so it's easy to readjust the cal of the speedo. 

[K7 VCT]

6 inch Apollos on my 310 with 185-60-13 nankang ns2r in street compound.

Been of for 2000 miles all good.

 

[tjuniper]

I have 15” orcas running cr500’s on my 310r. They are 6.5” wide at all four corners. I also have some 13” 8 spoke trackdays wheels 6” front, 8” rear running Kumho tyres. There is a larger gap between the front cycle wing/stay and the tyre when on the 13” wheels. As the fronts are also a little slimmer they do not align nicely with the front wings so the wheel looks a little inset. I have tried hub spacers but you quickly run out of thread depth for the wheel nuts. As a result, I don’t worry about the hub spacers and live with the slightly inset look of the front wheels when on Trackdays.

I’m no driving god and to be honest struggle to really feel a major difference when on either set. The only noticeable difference appears to be some understeer on very cold tyres when on the 15”orcas.

Bottom line, I much prefer the look of the orcas on my car and protect these from any major damage by having a 13” trackday set that according to the experts are generally better suited to the Caterham.