i need a set of wheels, any factory Ford ( I quess) alloys

[pxr5]

I dont have old wheels to measure back space etc, trying to keep costs down, is there any factory Ford wheels that work well on a rocket? thanks

[casesensitive]

Your hubs will be 4x108, centre bore 63.4 and offset for Rockets varies a bit. Stock Focus is 47 or so, but Stiggy recommends 25 - 35 I think.

www.wheelfitment.eu/car/Ford/Focus%20(1998%20-%202004).html

Like yourself, I haven't invested in new wheels, I pulled the wheels off my Puma Black Edition before I junked it, as they had new tyres.
They are offset 34 and fit grand.
www.wheel-size.com/size/ford/puma/2001/#trim-17i-eudm-123

Most Ford, Peugeot or, I think, some Citroens (sp?) have 4x108, and offsets from 25 - 50.

Depending on what you go with, you may have to tinker with the angles of your wheels, which will change slightly based on tyre position on the road etc. Mind you, your bushes are melted out, so I'm guessing you've allowed for that..

Same car, colour and trim as mine:

[pxr5]

Thats really helpfull, thanks

[merkinglue]

Whereabouts in UK are you?

I have a spare set of wheels with nearly new tyres on.

FOX Racing 5 spoke alloys.

[pxr5]

Banbury Oxon....

[merkinglue]

Lancashire for me so probably a bit too far

[Stiggy]

I used Peugeot on the rear of Sonic as some of those had 15 ET and therefore gave a wider rear track. This is subject to clearance of wing stays.
For front of Rocket I used 35 ET otherwise you will change the scrub radius.

[pxr5]

Thats great info' thanks

[jake]

Dec 14, 2018 11:06:34 GMT Stiggy said:

I used Peugeot on the rear of Sonic as some of those had 15 ET and therefore gave a wider rear track. This is subject to clearance of wing stays.
For front of Rocket I used 35 ET otherwise you will change the scrub radius.

Was the classic Rocket designed to use a ET35 offset wheel on the front?
There seems to be so much variation in what people fit?
In the original build guide it states the demo car is fitted with ET30 wheels, Mabbs used a ET40 others have used ET25...............
I assume it was designed with an offset in mind to give the correct scrub radius for the vehicle and any variation from this will surely have an adverse affect on handling and feel.
So is ET35 the ideal wheel offset for the front of a Classic Rocket that is was originally designed for?

[Stiggy]

To an extent it is personal pref and also depends if you are racing or touring.

Ford Cortina uprights were used on the MEV Rocket. Ford used a 45 ET wheel. Ford will have spent a fortune in design but then the Cortina had a heavy engine on the front axle driving the rear wheels unlike a Rocket.

I have seen Rockets with steel fabricated uprights and Focus rear stub axles bolted to them. These have a much larger positive scrub radius than cars using Cortina geometry uprights such as the Rally Design alloy units.
Get the Rocket wrong by using heavy large wheels or insufficient castor and it won't self centre too well and can catch you out.

Increasing the scrub radius will give the driver more steering feel and also increase steering effort/weight.
If you use say ET 45 (offset) wheels it will have a track width of 20 mm less than if using ET 35's.
This will also and change the feel due to scrub change. Explanation shown in my sketch, hope this helps.

[pxr5]

Thats very helpfull, thanks!

[kiwicanfly]

Dec 19, 2018 17:06:24 GMT Stiggy said:

To an extent it is personal pref and also depends if you are racing or touring.

So which way do you go for each of this cases?

[Stiggy]

depends on upright geometry, assuming Cortina MK 3,4,5 then a wheel offset of 35 is a good start point.
1. Does the car suffer from tram lining?
2. Is steering effort acceptable in high speed turns?
3. Does the steering have sufficient feedback?
Increasing the scrub radius by introducing a lower ET value will increase all 3 points above but we don't want too much feedback as you will feel it in your wrists.
Reducing scrub rad creates less chance of tram line effect and reduces the effect of steering effort build up as body roll/weight shift increases.
If the answer is yes to all 3 points the above then it must be about right.

[casesensitive]

Dec 19, 2018 17:06:24 GMT Stiggy said:

To an extent it is personal pref and also depends if you are racing or touring.

Ford Cortina uprights were used on the MEV Rocket. Ford used a 45 ET wheel. Ford will have spent a fortune in design but then the Cortina had a heavy engine on the front axle driving the rear wheels unlike a Rocket.

I have seen Rockets with steel fabricated uprights and Focus rear stub axles bolted to them. These have a much larger positive scrub radius than cars using Cortina geometry uprights such as the Rally Design alloy units.
Get the Rocket wrong by using heavy large wheels or insufficient castor and it won't self centre too well and can catch you out.

Increasing the scrub radius will give the driver more steering feel and also increase steering effort/weight.
If you use say ET 45 (offset) wheels it will have a track width of 20 mm less than if using ET 35's.
This will also and change the feel due to scrub change. Explanation shown in my sketch, hope this helps.
View Attachment

Ah... I inherently knew this, but never really thought about it. I've always assumed my ET35 was a little too wide, and have been been oogling ET25 aftermarket alloys, good to know I'm in the ballpark. 👍

[Stiggy]

remember that a lower ET value will create a wider track width and increased scrub radius.
Also worth noting that an increase in tyre diameter changes the scrub rad. See pics below of MX5 suspension.
MX5's MK1/2 have zero scrub, very little feedback and so Exocet uses wheel spacers or lower ET values than stock wheels.