Looking for some advice. Many LSIS cars are Sierra based or use Sierra hubs.

It seems to me that wheels which are designed to fit Ford Sierra hubs have an offset which means that the centre portion of the wheel is set almost out flush with the outer edge of the wheel, and in my opinion on some wheels for example a minilite/superlite/Compomotive ML style of 8 spoke it doesn't look as nice as if the centre of the wheel was more recessed from the outside edge.

Is it possible to fit a different offset of the same size of wheel (deeper dished with the centre of the wheel more inset)with the Sierra hubs when fitted to an LSIS car or do you have to stick with the Sierra offset ?


Any advice appreciated

Hi Angus

Have a look at this website:
http://www.alloywheelsinternational.com/FORD.html

Sierra wheels have a large offset which as you say, pushes the wheel into the wheelarch. The offset is identidied by the ET number and as you see the Sierra is in the region of 40mm. Many kit cars run on an ET of 21 or 23 and this not only looks good but it will sharpen the steering as well. If you decide to go for non Sierra wheels, try to make sure the counterbore is the same as the Sierra which is 63.4mm. The wheel is centalised by the hub spigot fitting into this counterbore. This will ensure freedom from vibration. There are many wheels to choose from out there and I am sure there are many in the Group more able than I who can advise you on what to look for.

Regards

John

You should try to stick to the offset that the uprights were intended to run.
If you deviate too far from the designed offset you will affect the scrub radius.
The reason some kit cars run different offset wheels is because of different uprights being used. ie. Sierra, Cortina, Custom made. etc. etc.

You should try to stick to the offset that the uprights were intended to run.

This will only apply if the suspension design and geometry is the same as on the Sierra where the scrub angle is dependant on the inclination of the Mcpherson strut. By modifying the Sierra upright to accept a top ball or Rose joint for a double wishbone system the suspension geometry is entirely different. Scrub, caster and camber will all be different from the Sierra irrespective of what wheel offset is used.

The later Phoenix has been designed around a donor Sierra and the wheel offset recommended by Jeremy Phillips is ET23.

It would be interesting to get feedback from Locost owners using Sierra uprights to find out what wheel offsets they are running.

John

Here's an extract from a posting on the Sylva group website. Just to add another factor to the pot
Go for the Escort / Capri uprights their geometry is better than the Sierra
and they are lighter.

The problem with the Sierra castings is the stub axle is offet to the front.
So the amout of trail that you get from the castor angle is almost
completely negated causing a lack of self centering.
It takes a massive ammount of caster angle to get a reasonable amount trail.

If you were to look from the side of the car and draw a line from the upper
to the lower balljoint and extend it until it reaches the ground, it should
strike the ground in front of tyre contact patch. The distance from this
immaginary line to the centre of the contact patch is amount of trail. Trail
gives self centering just like a Sainsbury's shopping trolly! On the Sierra
upright the stub axle is offset to the front of the car. This moves the
contact patch forward in relation to the immaginary line, reducing trail.

On the Escort / Capri upright, the sub axle sits on the line between the
upper and lower balljoints.

Jeremy at Sylva has stopped using Sierra uprights on the Riot and Mojo SE
for this reason.

The inference is, I think, to steer clear (no pun intended) of the Sierra upright altogether and to try to source an Escort or Capri unit.

John