Steering system types ?

[CompoSimmonite]

I'm currently working on my own "modern microcar" project (using swing axle front suspension and 125cc driven rear wheel).
The debate is what to do with steering - direct like Messerschmitt, steering box or steering rack.
What is the opinion of others who have driven several different types of microcars as to which works best for such narrow track (under 48") and  three wheels ?

Thanks

Paul H

[Smart51]

I've doing the same kind of thing.  In imperial, my front track is about 41" I think.  I've gone for rack and pinion but only because I found a small rack on eBay for not much money.  If you're used to driving a car with several turns lock to lock, you might want to make your micro similar.  A steering box may be easier for you to fabricate but I'd look to see what parts are easily available first.  Remember you may want spares in the future too.

[marcus]

If you have driven a Messerschmitt and like the feel go direct, if not I would go for r&p

[CompoSimmonite]

I've actually got several A35 steering boxes and idler relays (both quite small). I'd modify them by cutting off the steering column, add a bearing and have the remains of the column  stub on the box splined so UJ's could be used.
I've only had a quick look at SVA / MSVA rules but seems some sort of collapable system needs to be used which procludes an unaltered A35 steering box & column. The same would be needed with a direct system - some sort of collapasable link between wheel / handlebars and chassis mounting could be required.
I prefer a quick rack but am worried about bump steer with using swing arm suspension.

Paul H.

[marcus]

It sounds like you have already researched the rules and probably know much more than me, but a while back there were different regs for one-offs and also light 3 wlrs which were only governed by a much easier set of rules

[CompoSimmonite]

It sounds like you have already researched the rules and probably know much more than me, but a while back there were different regs for one-offs and also light 3 wlrs which were only governed by a much easier set of rules

The regs for three wheelers under 1000kg are still covered by the old MSVA ones and haven't changed like cars from SVA to IVA.
Still going to need a lot of research into components etc before working out the final design.

If anyone is interested I can email a full pdf copy of the MSVA manual.

Paul H.

[marcus]

That's good to hear, it leaves room for innovative small vehicles, I am interested in hearing how you progress.

[Chris Thomas]

Dear Paul

Is it worth looking at what the French San Permis vehicles use as they need to comply with presumably the same regulations.

From memory I think the Aixam uses a Peugeot steering rack and column which is very small and has links from the middle which would work with swing axles and could provide you with the approved collapsable link. The other way might be to look at the Vauxhall Corsa steering unit which is again quite small.

Chris Thomas

[marcus]

Some of the better (Go) Karts might also be worth a look at for parts