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Reverse trike front suspension options
dan8400 - 22/9/17 at 12:03 PM

Hi everyone

It looks likely that a friend of mine is buying my Tiger Supercat. This will then give me a budget to start my reverse trike. I have a chassis but I am stuck as to how to do the front suspension.

I thought I could add some mounts for the locost front wishbones. I think I would also add an anti roll bar. These parts are readily available. The only problem is, I would need to widen the front of the chassis slightly to meet the book dimensions. I would also use Sierra front uprights.

The other option is to have wishbones fabricated to fit the brackets that are already on the chassis. The original company is no longer around so I cannot source from them. I would really rather not guess at the suspension design.

Does anyone have any ideas? Will the locost suspension work on a trike? Or should I try something else.

Thanks
Dan


gremlin1234 - 22/9/17 at 02:03 PM

this page may give some inspiration
http://www.telegraph.co.uk/motoring/news/9675884/Three-wheelers-group-test.html

you could try 2cv... (or even triumph spitfire/herald!)


dan8400 - 22/9/17 at 02:23 PM

Thanks for the reply. I was thinking more along the lines of the Scorpion P6. Double wishbone suspension layout

Thanks
Dan


gremlin1234 - 22/9/17 at 03:14 PM

quote:
Originally posted by dan8400
Thanks for the reply. I was thinking more along the lines of the Scorpion P6. Double wishbone suspension layout

Thanks
Dan
spitfire/herald is double wishbone, and fairly narrow track, but is a 70year old design


dan8400 - 22/9/17 at 03:30 PM

Would my plan of using the book front suspension work? Would the wheelbase measurements be critical to Ackerman etc

Thanks
Dan


Sam_68 - 22/9/17 at 07:20 PM

Being cynical, you probably can't go too far wrong with the front suspension on a trike: unless it's truly, unbelievably dreadful, you'll inevitably end up with more grip at the front than at the rear.

There's an argument to say that you're better deliberately making it quite mediocre (particularly in roll), to moderate the natural oversteer tendencies.

Lomaxes did perfectly well with the leading arm Citroen 2CV suspension, for example, which gives you camber equivalent to roll angle, when cornering (ie. pretty dreadful, by normal standards). I seem to recall that Grinnalls use parallel wishbones, too (very long VSAL's, so near equivalency of camber and roll angles).

The Locost suspension will be designed for a 'normal' compromise between camber in roll and bump, so it might be viewed as 'too good' for a trike, but I don't suppose it would do much harm.

Fashions vary between 100% Ackermann and anti-Ackermann, depending on which way the wind is blowing, which probably tells you that it's not actually all that important: you can make anything work.


dan8400 - 22/9/17 at 07:54 PM

Thanks for the info Sam. That is the most straightforward explanation I have found after two days of googling.

I think I will go with the locost front end. It will be easier to get going. Wheelbase will be about the same too. So hopefully not far wrong.

Thanks
Dan


David Jenkins - 22/9/17 at 09:00 PM

I liked the description of the 2CV-powered trike: "the chassis has its own speed and prefers not to be rushed. "

quote:
Originally posted by gremlin1234
this page may give some inspiration
http://www.telegraph.co.uk/motoring/news/9675884/Three-wheelers-group-test.html

you could try 2cv... (or even triumph spitfire/herald!)


phelpsa - 23/9/17 at 12:37 PM

quote:
Originally posted by Sam_68
Being cynical, you probably can't go too far wrong with the front suspension on a trike: unless it's truly, unbelievably dreadful, you'll inevitably end up with more grip at the front than at the rear.

There's an argument to say that you're better deliberately making it quite mediocre (particularly in roll), to moderate the natural oversteer tendencies.

Lomaxes did perfectly well with the leading arm Citroen 2CV suspension, for example, which gives you camber equivalent to roll angle, when cornering (ie. pretty dreadful, by normal standards). I seem to recall that Grinnalls use parallel wishbones, too (very long VSAL's, so near equivalency of camber and roll angles).

The Locost suspension will be designed for a 'normal' compromise between camber in roll and bump, so it might be viewed as 'too good' for a trike, but I don't suppose it would do much harm.

Fashions vary between 100% Ackermann and anti-Ackermann, depending on which way the wind is blowing, which probably tells you that it's not actually all that important: you can make anything work.


I (unusually ) agree with Sam. Although I will also add that what's acceptable will be down to what tyres you choose to run. If bike tyres then lots of roll and roll = camber angle on the front could be good as they are often softer compound on the shoulders. If car tyres then you're going to want it very stiff in roll to control rear tyre camber, at which point geometry becomes largely irrelevant.

[Edited on 23-9-17 by phelpsa]


dan8400 - 23/9/17 at 12:57 PM

It's going to be car tyres all round. I will want it fairly stiff anyway I think.

Thanks
Dan