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Front end angles
newtrikebuilder - 15/6/10 at 07:49 PM

I'm trying to design my trike which will have a locost front end and want to know if anybody knows what all the angles are for. They could have made the front end completely square, would that just look ugly or are there other reasons for it? Is it if there is a crash so that it bends outward rather than inward and crushing the drivers legs?

One of the reasons I ask is because I'm making it narrower and I can't really have the top getting wider than it is at the front. So my top rails would be a single straight piece of metal.

Then the other thing I'm curious about is the sloping front, is that for looks, for the radiator, safety or something else? Is this sloping bit quite difficult to do because the metal slopes in two directions? I've been trying to do this in my CAD software and can't get the angles quite right .

RAYLEE29 - 15/6/10 at 09:27 PM

Hi, the reason for the way the chassis is made is so the suspension pickups are in the correct position you can make your rails parralel so long as your suspension pickups are in the same positions as the originals (assuming your using book wishbones). The top is wider than the bottom to you use unequal length wishbones which alter the geometry as they move up and down basically increasing camber as more load is put on the suspension.
hope this makes sense,
Ray

MikeRJ - 16/6/10 at 09:17 AM

The sloping front end is also for suspension geometry reasons; the top wishbone is much narrower between it's mounting points than the lower one, so the upper front wishbone bracket has to be further back than the bottom one.

You could make the front end "flat" by either using wide upper wishbones that have the same mounting centers as the lower one, or by adding extra chassis members to provide a suitably strong location to weld a bracket to. Either way it would end up a bit heavier than the standard design.

newtrikebuilder - 16/6/10 at 04:36 PM

quote:
Originally posted by RAYLEE29
Hi, the reason for the way the chassis is made is so the suspension pickups are in the correct position you can make your rails parralel so long as your suspension pickups are in the same positions as the originals (assuming your using book wishbones). The top is wider than the bottom to you use unequal length wishbones which alter the geometry as they move up and down basically increasing camber as more load is put on the suspension.
hope this makes sense,
Ray


I was under the impression that the suspension mounting brackets for each wishbone were all the same distance from the centre of the chassis, although I haven't done all of the maths.

I can understand the reason for the top one sloping now. I could see that the top wishbone wasn't as wide, but I didn't realise that it needed to be on a verticle support. That all makes sense now though.