Following discussions with some knowledgeable guys on here, I'd come to the conclusion that simply bolting a production-bike swingarm onto the
back of the chassis is not the best way forward.
One of the main concerns being the sideways forces for which the swingarm was not originally designed.
Problem is, I've spoken to all the custom swingarm fabricators that I can track down and none of them want to work on something outside their
comfort-zone.
Sooooooo... unless anyone can come up with a suggestion for an alternative manufacturer (professional or otherwise), then I think I'm just going
to have to guess which OEM motorbike swingarm is the strongest and give it a try.
Can anyone give any thoughts as to which design they think looks (or know is) the strongest? I'm thinking along the lines of Busa or ZZR1400...
Back in the day metmachex used to make some seriously well braced swingarms for not a lot of ££, worth a look?
Have you thought about a non-bike manufacturer? Z cars, for example, have trailing arms on their mini subframe kit that could perhaps be modified?
[Edited on 8/3/11 by JC]
quote:
Originally posted by flibble
Back in the day metmachex used to make some seriously well braced swingarms for not a lot of ££, worth a look?
quote:
Originally posted by JC
Have you thought about a non-bike manufacturer? Z cars, for example, have trailing arms on their mini subframe kit that could perhaps be modified?
How about MEV or RTR they are doing some things with reverse trike jobbies.
The R1 swingarm is a pretty sturdy item e.g. YAMAHA YZF R1 5PW 2002 2003 REAR SWINGARM SWING ARM on eBay (end time 09-Mar-11
18:44:54 GMT)
If the chassis is going to be somewhat wider than the swing arm at the back, it wouldn't be too difficult to add some braces from the end of the
swing arm back to the chassis with e.g. rod ends on each end. As long as you keep the chassis ends of the braces in-line with the swing arm pivot it
will work without binding, and this would effectively triangulate the swing arm.
[Edited on 8/3/11 by MikeRJ]
Had a look at RTR's site - looks like a Yamaha R1 swingarm.
Never seen one from the side before... looks too long for me!
I think that is the main problem with mid engine trikes like this, you can't use the space taken by the engine and rear suspension for anything
else, it just has to be tacked onto the end of the passenger area which makes it very long.
How about using a BMW shaft driven rear swing arm and having a front mounted engine with a proshaft? That would make it quite a bit shorter.
I like the look of the car but agree it looks to long. There must be some weight and stress on the single shock. Looks like excellent engineering though.
Do a search for the Vortex three wheeler. It has a strong swing arm, made of square tube, with th coil/damper mounted above it.
There is a Yahoo group on it.
quote:
Originally posted by MikeRJ
I think that is the main problem with mid engine trikes like this, you can't use the space taken by the engine and rear suspension for anything else, it just has to be tacked onto the end of the passenger area which makes it very long.
quote:
Originally posted by smart51
quote:
Originally posted by MikeRJ
I think that is the main problem with mid engine trikes like this, you can't use the space taken by the engine and rear suspension for anything else, it just has to be tacked onto the end of the passenger area which makes it very long.
unless you put the seats either side of the engine, which would make it quite wide. Not impossibly so, though.
Cheers.
Another thing I don't like about the tR1ke is that it uses the rear wheel from the R1 too. Again, that wheel was made to deal with a completely
different directional force... I don't think I'd have the confidence to push it around a high-speed corner for fear of it exploding on me!
I'm just finding a wee pic for the Vortex Trike, but certainly looks like a more substantial back end! Not sure I'm convinced enough to
hand over $90 for a set of plans just yet.
The guy who runs blackjack cars in Cornwall has been producing trikes for years, Richard Oakes I think his name is, and he has engineered his own -
might be worth getting in touch with him - though I expect he'll try and sell you a blackjack zero!
Chris
I have used a Honda VFR800 swinging arm in my trike.(see my archive)
I agree, it is hard to make a mid engined trike without it looking long.
The only way I can see to make it short is to have your pedals in front of the front axle as some American builders have done.
Denis.
The Vortex swingarm is made from 2 x 1 for the main 'U' and then 1 x 1 for the damper frame.
Look here:
http://www.briery.com/vortex/index.html
http://reversetrike.proboards.com/index.cgi?board=buildprojects&action=display&thread=120
[Edited on 9-3-11 by designer]
[Edited on 9-3-11 by designer]
might be a bit overkill, but how about F1 or F2 sidecar swing arms?
with the flat tyres they run, they must be designed for side forces?
maybe contact an outfit manufacturer?
I suggest bike engine in front of the front axle driving the front wheels, then use a car trailing arm rear suspension. This gives a shorter more stable vehicle with the weight on the driving wheels. Have to keep all the weight low though or it will tip up on hard braking.
quote:
Originally posted by Ratman
I suggest bike engine in front of the front axle driving the front wheels, then use a car trailing arm rear suspension.
Stable yes, but as much fun? Power oversteer? Sadly no.
Stick with rear drive 'd say, and a swingarrm like this beauty!
http://www.windlesidecars.com/blog/wp-content/uploads/2011/03/P1010423-300x224.jpg
Ad
Twin shock bike swing arms are generally shorter than monos, as there is no need for the rising rate lever arrangement.
If you used two shocks at the wheel end, and angled the tops outwards, they would also compensate for some of the sideways forces.
Yam FJ1300, Suzuki GSX1400 etc. may yield something suitable.
If the engine is at the front, then the length of the swing arm doesn't matter much, because it will mostly be under the slope of the seat back.
I have seen an R1 powered off-road hill climb buggy that used a long chain to drive the front wheels (4wd). I am wondering if a long chain down the
centre of the vehicle would work to connect a bike motor at the front to a std bike rear end. I guess the passenger seat might have to be only for the
narrowed bummed. The chain would need to run in some sort of guide (oily wood?) and it would probably stretch, and it would be noisy. A lot of
compromises.. but the concept is nice and simple. Might suit a single seater trike better.
Another thought is to put the bike motor on the right side of the car, just ahead of the swing arm and run the chain to the right side of the rear
wheel. Then just have a single seat on the left side of the vehicle. Would suit a big air-cooled V-twin. Nice short chassis with no special
drive-train engineering. Hard to make two seater though.
Cheers guys.
PS - It's a single-seater I'm building Ratman...
A fella called John Jamieson who we supply carbon bodywork for his ZX10R race bike has just had a pair of swingarm's commissioned. His first
quote was £26,000. Each 
£26k 
I'll have two!
Just in and got your phone message Steve... will speak tomorrow.
... and the more I read about swingarm design, the more it seems that there is a helluva LOT to get wrong!