If you make the wrong choice it is too late.
Many years ago when I started my career in motorcycle based trike building, I was asked which was best, independent suspension or, zero flex swing arm suspension.
As I had always used the system I designed, (the zero flex swing arm type) I needed to purchase an independent rear suspension trike kit to try it for myself.
I purchased the kit from a well respected trike builder and completed the build. I then went to tour Spain and Portugal for ten days. My pal was on my 1100 Drag star with the zero flex system and I was on a 1300 V4 Royal star a considerably more powerful machine. On a straight road I could leave him in the dust but when it came to bends he would out manoeuvre me with ease and the faster I went into the bend the more difficult it was to steer. So with test riding over, there was no competition between the two types.
It is all about the geometry and at Datum our priority was to create a trike that was available to all abilities without compromise.
So what are the differences and how do they affect the handling and enjoyment of the ride experience.
Our system prevents the trike from leaning over when you go in to corners or bends. Because of this the front tyre which is rounded stays vertical so the camber of the tyre does not influence the steering. The rider and pillion also stay in an upright position. The speed you go in to the bend makes no difference.
When a trike with independent suspension goes in to, say, a left hand bend it compresses the suspension on the right and the rider and pillion lean to the right. This in itself is disconcerting because the lean is in the direction of the force that wants to throw you off the trike. Same applies to a right hand bend. It also puts the front tyre on the wrong side of the radius, so the tyre now wants to turn right but you are steering left and the more you power in to the bend, the more it leans and the greater the resistance against your steering force.
So with this in mind, it raises the question as to why anyone would want a trike with independent suspension. In simple it is far easier to build a trike with independent suspension because the frame that the suspension bolts to does not move, so it gives you a corridor down the centre of the rear frame to run or attach your exhausts to.
We have just returned from the NEC motorcycle Live 2019 after running our stand there for 9 days. It was great talking to people about their own builds and sharing our knowledge with them. The one question we were asked more than anything else was about suspension. The conversations went like this. I wonder if you could help me, I’ve got a trike so I am not here to buy another one. Of course how can I help. Well I bought this great looking trike from—- and in a straight line it is great but trying to steer it round corners nearly rips your arms out of their sockets. I explained the geometry involved and why the trike he had was a problem and that pretty much all the independent suspension based trikes had the same issues. I asked him if he had put the same question to the company who built the trike. He said I went to see them shortly after I took delivery and rode it for about a week. I said it is great in a straight line but I am having a lot of trouble steering it round bends. Their answer was. “Well that’s the way we build them if you can’t steer it there is nothing we can do about that”.
At the NEC I met professional trike builders who have openly admitted that the steering and handling is an issue.
On a final note. A pal mine called bill, who I have known from the start of my trike building days had an accident on his trike and asked if there was anything I could do. His trike was an 1100 Drag star with independent suspension. It was severely twisted but Bill is getting on in years and his trike riding is his passion and life. So we agreed to repair and rebuild the trike. Bill was impatient to say the least as we were approaching the end of the rally, ride out season and he did not want to miss any. So I lent Bill one of our trikes until his was finished. When he left our workshop I informed him that you do not need any effort to steer our trike so enjoy. Our trikes also come as standard with an easy steer unit, designed by myself and patented in 2006. It took him a few miles to settle down to this easy to ride trike. Over the next few week Bill and his wife did all the rally’s with consummate ease.
We fixed his trike and off he went. I asked Bill to give us a call when he got home to make sure everything was ok with the rebuild. The phone rang. Terrific job thank you but your bloody easy steer has spoilt me, when I came to the first bend out of Oke I didn’t think I was going to make it round it, I had forgotten how much effort you have to use to steer it. Bills over all opinion of our trike was an amazing machine in power and performance.