Jump to content

  • Forum Rules


Crossbow V2.0

  • Please log in to reply
4 replies to this topic

#1 fenty



  • Members
  • Pip
  • 46 posts
  • Gender:Male
  • Country:northern ireland
  • Spinal Injury Level:T4
  • Injury Date:27-05-2012

Posted 10 October 2013 - 01:36 PM

After getting my reverse trike onto the road last year and putting a couple of hundred miles under the wheels, I found the handling to be really bad. It was great in corners, but on bumpy straights she wanted to tramline all the time.
At the time I got her built she looked like this...

I figured that the weight was too far back, going on the premise that the weight needs to be centered as close to the widest point for a trike to handle well (info from several trike forums and builders) As you can see, in the first version she looks to be very rearward biased.

I figured one way to move the weight forward was move the rear wheel back, so I picked up a lengthened hayabusa swingarm off ebay.

Following the FAQ's on the forum on fitting different swingarms, I got the pivot machined down to fit the MK1 frame and made up some adjustable dog bones so I could play around with the ride height. I then found that I had to get the hayabusa wheel and brakes (though it turned out SRAD 750 gear is the same and fitted fine), as well as a hayabusa shock linkage which I then mounted to the center stand mounts.

i had worried that this setup might cause chain rubbing issues, but since I have a car tyre mounted on the rear wheel, there is no overhang over the rim and the chain clears the swingarm and tyre nicely.

With the rear wheel now much further back, I found that this was going to clobber the wheelchair rack. I took it off until I had come up with something else. This meant I also lost the mount for the handbrake (needed for the MOT for a trike) Since the exhaust pipes now exit up front

I was able to use the existing silencer mount to attach a section of 7/8" alloy handle bar to hold the locking lever and cable routed to the quad bike caliper.

I still had to have some way of carrying my wheelchair so I bought a renntec rack of the forum here as
A) it was steel and I could modify it myself and
B) it was cheap and if I ballsed it up it wouldn't matter too much.
I offered it up to the axle tube and main seat support of my chair and found it was an almost perfect match, so I got some 20mm inside diameter steel tube and cut it along it's length and welded it to the rack to clamp the seat brace. The existing rack rail would hold the axle clamp and it all stays on with bungee ropes.
As you can see, this is much smaller and neater than the previous version and it easier for me to load the chair onto myself.

So after powder coating, fitting etc that was the mods to the back end sorted.

I was still worried that the 225mm wide car tyres up front were just too wide, and therefore contributing to the wandering and tramlining at the front end. I looked around for suitable bike wheels that had a 4 stud pattern, the obvious being VFR750/800 back wheels. However, these being a 180 section, I wasn't really reducing the contact patch by that much. I then looked at a VFR400 back wheel, but these were an 18" and would need a spacer machined to match the 100mm stud spacing to the 108mm stud pattern on my cossie hubs.
A random search on ebay found that the Ford Focus ST170 actually used a 16" alloy space saver spare wheel. At 130mm wide it would take a motorcycle front tyre and it was nice and light. Once powder coated it also looked OK (not like the standard steel versions anyway) So I sourced two of them, got them powder coated and fitted a pair of pirelli motorbike tyres and they popped straight on.


I was worried that they would look too skinny compared to the wider mudguards and would mean I'd have to source, paint, wire and fit a pair of bike mudguards, but I think they look OK. I may or may not change my mind over the winter.

The end result of all this is that the handling has seriously improved. It still takes a bit of concentration on a bumpy road, but even the Canam's with their computer controlled stability systems suffer from a bit of instability in these situations. It's at the point now where I look for an excuse to take her out for a spin now, whereas before i was looking for an excuse not to!.

Still to do? Well I need to upgrade the clutch as it takes a lot of abuse from the extra weight and I have a stage 2 jet kit to stick on to clean up the fuelling. Getting her onto a dyno is going to be a bit of an effort though.

What do you think guys?

"Alcohol and Calculus Don't Mix..... Never Drink and Derive..."

#2 Rob Wood

Rob Wood


  • Members
  • Pip
  • 131 posts
  • Gender:Male
  • Country:USA
  • Spinal Injury Level:T7 / T8

Posted 31 October 2013 - 09:28 AM

Can't wait to be back on open road but will b awhile till money allows. . Looks good

#3 Tetracyclone


    Cereal Poster!

  • Members
  • PipPipPipPip
  • 9,275 posts
  • Gender:Female
  • Country:Southern California
  • Spinal Injury Level:C 5-7 incomplete
  • Injury Date:27-05-2008

Posted 31 October 2013 - 12:21 PM

You suffer from too much fun.

#4 Tyrtaeus



  • Members
  • Pip
  • 128 posts
  • Gender:Male
  • Country:CR, CO, USA
  • Spinal Injury Level:Severe impact injuries
  • Injury Date:09-15-2006

Posted 29 November 2013 - 11:18 PM

I love it! Those reverse trikes are neat looking too.....might give in and get one sometime. :)


I've been trying to figure out a rack solution for my chair that can be attached to my Ninja500, perhaps using the bolts for the sissybar. Right now I just strap the chair down sideways onto the back of my seat, but my wife can't ride behind me if we have the chair. Where do you suggest I go to find a rack similar to the one you have?


Have fun and ride safe!

 "The backbone of success is...hard work, determination, good planning, and perserverence." — Mia Hamm 

#5 fenty



  • Members
  • Pip
  • 46 posts
  • Gender:Male
  • Country:northern ireland
  • Spinal Injury Level:T4
  • Injury Date:27-05-2012

Posted 03 December 2013 - 02:01 PM

This rack is made by a company called renntec in the UK. I think your bike is called a GPZ500 over this side of the pond so I searched the Renntec website for you and found these.



However, the  cost of getting one of these over to Colorado might be quite a bit so maybe have a hunt around on the web to see if there are any US companies that do the same thing.

"Alcohol and Calculus Don't Mix..... Never Drink and Derive..."

Spinal Cord Injury & Cauda Equina Syndrome Support

This website is a way for those with spinal cord injuries and cauda equina syndrome to share experiences and advice. Any medical matters, treatments or alternative therapies discussed on this website should be thoroughly reviewed by a medical professional or therapist before being acted upon. Under no circumstances should you alter prescribed medication or a medical care plan without consulting your doctor or care plan supervisor first.