Wheels and tyres

[hairy monsta]

Now please please please correct me if I'm wrong here but as I understand things I have to keep the overall wheel/tyre diameter to somewhere near the original Reliant figures if i want a balance between acceleration and a reasonable top end so depending which you start with the tyre width/profile would limit wheel diameter and vise versa

[Manky Monkey]

Check out the tyre size calculator in the Motors, 3 wheels, trike tech section of the main site.

tyre size calculator

It'll help you decide what size you need. The profile of the tyre is a percentage of it's width -so the height of a 70 profile tyre is 70 percent of it's width. Therefore, 2 tyres, the same profile, but different widths, will be different heights.
As a rough guide, we've found an overall wheel/tyre height of around 24 inches gives good acceleration in the first 3 gears, with 4th gear becoming a sort of overdrive for motorway cruising. From 0 - 60, our trikes will actually outrun a lot of road cars. They'll cruise at 70 -75 quite happily & slowly wind up to a top speed of around 85 -90 if you have enough road, but are happiest blatting around A roads at about 60 - 65.

[hairy monsta]

Thanks for the info Manky.
 I got the tyre width/profile bit, its more the effects of increasing/reducing overall wheel/tyre diameter will have and at what sort of rate??
 If I'm understanding it correctly a smaller wheel/tyre combo will increase acceleration whilst reducing top speed and a larger overall diameter would reduce acceleration and increase top speed.
 So i guess what I really need to know is what noticeable difference each extra inch makes. (Too easy don't do it ) and at what point it would become an issue. Any ideas folks?

[Manky Monkey]

Cheap innuendo's always worth the effort I find  Oh, alright then. 
Yup, spot on with the effects of wheel size. As for the exact point at which it becomes a problem -really not sure, as we've found a size that works & stuck with it. Maybe this will help. Maybe not.

Tyre size/diff ratio calculator thingy

Anyone else got an opinion or first hand experience?

[pagan]

I run these 185/80R14 91T TL HANKOOK K715 (14" rims 100pcd 4 stud) on me xj9 reliant axle trike with approx overall wheel height of 25", works great good acceleration through gears 1-4 (v quick from the lights). Not over reving n sits @ 70-80 all day...like MM says 24"+ give n take any 'finger nails'...works well...Triker tried n tested...

Cheers The Pagan