Are there size and weight laws in the UK?

[Dogtrousers]

I have no clue about legality, but it certainly sounds like an interesting project. Don't hesitate to keep us informed/entertained with whatt you do

 

[Reynard]

But there's no challenge in that for me, plus it's not very exciting.

Everything is already there except the actual cycling gear so I don't need to worry about brakes etc.

The engine is 1000cc and automatic gearbox so it's very large and spacious, easy to weld the gear into the chassis with all that out.

I'm going to build a simple shaft drive from pedal crank to rear differential drive. If I keep the sizes right I'm aiming for Sherco trials bike type gearing, in 1st.

I'd say it was like pushing a small to midsize motorcycle in neutral now that it's a rolling chassis. But if I change the wheels it'll be easier again. It's currently got 12 inch wide mud pluggers fitted.

OK, fair game. Looks like it's a "let's see if this can be done" kind of project then. Good luck, but (with my automotive engineer's hat on) you may find that it's far more trouble than what it's worth. If you can get it to work, I shall be impressed.

I'll still say that a scratch built chassis will give you far better functionality as a 4-wheel MTB given how big and bloated most American-based machinery tends to be, but then as a 4ft 11 female, the idea of pedalling something with the heft of a good-sized motorbike uphill has absolutely no appeal at all...

 

[classic33]

But there's no challenge in that for me, plus it's not very exciting.

Everything is already there except the actual cycling gear so I don't need to worry about brakes etc.

The engine is 1000cc and automatic gearbox so it's very large and spacious, easy to weld the gear into the chassis with all that out.

I'm going to build a simple shaft drive from pedal crank to rear differential drive. If I keep the sizes right I'm aiming for Sherco trials bike type gearing, in 1st.

I'd say it was like pushing a small to midsize motorcycle in neutral now that it's a rolling chassis. But if I change the wheels it'll be easier again. It's currently got 12 inch wide mud pluggers fitted.


This is certainly an issue, though I'm hoping that the ATV being a recent import from the states will help as there's diddly squat for it over here.

If not, it'll be an off roader only which is okay, I live on a farm on the Moors and there's plenty of trails and fields, though the roads are my main goal.

You're intending using the wheels and brakes as fitted?

With the extra rolling resistance from the tyres, and the friction from the shaft drive, I doubt very much you'll get it going under your own power. Heaviest load to date, moved under my own power was a third of a metric ton. This doesn't include rider weight. And that didn't move very fast uphill, took a fair bit to stop it. And a fair bit of forethought about stopping it.

 

[T4tomo]

Hello!

I've been looking around but can not find much regarding this, was hoping someone on here could help.

I'm wanting to build a mountain quad, like a mountain bike but with 4 wheels.
I'm going to take a full-size American ATV, strip it down and weld in the cycling gear but I'd rather it was road legal so I can use it like I do a mountain bike.

So does anyone know what the size and weight restrictions are in the UK?

Thanks.

I really would worry a hoot about legalities, unless your Chris Hoy on steroids you aren't going to be pedalling it along any road anyway.

 

[Jaydart]

OK, fair game. Looks like it's a "let's see if this can be done" kind of project then. Good luck, but (with my automotive engineer's hat on) you may find that it's far more trouble than what it's worth. If you can get it to work, I shall be impressed.

I'll still say that a scratch built chassis will give you far better functionality as a 4-wheel MTB given how big and bloated most American-based machinery tends to be, but then as a 4ft 11 female, the idea of pedalling something with the heft of a good-sized motorbike uphill has absolutely no appeal at all...

Pretty much. Yeah it's a big ass Quad, 8 by 4.5 foot. As a rolling chassis now without original 12 inch wide tires and the rear diff as I've ran into drivetrain issues it's around 200 pounds in weight, I'm 220 pounds and 6 foot 1 so it's not a big deal to move on the flat or uneven field but hills, it doesn't work..

Wheels, brakes and rear diff are or what's left to correct.

 

[Jaydart]

You're intending using the wheels and brakes as fitted?

With the extra rolling resistance from the tyres, and the friction from the shaft drive, I doubt very much you'll get it going under your own power. Heaviest load to date, moved under my own power was a third of a metric ton. This doesn't include rider weight. And that didn't move very fast uphill, took a fair bit to stop it. And a fair bit of forethought about stopping it.

I was, but they both must be changed now. Yeah 12 inch wide mudpluggers are no good.

The rear diff is my main issue, it needs to be taken out and I need to come up with another idea, was hoping to keep that bit..

 

[Reynard]

If nothing else, you need to reduce the rolling resistance, so swapping those wheels & tyres for skinny bike ones. That might be a joy, trying to get hubs to match though. And ditching the diff will also get rid of unnecessary weight. I suggest you have a look at the pedal-powered cuistax you see hired out to tourists on the Belgian coast for ideas regarding chassis and drivetrain.

 

[classic33]

Check the Atomic Zombie site for ideas.