Are there size and weight laws in the UK?

[Jaydart]

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.

 

[Alberto Balsam]

Interesting project.... When I read the first sentence I imagined 2 E-MTBs "Welded" together....
There must be plenty of websites out there that get into this kind of thing. Lots of people build kit cars and bespoke "Motor trikes" etc... Maybe start with VOSA / DVLA???

 

[classic33]

Is it going to be pedal or petrol powered? Along these lines.

Pedal power will place the weight limit on it more than anything else.

 

[Seevio]

There is no realistic weight or size limit from a legal perspective.* If there is electric pedal assist there will be speed and power restrictions.

*over 3.5 and 7 tonnes may require further investigation but I assume you want to be able to actually move the thing.

 

[Jaydart]

That's the problem, there isn't many sites giving legal advice.

And yeah, it'll be purely pedal power!

 

[Jaydart]

There is no realistic weight or size limit from a legal perspective.* If there is electric pedal assist there will be speed and power restrictions.

*over 3.5 and 7 tonnes may require further investigation but I assume you want to be able to actually move the thing.

Well this is what I've come to believe from the lack of information regarding it. I just don't want to be pedaling my ass into police hands.

The ATV is 740 pounds, but with the motor, gearbox, front and rear differential, drive shafts, oil cooler, exhaust system, turbo, radiator, battery, fuel tank, winch, towing hitch etc etc removed it's just over 200 pounds in weight.

Electric assistance might be an option if hills overcome my low gearing plan.

 

[classic33]

Well this is what I've come to believe from the lack of information regarding it. I just don't want to be pedaling my ass into police hands.

The ATV is 740 pounds, but with the motor, gearbox, front and rear differential, drive shafts, oil cooler, exhaust system, turbo, radiator, battery, fuel tank, winch, towing hitch etc etc removed it's just over 200 pounds in weight.

Electric assistance might be an option if hills overcome my low gearing plan.

200lbs won't be got moving by pedal power alone at any great speed. And is going to require more than decent brakes to bring it to a stop.
Given that you're looking at using a vehicle chassis, you may have to undergo the Individual Vehicle Approval test. With this in mind, check that out for size limits, if there are any.

 

[presta]

If you're talking about converting a motor vehicle to pedal power, I be asking the DVLA how to get it off their register without having to scrap it, otherwise I think you'll be needing road tax.

I've no idea whether this is legal, but I'd be interested to know whether the brakes and the chain will hold in on a hill.


View: https://www.youtube.com/watch?v=sjCjbV2EnJ4

 

[Ming the Merciless]

If you're talking about converting a motor vehicle to pedal power, I be asking the DVLA how to get it off their register without having to scrap it, otherwise I think you'll be needing road tax.

I've no idea whether this is legal, but I'd be interested to know whether the brakes and the chain will hold in on a hill.


View: https://www.youtube.com/watch?v=sjCjbV2EnJ4

Hmm, a four seat car can never be a bike by definition.

 

[Electric_Andy]

That's the problem, there isn't many sites giving legal advice.

And yeah, it'll be purely pedal power!

As long as it's pedal powered I wouldn't think you'd have a problem. I can't see plod pulling you for it, when they don't seem to know the rules even for learner legal 125s.

 

[presta]

Hmm, a four seat car can never be a bike by definition.

What's that got to do with anything? The point at issue is weight and law, and converting motor vehicles to pedal power.

 

[Drago]

You'll struggle to get a motor vehicle legal as a bicycle or HPV.

Simply removing the motor and drivetrain won't alter its legally defined status as a motor vehicle (or even mechanically propelled vehicle), and if you administratively 'scrap' it (which you can't unless youre an insurance company or licenced vehicle dismantler) but do not actually destroy the vehicle then you commit criminal offendes as well.

If its got - or had - an engine and a VIN then it won't matter where its from it will always be a motor vehicle regardless of what you do it it. There is no way of escaping that legal reality, and you will never be able to lawfully use it in a public place or on a road.

 

[Ming the Merciless]

What's that got to do with anything? The point at issue is weight and law, and converting motor vehicles to pedal power.

Well it’s kind of fundamental. Just like an elephant cannot be a shark or a castle a bus.

 

[Reynard]

Given the OP appears to know their way around welding kit, wouldn't it be FAR more sensible to design and build a simple chassis from scratch using something like 3/4 inch box section?

If nothing else, you don't have to deal with the limitations of someone else's engineering when going for what is essentially a custom build. It'll just end up being a botch-fest.

And as has been said upthread, you want to be able to move the thing under pedal power. Something that still weighs in at around 100kg is going to be a right arse to get going and an even bigger arse to stop. That's just basic Newtonian mechanics.

 

[Jaydart]

Given the OP appears to know their way around welding kit, wouldn't it be FAR more sensible to design and build a simple chassis from scratch using something like 3/4 inch box section?

If nothing else, you don't have to deal with the limitations of someone else's engineering when going for what is essentially a custom build. It'll just end up being a botch-fest.

And as has been said upthread, you want to be able to move the thing under pedal power. Something that still weighs in at around 100kg is going to be a right arse to get going and an even bigger arse to stop. That's just basic Newtonian mechanics.

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.

You'll struggle to get a motor vehicle legal as a bicycle or HPV.

Simply removing the motor and drivetrain won't alter its legally defined status as a motor vehicle (or even mechanically propelled vehicle), and if you administratively 'scrap' it (which you can't unless youre an insurance company or licenced vehicle dismantler) but do not actually destroy the vehicle then you commit criminal offendes as well.

If its got - or had - an engine and a VIN then it won't matter where its from it will always be a motor vehicle regardless of what you do it it. There is no way of escaping that legal reality, and you will never be able to lawfully use it in a public place or on a road.

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.