Board logo

Team MEV - tR1ke
Sonic7 - 8/5/10 at 11:12 PM

At long last Team MEV launch a video of the tR1ke in action

http://www.youtube.com/watch?v=sfaNVup27Z0

This could be my next project, interested to know what do people think of it ?

bmseven - 8/5/10 at 11:50 PM

NiIce

Peteff - 9/5/10 at 07:52 AM

It looks too long and low from the side, too much car and not enough bike like someone took two thirds of a car and stuck half of a bike on the back.

02GF74 - 9/5/10 at 08:57 AM

naughty - doesn't appear to be road registered.

can't say I like the look of it.

whitestu - 9/5/10 at 08:57 AM

I really like that - very sensible approach to using a bike engine.

zilspeed - 9/5/10 at 09:03 AM

quote:
Originally posted by Peteff
It looks too long and low from the side, too much car and not enough bike like someone took two thirds of a car and stuck half of a bike on the back.


That's because that's what they did though

The Venom Project - 9/5/10 at 09:31 AM

Its a lot of money for not that much kit really.

£4000 plus vat and you dont get wheels

You have to source a decent R1

Because it qualifies for MSVA you don't need a reverse so they don't even offer one or even have one available. The seats look shite that come with it, if you request you don't want the seats they don't offer a discount. I found just speaking to them weired as they seemed to think this would crush the reverse trike market.

I reckon I will spend my money on either a T3 Secma, Grinnall Scorpian or Malone Skunk.

Far far better vehicles, all of which have reverse and all look worth the money you are spending.

If I was really flash I would buy a Campagna Trex but they are a touch much at $58,000

tegwin - 9/5/10 at 09:55 AM

Sorry.. doesnt appeal to me..

Any any company who cant be bothered to use a tripod when filming promo material and then puts that crappy music over the top wont get my money!

Dangle_kt - 9/5/10 at 10:41 AM

I like it - crap video though, they would be better using that little "race" track they have used on the other vids. At least they could do more than 2 mph and be legal.

I dont think it is the best MEV product though - the sonic is my current favourite.

Good thing about kit cars is they dont need to appeal to everyone.

scootz - 9/5/10 at 12:21 PM

Me no likey...

big_wasa - 9/5/10 at 02:58 PM

I like the front. Hmm I like the whole thing.

About 50 other cars I would spend that much on before it.

smart51 - 11/5/10 at 05:31 PM

How heavy is it? I'd want it to be a lot lighter than a seven to be worth losing the extra wheel. Looks like fun though.

David Jenkins - 11/5/10 at 06:11 PM

I don't think it's that bad - I've seen many worse.

Bit daft to drive it on the road unregistered, AND post a video of it!

Sonic7 - 11/5/10 at 09:56 PM

Thanks for all the comments I suppose It's a little bit like Marmite (love it or hate it ?)

Found another video of it today, that's a little bit more exciting.

http://www.youtube.com/watch?v=WszJnYxvYz0

beaver34 - 11/5/10 at 10:14 PM

quote:
Originally posted by smart51
How heavy is it? I'd want it to be a lot lighter than a seven to be worth losing the extra wheel. Looks like fun though.


345 kg says on YouTube

smart51 - 12/5/10 at 07:14 AM

quote:
Originally posted by beaver34
345 kg says on YouTube


So potentially 20% faster than a seven with the same engine. Sounds good already. I bet snap oversteer is a bit of a problem when it loses traction. That might be "fun".

iank - 12/5/10 at 07:45 AM

The real problem with RWD reverse trikes (and I'm a fan) is you need to be very aware of their handling 'issue' if giving it the beans out of a tight corner.

http://www.clevislauzon.qc.ca/Professeurs/Mecanique/ethierp/3-wheels/class3.htm

vealmike - 3/6/10 at 12:20 PM

quote:
Originally posted by iank
The real problem with RWD reverse trikes (and I'm a fan) is you need to be very aware of their handling 'issue' if giving it the beans out of a tight corner.

http://www.clevislauzon.qc.ca/Professeurs/Mecanique/ethierp/3-wheels/class3.htm



The website you've linked to is almost correct.

The real problem with a 2F1R rear wheel drive trike is balancing traction with the centre of gravity.

The goal of a designer should be to ensure tha the tyres lose traction and slide before the trike starts to tip.

To determine when the trike will tip, we need to draw an imaginary line from the trikes centre of gravity to the ground. Imagine a string with a plumb bob attached.
The line represents the sum total of all the forces acting on the CofG.
As the trike accelerates, then the point at which the line intersects the ground will move backwards. Braking will move the point forwards. Turning right will move it to the left. You get the idea.

Keep this idea in your head, and now draw a triangle between the contact patches of the three tyres.
If the point at which our imaginary line intersects the ground falls within the contact patch triangle, then the trike is stable. However, if the contact patch falls outside the triangle, then the trike falls over.

To increase the trikes resistance to tipping, the centre of gravity needs to be moved towards the centre of the two wheel axle.

The website fails to realise that widening the distance between the two front wheels also widens the contact patch triangle and therefore increases the resistance to tipping.

With a motorcycle engine in a trike, it is debatable whether a front engine or rear engine layout is better. With a driver only, front engine is probably better. With a passenger as well, the occupants will outweigh the engine, so a rear engined solution is better.

The worst possible soultion would be one where, say, for example, a single driver sits high, near the rear wheel over a battery and electic motor - and the distance between front wheels is narrow.


OK, that describes how to control how much force is required to tip the trike and where to place CofG to maximise the cornering (or combined cornering / accerlerating / braking) forces required to make the trike tip.

This theory applies to ALL vehicles, not just trikes by the way.

I also said that traction is an important part in trike safety. It is, but here the designer has less to play with. It is simply a case of ensuring that the trike is not over tyred. If the tyres fitted are too sticky, then it will be possible to generate enough force (usually cornering) to tip the trike.


Front wheel drive trikes do have some immunity to acceleration + cornering induced tipping, so it's worth noting that they are a special case. It's really simple - turn hard and accelerate and the inside wheel will lift. As soon as it does, the diff will spin the lifted wheel, and power to the wheel on the ground will be lost. As acceleration is lost, the forces acting on the CoG move forwards again and the trike regains stability.

I hope that lot helps explain the detail.

iank - 4/6/10 at 08:07 AM

Actually if you read the whole website (he seems to be a prof of mechanical engineering btw to I'd expect his maths to be sound) it's safe to say he completely understands that widening the front track helps given this diagram elsewhere on the site, which diagrams the cog triangle/pyramid you describe.



IMO any car has to be safe with both single driver and driver+passenger and while it's a characteristic that can be controlled/avoided if you are expecting it it does seem to be very common with RWD BEC (BET?) designs (both Grinall Scorpion and T-rex are pictured lifting their wheels) since the wheels really have to be VERY widely spaced to overcome it in all circumstances.

You're right that the diff automatically saves you on a FWD design as well as the weight distribution advantages. Memo to self be cautious of LSD's in FWD trikes

scootz - 4/6/10 at 10:01 AM

How about grafting a bike onto the rear-end of a space-frame single seater (ex-Formula Ford???).

vealmike - 7/6/10 at 11:20 AM

quote:
Originally posted by iank
Actually if you read the whole website (he seems to be a prof of mechanical engineering btw to I'd expect his maths to be sound) it's safe to say he completely understands that widening the front track helps given this diagram elsewhere on the site, which diagrams the cog triangle/pyramid you describe.


Yup, you have me there, I did not read the entire website, just the one page. It wasn't obvious from that one page that the guy fully grasped what was going on.

Still, in my defence, understanding what is going on with CofG in a trike is so very important to driving one safely that re-posting this info is probably a good idea.

Every Trike pilot should know this stuff inside out IMHO.



quote:
Originally posted by iank

IMO any car has to be safe with both single driver and driver+passenger and while it's a characteristic that can be controlled/avoided if you are expecting it it does seem to be very common with RWD BEC (BET?) designs (both Grinall Scorpion and T-rex are pictured lifting their wheels) since the wheels really have to be VERY widely spaced to overcome it in all circumstances.


I don't think you can overcome it in all situations. Which is why it's vitally important to understand what's going on.

For example, a single driver in a right hand drive trike (2 seats side by side) will always corner faster to the right than to the left. Worth knowing that when a passenger is added, cornering speed to the right decreases and to the left increases.

One that caught me out was camber on the road. I was making a 180 around a roundabout on a hill - effectively a banked turn. The banking flattened whilst I was still turning, resulting in an airbourne inside wheel and a particularly blue string of expletives from my father in law in the passenger seat.
Actually, I was very surprised at how controlable my trike was in bike mode.
I was gently accelerating at the time, I kept the power on and the wheel slowly lifted. Come off the power and it hovered nicely, a quick dab of the brake was required to regain contact with terra firma. That said, I have not repeated the excercise.




quote:
Originally posted by iank
You're right that the diff automatically saves you on a FWD design as well as the weight distribution advantages. Memo to self be cautious of LSD's in FWD trikes

Yes, obviously fitting an LSD would allow you to keep the power on when a wheel comes up.


Once everyone understands the principals of trike stability, the next thing to consider is what would need to happen to "trip" a trike and of course what the results would be. I don't wish to scare people, but I honestly believe that you should be aware of what the vunerabilities of a trike are before you drive one.

tony-devon - 10/6/10 at 09:41 AM

quote:
Originally posted by scootz
How about grafting a bike onto the rear-end of a space-frame single seater (ex-Formula Ford???).


that sounds similar to what Im building

mike engined, bike front end, but the rear end is loosely designed around the haynes roadster, hence why Im on this site

IRS rear end, 110bhp shaft drive bike engine, should be in the region of 400kg finished, my motor once proven that it works well, will be force fed eventually.