gasket999
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| posted on 14/3/11 at 12:54 PM |
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building a GG Quad - chain drive or shaft drive
I'm moving quite quickly on my next project - a GG Quad inspired four wheeled motorbike.
I've found a garage and agreed rent and have maybe found a donor in the form of a Cat D Honda Blackbird available from a guy at work. Up until
now I had planned on sourcing a BMW K1200-type bike as it is shaft drive and the model which GG Teknic use on their £45k quads.
For an idea of the construction of the finished vehicle, please click
here
Drive will come from the honda engine/gearbox, leading to a rear diff with a pair of car-derived halfshafts, suspension and hubs are double wishbone
a-la Haynes roadster.
Up until now I have only considered using a propshaft between the gearbox and the diff (as this is what is used on the GG Teknic Quads), but after
speaking with Quaife this morning they were pushing a chain-drive diff, their QDF7ZR.
This would certainly be easier to engineer than the shaf-drive setup I was looking at initially, but I do not know the benefits of one method over the
other. To me a chain drive has always seemed a bit "Scrapheap Challenge" and I would prefer the safety of a shaft drive system.
The quad will be capable of, and used at, very high speeds (guessing at 130mph plus) and will be used for European touring so reliability and safety
are absolute number one priority - I'll hapily throw another couple of grand at the project if it will give me peace of mind.
High-speed touring rather than out-and-out racing are what I'll be looking at but I'd welcome any input you may have. The ideal from this
project is a an extremely well engineered motorbike-alternative rather than a bit of heath-robinson temperamental toy.
Any input or advice would be very welcome,
many thanks.
[Edited on 14/3/11 by gasket999]
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minitici
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| posted on 14/3/11 at 01:07 PM |
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Your vehicle will not be classified as a "Quad" (Light Quadricycle or Heavy Quadricycle) due to its power output exceeding 15Kw.
The "Quad" would need to undertake the IVA test rather than the MSVA 
MSVA only applies to:
"4 wheeled vehicle (heavy quadricycles)
Quadricycles (other than those referred to under light quadricycles above) whose maximum net engine power does not exceed 15 kW (20 Bhp)
more than 350kg but not exceeding 400kg (550kg for goods vehicles) unladen weight
if designed to carry goods a payload of a maximum of 1000kg
if powered by an electric motor the weight of the batteries must not be included in the unladen weight"
[Edited on 14/3/11 by minitici]
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The Venom Project
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| posted on 14/3/11 at 01:26 PM |
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GG Quad
No advice, but full admiration for you talking on such a vehicle, I have to say I don't see £45K in one, as I also don't see $58,000 in
the Campagna T-Rex, but I like it, as I like the GG Quad. I seem to think that Boom Trikes UK are the main importer for the GG if you needed to see
one up close?
Its an impressive looking vehicle, how far along are you with the plans / build?
Cheers
Nick
It's not that i'm lazy, it's that I just don't care.....
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matt_gsxr
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| posted on 14/3/11 at 01:41 PM |
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Sounds like quite a project.
If you want shaft drive, then could you not rotate the engine through 90deg and attach something like a Sierra differential directly to the output
sprocket. Maybe have some kind of short prop/doughnut.
Not sure where that puts the exhaust manifold (relative to legs), but motorbikes often have exhausts near legs it seems.
You might want to research the Blackbird number 3 cylinder oil starvation issue (if you haven't already).
I don't think chains are dangerous. If they snap (and they do sometimes) then it will be under load and I believe the chain is pulled into the
engine casing by the sprocket (it doesn't go flailing around like you might expect).
Interesting times. Well worth working out a clear plan before you start building (just ask Scootz  ).
Matt
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Richard Quinn
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| posted on 14/3/11 at 02:07 PM |
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My thoughts would be to try riding a quad before embarking on a potentially lengthy and expensive project. I was recently offered a Yamaha Raptor that
had been lowered, fitted with alloys and road tyres and the 700 replaced with an R1 motor as a trade against my car. It was a beautiful machine and a
very well done professional conversion but having ridden a standard Raptor on the road, I declined the offer. I think I would have either come back
from the 1st trip and locked it away in the garage or not come back from the first trip.
Quads are not a cross between a car and a bike, they are a type of vehicle in their own right and have a very specific riding style that isn't
overly intuitive (or at least not to me) to get the most out of them. I'm not trying to put you off, just suggesting that, if you haven't
already, you at least try a quad first and see what you think. Some people love them, some hate them.
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keithjardine
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| posted on 14/3/11 at 02:53 PM |
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Hi gasket999,
Has your research taken you to the cam-am renegade quad?
I believe they have a rear diff which is shaft driven and then two half shafts to the wheels........
They may also have an electronically controlled LSD which could be more controllable than the "live" chain driven quad setup such as the
raptor mentioned above which can be a handful on the road esp in the damp 
Not sure on the ratio etc etc but may give you some interesting reading
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tony-devon
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| posted on 14/3/11 at 02:53 PM |
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but dont Raptors have a solid rear axle?
riding one with a diff is a totally different experience
yes I beleive it creeps into IVA territory not MSVA but have to wonder at the complications involved in getting it built and tested with maybe a
smaller engine, then changing it?
or what does 15kw work out to in bhp? theres proper 33bhp restrictor kits in the marketplace for bike engines, for people with restricted licences.
edit as I just seen the 15kw/20bhp comment above
I have only ever done MSVA tests, but by the sounds of some of the IVA stories I have heard, its a hell of a lot easier.
I would still be tempted to build it, put in a smaller engine, take for test in bare metal etc, get it registered, then rip it apart change engine and
have all powdercoat etc done?
[Edited on 14/3/11 by tony-devon]
heavy is good, heavy is reliable, and if it breaks, hit them with it
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kipper
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| posted on 14/3/11 at 03:54 PM |
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if you think they are scary you should try riding a high powered motorbike and sidecar
denis.
Where did that go?
<<<<
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gasket999
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| posted on 15/3/11 at 12:27 AM |
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Hi folks,
thanks for the replies.
In terms of registering the vehicle, my understanding is that it would actually be registered as a car rather than a bike or heavy quad. At this
stage, I want to find a formula that would work in theory before I start bombarfing the site and my local SVA center with requests for advice on how
to make it pass. I believe that both the GG Quad and QTEC harley quad are registered as cars.
In terms of riding style, I have only ever riden quads - never bikes, so I am familiar with the driving style (steer into corners rather than lean and
counter steer, all the time squeezing like hell with your thighs to make sure you don't come off), but I do appreciate the pointers.
In terms of how far i've got, i've found a garage and will be moving my tools in there this weekend. I've now lined up a second
potential donor (a CBR600), but obviously won't commit to the biggest cost of the project before I know it'll work. I have to book my
remaining annual leave at work in the next few weeks and will be using my remaining three weeks to make a massive dent in the project, so in short
I'm looking to undertake the bulk of the work in the next couple of months. Once I get a bee in my bonnet with a project I tend to move fast so
this won't still be a half-finished lump oif scrap in a year's time. I have spent the last day solidly designing the chassis using Google
Sketchup - there's only so far i can get before I need the measurements from the donor-bike and diff setup. Once finished I'll post it
here for feedback.
Boom Trikes are quite close to me so I will be popping down to have a look, I've already spent some time around a GG Quadster but would welcome
the chance for another look.
I hadn't seen the Renegade or the Raptor up until now as I had steered clear of traditional quads in my research, but I will be sure to have a
look into it - thanks guys.
At the moment it looks like the easiest setup would be locating the engine/gearbox in the standard factory position but fit a chain-drive diff with
sprocket fitted at the back, and in that case would almost certainly be supplied by
Westgarage engineering who are specialists in diffs and driveshafts for chain-driven
cars. I am also interested in an electric reverse and custom driveshafts from the same supplier.
I appreciate that this is an unusual project but I have done both kitcars and chassis construction before so I'm quietly confident I can do a
good job - the planning stage will be really quite exhaustive!
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