MOTO G4

Skate Mac fun!

2011-10-01T10:38:00.000-07:00

Thought I'd just throw up the rest of the rolling test shots from spring when I broke my rib. We have sneaked the Mac up to a local skate park, but it's always the middle of the night and when we venture up on a sunny afternoon the park is full of kids on fruitboots and it's just not polite to barge them out of the way and start smashing an old computer down the half-pipe. It might be different without the parents there!

Good news though, as a couple of retired inline skaters we know have taken it up again and they're highly interested in getting on the G4. One of them has been busy over the summer building their own wooden skatepark out back, so stay tuned for some Mac skating sickness finally, provided we can get something filmed before winter sets in. Pff.

Quad Moto first test!

2011-07-30T07:04:00.000-07:00

Mac Pro Quad Core!!

2011-07-29T04:37:00.000-07:00

As luck would have it another donor-vehicle has cropped up for one of our crazy concepts!

This time its a 60cc mini-moto quad bike that has landed in our lap and could bring about something we never considered doing >>>>> The Mac Pro Quad!!

Apart from being a 60cc this time, the quad is already tuned with a cone air-filter, big-bore stainless race exhaust and a racing throttle-body. Boy that last one really makes all the difference! Its a little rocket!

Im sure empty Mac Pro cases, or G5s for that matter, can't be too pricey by now so with a little luck she could end up looking like the crazy 2009 concept image on the right...

MOTOG4 TURBO - Hooked the 'Busa pipe up.

2011-04-25T10:34:00.001-07:00

Hooked up the Hayabusa exhaust can today and got the supercharger working somewhat using a thick rubber-band and a short tube with a grub-screw to extend the crank-axle stub, although this needs a lot of fine tuning before it'll spin well under engine power. Thought I'd give it a try anyway and couldn't wait to hear the new exhaust sound, but alas she wont fire up. There's no spark for some reason, so I'll have to wait until next weekend to get it sorted, shame.

To get the new exhaust on I chopped the old one off on the up-pipe, removed it completely from its mount under the seat and cut the small silencer off leaving the start of the truncated section as the end of the pipe. With a little shaping with a ball-hammer the truncated section slips perfectly into the 'Busa can and fits tightly into the smaller diameter pipe a few inches inside it. To get the cut pipe at the manifold over to the opposite side I added a new 6" section, using aluminium pipe and fixed it into place with a wealth of ally-tape, it'll be fine for this application.

MOTO G4 TURBO!!!

2011-04-23T09:47:00.000-07:00

I've accrued a few natty parts lately so thought it was time to bring out the old MOTO G4 superbike and vamp it up with a sick new exhaust and some forced induction...

IHI Turbo from a diesel LDV van, has something like a 28mm impeller.

The exhaust turbine is stuffed so I've removed the exhaust-manifold completely and will replace the turbine with a small belt-pulley [to be driven off the crank/flywheel] - turning it into a rudimentary supercharger!

Exhaust silencer from a Suzuki Hayabusa (!) only a couple of years old. New owner replaced it with titanium and threw it in the skip...

Turbo bolted in position. Made a custom bracket from some angled billet-alloy and bolted it to the front fairing-bracket, so will probably need re-enforcing.

The exhaust isn't as heavy as it looks and bolts onto the rear fairing-bracket quite well, although fitting the Mac case back on will be tricky.

Just need to hook the belt up now, run a hose from the turbo to the carb-inlet and hook up the exhaust using metal flexi-pipe and probably lots of ally-tape. For you knowledgeable sceptics out there, I don't think the oil and coolant feed will be necessary, nor will the waste-gate fixture and setting make any difference - the turbo will only be spinning at crank speed. It'll look good and blow on the engine, but we're not going to see boost figures and besides, how much boost can this 49cc 2-stroke take?!

How we made the SkateMac

2011-02-10T14:00:00.000-08:00

Hmm... Macintosh fun times or active outdoor pursuit? Why not both!

The concept is very simple as you can see, just get the trucks off any old skateboard, drill holes in the bottom of your G4 case and bolt them on. There are a couple of issues along the way though...

The G4 case alone is a hefty old thing, so to keep as much weight off those tiny wheels as possible we got rid of everything we could from the Mac's insides, leaving only the metal frames under the drive-bay and power-supply for total rigidity.

This [above] was the obvious place to mount the trucks in order to keep the base of each truck within the length of the case-bottom. This is the strongest way, but the high centre of gravity is a pain in the ass and with such a short wheelbase the Mac is prone to tipping forwards and backwards. For any sort of stability at speed the trucks-axles need to be extended over the edge of the case-bottom, pictured below.

The two bolts at the back weren't going to be enough, so to keep the trucks as stable as possible with them over the case edge we drilled an extra set of holes in each truck, about an inch along from the original rear holes, pictured below. Bunching the bolts together on the inner half of the truck isn't the strongest method, but it's the best you can hope for if you're after a long enough wheelbase.

Welding the trucks on in this way would be ideal, but there is also the problem of case flex. We initially bolted the trucks straight on to the case-floor, with only the plastic spacers from the skateboard on the inside and we noticed the bottom of the Mac was bending around the bolt holes after just a short test. Spacers under the case is out of the question because the Mac rides a little too high as it is. As a quick-fix solution we added two plywood inserts on the inside of the case-floor to give the bolts some extra depth and provide a little bit of suspension-damping, pictured below. This seems to be holding up superbly to the knocks and bangs for now, but I'm sure there's a far better way to mount the trucks for maximum shock-resistance in future.

Read more in this post - Skate Mac Redesign

Ride responsibly!

iBroke my rib on the Sk8Mac!!

2011-02-09T06:44:00.000-08:00

Yes, unsurprisingly some would say, the Skate Mac has claimed its first broken bone! On its first real outing too!

I set off down the hill in my preferred lean-forward, legs-back position (like a superbike) to give myself the lowest possible profile and sluice through the air at top speed. Unfortunately my front wheels hit something (a small twig or a Rizla I think it was lol) and all that weight on the front sent me face first into the concrete so fast I didn't even have time to tense up for impact.

I thought I'd gotten away without injury, but it was so easily done that we decided to drop the lean-forward stance completely - so DO NOT try this one at home! That's what MOTOG4 are here for - to refine this sport and take it on the chin so you don't have to!

It was only after two painful days lifting at work that I decided to get checked medically. Turns out I've fractured a rib! I've been signed off work for 6 days and told to take painkillers, but apart from that I'm to just rest up until it heals enough to get the Mirror-Door rollin' again!

Here's the vid of me epic wipeout. Shame that the cameraman loses attention right at the crucial moment, it should be zoomed in, nevermind.

Getting a feel for the Skate Mac...

2011-02-06T14:06:00.000-08:00

As you can see, the iSkate is now starting to earn some battle scars. We spent a few hours trialling it down some downward slopes today to try and get more speed, distance and basically more confidence on the thing. We had intended to take it to a skatepark in nearby Heswall, but it was full of young children with their parents and we figured that two grown men would ruin their Sunday afternoon by barging them out of the way and filming it.

We did find a nice quiet downhill path in a local park though and got rolling. After a horrific face plant however, we have decided that the leaning-forward / legs-back position is a total no go, if the Mac slows suddenly in any way you go straight over. Instead, the leaning-back position is a must to keep upright at any sort of speed.

** I will post the videos as soon as possible!!

Skate Mac 1st Test

2011-01-17T16:10:00.001-08:00

Just a quick vid to show the skater in action, but it was dusk so its hard to see anything on the phone camera. Time for some serious downhill practice and big speed before we film some more tests in the daytime and we're scoping out the local skateparks to find a suitable ramp to get some air on the old mirror-door, maybe do a tabletop or something who knows.

Skate Mac Redesign

2011-01-16T16:31:00.000-08:00

The iBoard looked the part, but it was a nightmare to ride. I'm no skater, so I put the trucks on to maximize the wheelbase and an informed friend told me I had them on back to front. I'd never have though it would make a difference, but you had to tilt opposite ways to steer. Leaning away from the corner means you just fly off, not that this would matter as the wheelbase was still too short to get any speed up without toppling forward or back anyway.

The real problem, however, was the severe lean to one side. It turns out that the steel-case isn't central to the overall Mac. The plastic sticks out half an inch on oneside for the door mechanism, but naturally when I made the holes for the trucks I measured dead-centre to the metal-case so even if you could get rolling for a moment you just veered to the left. In other words the thing plain didn't work.

To rectify things we had to measure to the centre of the entire case and move the trucks over. They also needed to be mounted the other way round, but this meant the wheels would be even closer together. They were already at the edges of the steel-case, so we were forced to have the trucks overhang at each end and put the four bolts less than an inch apart, making it not the strongest of designs, so we threw in a couple of strips of 5-ply wood on the inside of the caseand bolted the trucks through them. This should take a bit of stress off the case-bottom and may even soften the ride up a bit.

All in all the wheelbase in 2" longer and its a completely different animal to ride now. Much easier to ride straight, no jerky turning and you can steer now, although the centre of gravity is still so high that it'll take a bit of practice to not need a bit of feet down correction, so I'll post some test vids soon.

iBoard / Skat-E-Mac

2011-01-09T14:49:00.001-08:00

Old 'Project Buran' Super-Macbike Pics

2011-01-05T14:27:00.000-08:00

After a disasterous firstattempt at building a Pro-Stock skate Mac from the case of our trusty late 90's G4 'Sawtooth' Powermac we decided to step-up our efforts and debut the MOTO G4 series! This involved completely gutting the case and building it onto a mini-motorbike frame. We named the project 'Buran' after a space-shuttle the Russians spent billions constructing, but ran out of money before it ever flew. (NB: The bike has ridden once though so maybe 'Spruce Goose' would have been better.)

The pics below catalogue the ongoing conversion process of this astonishing machine from retro-Snapple to superbike.

This was the original concept on which we based the Mac-Moto - bicycle steering and the engine inside the Mac case. Turned out we were using an air-cooled engine so we ended up mounting the engine just in front of the case even though it would have fit inside. I would not advise fitting the engine completely inside the case unless you have a good duct system or a water-cooled motor.

First we removed all the plastic panels and cut apart the Mac case to fit the bike frame. This involved stripping everything inside the case, including the metal drive-tray and the Airport, down to a bare metal box. To make the hinged side-panel lift up instead of down we had to turn the case upside-down to fit onto the bike. This makes the plastic panel-fit not exact, but close enough to screw back on. Rather than have the back of the Mac-case on display at the back of the bike, with all it's sockets and fan holes, we also decided to turn the Mac round so that the smooth case-front would be on show.

Welcome!

2011-01-01T16:09:00.000-08:00

Welcome to the MOTO G4 blog covering our Apple-Mac based motorbikes and skatesports!

This blog is part of ScoobyLab.co.cc - Impreza knowledge-base and '98 WRX STi project car blog. http://scoobylab.co.cc