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Discussion Starter #1 (Edited)
Hi everyone, it's been a really long time since I posted any of my work on this forum but I am getting near the end of this big project of mine and I thought it would amuse people if I posted some pics of it.












Specifications

Engine: Genuine Blata W50cc, rated at 12kw / 16HP at 11,500RPM.

Frame: Apart from the head tube it's all home made.

Wheels: 8" diameter and x 7" wide off a big quad bike.

Radiator: Originally intended for a 250cc ATV.

Fuel tank and seat: Originally to suit two different motorbikes, wasn't easy to make them work together.

Seat height: 660mm / 26".

Measured dry weight: 45kg / 20.5 lb.



It doesn't need that much to finish it off. I need to sort out an issue with the fuel inlet on the carby, I waiting for the sprocket which I couldn't make myself with the equipment I have and there are a few other odd things to do still.

It will be made off-road legal with "Recreational registration", this lets me use it on country roads and into the state forest that's about an hour from me.

I can post a heap of in the build pics if anyone would like to see it.
 

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Very nice build !!! I love that it's powered by A 50cc blata, been waiting to see a blata engine in some kind of custom build like a cag... it's usually a polini or BMZ engine if it's high end
 

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Nice project, very well done, that's what happens when you take your time and do it right, lol. I got a headlight just like that for 8 or $9 online shipped. I got a black set of your front handle bars w/ alum bar brace for $17.99 shipped, they all alum, strong but nice and light. I have 4 water cool mini motos. Keep posting photo's it's getting boring here, lol. Getting ready to start on a bunch of projects since the weather is getting better, lol. You could put it under the mini bike section.
 

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Discussion Starter #4
thanks, I wasn't sure which section to put this under because lets face it it doesn't exactly suit any too well Which section do you think I think I should post this under? the "Watercooled pocketbikes"?

I could retroactively make a build thread for this, some people might find it interesting as there was a lot involved and I know projects like this are rarely seen.

That headlight is just there for legalities and I don't plan on using it as I don't wish to go out in the dark. I wish to keep this as safe as possible which means riding in the dark is a no go.

Here are 3 more pics showing how it was during the build process, as you see see I really started with almost nothing.






 

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PBP OLD SCHOOL MEMBER
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Frickin awesome, I love custom sh*t! and this build is sick. Great job :thumbsup:
 

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Accually, your right, it is a water cooled mini bike. This project is so rare you could put it a lot of places here.
 

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Ninja Racer
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its like u stuffed a vette motor into a rx7
I bet that could do a mud rooster tail like no other mini
 

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Discussion Starter #9
Alright I will retroactively do a worklog for this bike. I might as well make it here as I can't see it fitting any other section better. I am a pretty busy guy so I will do it bit by bit. Questions welcome.
 

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Discussion Starter #10 (Edited)
----------------------------------------------------------------------------
-------------------------START OF WORKLOG-------------------------
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[April 2015] - Early concept, this is actually the second remake. The earlier version used the smaller wheel / tyre combo that can be seen to the back left, it looked disproportionate so I upgraded to these larger ones. The frame started with one sourced from an upright scooter that was heavily modified. Despite being the remake I still wasn't overly happy with how the frame was looking despite how much time it took to do. I decided to remake everything.




My ideas at the time on how I was going to lay out the frame.



Early stages of fork modification. It's originally a BMX fork that I cut and milled to let a pipe spread the fork arms apart. I also held each fork arm in the mill and enlarged the drop-outs from the BMX 10mm up to the 12mm I was using. I made my own axle by modifying a length of hard chrome bar. I did so by welding on a drilled out nut on one end and then machining the hardened skin off the other and cutting an M12 thread into it.
 

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Discussion Starter #11 (Edited)


The quad bike hubs where not that well suited and even if they where they where heavy. So instead I made my own, this is the rear hub without the sprocket drive on it. To save on the material cost I made them with more than one piece, in hindsight this was a bad idea. Holes put in to keep the weight down.



The replacement rear fork made up in it's basic form with the axle and hub in place. I dislike traditional drop-out designs so I turned up some that where like tubes that the axle slid through. The basic fork shape was made out of 25mm mild steel pipe and tack welded on. No special frame materials this time round.


All of these tubes much like the rest of the frame all had their ends machined in either the lathe or mill. If anyone wants to know how I did this then I will happy to show them.
 

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Discussion Starter #12 (Edited)


Test fitted with the wheel in the position that I predicted I would run. Brake disk also fitted and I used some wire to hold the brake caliper in a clamped position to hold it in place. It was looking promising.



How the front looked when assembled. The custom front hub was much narrower.


Enough for now, more soon, I hope you guys like it.
 

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Discussion Starter #13


The early mock up of the new frame. The only thing left of the original scooter frame at this stage was the head tube and that's it.

I intentionally let the bottom front of the frame stick far more forward that where it would end up, this was to make it easier later on.

I tried to make do with a fairly simple frame jig at first and using the front wheel but it was problematic and I upgraded this later.
 

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Discussion Starter #14
Now this here is the simple most difficult part of the whole project. After doing a lot of measuring and looking at photos I took some educated guesses on what seat and fuel tank would work the best for me and ordered them. It was a pretty big gamble but it paid off, eventually anyway.

These were from different model motorbikes so they weren't made to suit each other and on top of that I wanted them to be held in a much different position to how they would normally be fitted.

After a significant amount of time I worked out how they needed to fit together and what sort of frame shape I would need to suit it.

After this was painful, neither of these had a single proper reference point anywhere on them. This meant doing my usual method of measuring, calculating and making was a total no go. Because of this I had to do a lot of trial and error and used lots of different tricks that I won't get into. All this was just to get the basic ladder shape. The tank needed to be bolted down and I wanted to keep the original latch system that the seat used. I eventually was able to do everything except for the front tank mount which could be done later.


Below is the final result. it sure doesn't look like much.





 

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Discussion Starter #15 (Edited)


I found a deal for this Blata W50 and went for it, it had a lot more power than what I was looking for but at least it would be a nice reliable option, or so I thought anyway.

Seeing the bike was now going to need a radiator the Y-join from the head tube to the bottom part of the frame was no longer an option. Instead I was going to keep the angled upright pipes as spread apart as the bottom of the frame which would hopefully let me fit a nice radiator inbetween.

The upgraded frame jigs are also visible, they where made to be self supporting and I also made one to simulate the front wheel.





To try and work out where the seat needed to end up I tack welded these flat steel uprights to the seat frame. The bottom end of these where clamped instead. This let me change both the height, forward / aft position and the angle of the lot.

Doing this I could carefully sit on it and see what I liked. Once I had it in the right spot I measured the distances and angles to then work out what was needed to join it to the rest of the frame.

Also visible is the small flat piece of steel clamped on an angle on the left, this was to simulate where I wanted the down-tubes to go.
 

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Discussion Starter #16
I welded joiners between the middle and front fork jigs, this is so the fork position could no longer move. This was to allow me to do the next part of the frame fabrication without constantly trying to keep the front in the right spot.

Below is how I made the head tube to bottom frame section.




 

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You get the Member of the Month Award, maybe even the whole year, lol.
I worked in a machine shop-fab shop alum and plastic mostly, made a lot of stuff for IBM and Hewlett Packard. I know what Quality Machining looks like. That thing is going to scream, lol. I have a bunch of water cooled bikes, Euro and China.
 

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dude if you made extended swing arms for the 18/19 you could make a few Gs I bet, ive been offered 500 for mine and I just cant let it go
 

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You are one talented person, lol. I was thinking the same thing, all kinds of small stuff you could make & longer rear arms. Lift brackets for the X Super Bike rear shocks, raises the top mounting point of the shock so you can put a longer than 5" long shock. When I got a real 6" shock and put it on, it raised the rear of the seat section 4", way to much rake. So, I had to make my own bracket, been a lot easier if I could have bought one, lol. I used a 6" BMX bicycle shock with heavier spring.
Round 1" front fork spring spacers to compress the spring more, and on & on. Where can I get a longer swing arm is all I hear all the time here.
 

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