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The mkiv Supra Owners Club

Project Tadpole


JustGav

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A few months back I acquired a CBR900RR that had been dropped with very little engine damage, the initial plan was to install the engine into a go-kart but some common sense kicked in and that has been parked until I can source a 400cc lump rather.

 

So I was left with what to do with the blade, given that I will not be seen on a bike, both parental and spousal insistance.

 

Well after much sitting around the kitchen table looking at plans and designs, and doing a whole stack of measurements and even more measurements. The idea of the tadpole was stumbled upon.

 

After an initial setback due to the fact that a fireblade frame is aluminium and our chassis will be box section we had to work out how to replicate portions of the old frame but yet still maintain the same mounting points.

 

After a bits of fabrication by ben, he came up with a combined jig/swing arm frame which we are building on, and will be stripped back and the excess material removed.

 

However day 1 saw very good progress with both the rear H-frame being constructed as well as the rear engine mounts.

 

The cockpit section has been laid out with a set of seats in order to get rough idea on spacing and hopefully have the frame laid tomorrow and initial sizing set out. Ben is doing the chassis frame on a jig tomorrow while I sort out the wiring... we may even have a rolling chassis of a real basic kind tomorrow :)

 

http://www.slipstreem.net/tadpole/DSC00207.JPG

http://www.slipstreem.net/tadpole/DSC00208.JPG

http://www.slipstreem.net/tadpole/DSC00209.JPG

http://www.slipstreem.net/tadpole/DSC00210.JPG

http://www.slipstreem.net/tadpole/DSC00211.JPG

http://www.slipstreem.net/tadpole/DSC00212.JPG

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So whats it going to be? apart from unbelivably quick?

 

It is going to have two wheels at the front, with a single drive wheel at the back, hence the nickname tadpole. A lot further down the line, I will be laying either fibreglass or polyacrylic over the frame to create a bodyshell.

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Nice one dude, how are you going to do the front end? I presume you'll be having more car-based controls.

 

I'll tell you what; if you get the geometry right, it'll be a wick little bugger! I built a cavalier engined trike like that about 10 year back, probably a fair bit bigger than yours, but it was a hoot to drive.

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Nice one dude, how are you going to do the front end? I presume you'll be having more car-based controls.

 

I'll tell you what; if you get the geometry right, it'll be a wick little bugger! I built a cavalier engined trike like that about 10 year back, probably a fair bit bigger than yours, but it was a hoot to drive.

 

Yup, the front end is entirely based upon a caterham style front end but without the engine bay area.....using a smaller steering rack from a fiat sciento. So it will have the usual three controls in the foot well, with a simple click-up/down gear stick linked back to the bike's gearbox.

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Day 2 - Lower outer chassis built and all uprights measured and cut ready for tomorrow's bit. This is where it gets interesting now as we are planning on mating the drivetrain subrame up to the middle/front assembly. So tomorrow I'm fitting the lower front wishbones with a mock up suspension so we can measure the upper chassis bars and get them lined up and laddered properly

 

Was bored, so sat in the seats going 'brrrruuum'

http://www.slipstreem.net/tadpole/DSC00213.JPG

 

http://www.slipstreem.net/tadpole/DSC00215.JPG

http://www.slipstreem.net/tadpole/DSC00218.JPG

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I know an MOT place in Somerset (not that local I know) who seems to MOT anything different, inc bikes, trikes & one-offs.

 

Let me know if you need contact details.

 

Good luck with the project...

 

G

PS... if it doesn't go to plan, how about putting it in a stripped out. lowered, wide, Smart Car ! :)

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Gav you smoke waaaaaay to much lol......;)

 

pfffffft.......:p

 

I know an MOT place in Somerset (not that local I know) who seems to MOT anything different, inc bikes, trikes & one-offs.

 

Let me know if you need contact details.

 

Good luck with the project...

 

G

PS... if it doesn't go to plan, how about putting it in a stripped out. lowered, wide, Smart Car ! :)

 

Will definitely pick your brain re the MOT and SVA thing when it crops up.

 

The smart car idea is a working idea, I actually fancy a smart as daily runner with a bike engine.... so MAYBE... :p

 

 

This reminds me of American Chopper, good luck with the project! :)

 

Except less ego's and more swearing :)

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Haven't done much today on the fabrication side, mainly look at ball joint setups that we need for the front wish bones.

 

However, here is a question for an SVA savvy people...the speedo on the car needs to be accurate, this accept, but could I use a GPS system to calculate the speed. I'm just thinking that I have got a mini itx pc, touch screen and GPS system from my old carpc setup.

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Lot of work done on the chassis today...

 

http://www.slipstreem.net/tadpole/DSC00219.JPG

http://www.slipstreem.net/tadpole/DSC00220.JPG

http://www.slipstreem.net/tadpole/DSC00221.JPG

http://www.slipstreem.net/tadpole/DSC00222.JPG

 

Called it quits for today :)

http://www.slipstreem.net/tadpole/DSC00223.JPG

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Bloody hell! You're flying through that, I would still be at the talking about it stage.

 

We spent 2 days just getting the bottom chassis bars ABSOLUTELY spot on square and flat, so the uprights and upper section were a lot easier to measure, cut and weld into place. We have now got the tricky part of getting the wishbones on the front in alignment with the rear wheel and get it all tracked up right. The rear subframe assembly can then be attached to the body with the correct beams.

 

There are plenty of ladder beams to go into the chassis, what you see above is a basic external chassis and doesn't include anything strengthening, seat beams, laddering or bulkhead bars yet.

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Have you thought about a body for it? maybe modded sportsbike fairings?

 

The body will either be fibreglass or hopefully a few sheets of polyacrylic (I personally fancy some of the ballastics grade stuff) folded over the finished chassis. The chassis will have some additional thin tubing attached to it to give a bit of shape. Don't worry it won't be all square box tubing.

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However, here is a question for an SVA savvy people...the speedo on the car needs to be accurate, this accept, but could I use a GPS system to calculate the speed. I'm just thinking that I have got a mini itx pc, touch screen and GPS system from my old carpc setup.
AFAIK they check the speedometer on a rolling road, so......
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