My (modern) version of a Board track racer.

GoldenMotor.com

damisch

New Member
Jul 26, 2013
24
0
0
Sundsvall, Sweden
Hi guys, thought I would start a build thread for thoose who's interested and also cause I need a LOT of help ;) (I work as a designer so I know CAD and stuff like that but have very little experience working with steel tubing myself, I can use a lathe and know how to machine parts though).

I will probably break a lot of BTR-"rules" so be forgiving...

I will build the frame/fork from my own drawings, it will use larger diameter tubing then most similar builds. My power plant will be a tuned gx200-clone tilted upright with a torque converter, moped rear hub etc.

Here's some rendered cad-files of the frame/fork/handlebars and some process images to start with!

Hope you like it :)

 
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damisch

New Member
Jul 26, 2013
24
0
0
Sundsvall, Sweden
More photos from the actual build so far:

A friend of mine bend the tubing for me. I've bought some rims and Maxxis Hookwork tires and I've used a mill and lathe I have access to for the dropouts and other parts.




 
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damisch

New Member
Jul 26, 2013
24
0
0
Sundsvall, Sweden
On to my first "stupid" question. How do you guys that do not have a notching tool notch your pipes, I have a drillpress/mill but I've never notched anything with it and the angles are very steep on most of the small tubes...?


Thinking about doing something like this:
 
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buba

Member
Jul 2, 2010
914
10
16
los angeles
looking good

I think you have it all covered

how do they treat motored bikes in Sweden -- any legal issues????
registration, identification of vehicle, insurance or????
 

damisch

New Member
Jul 26, 2013
24
0
0
Sundsvall, Sweden
looking good

I think you have it all covered

how do they treat motored bikes in Sweden -- any legal issues????
registration, identification of vehicle, insurance or????
We have very good laws (actually one of the best most forgiving in the world) for home build cars and motorcycles. The only problem is that this
build will go under the same rules as any fullsize 100bhp motorcycle would. I don't know if I will make it legal or just ride it anyway (I would have to have headlight and brake light so alot of electrics would have to be added and I want a pure race-bike-feel) , time will tell.

Got to watch this build,looking AWESOME so far. I am likeing your ideas.............Curt
Thank you mate!

Cool build, looking forward to seeing your progress.

http://www.harborfreight.com/pipe-tubing-notcher-42324.html

Thank you. I will consider this but looking for a method in witch I want have to buy a new tool.

Your frame looks perfect for my next build......everything looks great so far!

.wee.
Thank's. I put in a lot of time in the designing stages to really get it to how I want it. I'm happy with the design. If it turns out well I might make the drawings available if anyone would want them.
 
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scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
Thank's. I put in a lot of time in the designing stages to really get it to how I want it. I'm happy with the design. If it turns out well I might make the drawings available if anyone would want them.
This is a current pic of my 212cc (Honda GX200 clone) race bike built with an unmodified stock Felt beach cruiser frame......the engine sits fairly high in a slanted position. The engine is right around 20hp. Compare with your drawing and you can see how the engine will sit much lower in your frame, even with it mounted in the upright position.

My wheelbase is also 48.5"


 

damisch

New Member
Jul 26, 2013
24
0
0
Sundsvall, Sweden
This is a current pic of my 212cc (Honda GX200 clone) race bike built with an unmodified stock Felt beach cruiser frame......the engine sits fairly high in a slanted position. The engine is right around 20hp. Compare with your drawing and you can see how the engine will sit much lower in your frame, even with it mounted in the upright position.

My wheelbase is also 48.5"
Thanks for the picture! Your bike looks great! I created a CAD of the engine with the dimensions I found online so I have an idea of how it should fit/look. With that being said, cad's one thing and the real world is often slightly different...

Are you happy with the wheelbase?
What's your head tube angle?
 

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
Thanks for the picture! Your bike looks great! I created a CAD of the engine with the dimensions I found online so I have an idea of how it should fit/look. With that being said, cad's one thing and the real world is often slightly different...

Are you happy with the wheelbase?
What's your head tube angle?
Yes, the wheelbase is fine, especially since I run 24" wheels (Hookworms & CST Cyclops).

Not to sure on the head tube angle as I've yet to measure it but would guess around 69*.

Here's a pic of my 99cc commuter bike with the engine in the upright position and another pic of the flipside of my race bike...





Cheers!
 

MotorBicycleRacing

Well-Known Member
Jul 28, 2010
5,844
109
63
SoCal Baby!!!
www.facebook.com
This is a current pic of my 212cc (Honda GX200 clone) race bike built with an unmodified stock Felt beach cruiser frame......the engine sits fairly high in a slanted position. The engine is right around 20hp. Compare with your drawing and you can see how the engine will sit much lower in your frame, even with it mounted in the upright position.

My wheelbase is also 48.5"


 

damisch

New Member
Jul 26, 2013
24
0
0
Sundsvall, Sweden
Some updates.
Bought a very cheap Puch moped rear hub and sprocket. Glass blastered it to look like new (might paint it matte black later on). Made some spacers on the lathe to move the sprocket outwards to clear my 80mm wide rear tire. I made the spacers to have full contact with the hub for support and for the sprocket to be perfectly centered. Hope you like it.

I got apair of old motocross handlebars from a friend that I cut and modified I've also made the clamp that they will be welded to (not pictured).

Handlebars:


Cut the headtube from an old bmx frame:


The hub before glass blastering:


The hub and sprocket glass blastered and the spacers I did for the sprocket (it now sits 12mm/ almost 1/2'' further out):
 
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buba

Member
Jul 2, 2010
914
10
16
los angeles
glad you are sourcing the head tube from the bmx

there are many great lug parts to be harvested from bmx bikes

I chopped up 6 of them today-- now to design just how they will be utilized on another batch of original designed frames constructed to take any engine one would be aware of here on www.motorbicycling .com --no problemo!!!!

let your mind soar-- and sing.. "that is how we do it"