chain drive brompton folding bike

[fireball_jones]

been working all weekend (again) thought i would start showing you guys what ive been up to.

its still in process.

and alot of thought was put into enable the bike to still fold. just undo the four engine bolts.

anyway this is my lunch hour i post more stuff as i complete it

what do you guys think?

thanks

 

[Happy Valley]

Looks pretty cool. What engine and and transmission arrangement are you using on that?

 

[fireball_jones]

thanks happy valley. yeap it was alot of thinking to get to this. its pretty much MY ultimate transport especially once proved reliable.

im using a eho35 robin subaru, the choice of many motorbicyclists. the transmission is a 5:1 gearbox 8t custom made drive sprocket (made painstakingly one week end with a angle grinder a a template i drew if anyone know where i can buy one get one made or can make one for me that would be greatly apprcieted. ) a 24 t stumley archer sprocket (the largest avalable ) which runs an internal geared hub with a total of .73 to 1.36 reduction/increase, of in 1:1 its calculated a 20mph ( i could get 27mph in first but im just to chicken sorry) however i think in the real world this is much lower due to efficency loses, of which i would be intrested to learn what peoples opinions are.

thanks

i know some people may consider a full suspension 26" moutain bike "cool" but for me a bicycle that can fold as small as this, as ride as good, and potenialy be motor assisted is VERY cool.

 

[Happy Valley]

Thanks fj, just caught your update, nice work there. The black Robin threw me though, I have a few myself. You paint it?

BTW, a motorized folder is definitely something I want to do one day great for traveling and that's cool.

 

[fireball_jones]

yeap i painted it only temporaryly (or however you spell that word . other wise the engine sticks out to much, visually or in other words its very noticable. anyway in the states in good old kansas city where i used to live, engines are fine on bicycles if they are under 50cc (even had a police officer complament my tig welding on the frame mount i built) however here is the uk this are not so nice, so i have to be more secrative. ill take a photo becaue i also hid it within a pannier bag, with stratigic opens for the car and exhaust.
ill post it up when i finish my tea.

 

[fireball_jones]

sorry cant find camera at the moment so ill have to update you guys next time. any whey took it out for a run this mornig and the chain seemed a bit bouncy i might try puting on a mini moto chain i haveing one of these shiped over
http://cgi.ebay.co.uk/Mini-Moto-Bik...trkparms=65:12|66:2|39:1|72:1688|293:1|294:50

i need to use a small one to have one emough gear reduction and clearance. etc

 

[fireball_jones]

p.s

as with many other enthuiasts, we are on a journey of discovery, this leg im on began with this bike. illustrated in the thread below.

http://www.motoredbikes.com/showthread.php?t=12696&highlight=lightest&page=4

 

[5-7HEAVEN]

I mounted a Subaru engine w/1.125" friction drive on my folder bike. It ran very well but wouldn't fold anymore. 27mph was tops.

Then I installed TLE 43cc Mitsubishi engine with chain drive on the Dahon. Now it folded, but was spooky fast.

For safety reasons I abandoned the project, gave the bike away and transferred the Mits engine to a 26" girlie cruiser.

 

[Mountainman]

nice -- heavy duty looking set up !!

how sweet it must be to ride on that thing !!

 

[DetonatorTuning]

HI fireball,

thanks for visiting my thread today.

what you have done here is quite inovative. the internal geared hub up front is a wonderful choice for compact design and function.

hows the weight of the engine out front affect the stability while riding ? is there any "torque steer" sensation ?

getting many miles on it yet ?

steve