head tube angle question

[Namelessjoe]

hi guys

ill try to post some pics of what im talking about tonight but ill start asking now

I was wanting to build a penny fake thing so i cut a mtn bike I got for parts a while ago in half (chopped the front off)

then i realized why make the back leg when i can use a little kids bike and just put a big fork on it?

whell when i was in the process of assembling i changed my mind and decided im going to try to flip the rear triangle around so the BB is behind the mtb wheel i know ill need to take the pedals and crank off and flip them and the wheel but i think it will work

ill just need to cut the fork and find a buddy with a welder(i have a few ) to weld it on to the rear triangle

the little kids bike seat to where the bb on the mtb bike sits is about the same distance as on my cruiser so seat to pedal fit should be ok I think

so my question: is this going to steer "ok" do those of you who have played more then me think it will be figity for steering or just want to drive itself due to the extra weight of the rear triangle on the front wheel?

it might be easyer to see once i get some pics up

thanks
Alex

oh also is the a head angle i should shoot for? (or just not worry about stuff like trail or steer-ability)

 

[raggedjim]

Alex, this is a text book example of "a picture is worth a thousand words"!

Good luck, Rg

 

[Namelessjoe]

ok so lets see if this works

there we go half a bike with a little bike with big fork on it

from the other side the idea would be to cut off the fork-ends and rotate the fork to meet with the seat tube to make the proper BB spacing and head angle

 

[LukeTheJoker]

Because you are driving from behind the wheel, a dérailleur system will not work, so you will have to change to single speed and flip the cranks side to side.

Penny farthings have the pedals almost directly below the seat as the torque when pedalling will go straight down in line with the wheel, with the seat so far behind the wheel, when you push forward on the cranks, the wheel will want to steer away from you, so you will need a firm grip on the bars to offset the effect.

Luke.

 

[Namelessjoe]

ya i figured as much with the derailleur do you think the springs would be strong enough to lift the chain if mounted upside down i know the tension would be on the bottom chain so you wouldn't want to have it just mounted on the bottom anyway


so as far as steering the angle shouldn't matter much as long as i have a well positioned handles for grip

 

[Namelessjoe]

hi guys i have a bit of an update friend of mine said he'd weld it up

so my next question is is it ok to leave assembled or even have the cranks flipped already or do i need to pull it all to be sure nothing arcs and sticks together? (if that could/would happen)

thanks in advance