Stump Puller

[whg1635]

So I had an idea... Find the smallest front crank and largest rear gear I can. I'm talking much lower that Shimano's "super-low" :

Then, put the widest mountain bike tire possible on the back, and put a 25 pound weight on a rack over top of it for traction. Add training wheels to cope with the ridiculously low speeds, and pull a car out of a ditch with it.
Possible? Not sure if there is anything lower than in the picture above, or if there are any extremely small cranks available.
The exact opposite of this bike:

Thoughts???

 

[CRASH]

Are your forks going to be installed backwards too?

 

[socal_jack]

SRAM & Shimano make a 36t cassette for MTBs, and SRAM is showing a 42t cassette for a new 1x11(yep, it goes to 11) drivetrain supposed to be in production soon. In chainrings 22t up front is about the smallest production chainring I think, unless you go for some Middleburn cranks they make 16t and 18t chainrings for trials riding(these might work on some of the new sHimano and SRAM cranks with that interface).

 

[Philphine]

a trike so you don't have to keep balance, and a drive train with a jackshaft to to get even lower gears? and maybe a flywheel from an exercise bike.

 

[Bendix]

if i remember correctly the older 'autobikes' (the blue/black ones) have a single front freewheeling setup that is actually just a bmx freewheel body with a chainring sized sprocket. spin one onto a rear wheel if you like to go nowhere fast.

 

[jackdaw]

Fun!! Show us what you come up with. I wonder if you could figure out a way to use one of those big...old chainrings as your cog? You might be able to bolt a chainring onto a single speed cog, if you could find one without lightening holes. I'd think you'd want rear facing dropouts too :lol:

 

[BlackJack]

Are your forks going to be installed backwards too?

Those forks were like that for a reason so that the rider could get as close to the motorcycle they were drafting off of to get up to 150 mph.

I see some flaws in this idea as far as having a puller bicycle. Using the idea of pulling a car, etc it would be limited by the strength of the rear dropouts, chain/seat stays, chain, Rear hub/spokes if not using a solid rear wheel, traction capabilities of a 2" wide rear tire and clearance next to the rear wheel at the stays for the giant rear gear. Gym weight plates would need to be hung off the stem, front axle, or on a front rack. The rider would have to be Olympic strong as well. Should make a nice wheelie bike though!

 

[deven_science]

I have a front chainring that someone in the past had made out of a rear sprocket. It's got only something like 18T. I've never had a use for it, so I'd be willing to part with it cheap, if you're interested.