mounting motor on/above top bar - massif fatbike

[Albula vulpes]

looking at this photo Im thinking that isnt gonna work unless engine is set up to run counter clockwise, unless there is a gear box on the other side that causes the output shaft to rotate counter clockwise when the engine is runnng clockwise... there must be a gearblox that just cant be seen.

This bike is still running. I wish though that I would have built it with a Honda GX31 though instead of a Honda GX35.

 

[mapbike]

This bike is still running. I wish though that I would have built it with a Honda GX31 though instead of a Honda GX35.

im not really all that familiar with the small Honda engines like that but Im thinking you wish it was a 2 stroke I stead of a 4 stroke?

correct me if Im wrong on this.

map

 

[mapbike]

what ki d of gear box did you use on that bike?

map

 

[Albula vulpes]

Mounted a 2 stroke to it and broke the ears off of the transmission. If I had my choice of building it with a NOS Honda GX31 or a new Honda GX35, I would pick the NOS Honda GX31.

 

[scotto-]

Regarding my top tube mount, I use a piece of angle aluminum to guard the drive side of the chain more for oil flying up, than for safety since I've never had the engine driven chain fly off. The chain from the BB back to the rear cassette came off once or twice in the beginning, but I fixed that by mounting a larger chainring to the inside of the 24T chainring acting as a chainguard.
I thought about running all chains within chain tubes (similar to a recumbent) but since I haven't had any more derailment problems, I didn't.
-Low-

Don't ever think the primary chain can't come or fly off no matter what length it is.....they can! Use chain guards in places that could keep you from wearing a "chain gone wild". Just a precaution.

 

[Albula vulpes]

I've built 2 of these shifter bikes. The first one the engine chain came off and got wrapped around the cranks and broke the engine in half. I got a new engine, and put a tensioner/chain guide in place and had few problems with the engine chain coming off. The second one I had the engine chain come off but nothing bad happened, so I got another tensioner and have had relatively few problems as well.

 

[lowracer]

I also run the engine driven chain back through a rear derailleur mounted upside down on the non-drive side to provide both tension and precise chain alignment onto the big chainring. Works like a charm.
-Low-

 

[donb4103]

Maybe you could do it the same way i just did mine. I just posted a few pics of "The Beast" in the cruiser section.

 

[TheSignGuy]

Wanted to get some thoughts from the experts here -- what about the possibility of mounting a motor above the top bar on a Mongoose Massif (20" fatbike) by using a longer seat post to make it 'adult sized' like the pic below:

Ideally a small 4stroke and a qmatic if that were possible.

Holly **** I what my pantz, from your tire size.


Quick tell your bike to pull out its shifter cable and breed with my HUFFY so they can make deformed hybrid babies!