New Guy with a question

K

KoOni

New Member
Hi, I've been looking into putting together a cool motorized bike, but am a little worried about some of the logistics. I want to start out with a fatbike (something like this: link) but I know that most engine kits require hooking up a secondary bike chain and I'm afraid that the fat tires will get in the way of the chain. In the end I'd love something that looks like a mini cafe racer, but I'm just scared of that issue with the tires.

Anyone dealt with something like this before?
 
Howdy KO, welcome.

I have no experience with fat bikes. But with out a doubt, there is gonna be an alignment issue/speed bump. (Can always get over bumps)

Can probably get around the tire with the chain if the rear wheel hub is matching but the drive chain comes off the engine for a much narrower alignment. Off the top of my addled head, you would have to DIYer a jack shaft or to simplify jack shaft over and use the bike gears. Just as an example, some thing like a sickbikeparts shifter kit.

The sky really is the limit and you can make any bike work. Just a matter of tools, parts, imagination and time.

Build some thing cool!
 
Thanks Dan! Would something like this be a good/reliable work-around?
link


Your so very welcome.
That would be the way I would go with that bike. But many ways to feed a cat and that is just me.

Honestly, many options and ways to go.


Post lots of pics! Gonna be a cool build!
 
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You need more info. Get a cheapo old bike, get a kit, build that. By the time you have that running good, you'll know enough to decide if you have the skills for the fat bike.
 
crassius said:
You need more info. Get a cheapo old bike, get a kit, build that. By the time you have that running good, you'll know enough to decide if you have the skills for the fat bike.
Click to expand...

Is good advice. Great learning tool. A fat is a tuff first build.
 
I have a chopper that has a similar rear wheel and, aside from the engine mounts (the frame om choppers are different), chain alignment is no different.

Two problems I see with the fat bike, 1; disc brake is on the left rear, where the sprocket would go normally and 2; no room for a jack shaft as per problem no.1.
 
Dan said:
Your so very welcome.
That would be the way I would go with that bike. But many ways to feed a cat and that is just me.

Honestly, many options and ways to go.


Post lots of pics! Gonna be a cool build!
Click to expand...
Will do. I work as an artist with a bit of training in design, so this should be interesting.

crassius said:
You need more info. Get a cheapo old bike, get a kit, build that. By the time you have that running good, you'll know enough to decide if you have the skills for the fat bike.
Click to expand...
Sometimes when I do things I need to go whole hog if I'm going to get it done. I think its one of those artistic showoff personality type things. I had an awesome scooter a while back (1961 vespa vbb) that I totaled, and a beater bike with an engine strapped on just won't cut it for me. I gotta do this thing, do it right, and have something that I feel like I can show off.

SchwinnStingray said:
Two problems I see with the fat bike, 1; disc brake is on the left rear, where the sprocket would go normally and 2; no room for a jack shaft as per problem no.1.
Click to expand...

Good thoughts, but...
1. I'm thinking the disk brake shouldn't be a prob with the shifter kit that I posted; it hooks the drive train directly into the bike's pre-existing chain setup.
2. Not sure which part a jack shaft is. Will this be an issue with a shifter kit? (I'm naturally mechanically adept, but not trained on what stuff is called. For me most of it is "that thingy that comes out of the thing in the engine and attaches to the toothed wheel thingy")
 
Hello and welcome to the club!
I once built an OCC with a Chinese 66cc. Those have huge rear tires as well, and the motor mount plate we fabricated had to be compensated accordingly. It slid the motor outside the frame just enough to keep the chain from eating the tire. I'm sure the build thread is in the chopper section somewhere.
 
A very basic idea of what I'm thinking:

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Just found a similar thread on the subject, but still can't figure out if anyone has done it yet. All the more reason for me to try.

link to thread

Need to look closely at the fatbikes they've got at Wally-world, make sure there's enough clearance between the frame and tire to fit in a shifter kit, and maybe a fender (don't want to be flinging dirt into the shift-kit gears, and here in New Orleans the streets get mighty dirty)
 
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That's the shift kit .. a "jack shaft" in order to install it you will need , I believe it is , about an inch and a half clearence between the seat tube and the rear tire ... which I'm pretty sure , judging from the picture posted, that this bike doesn't have ... therefore you will have a choice ( or two ) ta make .. you could get a different bike too start with ... or ooo you can loose the reasr disc and replace it with the required sproket that the motor will require ....
 
image.jpg

I built one of those same bikes with a shift kit. It's a pretty challenging build, and it requires some customization - one item you'll need is a longer 5/8" keyed shaft because everything is so wide. The stock tire would rub on the left hand sprocket of the jackshaft so you'll need to get a tire that's not so tall and also set back the rear wheel about 1/4" for total clearance. And the rear sprockets & chain on the bike are junk so throw them away & buy a good 7 speed cassette & a heavy-duty chain for the 7 speed cassette. Everything else is pretty OK quality (new seat for comfort is a must however) and as things break just replace them with upgraded items.
 
Bzura ... nice build ... looks like a few "alterations" were needed around the "fat-ness" of it all ... lol ! But I like it .
How do those tires handle the speed and power of the motor ? Bet they could really get "hummin'" on the pavement ?
I like it with the jack shaft tho ... well worth the extra $ and effort on any build if you ask me.. I can't see ever going back to a single speed set up ... Once you've rode with all the gears at your fingertips it's pretty hard ta go w/out them ... takes the motorized bicycles too the "next" level ...
Anyways ... Nice job !
 
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