3 inch wide tire question

[bikejock]

I'm about to start installing my 4G bicycle engine kit on my crusier and it has a pretty wide rear tire. I was wondering, is this going to be an issue with chain clearance? Should the 415 chain be able to move OK without bumping aganst my tire?

I've seen the 4G kit installed on a magargi stealth cruiser which has a tire width of a little over 2 inches. My rear tire is one of the thicker than usual bike tires (24x3) Has anyone ever had problems with a 4G kit using the 415 chain on a bike with a 3 inch wide rear tire? I would hate to have those tires ruined by the 415 chain because my rear tire is pretty hard to find now.

 

[butre]

there should be clearance but if it's touching it'll be touching lightly. worst case scenario you might have to dish the rim towards the pedal side.

 

[Purple Haze]

You will have to keep the tensioner adjusted so there's no slop in the chain. Even better would be to install a spring-loaded tensioner. The rear tire is a pain to remove once your kit is installed, so do everything you can to protect the tire.

 

[bikejock]

You will have to keep the tensioner adjusted so there's no slop in the chain. Even better would be to install a spring-loaded tensioner. The rear tire is a pain to remove once your kit is installed, so do everything you can to protect the tire.

I'm planing on going tensionerless with this build. I had a few bad experences with a tensioner/idler wheel on my last build. To me, it's just another part that puts other parts of the bike & the engine at risk. I'm just going to shorten the chain to the point of it not needing a tensioner/idler wheel.

 

[butre]

you will probably end up needing a half link then. or even better, stick a derailleur on the pedal side and let it do your pedal side tensioning, while the drive side is a straight shot with no weak links. shift kit is also an option if you got an extra $150 or so to spend on your build

 

[bikejock]

I pared my chain with my tire and it looks like it should move fine without bumping it much. I won't know more until I take it on its first test drive. Looks like I gotta cut or bend my fender so the chain isn't rubbing aganst it.

The rear fender on my bike was designed to match up with the 3 wide rear tire which looks cool but gets in the way of the chain. I'm thinking of cutting a slit at a certain point and bending the area the chain goes through so I can still use my rear fender.

 

[Deleted member 12676]

Why don't you make a sheet metal tire guard?

 

[bikejock]

Why don't you make a sheet metal tire guard?

That's not a bad idea. I might try that but I also want to preserve the look of the bike. I might make something out of an old chain guard I have from an old bike which I could proabably shape in to a tire guard of some kind.

 

[KCvale]

4G with a 100 tooth fixed T-belt pulley and 18T freewheel sprocket?
Coaster brake single speed Fito?

Yes, you can make it work.
You need the back sprocket cupped out until it's wider than outside of big tires, and then mount the engine to the left so the unmovable sprocket is outside the tire too.

You need at least 1/4" from the fattest part of the tread in a straight line between the 2 sprockets to keep the chain from rubbing on the tire.
I generally wont mess with direct driving fat tires, the pedal side already has chain line that clears and you get gears as a bonus.

You can't 'bend' a 415 chain around a tire wider than it's 2 sprockets width and chain path like you can a thin 7-speed chain.

 

[bikejock]

Tried installing my sprocket today but then noticed I got something wrong in the sprocket clamp assembly and noticed one of the nuts became stuck on one of the bolts. I can twist the nut on the bolt freely but does not unscrew off the bolt. I think the thread was damaged on the bolt so I'll have to get a bolt cuter and cut it off and request a replacement bolt. On the upside everything in the sprocket assembly seems to fit even with the grease cap on but I'll need to bend my coaster brake arm. I'm thinking of going with a jack shaft kit someday so I can bypass all this rear wheel sprocket stuff. I was thinking of installing a 3 or 5 speed cruiser style rear hub transmission anyway at some point.