john from north dakota

[johnmartinwright]

hello everybody am new to this have 80cc engine strapped to my mountain bike have engine broken in and have been riding the crap outta this the only problem of late has been the cheap chain tensioner provided with the kit i ordered from bike engine.com everything has been working perfectly but this one part has my bike shut down for the time being anyway love to know that this forum and additional help plus newer and better ideas are near at hand thank you for reading this and will look for your suggestions and help with this particular problem that i have at this time

 

[Matheneyr3]

Welcome!!

Search, John, Search the threads through and through... Myself, I have modified a Chain Deraileur to suit the job on my bike- works great! Many of the great folks here have similar soloutions to the same problem.

Again, Welcome!

 

[upsrogue]

Hi John
I'm new to the forum but I had the same pain too and looks like everybody else from looking at the the threads.
I just did away with the tensioner, chucked it, and took my chain down link by link (about 4 links) with a tool made to do this with (my dad years ago gave it to me, don't know where you can buy one probably a industrial supply) anyway I was able to put the chain on using the master link but it was still to tight so I took the engine off the frame and there is a "block" as part of the rear engine mount that slides on the two bolts threaded into the engine block. I filed on the flat side of that engine mount block about a 1/4" off with a file and put it all back together and had just the right amount of slack in the chain and it works perfect. When I need to take the chain off I just take off the master link.
The way I see it if you have the proper amount of slack in the chain for operation you don't need a cheap chain tensioner that does'nt work right anyway. Right!!

 

[Finfan]

I just tried this out for the first time today and so far it works. The design seems sound although I did have to fiddle with it for a bit to get it to clamp to the stay properly. Since the web page doesn't have a picture I added one of my own.

Spring Loaded Chain Tensioner for Gas Motorized Bicycle Plans | All Parts | Parts for Gas Powered Bicycle Motor Kits | Live Fast Motors - Gas Motorized Bicycles and Gas Motorized Bicycle Parts

 

[silverbear]

Interesting thread and I especially appreciate the links. Regarding the skate board wheel tensioner. I made one for my bike a couple of years ago and lacked a lathe or anything else since giving most of my tools away to my kids. But necessity is the mother of invention as the saying goes. What I did was pretty simple using tools most anybody has and pretty hard to hurt yourself using them. I got a bolt of appropriate size to fit through the wheel and placed two large washers on each side of the wheel... then put the nut on tight so that the wheel could not spin on its bearing... then chucked the bolt into a heavy duty drill and since I no longer had a vise used a C clamp to hold the drill so that both hands were free. I turned the drill on, locking the trigger so that it kept running. Using a flat file (I had a large one so turned it on edge) I "cut" the groove as the wheel spun around in the chuck. Simple and only took a few minutes. I'm still using that wheel after I don't know how many hundred miles, a lot, and it shows no wear to speak of. Thought I'd pass that along in case you want to make one and don't have much in the line of tools.
Silverbear