working crusier without a tensioner

upsrogue · #1 07-16-2009, 05:45 PM

I explained the process with John from North Dakota but if some body wants more info on how let me know

captainrichhill · #2 07-17-2009, 12:58 PM

If your particular build works out that you don't need to take any slack out of the chain then you won't need to use a tensioner. BUT, the new chain will stretch and you will need one eventually. Some guys have had success using shims in the engine mount to take up the slack in the chain and therefore eliminating the need for a tensioner. Shifting the engine forward has double the effect tightening the chain. (ie. move the engine forward 1/16" and you get 1/8" tighter chain because of the top and bottom runs of the chain are both effected by the 1/16" movement of the engine.

upsrogue · #3 07-17-2009, 05:36 PM

Hi, well my particular build did'nt just work out that way I put the tensioner on at first, it did'nt fit the frame right so I could never get it clamped down tight enough for it to do the job to begin with. Then when it received some real tension fom the chain it bent in toward the spokes and bent the rim, after replacing the rim and of course changing everything out again sprocket ect. I felt well this is going to happen again FIX IT.
Thats when I seen that by taking out four of the links in the chain I could just get the chain master link on with no tensioner, but there was no slack in the chain so I took the engine off and filed down the rear motor mount block that slides onto the two bolts that thread into the engine its self, I filed maybe an 1/8" off the flat part of that motor mount block and got the proper slack in the chain that was needed to operate correctly. So I figure IF the chain stretches I can always put a spacer back into that spot that I filed away on that motor mount, if it streches even more I'll take out one more link in the chain.
To me it beats bent replacing high dollar rims and making up skate board wheeels, derailers, and what ever kind of brackets that have to be made up in order to fix what I think is a design flaw.
If I need to take the rim or engine off all I have to do is disconnect the master link and the chain is off.
If somebody on the forum can see where I'm developing some other problem, that I'm not seeing please let me know I'm new at this and learning too. Thanks

Junster · #4 07-18-2009, 02:07 AM

Not using a tensioner is a very good thing. Like Capt. Rich said you can make a aluminum shim to drop in behind the rear mount to adjust the chain when you need to. Some ppl have no choice thou because of chainstay clearances.

captainrichhill · #5 07-18-2009, 08:12 AM

upsrouge,

If you run into using the tensioner again, you can use a small set screw in the side of the derailer to prevent it rotating into the spokes. Just get the tensioner into place and drill a small hole through the tensioner AND into your frame. Then put a sheetmetal screw or something in the hole to keep the tensioner in place. FYI

floridaboy · #6 07-18-2009, 08:30 AM

If you would like to build a tensioner that does not rely on useing set screws and can no way turn into your spokes you might like what i did on my bike and it worked out real well.

Just_Gassit · #7 07-18-2009, 11:45 PM

Well done, that tensioner is a great idea! Simple too.

silverbear · #8 07-19-2009, 12:01 PM

Ah, that's the one I'm going to make. Perfect. Are those conduit clamps or U bolts you're using? Thanks for sharing that. Along with a guide wheel I made from a skate board wheel it should be a good setup.
Silverbear

floridaboy · #9 07-19-2009, 08:34 PM

The clamps were from Home Depot in the elec. department. They were for 3/4 inch tubeing. The metal used was 1/8 inch alum. The hardest part was cutting the slot for the bolt for the tensioner. It has proved to work out real well. Hope this helps.

**2door** · #10 07-19-2009, 08:56 PM

If you're a welder and have access to a welder here's another approach. I TIG almost everything but the same could be done with MIG or brazing. 1/4" X 1" flat stock works well for this. I put a bend in the bracker just to follow the contours of the frame but it's not necessary. A straight piece will work as well.
Tom