Idler wheels vs sprockets

My guess would be that using a sprocket instead or a "wheel" would require a lot more attention to chain alignment and tension. A sprocket would be much less forgiving of a chain that was not properly aligned with its drive and driven sprockets. Also the chain tension will play into how well an idler sprocket would perform.

There is also the consideration of the composition of the sprocket used as a tensioner. Some will suggest using one from an old derailer mechanism. I suspect that if you research this you'll find that many derailer sprockets are made of plastic which might not stand up to the rigors of the engine drive chain. There are high end derailer sprockets made of machined aluminum with good bearings as opposed to the cheaper, plastic ones that have a simple bushing.

As for noise and friction, I don't really see how a soft polyurethane wheel with good bearings would add any resistance to the drive chain. Properly aligned with the chain path, the wheel should spin almost effortlessly and with little noise or drag applied to the system.

That's one opinion. You'll get others.

tom

When choosing a skate board wheel keep in mind that some of the cheaper versions are actually a two piece construction. They will have a hard plastic inner core with a softer outer layer. These don't lend themselves well to our application. When you try to groove the wheel for the chain they will come apart, the outer layer separating from the inner much like a truck tire retread.

Look for wheels that are made/molded in one piece and preferably ones with a good roller bearing. Also make sure the wheel/groove is aligned with the chain path. That often requires a slight twist in the bracket or mount to get the center of the wheel to align with the chain. This is true even with the kit supplied tensioner bracket. A step that many new builders neglect and is the cause of so much chain/sprocket problems such as chain derailment and noise.

Good luck.

Tom