The idea behind the Multi-Purpose Idler Kit is to supply you with everything you need to optimize the chainline on your bike, even when you aren't sure what you need. You can think of it as an Experimenter's Kit.
The Clamp-On Idler Mount allows you to relocate idlers to where they work best. A Power Idler and a Return Idler give you the adaptability for any configuration. Having separate idlers opens up lots of possibilities for you to perfect your chainline: Under/Under, Over/Over, and Over/Under combinations are all possible. Finally, a Clamp-On Double-Sided Chain Keeper enables the idlers to float with the chain for high efficiency and low noise. This combination of beautifully crafted, insanely durable parts ensures maximum configurability so you can find the chainline that works best for you bike.
1. What can I do with this kit?
Lots of different things. Since it comes with a Clamp on Idler Mount, you're no longer limited to the stock idler position. The idlers can now be in lots of other positions. Since it comes with independent Power and Return idlers, you are free to experiment with the chains going over both, under both, or any combination of both over and under. Clamp on chainkeepers means the chainkeeping function is independent of the idler mounting function, letting the idlers float with the chain as you shift for maximum efficiency and lowest noise.
2. What are all the different mounting positions?
The Clamp on Idler Mount lets you position the idlers above or below the main tube of your bike/trike. The mount has 3 mounting holes, so you can vary the up/down position as needed. The clamp can be positioned anywhere along the main tube that is not strongly bent.
3. Talk to me about chainkeepers.
Clamp on chainkeepers considerably simplify chainkeeping. Basically, you can move the idlers and chains around into whatever configuration you'd like, then pop the chainkeeper onto the end of the idler mounting bolt and clamp it down.
If you get the double sided chainkeeper, you can run the chains in the over/under configuration without worrying about the chains coming off. If you aren't sure what chain configuration you're going to wind up with, we recommend getting a double sided keeper. If you wind up not needing the double sided function, it's no problem to have that option there without using it.
To most easily experiment with idler positions, put one of the idlers on the provided idler bolt. Holding the bolt in one hand, push the chain up or down with the idler and move the idler around to different places and see the effect on the chainline. When you have identified a promising spot, attach the clamp on idler mount there and see how it works.
- The Clamp On Idler Mounts in this kit range from 1.5 inches to 60mm. We also make some other odd sizes, like 50 and 54mm, that you can order. Just make a note of that in the area provided.
- The clamp on mounts are sized very accurately for the particular tube size, right down to an allowance for the paint thickness. If there is a question about the size of your tube, measure accurately, or contact us to see if we know the size.
- If you know you only need to relocate one idler, and don't need both a Power and a Return, it is possible to purchase only the parts you need from the Idlers and Chain Management Accessories sections of our website.
- The clamp on mounts are made for round tubes that are straight or nearly straight. If your main tube is curving where you'd really like to put the idlers, it is unfortunately not possible to clamp there. For the clamps to grip strongly, the fit is very exact, and there's just no way to predict that on a curving tube.
- Generally, it's valuable to allow the power side idler to float inwards as much as possible. The position of the chainline in the lowest gear is usually very close to the level of the outside of the main tube. For that reason, these mounts are designed to put the idler mounting options in as close to the frame as possible. This means the idler mounting holes in the clamp on mounts are either above or below the main tube and not near the centerline.
- If it is absolutely necessary to have the idlers somewhere near the centerline of the main tube, or to have them radically above or below the main tube, we do offer an Adjustable Idler Mount. Right now, we only make them in two sizes, 1.75 and 2.0 inches. This is an extra cost option, but does give a wider range of mounting positions. Unfortunately, to do this necessarily requires increasing the minimum closeness to the outside level of the main tube by about 3/8 inch (10mm). If you have a hub gear, this will be OK, but for most deraileur systems, this would put more side bend in the chain in lower gears that you will probably want.
- This kit is for the many bikes where
- a) the way they are configured (boom position, chainring sizes, etc.) strongly affects how you want to set up the idlers,
- b) the many small run bikes we just don't have formal kits for, and
- c) some of the brands of bikes where the model name may be the same, but the details change frequently (Performer, TW Bents, Actionbent, some others).
- This kit provides maximum reconfigurability to enable maximum experimentation.
Needed to add idler on my wife's trike to keep chain from hitting the frame. However, the location is rather far back on the frame in a location where the idler needed to travel about the width of one idler to maintain alignment with the rear gear cluster. Took off the return idler and left only the power side idler and I have frame clearance and smooth shifting and of course, a very smooth running chain. I've had terrific performance from TerraCycle idlers since 2011.