Elite Power 15 Tooth Idler

SKU: IDL139.1

The T-Cycle Elite Idler is the artisanal, hifalutin, blinged-out drivetrain upgrade that recumbent enthusiasts worldwide dream of.  Held rigid with super-tough, exquisitely machined, all-metal construction from beautifully crafted 6061 aluminum sideplates, a cog built for supreme durability out of aeronautic-grade titanium, and an immaculately designed aluminum inner core.  Spun on luxury with either the unbeatable resilience and consistency of the precision hybrid ceramic/steel bearings (8mm only) or top-quality ABEC-7 steel bearings (for other sizes).  This idler is for those who want their ride to look as opulent as it feels.


1. What's so great about this idler?

Elite Power Side idlers have a solid metal core surrounded by a very light machined out AL frame and machined AL sideplates. Your chain is carried on a specially shaped 6AL4V Titanium cog for maximum efficiency and long life. A heavy duty aluminum bearing carrier pressed inside the cog carries a pair of high quality bearings. It's tough, light, and really sharp looking. It's the ultimate idler for almost every power side idler application.

2. How big is the idler?

We make two sizes of Elite Series idlers: 15T, and 23T. This product page 15T size. The 15T idler has an outside diameter of 2.75 inches, or 70mm. With 8 or 10mm bearings, it is a drop in replacement for many power side idlers on a wide range of bikes and trikes. The 15T is 0.62in (15.5mm) thick.

3. I see it has bolts. Can I take it apart?

Yes, but we do not recommend taking them apart. If they have many thousands of miles on them and you have reason to believe the bearings are finally worn out, please contact us. They are precision made and there are some steps to the disassembly/reassembly that are important to follow carefully. Since the bearings are pressed into the core, you will need a bearing press if you ever need to remove them. With any kind of reasonable care, the bearings should last tens of thousands of miles, though, and it would be rare to replace them. With a press, even a simple one, it's easy to do.

4. If I ever wear out the cog, can I replace that?

Yes, we can replace the cog assembly if that's ever necessary. We haven't had to do that yet, but with so many idlers out there, we're sure it will happen some day.

5. What about efficiency and noise?

We make exclusively toothed idlers for power side applications because they are both quieter and more efficient that way. There are a host of technical reasons for this, but the biggest and most basic one is that chains are designed to be carried by the bushings. It is a nice, big flat area designed for forces to be applied to it. Chains are not meant to be carried on the edges of their sideplates. It just doesn't work as well. Since the core of the idler is all metal, from the chain bushings through to the bearings, there is no sponginess to soak up power. The chain sideplates aren't used to transmit power down into the idler, so there is no rubbing contact like there is on plain bedded idlers. Noise is a complicated issue, but we expect you'll find these idlers are quieter than other idlers. The cog is specially shaped to smoothly and repeatably mesh with the chain, and unless the chain is being pulled sideways quite a bit, there will be very little rubbing. We always recommend allowing your power side idler to float side to side with the chain as it shifts. Another common source of noise in drivetrains is insufficient contact on the idler. If there is not enough deflection of the chain at the idler, the chain and the idler don't have a chance to mesh properly. This is true for all types of idlers. You'd think that a chain only lightly touching an idler would be quieter, but because of the complex geometries involved, there is a minimum amount of bend or wrap required to get maximum silence. The amount varies with the diameter of the idler, the larger the idler, the smaller the angle required.

6. What bearings can you get with these idlers?

We make these idlers with 8mm Hybrid Ceramic bearings (ceramic balls, stainless steel races), 10mm, 12mm, and 3/8" ABEC rated steel bearings. We can make them with 5/8" bearings also, but that is for a special version for some RANS idler kits.

7. What's the difference between these idlers and the Sport Series idlers?

The Elite Series idlers have titanium cogs, hybrid ceramic bearings, and completely CNC machined frames. The cog and frame are extensively hollowed out for lightness. They are designed to look as good as they work. The Sport Series idlers have 7075 Aluminum cogs, top quality steel bearings, and injection molded fiberglass reinforced Nylon frames. They are designed to be simple, high performance, and tough. The look is much simpler, more businesslike than bling.


  • Available with 8mm, 10mm, 12mm, and 3/8 inch ID bearings. 5/8 inch bearings are available by special order. The most common bearing size on recumbents is 8mm. Some older bikes and trikes were made with 10mm idler shafts, and only a few bikes were ever made with 3/8" bearings. Some newer European bikes use 12mm bearings. Chances are you need 8mm bearings.
  • If the outside diameter of the idler is not restricted, we recommend using the slightly larger 15T version.
  • The cog is precision machined, but there is a break-in period while the cog and the chain get to know each other. After that, you can expect your idler to last many, many thousands of miles before needing service.
  • We also make matching compatible Return and Over/Under idlers in the 15T size.
  • In case of damage, all parts are individually replaceable. Contact us for details.
  • The red highlight rings are fully functional and are part of the sideplate retention mechanism.
  • We use stainless fasteners because we know you don't want things rusting.
  • The cog is made from 6AL/4V titanium for the ultimate in durability. The cog and frame are extensively machined out for lightness.
  • Weight: 15T: 77g
  • Bearing Care: The bearings are shielded, not sealed. Shielded bearings have less rolling resistance because the seal, while super close, doesn't actually rub. True sealed bearings are rare, when people talk about "sealed bearings", they usually actually mean shielded. These are top quality shielded bearings and will last a long time. What kills bearings is solvent, dirt, and water intrusion. As long as you don't spray things on the bearing faces, you will be OK. Regular amounts of dust and dirt getting on the outsides of the bearings won't be a problem, as it's hard for it to get past the shields (the shields really do come *very* close to the bearings). When you clean them, what you want to do is gently wipe dirt off and away from bearings, rather than rub aggressively and push the dirt past the shields. There is no need to lube the bearings, the special grease that's in them is what they need.
  • No maintenance should be required other than occasional cleaning with a paper towel or soft cloth. We recommend keeping solvents and soap and water away from the bearings, they don't need aggressive cleaning and solvents and soaps tend to go after the grease. It's water resistant, but solvents and soaps are harder to deal with.
  • You will probably never need to disassemble your idler. Should you ever need to, a 2.5mm Allen wrench is all you will need.
  • We recommend setting up your idler so it can float side to side with the chain as you shift. If your existing idler mount doesn't allow for this, we offer a variety of upgrade parts to make this possible.
  • The 15T size is a direct replacement for many idlers on lots of different bikes and trikes. 8mm is the most common bearing size. These idlers can also be ordered with 10mm, 12mm, or 3/8 inch bearings. A larger 23T idler is also available, it has it's own item page because it has some unique options.

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4.8 Based on 4 Reviews
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Rolf B.
United States United States
Quiet quality

Much better quality and quieter then stock ICE front idler.

Dennis V.
United States United States
Good product

Seems to be a good product...no complaints

Jack O.
United States United States

Teracycle quality does not disappoint, the idler is functional bicycle jewelry.

Exceptional build Quality and Performance

I currently ride the Catrike Pocket and 700 and have had no issues with the standard Sport idler , which is widely used on most major brands . Because I am always striving to make the 700 perform just a little bit better without breaking the bank I thought to change the idler to the Elite Series , but mostly because it looks badass against the all black trike . On that note the all aluminum body and build quality makes this a fine piece of jewellery . But how does it perform ? I didn't think there was going to be a noticeable difference but on the first ride there was certainly a noticeable difference . The first thing was how smooth it was , even when you pedal backwards to don't get the light clatter you sometimes get and able to get up to speed just a bit quicker too . And well priced too for what you get . . Now I need to change the idler on the Pocket now . The Recumbent world is just alittle bit better because of Terra Cycle and the quality of there components and service overall . 5 stars all day long and into the night ..