Idler TerraCycle SPORT Over/Under 15 thooth Al and high quality urethane band, OD 70 mm
- Over/Under chain line design
- 15 tooth aluminium cog and HQ urethane ring
- Diameter: 70 mm
- Width: 30 mm
- Inside diameter: 8 mm
- Bearings: ABEC7
- Cog: 7075 aluminium, CNC machined
- Carrier: 7075 aluminium, CNC machined, anodized
- Side plates: aerospace grade ballistic nylon
- Bolts: 18/8 stainless
- Weight: 104 g
- Additional accessories for recumbent models like Bacchetta (2 mm spacer) and Schlitter Bikes (9 mm spacer & jam nut) available
CNC machined idlers with tight tolerances deliver more power to your drive train and are quieter, smoother, and allow the chainline to run with less vibration. The drive train is one place on a bike that deserves the best parts you can afford. Because of the long lengths of chain that recumbents with rear wheel drive have, a quality idler system is really key. Everywhere else in the power side of your drive train (chainrings and cassette) toothed cogs are used. Why should the idler be any less important? Running a loaded chain over a non-cogged surface causes friction and power loss as the chain attempts to dig itself a groove in the plastic idler, or worse yet, with harder plastic idlers, the chain simply bumps its way along from the drive wheel. A chain has a very specific shape that is designed to run on only one thing when loaded- a tooth cup. Don't let anyone tell you anything different because any good engineer will tell you that simply isn't the case. Chains are not smooth and continuous, they are metal segments with specific contact points designed in.
The TerraCycle idlers perfectly designed transferring chain power to the rear wheel of your recumbent bike or trike with the CNC machined cog made of leightweight 7075 aluminium. When deciding between a titanium of the ELITE idler or an aluminum cog of the SPORT idler, we advise that stronger riders or any rider doing high mileage go with titanium. The aluminum cogs will give a long useful service life but will show more wear after tens of thousands of miles. We generally recommend a titanium cog for trikes since the angle of the chain line tends to be larger putting more stress on the idler.
All TerraCycle idler contact points are metal-to-metal joint from the CNC machined idler cog and idler carrier down to the industry grade ABEC 7 bearings. No plastic is involved in order to dismantle the idler cog from the idler carrier. Each idler is fully rebuildable (bearings and cog are replaceable of course) if that ever becomes necessary. TerraCycle idlers initially cost more, but if you factor in the longevity, the fact that they are not prone to failure, plus the minimized noise level and pedaling efficiency you will gain, then they really are a great value!
Handmade in the most cycling friendly city Portland, OR USA.
Read the Velovision Magazine Review "TerraCycle Idlers" Reviews/Velovision Issue 34 June 2009