Idlers & Chain Management

TerraCycle - The Expert Source on Recumbent Chainline Management

TerraCycle is one of the world’s greatest expertise in recumbent chainline management. It makes up much of what they do and work with day in and day out. Terracycle has spent years developing and improving the idlers, clamps and mounts, to make your ride run smoothly and efficiently. Years of experience talking to riders, plus their own experiences with everything from streamliners to touring bikes, has taught them a lot about what makes recumbent chainlines work better.

TerraCycle idlers have been recognized as the finest available. Each idler is made locally in Portland, Oregon in their own machine shop with complete dedication to detail and quality.

TerraCycle idlers are quiet, smooth, and durable - big differences that you'll feel on your very first ride, and appreciate more and more as the roads add up!

- Made in bicycle friendly Portland, Oregon-

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Terracycle Idlers and Chain Management

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. The industry standard has been to use inexpensive solid plastic rollers that are highly inefficient at transferring chain power to the rear wheel.

iTerracycle dler of the year

Bumping chain along a hard non-toothed surface on the power side makes no sense at all. 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 Bent Rider Online: ACCESSORY OF THE YEAR 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.

The shape of a smooth plastic non-cogged power idler is probably better designed for the lines on a boat. Unfortunately our bikes aren't run with ropes, we have chains, so what we run that chain over shouldn't look like something designed for rope. Chains are not smooth and continuous; they are metal segments with specific contact points designed in.

There is one exception to the cog only rule and that is for the return chain. Return chains are only loaded by their own weight plus the tension from the derailleur arm spring. In this application a non-cogged idler is an option if it is well made; that is to say, has high quality bearings, has durable, quiet sidewalls, and has a bed not prone to premature wear.

The TerraCycle return idlers use the same industrial urethane material in the beds as is found on mining equipment and other heavy duty industrial situations. Because the return chain tends to wander side to side within the idler without the higher loads, a floating return system allows the change in chain angle to be accomodated as you change gears.

To illustrate the issues with solid plastic power idlers for longevity, TerraCycle recently received a call from a customer on a cross country trip who called from a remote location, telling them that his stock idler system had completely disintegrated, rendering his bike un-rideable. Many customers report that their stock idlers are wearing out in a matter of a few months. Pat Franz’s belief is that drive train components should be much longer lived and more efficient than this, which is why he designs the TerraCycle idlers to last the life of your bike.

Some manufacturers are using softer plastics or rubber O rings in an attempt to fool you into thinking that the idler is working better because it sounds quieter than the harder plastics, but again don't be fooled, you aren't gaining anything and may be even losing even more power than you imagine. Lower noise does not automatically equate to efficiency. Squishy things are not a good idea in the power side of your drivetrain.

While we are on the friction topic, chain tubes cause friction on a chain. No matter how nice the tube is (and there is a wide range of tube qualities out there) you are still running a chain on or through a surface it isn't optimally designed for. Chain tubes wear out, but even the best of them don’t last more than a few thousand miles. Chain tube with lots of angle changes between the cranks and your rear wheel can produce up to a kilogram of drag. Straight is definitely better with chain tubes.

If the goal is to keep your pant leg free from chain grease on a commuter bike, then by all means the trade off in efficiency is probably worth it. The number of customers who call TerraCycle asking them to help them get rid of the multiple feet of tubing their bikes came with is phenomenal. TerraCycle uses chain tubes on a few of their kits, basically where the bike and the chainline absolutely require it. They use high quality, low noise/low friction tube, keep the lengths short, and flare both ends of the

tube to reduce entry/exit vibration. If you think about the thousands of pedal strokes you do annually, and then think about power robbing idlers, or multiple/long lengths of chain tubing, it makes no sense at all!

TerraCycle knows performance riders who brag about the latest wheel set or special crank as they attempt to squeeze a little more speed or a few more miles out of their rides, but then they see plastic idlers on those bikes and think - Wow! Now there is some energy being wasted that could be turned into power!

TerraCycle sponsors several teams, including the very successful "Race Across Oregon” (RAO) Speedwagon Recumbent Race Team. For the last several years, they have won the recumbent division, plus a first and second overall. The Race Across Oregon is known as the hardest RAAM (Race Across America) qualifier in the nation (539 miles / 45,000 plus feet of climbing / Non-Stop). Each of the team bikes, from Streamliner to High Racer, have TerraCycle Idlers on them, because the team knows that when you are racing on a course that challenging you can't afford anything but the best in your drive train to ensure no amount of energy is wasted.

TerraCycle idlers help the team push to their limits, riding so many miles very fast with so much climbing and very little rest. This kind of performance demands that you gain those critical minutes for every hour of pedalling, because in the end the winning margin can end up being very small. TerraCycle has for many years supplied idlers to teams competing in the ASME (American Society of Mechanical Engineering) races. The engineering students build a variety of HPVs and need efficient and powerful chain management to get the most out of their vehicles in this very demanding competition. TerraCycle prides themselves on helping the Engineering students with their state of the art idlers in a variety of configurations to meet their unique needs.

TerraCycle idlers initially cost more, but if you factor in the longevity, the fact that they are not prone to failure, plus the pedaling efficiency you will gain, then they really are a great value. All TerraCycle Elite Series idlers use hybrid ceramic bearings (use replaceable, of course), as well as industrial grade urethane beds on the return side. The premium idler plates are machined aluminum and high grade polycarbonate. All fasteners are stainless steel. Idler cogs are 6Al/4V Titanium or 7075 Aluminum. Each idler is fully rebuildable if that ever becomes necessary. So far TerraCycle had to do only a very few of these, and most were due to damage from accidents. All TerraCycle idlers are fully warranted for five years. No other manufacturer comes close to that kind of guarantee.

TerraCycle is always working on new designs for bikes that they do not presently cover, so check back regularly to get updates on what is new in their product line. When deciding between a Titanium or an Aluminum cog, 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.

Please call us to discuss any of the above if you need more information or want to discuss the specifics of your bike. We are always willing to spend the time to ensure you feel confident about making a good decision that has real benefit for your riding

TerraCycle Idlers
ø outside 65 mm (14 tooth)
70 mm (15 tooth)
101 mm (23 tooth)
ø inside 8 mm for ball bearing /Hybrid Ceramic/ ABEC 7 (Elite/Sport) 608-2RS (8 mm/22 mm/7 mm)
10 mm for ball bearing 6900-2RS (10 mm/22 mm/6 mm)
width 16 mm (Power 14-23 tooth)
16 mm (Return)
28 mm (Over/Under)
weight 70 g (14 tooth)
75 g (15 tooth)
115 g (23 tooth)
60 g (Return)
105 g (Over/Under)
material Titanium 6AL/4V or aluminum 7075 (cog)
Durometer Urethane 70A (ring of return idler)
Aluminum 6061-T6 (carrier)
Aluminum 6061-T6, Nylon (Elite/Sport side plates)
TerraCycle Chain Management Accessories
Chain Keeper


Aluminum 6061-T6 or
Stainless steel 18/8
Clamp-On TerraCycle Idler Mount
material Aluminum 6061-T6

ø frame

50 mm
60 mm
Custom M8 Stainless Bolts
material Aluminum 6061-T6


TerraCycle Sechskantinnenschrauben

M8 x 33 mm
M8 x 43 mm
M8 x 50 mm
M8 x 58 mm
M8 x 60 mm
M8 x 75 mm
M8 x 90 mm
M8 x 120 mm
material Aluminum



2 mm
4 mm
6 mm
7,5 mm
15 mm


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