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How would one know if they needed to replace a chain idler?

The idlers have two main parts: the bearing and the surrounding idler wheel itself. If the bearing becomes contaminated it will stop turning smoothly and add friction to the drivetrain. If this happens a new bearing is needed. You do not need to get an expensive replacement bearing though. Just one that fits properly.

The Lightning idlers have a little rubber ring around them that keeps the drivetrain quiet. The rubber ring will not last long, but the idlers can still be used for a very long time without the ring. I have tried experimenting with wrapping my older idlers with heavy cloth tape in order to keep things nice and quiet. Lasts for a few months of riding, and it then disintegrates.

Eventually the chain will chew through the Delrin plastic of the idler. Because Delrin is extremely tough, this might take tens of thousands of miles of riding. It is the power side idler - the one under your seat - that leads a tough life. The front idler - the one close to the fork - should last almost forever.

Safe riding,

I replaced my original Stealth idlers with TerraCycle ones. Unfortunately, The return idler sliced through my bottom seat mesh on one of my longer rides. Okay, perhaps the mesh could have been pulled a little tighter and I could stand to drop a few pounds . When I replacing the old mesh with "new" style seat mesh, I found that the new fabric design put the mesh even closer to the under-seat idler. I ended up putting the original lightning idler back on. It is slightly smaller in diameter and more "rounded" on the edge. I didn't want to take any chances with my new seat. The front however, still sports the TerraCycle power side idler.

I have no personal experience with the Terracycle replacement idlers. Do they last longer than the standard Lightning idlers? Are they more quiet, or smoother, or better in some other way?
I know the Terracycle guy says they are wonderful, but does anyone have any actual experience they could share?

On their website, they say that you can choose between aluminum and titanium cogs, with the ti cog idler boosting the price from $145 up to (gasp!) $165.

Using an aluminum cog in this application just seems nuts. Aluminum is a soft metal, and bike chains are made of steel. But what do I know?

Safe riding,

After replacing the stock Lightning idlers twice on my P-38 (from just plain normal usage wear and tear), I went out and bought the Terracycle idlers and have not been disappointed. Quite frankly, the stock idlers are junk compared to the Terracycle ones.

I have to agree with Wolverbob. I went through 2 sets of Lightning idlers in less than 9,000 miles. I replaced them with the Terracycle idlers and have gotten more than 12,000 miles on them and they're still going strong. No regrets.


BTW I opted for the aluminum cog, but I'm not sure if I had an option when I purchased the kit. I think this is an aluminum alloy. My chainrings are aluminum alloy, so I don't see that there should be a problem with an aluminum cog. You can take the idler apart and see that it's just a 14 tooth cog for which you can get a replacement, if necessary.


I'm no metallurgist. But while your chainrings are probably made of aluminum, or some aluminum alloy, your cassette cogs are made of steel. A 14t idler cog is small, and will wear out a lot faster than a chainring.

Though that is just theory. If the things last a long time in practice, that is what really counts. So I count at least two happy customers so far.

I cannot resist posing one more question: how much $ will Terracycle charge you for a replacement aluminum cog?

Guess I'm just a cheapskate. Who else would bother to wrap heavy cloth tape around their old Lightning idlers in order to squeeze more silent miles out of them?

Safe riding,

would anyone know approximately how long the chain idlers last and how do you know if they need replacement. hopefully it's not when it falls apart on a long uphill climb(or bombing downhill in the big ring at 40+ mph)! I have over 5,000 fun filled miles on my two year old P38 and other than tires, have only replaced the seat lacing (oh...and the big chain ring when I crashed into a bridge railing)!

A year and a half ago I sold my fishing boat, which I loved, and bought a Phantom, which I love even more! Still my favorite is the P38.

Hi Scooter,

The chain idler close to the fork leads the life of Riley. It should last longer than you. So in most cases you will not have to worry about it.

The other idler - under the seat - has a tougher life, because it deflects the part of the chain that is under tension. The little hard rubber O-ring that sits in the Delrin idler wheel groove will probably wear down to nothing pretty quickly. The O-ring helps quiet the drivetrain, but the idler is still fully functional long after the rubber ring is history. The chain will bed down into the Delrin plastic and create a pattern that looks like the teeth of a rear derailleur pulley. I guess you could keep using the idler wheel until it eventually ground down right through the Delrin plastic and exposed the cartridge bearing. This would probably take tens of thousands of miles of riding.

If you have put 5,000 miles on your Lightning over two years of riding, I would probably wait another few years before replacing the idler wheel under the seat. If the cartridge bearing becomes contaminated, the idler wheel will not turn freely and will cause drivetrain friction. Just replace the cartridge bearing with a fresh one that fits properly. You can buy cartridge bearings almost anywhere. They are a standard part of electric motors. A cheap cartridge bearing is all you need.

If you poke around this thread, you will see that some recumbent riders prefer the Terracycle idlers to the Lightning originals. I have not tried them myself, being too tight with a buck to experiment. I remain dubious about the cost-effectiveness of $145 chain idlers. Especially when the power side idler has a toothed cog made of aluminum.

Oh, wait. Terracycle has recently reduced the price of the Lightning idlers to a mere $110. What a deal! Though the titanium ones with ceramic bearings cost $175.

I am waiting for idlers made of carbon fiber with bearings lubricated with blue whale snot.

Nothing is too good for my Lightning bikes.


Thanks Joel for the helpful tips. I'm almost certain that the rubber O-ring on my seat idler is completely worn off. The idler almost looks as if it has cogs cut in it where the chain is riding! So it sounds like the best thing to do is just keep an eye on it and at some point decide if I want to spend a lot or a little to replace it! I'm not too worried about it now. I had to replace the idler bearings on the Phantom already. They were pretty noisy shortly after I bought it so I took the idler apart and ordered new bearings from WW Grainger and that did the trick. I don't recall how much they were, just know they didn't break the bank! And it was an easy fix to do.


aboutr two years ago, I replaced my stock idlers with terrycycles on my 2002 phantom. great weight loss.the lightning idlers are real porkers,compared to the stock lightnings. ride is fine. there may be some close space between the rear idler ( power) and the bottom of the seat, but I tied some webbing below the seat to bring up the "rear" a little and no problem. I suspect these idlers will outlast me. after two years still work great. i did turn the chain keeper in, instead of out to keep the chain from jumping out, and that necessitated cutting the keeper a little, but that was easy with no loss of function.


I have been going over my P38 and noticed when cleaning and lubing the idlers that my drive idler has worn down in an odd way. The chain now lays on it at a 45 degree angle, the inner surface where the chain lays having worn down more on one side than the other. I took it off and cut it down until is was flat again and it works fine now.

I don't see the idlers on the website. Can they be ordered from Lightning off the site and how much do they cost these days.

After 15 years the bike is still running like a dream. I do want to replace that drive idler soon but it is fine for now after the reshaping work.

Hello Arizona,

Lightning will be happy to sell you new idlers. Last time I checked they were $25, but that was long ago. You will need to email Lightning to find out the current price.

This might seem like a lot for a chain idler, but it is well made and lasts a long time (except for the rubber O-ring). Compared to the Terracycle idlers the Lightning ones are a real bargain. (Though Bob K. of Michigan has a different opinion about this.)

A Lightning rider who goes by the name of ncaudio on both this forum and the Bentrider Online forum has used idlers purchased from TerraTrike (not to be confused with Terracycle!) with good results.

Safe riding,

That is great info Joel. The 10 tooth TerraTrike idlers look very interesting and priced right too. The stock Lightning idlers are fine too. Mine have lasted a long time and the front as you say, shows almost no wear.


Hey EM, I'm replacing my P38 under seat idler very soon. I see the rubber O-ring is gone. I e-mailed Tim and he sent a new one out for $25 plus $5 shipping. I have almost 8,000 mls on the bike. Good luck.



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