Three Wheels of Magic (TWM) — technical note for dealers and service technicians
Falco eMotors Inc. July 20, 2026 (This Article is Applicable to TWM models shipped from July 2026 onwards (2027 Models)
We removed most of the tubes for one reason: a chain tube is a sliding bearing, and sliding bearings are the most expensive way to support a chain.
- The Chain Path
The picture above is the whole story in one frame. Two parallel Chain runs, the full length of a recumbent boom, entirely open to the air.
Working forward from the rear wheel:
The cassette. A 10-speed Shimano cluster with a 48-tooth low cog, driven by a long-cage rear derailleur. The wide range is deliberate — this trike is ridden by people who need a very low gear available on demand, and the electric assist does not remove that requirement.
The power side. The upper run leaves the cassette tangent, passes the idler at the frame junction, and runs forward to the chainwheel unsupported.
On the return side. The lower run goes straight from the derailleur back to the chainwheel, unsupported and untouched. It carries almost no tension. It does not need help, and giving it help costs power.
2. The Cassette End
The Chain enters on the cassette tangent. There is no intermediate guide between the idler and the cassette, so the chain line here is set entirely by the frame and the derailleur, which is why the frame-junction alignment check in section 4 matters.
3. The idlers
4. The Frame Junction and Chain Clearance
This is the clearance you need to check, and it is the one thing open routing genuinely asks of you that tubes did not. With a tube, the Chain was held away from the frame, whether you thought about it or not. Open, the Chain sits where the geometry puts it.
Check clearance at the pivot and along the boom at every boom position, not just the one the trike arrives in. A boom that clears at the short setting can foul at the long one.
We have provided extra tubes that can be used in conjunction with Terra Cycle's floating chain tube holder (CHM136.1, about $23, not included; https://t-cycle.com/products/floating-chaintube-holder), as shown below. Keep the tube 4–12 inches, let it float, the holder has a 4.5" reach.
5. Why did the tubes come off
A chain tube works by allowing the Chain to slide against a plastic liner along the entire length of the run. That is sliding friction, and it is present on every link, on every stroke, for the entire life of the trike.
An idler works by allowing the Chain to roll over a pulley that turns on a sealed bearing. The loss is a bearing loss at a single point.
The difference matters more over time than it does on day one:
- A new tube liner is reasonably slippery. A tube liner at eighteen months is glazed, scored, and full of grit that got in and cannot get out. Drag climbs steadily, and the rider has no way to see it.
- Lubricant applied to an open chain stays where you put it and stays visible. The lubricant inside the tube migrates into the liner, turning the trapped grit into a mild grinding paste.
- Every tube end and every deflection point adds its own loss on top of the length-wise drag. On a folding frame, you need a flexible section at the fold, and that section is another deflection point.
For a rider with a 750 W legal assist limit and, in many cases, limited leg power of their own, drivetrain losses are not an abstraction. They come directly out of range and directly out of how the trike feels on a hill.
The honest trade-off: an open chain is a visible chain. It can mark a trouser leg, and it is dirtier to touch than a tube. We think a drivetrain that stays efficient for years is worth that, and we would rather tell you the trade-off than pretend it does not exist. Riders who want protection can fit a chainguard at the chainwheel, which is where clothing contacts the Chain.
6. What Changes at the Bench
One procedure genuinely changes, and it is the one you will do most often.
With tubes, a boom move was partly absorbed by slack inside the tubes. With open routing, there is no slack to absorb anything. Chain length is now part of the fitting, so it's no longer a step you can skip.
Correct sequence for a leg-length adjustment:
- Slacken the boom clamp. Release the clamp bolts. Do not substitute the supplied hardware — unauthorized changes to the boom's fasteners have caused cascading failures on earlier trikes and will not be covered under warranty.
- Set the X-seam. Slide the boom to the rider's leg length, retorque to specification, and confirm the chainwheel is square to the chain line.
- Resize the Chain. Add or remove links to suit the new boom position. Use a fresh quick link; do not reuse one.
- Test through the range. Cycle all ten gears under light load. Listen at the idler. Confirm that both runs clear the boom and the pivot throughout.
Pre-delivery checklist
- [ ] Chain runs smoothly through the full gear range, no hesitation at either extreme
- [ ] No chain rub on the frame, on the boom, on the pivot hardware, or on the tie-rod
- [ ] Both Idler bearings are silent under load
- [ ] Both runs clear the boom at every boom position
- [ ] Idler fastener torqued to specification
- [ ] Chain correctly sized for the delivered boom position, quick-link seated
- [ ] Derailleur cable routed clear of both Chain runs
- [ ] Chain lubricated and wiped; no surface rust on any drivetrain component
7. Talking to the Customer
Most Three Wheels of Magic riders are over seventy. They are not going to ask you about sliding versus rolling friction. What they will notice, and what you can tell them:
- It is quieter. The noise complaints on the earlier trikes came from the idler and the keeper. Both are resolved.
- It stays that way. There is no hidden liner wearing out that they cannot see.
- They can see the Chain so that they can look after it. Wipe it, lubricate it, and check for any problems before they require a repair.
- It is standard. Any competent bike shop can service it with ordinary parts. They are not tied to us for a consumable.
That last point is worth making. A drivetrain reassures a nervous rider who is worried about being stranded that any shop can fix it.
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