Comparison

Belt drive vs chain

A carbon belt runs two to four times longer than a chain, needs no lubrication, and does not mark your clothes — but it requires a frame with a split in the rear triangle and a gearbox or internal hub. A chain is cheaper, universally serviceable, and works with any transmission.

What we build, and why

Belt, and we accept its consequences: the frame has to be designed around it from the first sketch, which is exactly the kind of decision that cannot be retrofitted later.

Carbon belt drive compared with Chain
CriterionCarbon belt driveChain
Service life20,000–30,000 km3,000–8,000 km on an assisted bike
LubricationNone, everEvery 200–400 km, more in winter
Frame requirementNeeds a split or removable dropout in the rear triangleAny frame
Transmission optionsInternal hub or gearbox onlyDerailleur, hub, or single speed
Cost in the BOMAround €62 for belt and sprockets€12–25
Roadside repairSpare belt or a taxiA chain tool and a quick link
ClothingNothing to transferLubricant on every trouser leg eventually

The frame decision comes first

A belt is a closed loop, so it cannot be threaded through a rear triangle the way a chain can. The frame needs a break — usually a bolted section in the seat stay — and that break has to carry full drive and braking loads for the life of the bike.

It is a structural decision made at the geometry stage, not a component choice made at the specification stage. Retrofitting a belt to a frame designed for a chain is not possible, which is why belt bikes tend to be designed as belt bikes from the start.

Where a chain still wins

If you ride far from a dealer network, a chain is repairable anywhere in the world for a few euros. If you want a derailleur — for the gear range, or for the weight — a belt is simply not available to you.

And if the bike is stored indoors and ridden in dry weather, a well-kept chain lasts long enough that the belt premium never pays itself back.

Frequently asked

Modern carbon-cord belts are more likely to fail from a stone caught between belt and sprocket than from fatigue. Running a belt guard removes most of that risk.
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Where this decision lands