Gates belt drive

The SPEEDHUB and a Gates Carbon Drive belt make a good pair: no grease, quiet, and a drivetrain that runs almost without maintenance. But the combination comes with strict conditions — if any is not met, the SPEEDHUB’s warranty is void.

Requirements

1. Frame approval. A belt only runs reliably with a stiff, precise rear triangle. The frame model must carry a Gates approval, confirmed by a test-rig test, in combination with the SPEEDHUB. We do not recommend an untested frame — an individual test can be requested.
2. Snubber. Every Gates–SPEEDHUB bike needs a snubber (a non-contact belt guide roller) that stops the belt jumping off in extreme situations.
3. A Gates-ready frame. A closed belt needs an opening point in the frame (frame split) and a way to tension the belt.
4. The makers’ instructions — both Gates’s and Rohloff’s fitting instructions.

When converting, if the hub already has a Splined Carrier L (with lock ring, Art. no. 8540L), fitting the splined belt sprocket and the snubber can be done in a workshop. Whether your frame is suitable is what a check shows: The check before a conversion.

The lock ring carrier

The Gates splined belt sprocket is held on the carrier not by a circlip but by a lock ring. Worth knowing:

• before any work, shift to gear 14, and clean the hub shell, carrier and belt sprocket thoroughly;
• the carrier’s inner thread has a slip coating — do not remove it;
• the belt line is 55 mm on 135/142 mm frames, 52 mm on 148 mm, 73 mm on 170–197 mm (±1 mm). Before converting, check that the new parts give a similar belt line — the belt sprocket’s orientation affects it too;
• with the carrier off, do not tilt the wheel towards the drive side: oil can run out.

The lock ring carrier also takes splined sprockets (from 15 teeth), but for a chain we recommend the 8540 or 8540S carrier: with a splined sprocket it makes no noise, and the circlip allows tool-free sprocket changes.

Tools: lock ring tool (Art. no. 8518), sprocket remover (8508 or XXL 8509), chain whip, Gates belt wrench, the POM Key with inserts, and a 46 mm flat wrench with a ½” torque wrench.

Fitting

1. Put the splined belt sprocket on the carrier’s splines.
2. Turn it in the drive direction to the stop while screwing the lock ring onto the carrier’s outer thread.
3. Tighten the lock ring to 30 Nm. Do not use threadlocker.

On the road, without the tool

In an emergency the lock ring can be tightened with a punch or flat screwdriver and a hammer — holding against the tyre or rim. The torque cannot be checked that way, so have it retightened at home.

Removal

1. Remove the wheel.
2. Holding the belt sprocket, unscrew the lock ring anticlockwise.
3. Take off the belt sprocket.

Without the tool, in an emergency: do not remove the wheel; with the bike standing and the rear brake on, hold the belt taut with the crank and loosen the ring with a punch or screwdriver and a hammer, then take the wheel out.

Converting to the lock ring carrier

1. Remove the wheel. Take off the old carrier (8540 or 8540S) together with the belt sprocket and circlip, just like a threaded sprocket: Sprocket: turning, replacing, splined — it needs the Gates POM Key and inserts.
2. With the sprocket remover on the driver as a guide, screw the 8540L (or 8540SL) carrier on clockwise to the stop.
3. Fit the belt sprocket as above (30 Nm).

Caution

Do not reuse the removed 8540 or 8540S carrier and its circlip: make them unusable and dispose of them. If the POM Key will not shift it, take the belt sprocket off with the circlip, fit a splined sprocket in its place, and remove the carrier through it with a chain whip.

A threaded sprocket or threaded belt sprocket can also be converted to the lock ring splined system: once the old part is off, the 8540L carrier goes on in the same way. Then check the chain or belt line and the chain tensioner or snubber setting.

If the belt is noisy

A belt squeaks or gets noisy when it rubs hard against the sprocket flanges — caused by a misaligned sprocket or wheel, or worn, damaged parts. Spraying water on it can stop the noise for a few minutes, but the lasting fix is correcting the alignment or replacing the damaged part. A loose front sprocket can also be the source. With a splined belt sprocket always use the Splined Carrier L with lock ring: on a circlip carrier the sprocket’s inner splines wear and get noisy.

On muddy, sandy ground, sand and water sticking to the belt can cause noise too. Usually rinsing belt and sprockets after the ride is enough. If it persists: wet the belt, let it dry, and spray a thin coat of dry silicone spray on its toothed side — it dries fast, helps the sand fall off, and does not shorten the belt’s life.

On Gates belt tension in winter, see Riding in winter.