Jab Derailleur Clutch Types

	Gravel Clutch	MTB Clutch
Typical Uses	Gravel, road, light/medium MTB	Medium/heavy MTB, Enduro, DH, eMTB
Adjustable	Yes	Yes
Adjustment Range	Narrow	Very wide
Adjustment Method	More/less metric ring shims	More/less metric ring shims
Adjustable to Off	Yes	Yes
Rebuildable	Yes	Yes
Mechanism	2-way friction plate	Ratchet friction plate with 2 pawls
Engagement Angle	Instant	2 degrees

 

While the gravel clutch is intended for gravel and light MTB riding, and we have professional mountain bike racers running the standard clutch. This clutch is simple, applying friction in both rotation directions, which helps calm the chain down whenever the cage is moving. This is analogous to your suspension, which has both compression and rebound damping to calm the motion in both directions. Most derailleurs apply friction in 1 direction (forward) and no friction in the return direction. This clutch applies about as much friction as a new SRAM MTB clutch, and it is adjustable within a narrow range.

The MTB clutch is intended for aggressive MTB riding. The clutch uses a ratchet mechanism with 2 pawls to achieve a 2 degree engagement angle. The friction level can be adjusted very high - much higher than any other derailleur. This is ideal for the most aggressive riding conditions. It is full serviceable and adjustable.

Clutch FAQ

What is the main advantage of the gravel clutch? It has 2-way friction. Like all clutches, it provides friction in the expanding direction, but our clutch provides light friction in the return direction, helping calm chain vibration. 

What is the main downside to the gravel clutch? The one downside is that that friction cannot be "turned up to 11" like the MTB clutch.

What is main advantage of the MTB clutch? That its friction can be "turned up to 11", providing the best chain retention on the most aggressive terrain.

What is the main downside of the MTB clutch? It is a bit more complex and harder to service.

Does the ratchet in the MTB clutch make noise? Yes, a tiny bit. However, you cannot hear the ratchet clutch while riding because the pawls are too small, and the chain makes more noise by comparison. The overall effect of the super clutch is less noise while riding. When the bike is in a work stand, you will probably notice the ratchet sounds while shifting though.

Why are there 2 clutch types? Mountain biking requires maximum chain retention, but the function of the MTB clutch is overkill for gravel riding. 

Doesn't the 2 degree engagement angle of the MTB clutch allow some chain vibration? While riding, this small motion is not noticeable. Through testing, we found that keeping the angle at about 2 degrees worked great. We've tested everything from 5 degrees to 1 degree. One open question is whether or not the engagement angle provides more suspension freedom (e.g. small bump sensitivity), but we haven't focused on this detail.

What is the factory friction level of each clutch? We check and tune each clutch on the assembly line to ensure it is within our intended range. The gravel clutch feels about like a new SRAM MTB derailleur, and the MTB clutch feels much stiffer, but still smooth (not sticky like some Shimano derailleurs can sometimes feel).

How do I adjust the clutch? This requires common tools, thread locking compound, grease, and extra metric ring shims. It takes about 5 minutes and is easy to do without removing the derailleur from the bike. It is not a tool-free process, and does require removing parts. We do not recommend adjusting the clutch on a ride because the clutch housing needs to be removed, creating the chance that dirt or water will get inside the clutch. Refer to the Support Center for the guide.

How often will I need to adjust or service it? There is an initial break in period for each clutch, so it may need to be adjusted after 5-10 rides, but then it should be set. Just like most derailleur clutch mechanisms, it will slowly wear with use. We recommend to adjust or service it when you feel that it may not be keeping the chain as calm as you would like. The frequency of service depends on how much use it has seen and how picky the rider is. The nice thing about this clutch is that you can adjust it or service it to get it working smooth and to your desired level of friction.

Can I switch the clutch type on my Jab derailleur? Yes, the clutch housing is the same for both types, so all that is needed is the kit of parts to do the conversion.

Where can I get spare parts? Madrone has spare parts kits available. In addition, fasteners, shims, and conical springs are common off-the-shelf metric sizes, so you can get those from other sources too.