Effigear belt drive gearbox bike (4)

When the discussion turns to gear boxes, Pinion seems to be getting all the attention these days, but there is another gear box which has been around for some time. Currently being used by companies like Cavalerie and Nicolai, the effigear gear box offers a tuneable range of gears from 6 to 9 speeds. While some of the Cavalerie bikes have only changed slightly in the past few years, they will now be available in the US through Philthy Bikes. Not only are they available, but the company does have a new Enduro bike in the works…

Effigear belt drive gearbox bike (3)

Effigear belt drive gearbox bike (9) Effigear belt drive gearbox bike (7)

As their full on DH build, the Falcon has seen a few small tweaks since its introduction a few years ago. Rear travel is still 200mm from the single pivot design. Since the drive is concentric with the pivot, Cavalerie claims pedal feedback is almost completely eliminated.

Effigear belt drive gearbox bike (8) Effigear belt drive gearbox bike (5)

Effigear belt drive gearbox bike (13)

Since the gearbox itself has a freewheel built in, all of the Cavalerie bikes use a fixed gear rear hub. That makes for less unsprung weight. The hubs are made by Aivee with the belt drive cog splines machined directly into the aluminum hub shell. The replaceable dropouts also allow the belt to be installed and offer tension adjusters to tune the belt.

Effigear belt drive gearbox bike (14)

Effigear belt drive gearbox bike (16) Effigear belt drive gearbox bike (15)

Effigear belt drive gearbox bike (2)

Built with a 3 axle system, the effigear gear box holds two sets of pinion gears which offer the capability to run different speeds. To drop up to 3 gears from the standard 9, each set of pinion gears can be removed and replaced with aluminum spacers which decreases the weight.

The included freewheel runs 48 engagements points for 7.5 degrees of engagement. At the full 9 speeds, the gearbox range is 444% – roughly the same as a double 24/36 with an 11-34 cassette. Dropping it down to 8 speeds nets a 360% range, 300% with 7, and 260% with 6 speeds. Compared to a full derailleur equipped drivetrain, the effigear gear box is claimed to add only 5-100 grams.

In order to keep the gears running smoothly, the box is sealed and filled with gear oil. When it’s time to change the oil, simply open the drain plug and replace.

Effigear belt drive gearbox bike (10)

Effigear belt drive gearbox bike (12) Effigear belt drive gearbox bike (11)

Sitting at 185mm of travel the Squirrel is aimed at the freeride or big mountain market. The Squirrel is very similar to the Falcon in a smaller package.


image c. Philthy Bikes/Cavalerie


While it wasn’t on hand at Sea Otter, Cavalerie has a new bike they have been working on called the Anakin. Built for Enduro (what else?) the frame runs 650b wheels, 160mm of travel, and is still a Gates Belt drive effigear equipped shredder.



  1. MikeK on

    Seems like a good idea although i’d be interested to know what it weighs compared to a normal crank and cassette. It looks beefy so I would assume more, plus the added weight of oil. I don’t know if the lower unsprung weight outweighs its overall weight

  2. Gunnstein on

    “Since the gearbox itself has a freewheel built in, all of the Cavalerie bikes use a fixed gear rear hub” – better not get any clothing or shoe laces stuck in there while running downhill, it’ll rip your leg off. Other than that, glad to see more products in the internal gearing market. Had never heard of this one before.

  3. Alex K on

    I agree with Gunnstein – why would you want the belt constantly moving? it seems like the weight is there, whether you put it in the rear hub or the gear box – it’s still there, and still unsprung.

  4. paul woodman on

    the freewheel is built in to the gearbox,so the belt doesn’t always move. No worries about ripping your leg off,gunnstein. the freewheel weight is sprung with the gearbox then,probably runs quieter than a standard freehub. I like the added ground clearance as well.

  5. groghunter on

    The gearbox wouldn’t be unsprung weight. It’s got a suspension pivot between it and the ground, therefore it’s sprung. secondly, it’s at the center of the bike, at the lowest point, which is the best place for excess weight to reside. However, going to a single pivot, BB-pivot suspension design is DUMB DUMB DUMB. It doesn’t matter how great the drivetrain is if the rear suspension feels like garbage. and it’s all in service of using a belt instead of a chain. use a chain, and you can use an idler and a modern suspension design. There is no way the slight (and debatable) advantages of using a belt over a chain are worth the suspension trade-off.

  6. Smokestack on

    None of these systems are BB concentric. They’re a high (160 bike) or high forward pivot system (the other two), the drivetrain force is inline with the swingarm. The brake jack issues of long travel BB concentric pivots aren’t an issue. As for the fixed rear hub, absolutely a killer idea as you can shift when coasting (think the old Schwinn crankset freewheel mech on their old road bikes), but yep, be mindful of what you wear. Still curious about the weight and when these folks, or Pinion for the matter, will develop a trigger for em.

  7. Gunnstein on

    @paul woodman “the freewheel is built in to the gearbox,so the belt doesn’t always move” Yes it does. The hub is fixed gear, so if the wheel turns, the belt moves. Can lead to serious injury, just ask on a fixie forum.

  8. Gunnstein on

    @Smokestack “As for the fixed rear hub, absolutely a killer idea as you can shift when coasting” – And you can’t do that on the Pinion 18 gearbox? Their homepage says “Lightning-fast shifting of any number of gears in any situation” which should include coasting.

  9. groghunter on

    @smokestack Hmmm, I didn’t consider the fact that the front drive wheel isn’t part of the cranks , you’re correct. However, I’m curious how no chain tension increase due to stay lengthening will affect pedal bob. (I don’t mind some, as an active suspension helps traction during climbs.)

  10. hellbelly on

    It states that max weight addition over a standard drive train is 1.1 lbs. The weight is non-rotational and at the lowest point on the bike. It has little to no maintenance and a near indestructible belt drive. I agree the bikes presented look a bit cobby. However build one of the high zoot carbon wonder bikes flooding the market these days with a dope suspension lay out (take your pick, KS-link, FSR, VPP, DW-link, whatever) and this thing could be amazing.

  11. groghunter on

    @hellbelly You can’t use any kind of chain-stay-lengthening suspension design with a belt drive. That excludes pretty much all of the systems you mention.

  12. groghunter on

    @Gunnstein You’re absolutely right, there is danger from the fixed rear hub, (probably more than a normal fixed gear, due to the higher tension of a belt) and you don’t need it for coasting shifts. but it does make sense from a reducing unsprung weight standpoint, and I’m sure they’re counting it as part of the minimal weight gain they’re touting: put a freewheel on there, and it weighs more than 100g claimed weight difference. Belts are lighter than chains, too, so part of their pitch here is that you need to go both belt and fixed gear to make one of these bikes weight competitive with a standard drivetrain. My thought on this is that they should make the drive side chainstay big and boxy, with a detachable cover on each end, and run the drive belt THROUGH the chainstay: that way you’re protected from the fixed gear belt, and the belt is protected from the elements.

  13. Drew Diller on

    Looks fantastic! Sign me up.

    I have some other ideas about drivetrains but this looks like a very competent option. Also would like to know pricing.

    As a guy who has made some HEAVY bikes, I can say confidently that if you’re going to have anything heavy, put it in the middle of the bike, emulate the motocross guys. I had a two speed with a Hammerschmidt in the middle and that bike rode awesome, I sincerely regret parting it out.

  14. Smokestack on

    If the wheel is moving the shift is that much faster. Plus, your continuously lubing the gears as long as the wheel is moving. Totally a good idea.
    The stay isn’t lengthening compared to drive load. That length stays constant. It is only lengthening relative to the center of the bottom bracket/crank arm interface. Since drive load is no longer a part of the suspension equation, a well designed and valved damper unit is all you need to compensate for spinners or squares.

  15. groghunter on

    @smokestack There are more inputs to a suspension system than just braking and driving forces, and I’m not quite ready to believe that this system either A: completely ignores either, or B: even if it does, that a well made damper is enough to counter those other inputs. Even trophy trucks and racecars use more than just an A-arm and a damper. Example: it could argued that this design doesn’t have enough rearward axle path to conserve momentum through square edged hits.

  16. Gunnstein on

    @groghunter That would work, though I would rather just use a freewheel hub. Lighter than a full belt cover, and these belts supposedly handle the elements well.

  17. groghunter on

    @Gunnstein I don’t think that it’s certain that it would be lighter, with advanced aluminum and/or carbon fiber construction techniques. It wouldn’t need that much more mass, and there doesn’t appear to be much ratio between the two belt wheels on this, so they could make them smaller, which would narrow the belt path and how tall the stay would have to be.

  18. Tom on

    Sooo, seeing as the rear hub is fixed gear. Bombing downhill at 50+ km/hr, your shoelaces/pant leg/ankle will get nicely sucked into the humming drive and rip you off the back.

  19. hellbelly on

    @groghunter even if none of the aforementioned designed would be applicable wouldn’t designs like the old Balfa BB7 and the Brooklyn Machine Works elevated chain torque models be ideal? The biggest downsides to those bikes were their weight and the addition pulley systems. The complication would be unnecessary and the weight would be could be easily managed while delivering a nicely pedaling bike.

  20. Pete on

    why couldn’t aa enterprising owner rebuild the wheel with a regular single-speed hub (even if still a belt drive – they make em), and remove or somehow disengage the coast feature from the tranny?

  21. grog on

    @hellbelly My understanding, which I’ll admit I’m not 100% confident in, is that you can’t use any kind of idler with a bicycle belt system, due to the high tension required. Idlers are usually supported via a one sided bracket, and too much tension on the belt would bend the bracket. In this case, if you’ve got a variable drive path, the idler would need to be spring loaded, as well. a spring strong enough would probably carry a significant weight penalty. These factors, to my knowledge, are the reason why you don’t see full suspension bikes with belts. These Calvarie bikes don’t seem to have any distance changing between the two belt wheels, so they can function like a hard tail single speed.

    All the things I’ve said may come off like I’m not a fan of these bikes: I’d actually say they’re the best gearbox bikes I’ve seen, and I’d love to get one. Just not sure if the way the rear suspension performs would change my mind once I rode it.

  22. PaulM on

    @grog – you’re correct, you can’t (at the moment0 run an idler with the belt for 2 reasons. The main one is that the belt cannot be bent backwards, and secondly, it requires constant, fairly-high, tension, so would need some form of constant-force spring applied to the inside of the belt.

    Not impossible by any means, but not simple either. For that reason, its easiest to run a single pivot, concentric with the main output shaft. Like a Kona A.
    If only someone did a belt-conversion on a Kona A. Oh, I have, and its superb 😉

    And I don’t know why you’re all getting het up about the fixed/freewheel issue. Yes, fit a second freewheel to the wheel if you’re worried about tearing chunks out of your leg. Don’t forget you’re talking about a rubber belt, not a steel chain though.

  23. gee on

    @hellbelly – DW link, VPP, FSR etc are probably all rules out – need constant tension on the belt, do anything with chain growth is out – maybe could be made to work with a chain and tensioner, but not with a belt. Think you’re stuck with single pivot with the belt on the swingarm axle- but that high pivot design can be made to work well with a decent platform shock – Orange make great bikes that way. Brake jack probably an issue here, though.

  24. groghunter on

    I did actually come up with a method last night that would allow you to use an interrupted chain-stay: have an axle run through the chainstay pivot with a belt wheel on each side, and run two belts, one on either side of the pivot. lots of other reasons why that might turn out to be not viable though: weight, drag, reduced reliability due to complexity, etc.

  25. Rick on

    @groghunter, I kinda dig your internal belt idea, but you would need the beltstay to open up down its entire length, as just on the ends would not be enough for you to get a belt into the frame.

    Your axle-through-pivot idea… now that one I can’t shoot down… it’s both overtly excessive and diabolically genius at the same time… sort of like these Cavaleries xD

    Also, extremely thoughtful discussion; really glad everyone is being constructive. I love bikes.

  26. Charles on

    Funny all you guys worrying about legs getting ripped off, lol. Every single motocross bike, off road motorcycle, and street bike built in the last 40 years or more has a fixed rear sprocket. Worst thing that every happens is a cut or broken finger from adjusting chain slack adjusters or changing tires, and motorcycles have massive chains compared to mountain bikes with huge gear teeth. This bike uses a friggin belt. All these guys are trying to do is make the bike work better by taking the drivetrain off the rear wheel, where it ISN’T supposed to be. Remember Greg Minnar’s world cup Honda downhill bike that he was able to dominate the competition with? That thing had a fixed rear sprocket, and it was designed by some of the smartest engineers on the planet. Last I checked, Greg has both legs. You guys are too much!!!! Same people who freaked out about hydraulic brakes busting lines on the trail and having no brakes with oil leaking everywhere, or worried about changing tires on the trail without QR hubs. Goodnight.

  27. chris on

    Cavalerie says the “gearbox” weighs 2kg and they say their system weighs about 100g more than a standard drive system. I’m sure the unsprung weight saving is a plus and most of the weight low and center makes sense. Also I bet it works well, but there seems to be something wrong with their numbers.

    This a quick list of weights and doesn’t take everything into account, but still, 100g? I don’t get it.

    Xtr chain 259g, Gates carbon belt 82g, so +177g, xtr rear der 208g, xtr ft der 132g, xtr 11/34 cassette 254g, 1 xtr shifter 103g, 38g for a Raceface 32tooth chain ring = 912g approximate total weight, vs 2000g. And that’s assuming the 2kg “gearbox” includes the full drive train, which I don’t think it does. I think they forgot a zero, at least. I’m sure it is a great system, but you have to keep it real or people will be pissed off. Am I missing something obvious?

  28. ginsu on

    ah man, great ideas constrained by chain/belt growth as far as design is concerned it really limits you to a single pivot suspension, although you could improve the braking by doing an axle located pivot ala TREK ABP, or Dave Weagle Split Pivot. that would be a big improvement to this design.

  29. German on

    Hey Chris in the future you will have to add the weight of oil and a chain/belt guard, even though lets face it…maintenance free, faster/!coasting gearing and bigger clearance, are tickling everybody all over

  30. Brian on

    They need to seal that belt! Just design a plastic cover for it! I want an MTB drivetrain that stays clean and maintenance free. I hope the industry starts using gearbox based drivetrains like this soon. I’ve had so many problems with chain and derailleur systems.

  31. 'Ol 'Shel on

    Putting big torque through small internal gears makes a lot of drag. There’s no way around it.

    This is probably OK for local-level DH, but not for riding uphill.

    As a designer, I wish gearboxes and planetary systems were more viable. They just aren’t.


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