Found: HXR Easy Shift Drivetrain Hints Fixed Gear is the New Enduro

HXR EAsy shift

With no details anywhere, other than a video posted on Vimeo, a French company called HXR is about to release a transmission for enduro riding. Designed as the opposite of current systems, the HXR fixes the cassette position to the rear hub so that it cannot freewheel, and then allows the chainrings on the crank to freewheel around the crank arm. It may sounds confusing, but its pretty simple, basically nothing changes about how you ride the bike, except the drivetrain never stops moving while the bike is moving.

This can possibly give some advantages such as being able to shift while coasting, so that you could drop a few gears while going through a corner, and come out strong. That seems to be the idea HXR is going after since they are aiming this product at the emerging Enduro market.

While the good idea is there, it is actually nothing new. Schwinn made a series of bikes in the 1970’s that did exactly the same thing. If you have ever ridden one of those bikes, you would know that it is actually kinda novel when it is working properly. But if it derails, chainsucks, or jams a shift, the bike can come to a very abrupt, skidding halt. This could be a huge concern for modern mountain bikes, where a chain lodged between the tire and carbon chainstay, yet being pulled by the full momentum of a moving bike could destroy a bike in seconds.

We will have to wait and see all the details when they fully release it in the near future. Jump past the break to see the drivetrain in action…

HXR EAsy shift hub

One of the benefits to the design could be less unsprung weight since the hub no longer needs the freehub mechanism. It looks like HXR might be taking that to the extreme with a machined hub shell with large lightening holes. Let’s hope the bearings have excellent seals.

As promised, the Schwinn freewheel crank from Youtube user micycle01. Freewheel cranks are also popular on trials bikes, though typically single speed.

hxr-vtt.com

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mudrock
mudrock
7 years ago

ugh..too many closeups

beardface
beardface
7 years ago

The old honda DH racing bikes used a similar concept. I had one of those schwinn’s in the shop once- it was very strange to work on, and ride.

Doug B
Doug B
7 years ago

Well if all these new 1x systems and clutch derailleurs work as advertised, then mashing your carbon frame should not happen.

m
m
7 years ago

Neat idea, similar to Trials bikes where the freewheel gets threaded onto the crank and the rear is fixed.

Alan
Alan
7 years ago

Browning had a series of 10-speeds around 1980 that used Shimano’s “FFS” front freewheel system, that did exactly this. I’d be surprised if the patents didn’t infringe.

Psi Squared
Psi Squared
7 years ago

This is a bit off-topic, but does anyone actually like how Vimeo functions?

rob
rob
6 years ago
Reply to  Psi Squared

…so the problem that FFS had was that people were dumb? Shocker!

Dave B
Dave B
7 years ago

Shimano had exactly the same system in the early 80’s with their FF (Front Freewheel) system.

It never caught on and one real problem was that the chain was moving whenever the rear wheel was turning. Working on the drivetrain could cause serious injury if you turned the crank and then touched the chain while the rear wheel was still turning but the crank was stopped.

MissedThePoint
MissedThePoint
7 years ago

And enter the tweener version, where both the crankarm and the rear hub freewheels…

pdxfixed
pdxfixed
7 years ago

This would only work if the rear hub had an emergency clutch that would disengage with enough force to prevent disaster when a stick hops into your derailleur.

Drew Diller
7 years ago

I’ve had this idea, but also thought, what about a freewheel that has JUST ENOUGH friction to drive the chain forward while idling (for that shift-while-coasting effect), but if something bad happens, it would break free and the wheel would continue to turn, albeit with a mild freewheel drag.

You’d be able to survive whatever bad thing is happening with the chain and cassette.

Carl
Carl
7 years ago

Psi Squared – Of all the video streaming services available Vimeo streams the worst on both of my computers. – C

Timmbers
7 years ago

Fancy Positron!

Hank Hill
Hank Hill
7 years ago

Drew Diller, I am like 90% sure that’s how Positron worked. I remember being in awe of some seriously sticky freewheels at the shop, and an old mechanic enlightened me that they were for a front freewheel system.

Terry
Terry
7 years ago

@drew diller:
the shimano front freewheeling system did have a method to stop the movement. the freewheel (if you could call it that) had built in drag. kind of necessary since the system was targeted at novice riders.

was a solution in search of a problem then and still is now!!

Menga
Menga
7 years ago

The video looks like a ROSS bike, they had that system like 30 years ago.

Sánchez
Sánchez
7 years ago

Enduro is the new Fixie, excuse you.
Color cordination, forums everywhere, “I was riding enduro before it was cool”, religious obsession about the “real” thing. Yeah, 2007 all over again.

Bog
Bog
7 years ago

My kids Early Rider Belter 16 has this. It’s actually not a good idea.

Frippolini
Frippolini
7 years ago

I think it looks neat. Main advantages as I see vs “traditional” system is (1) less weight for the rear suspension to carry and a lighter rear hub, (b) concentration of weight to the center and lowest point of the bike, (c) any-time executed shifts, (d) potentially significantly stronger pawl mechanism. I think it looks like having a good potential and I look forward hearing, reading and understanding it more.

@ PSI, for me Vimeo always works great, far better than YouTube (faster loading, no hick ups), and signals a more serious image for the video uploader vs uploading a video on YouTube.

Happy New Year everyone!

Big mike
Big mike
7 years ago

I like the use of the term “unsprung weight”. I have really been worried about that 100grams of weight in my free hub. The fact that I am 30 lbs over weight and eating Oreos for breakfast has no impact on my total weight of me and bike.

PBJoe
PBJoe
7 years ago

With the Narrow-wide single front, you also rid the fear of having a buzzsaw near your ankle.

There may be advantages to the system (shifting when coasting, and such) but the drawbacks of a constantly moving chain can be a problem with things like pants, fingers and other objects getting shredded very quickly.

duder
duder
7 years ago

@Alan US and international patents last 17 years, so something from 1980 would be long out of patent protection…

aaron
aaron
7 years ago

The article talking about the bike becoming damaged with a system jam, well this guy would be more concerned about getting my sh!t broke at speed due to a drivetrain malfunction…
just a thought.

@psi squared. vimeo works fine, but i have knowledge with computers/devices. Also I trade in and update my equipment every year to 18months.

chasejj
chasejj
7 years ago

I like the idea. But I am curious as to how it works in rough terrain.
The tension on the top run of chain helps keep the chain aligned and seated on the teeth. When this thing is freewheeling when descending there is no tension on the chain. You may need some additional derailleur tension to keep things on line.

craigsj
craigsj
7 years ago

Worst idea ever. Throwing a chain would be a disaster and that’s always possible with a derailleur-based drivetrain. (deleted)

TheKaiser
7 years ago

SRAM tried this in the late 90’s with a DH front freewheel crank. I remember seeing HB testing it out at Mt. St. Anne if memory serves. Same idea in terms of allowing shifting while coasting, and same problems in that HB said that they had been having a tough time dialing in adequate chain retention. His was running some variation of a MRP two roller two plate system. 15yrs later they are obviously not using it anymore, so I guess it didn’t really work out for them either.

As ChaseJJ points out, with a system like this the bottom run of chain will drive the system when coasting, with only the derailleur clutch and spring to keep it tensioned. Neither of those mechanisms were designed for loads of that size, so it seems that they would need to be reworked too, hopefully without messing with shifting function.

Terry
Terry
7 years ago

if you really need to shift when coasting then just get a internal geared hub like a Alfine or Rolloff. Solves the chainsuck and chainslap problems as well. no buzzsaw near your ankles either.

again, a solution in search of a problem. most serious riders have no trouble spinning a few pedal rotations if they need to shift going downhill. second nature actually. prolly why Shimano never created a pro version of this clever but unnecessary gimmick.

Charles
Charles
7 years ago

@Terry—It’s a solution to a huge problem. Rear derailieurs are road bike tech, same with 9mm quick-release and rim brakes. None of that stuff has ever had any business on a mountain bike, yet mountain bikers have fought tooth and nail to keep them. The transmission should be in the frame, and the rear sprocket fixed. It’s a no-brainer. All of our bikes are compromised because we’re unwilling to break old habits. We’d have been riding stiffer, better performing full suspension bikes a long time ago, with less unsprung weight, more centralized mass, with vastly stronger and stiffer rear hubs, less pedal feedback, and yes, the capability to shift while coasting (probably the least significant advantage). Last I checked, having a fixed rear sprocket doesn’t seem to cause motocross bikes to blow up too often. I’d say the fears are of a runaway chain are totally unfounded. In 10 years enduro bikes will all be running fixed rear sprockets with a 7-10 speed transmission in the frame, guaranteed. We’re already seeing the progression with mountain bikers ditching the triple and double ring crankset (road bike tech) overnight.

Lance
Lance
7 years ago

So your drivetrain will wear out 5x faster

Glass
Glass
7 years ago

You could do the same with the old hammersmit cranks. I have been talking about this idea for years. I’d be interested in getting those cranks. Shifting while coasting would make for smoother transitions from downhill to sudden uphill especially when pedalling might cause your pedals to hit something!

Pete
Pete
7 years ago

This reminds me of the un-heralded advantages of the hammerschmidt system. Besides the overdrive gear being basically useless because of the noticeable drag, the freewheeling crank was super cool; backpedaling in the rough wouldn’t launch (or move) your chain. Modern 1x systems can still launch the chain (albeit much more seldomly) when backpedaling in the rough.

Also the clutched derailleurs that 1x systems rely on exacerbate the chain’s influence on the freedom of the suspension. I think this would be the largest advantage of the freewheeling crank, allowing the suspension to freely move (where the chainstay length generally grows) without either overcoming a force of propelling bike and rider slightly forward (chain force at rear wheel) or lifting the rider’s mass (chain force at crank).

I want one, but will keep my freehub body.

nsp234
nsp234
7 years ago

Interesting… but I’m a bit disappointed it’s not e improved version of the hammerschmidt as iI expected from the picture

MBR
MBR
7 years ago

Physics 101 – How can the always moving cassette, chain and chainring mass offer any advantage over the [what, 100g?] added mass of the cassette freewheel/pawls, which doesn’t move when you coast? Perhaps the new fashion wave niche for those who already think that SS and/or 1×11 is passe…

suede
suede
7 years ago

For the record the Shimano FFS system has pawls on each individual rear cog allowing it to disengage when enough reverse load was applied.

Andre
Andre
6 years ago

Bike Rumor, I don’t like the new layout at all. Way too many add on top, Way to much space between comments.