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Here Comes The Hot Stepper
June 14, 2011 8:38 AM   Subscribe

Is this the future of the bicycle? The Bezerra Corportation believe that their 'Stepper Mechanism' holds the future of bicycling for the new millenium. Bezerra Corporation's revolutionary cycle feature is its pedal-crank mechanism, referred to as the "Stepper Mechanism". When placed in its bicycle application, it operates in a vertical, up-and-down, "stepper" motion, and is designed to replace the 6.0" to 7.5" conventional rotary crank arm
posted by SyntacticSugar (73 comments total) 4 users marked this as a favorite

 
This is the future of the bicycle:

The Unicycle.
posted by empath at 8:41 AM on June 14, 2011 [1 favorite]


Is that new? I'm pretty sure that I've seen similar stepping bike schemes like that years ago in Popular Science or Wired.
posted by octothorpe at 8:42 AM on June 14, 2011 [1 favorite]


hogwash.
posted by djseafood at 8:46 AM on June 14, 2011 [1 favorite]


odd that there's not a single shot of anyone actually riding one (non-stationary, anyway) in the promo video. let me guess what that means...
posted by demonic winged headgear at 8:46 AM on June 14, 2011 [9 favorites]


Turning a rotary process into a reciprocating one is usually a bad idea. You'd really like to convert the other direction.

The only reason to do it for bikes is that we can push down efficiently, but not so much sideways, so when one crank is down and the other up you don't get much force. A better solution is to just add more legs. Three legs at 120° intervals or better yet 4 at 90° intervals could do a lot.
posted by DU at 8:46 AM on June 14, 2011 [15 favorites]


Sort of like a treadle bike?
posted by Stagger Lee at 8:47 AM on June 14, 2011


People have been trying to come up with successor to the double-triangle safety bicycle drivetrain ever since it appeared a hundred-plus years ago. The linked mechanism is a wacky idea in a long tradition of wacky ideas.

if we're talking about bike driveline innovations, I myself like the lubrication-free belt drives produced these days by Trek and others.
posted by killdevil at 8:48 AM on June 14, 2011 [1 favorite]


Prior art, slightly different implementation but same principle.
posted by SyntacticSugar at 8:49 AM on June 14, 2011


That mechanism seems like it would be very difficult to built without it snapping off all of the time.
posted by Legomancer at 8:50 AM on June 14, 2011


The Alenax is a great example of an outsider inventing a solution to a perceived problem, creating something that is useless for the intended user. Much money was thrown into the design and manufacture of the Alenax and several years of bicycle show attendance with many models.

That's exactly how I felt skipping through the posted content. And of course most serious cyclists use the upstroke as well as the downstroke, so I'm not sure there is a problem.
posted by Stagger Lee at 8:53 AM on June 14, 2011


They've been working on this for over 21 years! Maybe they should have spent more than 21 minutes on the promo video.
posted by orme at 8:53 AM on June 14, 2011 [1 favorite]


demonic winged headgear: odd that there's not a single shot of anyone actually riding one (non-stationary, anyway) in the promo video

It looks like he's riding one at 3 minutes 52 seconds into the clip. It doesn't look very stable, to be honest.
posted by filthy light thief at 8:55 AM on June 14, 2011


The only reason to do it for bikes is that we can push down efficiently, but not so much sideways, so when one crank is down and the other up you don't get much force.

Anyone remember Biopace? The idea seemed great on paper. But with the amount of biomechanical testing that goes into bike design, they must have been shitcanned for a reason.

Biopace is a tradename of a type of ovoid bicycle chain ring manufactured by Shimano from 1983 to 1993 The design was intended to help overcome the "dead zone" where the crank arms are vertical and riders have little mechanical advantage.
posted by uncanny hengeman at 8:56 AM on June 14, 2011


Their website uses the demo version of some sort of slideshow software from "SymfoniP". If they're too cheap to pay for that, I'm not sure I'd trust their device on my bike.
posted by cmonkey at 9:00 AM on June 14, 2011


I had a Biopace chain ring. Honestly, it didn't feel any different to me than a round chain ring. I was told by serious cyclists that it just made things worse, but I don't know that I believe that. I wonder why Shimano stopped making them?
posted by Nelson at 9:02 AM on June 14, 2011


oops, my bad. Still, if you want to make a demo video, and you only include one slo-mo shot like that, it screams "i'm hiding something!"
posted by demonic winged headgear at 9:04 AM on June 14, 2011


Anyone remember Biopace?

Hah! I still have mine! I took my bike Judy in for a tuneup a while back (she's 21 this year, and is still doing great), and the kid in the store who took my bike in looked like he saw a dinosaur walk in (and perhaps he did).

When I got the bike back, we did the usual chitchat, and buddy was all "well, back in the day, they thought that Biopace was the way of the future", with the implicit "but we all know better than that now, don't we, and why are you still riding this?"

The way he said "back in the day", it was like he was discussing how to arrange my four horses in height to better my chariot for the grading at the Circus Maximus.
posted by Capt. Renault at 9:07 AM on June 14, 2011 [8 favorites]


The whole thing is a parade of LOL, but my favorite part is the caption reading "That 4000 pounds is still produced even in the presence of gravity." Well... yeah. Good. Introducing a drive that fails in the presence of gravity would have been, in some sense, even more spectacular.
posted by Wolfdog at 9:08 AM on June 14, 2011 [8 favorites]


That mechanism seems like it would be very difficult to built without it snapping off all of the time.

Steel is stronger than you think, I can easily see how the system could handle someone even of my mass. However, it'll be heavier.

This isn't new -- Preview tells me that SyntacticSugar has already point out the Alenax. The biggest problem is the return. Most people count on one foot lifting the other pedal up, and the rest will actually pull the pedal up, getting that much more power into the cycle. Worse, if they're independent, you can't post up -- you stand, and both pedals drop.

Biopace: Shimano screwed up with the initial adverts, and said it was suitable for cadences under 90RPM. This immediately made them a no-sell with the race community, and if they're not buying, they don't trickle down to the low end groups. They also had the reputation of wrecking your knees, but that was only true if they were installed wrong, and then only true if you then kept stomping at low cadences. The real knee wreckers were the original elliptical chainrings from the early 1900s. Of course, stomping will wreck your knees anyway, but the extra leverage you had when the rings were installed wrong made the forces on your knees higher.

Installed correctly, they noticeably smooth out the pedaling cycle for people spinning in the 70-100rpm range. Higher than that, you probably don't need them, anybody who can comfortably spin at 120rpm is smooth enough with round rings.

Sheldon Brown loved them -- even rode fixies with Biopace rings.
posted by eriko at 9:08 AM on June 14, 2011 [3 favorites]


My BS detector went off when he made lots of noise about how much force the rider could impart to the wheel. My bike has no problem putting 4000 lbs of force or whatever on the wheel -- that's what gears are for.

It seemed like when he said "inefficiency" he was talking about lost opportunities for the rider to put power into the system, but I don't think that's a problem for most people. In the "dead zone," for example, the rider isn't putting power into the system, but they're not expending power either. Basically, the dead zone forces you to coast for short periods of time. But most people coast a lot -- few riders are really trying to maximize the amount of work they're putting into the system.

Real efficiency gains would be about finding mismatches between the bike's inputs and the power outputs of the human body -- for example, correct seat height is partly about putting the pedals at the leg's most efficient extension point -- and/or mechanical inefficiencies in the bike's power transfer. I don't see any of that here, and in fact their pedal arm -> cable -> gear -> chain -> wheel assembly strikes me as likely to dissipate a lot more power than the straight gear -> chain -> gear system currently in place.
posted by bjrubble at 9:10 AM on June 14, 2011 [1 favorite]


I myself like the lubrication-free belt drives produced these days by Trek and others.

How do you change gears with a belt drive? I can't imagine a chain-style derailleur working well with a belt, because of the increased tension. Doesn't seem like it's ever going to be very popular if you can only put it on a single-speed bike.

Although I suppose there's no real reason why you couldn't build a bicycle like a motorcycle, and put a geared, completely-enclosed transmission right next to the 'engine' (the crankset) and have the belt move at a fixed angular velocity with respect to the rear wheel all the time. I can only assume there are reasons why this is not more popular, given that it seems to be an obvious idea.
posted by Kadin2048 at 9:10 AM on June 14, 2011


Oh, the other issue with Biopace is that it takes the hardest adjustment to get right on a bike* -- the front derailer -- and makes it even harder.


* No, not cone bearings. Those are easy once you build a jig to put tension on them, like, say, a quick release skewer with a couple of worn out cones on them, or if you adjust them on the bike. Front d's are a pain in the ass to get exactly right -- which means they shift well and handle the widest cross possible without rubbing. ]

How do you change gears with a belt drive?

Internal hub gearing.
posted by eriko at 9:12 AM on June 14, 2011 [1 favorite]


Related?
posted by en forme de poire at 9:12 AM on June 14, 2011


How do you change gears with a belt drive?
Internal gear hub.
posted by Wolfdog at 9:12 AM on June 14, 2011


How do you change gears with a belt drive?

You have to use an internally geared hub.
posted by orme at 9:13 AM on June 14, 2011


I remember seeing something like this years ago, being given away as a prize on Price is Right. Even then it seemed like a solution for which no problem exists.

Asymmetric chainrings are still somewhat popular on time trial bikes. I believe Bradley Wiggins uses them.
posted by TheWhiteSkull at 9:13 AM on June 14, 2011


That looked intriguing, until the guy riding in slow-mo couldn't seem to keep his line straight. If you look wobbly when slowed, you're gonna be goddamned rickety when you're riding at speed.

As far as the pedals not coming back up, it looked like there were springs attached to the cables to return them.
posted by klangklangston at 9:13 AM on June 14, 2011


Anyway, as revolutionary as this is, they'll have no trouble setting a crushing new hour record with it. I look forward to it.
posted by Wolfdog at 9:15 AM on June 14, 2011


Honestly, it didn't feel any different to me than a round chain ring. [...] I wonder why Shimano stopped making them?

Ditto here! Didn't even realise I had funky chainrings until a fella pointed them out to me. I didn't research past the Wiki link, but when it got to the part where they were found to be unnecessary, it has the infamous [citation needed] disclaimer.
posted by uncanny hengeman at 9:19 AM on June 14, 2011


How do you change gears with a belt drive?

CVT
posted by DU at 9:22 AM on June 14, 2011


Biopace: Shimano screwed up with the initial adverts, and said it was suitable for cadences under 90RPM. This immediately made them a no-sell with the race community, and if they're not buying, they don't trickle down to the low end groups.

Yup. Failure in marketing, not in design.

Biopace and Rapid-Rise (top normal derailleurs) are victims of Shimano's dogged determination to back the fuck away from anything that looks like real innovation at the first sign of resistance, and Campy's refusal to acknowlege Shimano could get anything right.

Rotor and Osymetric both make modern aftermarket ovoid chainrings, which are a lot more effective than this treadle-bike retread.
posted by Slap*Happy at 9:24 AM on June 14, 2011


Sheldon Brown on the Shimano Biopace
posted by wcfields at 9:27 AM on June 14, 2011 [1 favorite]


demonic winged headgear: oops, my bad. Still, if you want to make a demo video, and you only include one slo-mo shot like that, it screams "i'm hiding something!"

I agree, and I think the hidden fact is that pumping your legs isn't as stable as spinning. It made me think of people on powered bikes traveling at slow speeds - they were moving ahead, but they looked awfully wobbly from time to time, even when going on a straight, level path.
posted by filthy light thief at 9:28 AM on June 14, 2011 [1 favorite]


Is this the future of the bicycle?

No. The answer to this question is pretty much always no.
posted by 7segment at 9:37 AM on June 14, 2011 [9 favorites]


I ride an early-80s Cannondale with a Biopace chainring. It is noticeable, I guess, but I've never been able to decide whether it's more than a gimmick. I do appreciate the cornball COMPUTER DESIGNED DRIVE SYSTEM logo...
posted by brennen at 9:38 AM on June 14, 2011


No joke, back in 1885, the star bicycle company had the exact same idea. I've seen one of these in person, and they do go fast, but fact of the matter is that this is not a new idea at all.
posted by DeltaZ113 at 9:40 AM on June 14, 2011


How timely. I was at a family reunion last weekend, and one of my mother's cousins has been working on a new crankarm design that he claims will eliminate the dead spot at top dead center. He had a bike there and I rode it briefly. It wasn't sized for me, but the pedaling motion did seem somewhat smoother.
posted by Johnny Wallflower at 9:57 AM on June 14, 2011


I actually see a woman riding one of these around San Francisco every once in a while. I think she works for the company. It looks incredibly dopey to ride, but the biggest issue it takes a HUGE amount of space on our commuter train's bikecar.
posted by NoRelationToLea at 10:10 AM on June 14, 2011 [1 favorite]


Regarding Biopace, I could never tell the difference, respect to Sheldon and all. Judging by the steel Biopace rings and Biopace sprockets I've seen pressed onto crank arms, I'd say they did trickle down without problem. Maybe even too fast, and the association with low end bikes killed the high end demand.

Viable CVT for a human powered vehicle is a bit of a holy grail. They tend to be too heavy, lossy, and costly for the widespread adoption. But for powered bikes/lightweight alternative vehicles, they seem to fulfill a niche.

As far as the Z-Tourque crank arm goes, uhh, yeah...
posted by 2N2222 at 10:25 AM on June 14, 2011


Working on it for 21 years and they haven't bothered to put it in a race yet? I don't care if he's "convinced" the bike could "blow away a conventional" bike. Enter it in a damn race and prove it. If the claim is anything more than marketing bluster, BLAM! instant investor funding.
posted by Dodecadermaldenticles at 10:26 AM on June 14, 2011


Biopace is back, baby!
And the Z-Cranks seem familiar too.
posted by SyntacticSugar at 10:32 AM on June 14, 2011


Novelty-shaped crank arms (Z-Torque...) are also not the future of cycling. If you want heavier, possibly stiffer crank arms, just swap out your aluminum cranks for steel.
posted by 0xFCAF at 10:32 AM on June 14, 2011


There is another aspect of the standard crank that is more appealing is - it has fewer parts, which means less maintenance and less stuff risking breaking. Moreover, almost anyone can put the chain back on the gears if it comes free. Having looked at the stepper, there's a lot more to it, and a lot more that can fail.

Now, I'll beliee the force that they can apply. I'll believe that it can travel faster. What I can't believe is that if it does do this as well as they say, that they don't have disc brakes on it.
posted by Nanukthedog at 10:41 AM on June 14, 2011


Bah. When I was 12, I know what the future of bicycling was, and it wasn't a new crank arrangement. It was THIS.

And damn it all, I'm STILL waiting for after-market rocket boosters for my bike.
posted by happyroach at 10:44 AM on June 14, 2011 [1 favorite]


Man, that guy can mash himself some pedals. I guess maybe this wacky system is OK for low-RPM mashers, but I'd like to see someone actually "pedaling" it at 100+ RPM. I'm not sure of it would work.
posted by GuyZero at 10:45 AM on June 14, 2011


Also, I saw somebody "pedaling" their Eliptigo across Google campus last week... seems like basically the same idea. Also, the treadmill bike.
posted by GuyZero at 10:47 AM on June 14, 2011 [1 favorite]


killdevil: "People have been trying to come up with successor to the double-triangle safety bicycle drivetrain ever since it appeared a hundred-plus years ago. The linked mechanism is a wacky idea in a long tradition of wacky ideas."

It is kind of fascinating that the basic design of bikes jelled so early and has stayed so constant. Here's a picture of a bike from 110 years ago that basically looks like a bike; if someone road past you this afternoon riding that model, you probably wouldn't even notice.
posted by octothorpe at 11:23 AM on June 14, 2011


Actually that bike has no stem to speak of - the handlebars sit right on top of the steerer tube and the fork has a really big rake. Those two things distinguish it from most modern bikes. But yeah, otherwise, it's a bike.
posted by GuyZero at 11:28 AM on June 14, 2011


From my vantage point behind the wine bar in the finish line hospitality tent, I heard a couple of the race commentators mentioning that several of the racers in this years Tour of California were sporting elliptical chain-rings.

The expressed opinion was that they were a fad that seems to come and go among racers.
posted by Pirate-Bartender-Zombie-Monkey at 11:30 AM on June 14, 2011


It is kind of fascinating that the basic design of bikes jelled so early and has stayed so constant. Here's a picture of a bike from 110 years ago

Guns and ammunition are similar. It took a while to plateau, but the basic designs aren't changing any more, and designs from 100 years ago remain modern staples.

The very concept that a basic design layout can be done, can be as good as it gets (or close enough as near makes no difference), is anathema to me growing up in the digital age, but there is evidence in the world that it happens, and isn't uncommon, even with fairly complex devices.

So weird.
posted by -harlequin- at 11:35 AM on June 14, 2011 [1 favorite]


One of the things that I adore about bicycles is exactly how hard it is to "revolutionize" their design, and it's hard because they are a mature, complete technology. Sure, there are people who come out with the next big thing, automatics and shaft-drives and belts and bizarrely structured recumbents and so on and so forth, but all these things do is to add complexity and remove reliability. In the case of shaft drives and automatics, they also sap power, which isn't the best thing when you're your own engine.

I've got a Biopace on the little mountain bike I keep in a shed in a friend's house in LA so that I won't have to be trapped in a car when I'm out there visiting, and it feels like it's doing something. That may be a sort of placebo effect, a little silly side to my love of nifty notions, but it's an evolutionary thing.

Most of the best things that have happened to bikes has been evolutionary, little hardware upgrades like cantilever brakes and standardized parts sizing (I'm split between Chicago-era Schwinns, Gitanes, and Raleigh three-speeds in my little fleet, which is threading hell.). As a devotee of the church of Sturmey-Archer, I bristle a bit at the market domination of clattery, fussy derailers (observing the Sheldon spelling here, in memorium), which don't meet my post-apocalyptic standards, but there are some damn fine bikes out there today that pretty much follow the same pattern as, say, a 1916 Mead Ranger, and that's a good thing.

I've spent my adult life trying to figure out why there is never the right plug on the end of any cable to fit a socket, or never the right file translation, or the right kind of disc, or the right file type, which is why getting on a bicycle and knowing that it's a damn fine machine with a hundred year pedigree is just so calming. All that's left are little tweaks to come up with new or revisited geometries, better materials engineering, and the courage to go back to things that worked perfectly well at everything excepting making us feel hip, with a bit of modern refinement (and brakes that work).
posted by sonascope at 11:59 AM on June 14, 2011 [3 favorites]


Seeing as how we are posting links to alternative-drive bikes...

Driveshaft Bike

Anybody have any experience with one of these?
posted by mmrtnt at 12:20 PM on June 14, 2011


I've never wanted anything but circular chainrings. I attempt to pedal with power on all the way around the stroke, pulling up and pushing down simultaneously - in part because it's more powerful and in part because I'm a runner and it uses more hamstring. I'm much stronger in the hamstrings and much weaker in the quads than most cyclists.

I don't think the general design of the bicycle will change much, if at all, for a long time. What I do think will change a lot is a refinement of the materials such that stronger bikes can be built to be much lighter, faster, more comfortable and easier to maintain.

Living in a hilly place I'm not overly keen on having a single-speed commuter, though Trek's District Carbon is a drool-worthy fantasy and pretty close to my idea of the perfect bike. I really like the new carbon drives and internal hubs - the Alfine 11-speed hub has reliability issues, I'm told, but once they get that figured out a carbon belt-drive coupled with it and a lightweight, durable carbon frame would be a dream to ride. The achilles heel of the current drivetrains are the complexity of the rear derailleur, even though they're really not all that difficult to maintain if you spend some time learning how to do it.
posted by jimmythefish at 12:30 PM on June 14, 2011


So we have every freaky HPV around here it seems. A co-worker had a driveshaft bike. He said it was Ok but that it wasn't really any different from a regular bike. I don't recall any comments about maintenance being any harder than normal. Also seen recently: a three-seat tandem and a tandem recumbent. Also an electric unicycle.
posted by GuyZero at 12:34 PM on June 14, 2011


Surprised that no-one else seems to have picked up and commented on the oddly aggressive-slash-desperate pseudo-Tweets on his site's front page:
I am so tired of begging for money to bring my products to the market. 117 days ago

Listen to "Inside Bezerra Technologies" hosted by wilsonxb on 1/31/2011 5:00 PM #BlogTalkRadio http://tobtr.com/s/1461536 140 days ago

Is anybody listening to me.. email wilson@bezerra.com or call me directly 973-2771526 140 days ago

Call in number for blogtalkradio.com/wilsonxb (619) 638-8464 Help me win this race.... 140 days ago

I will be going live in 3 minutes. www.blogtalkradio.com/wilsonxb at 5pm now Listen to what I have to say. 140 days ago
The top one ... umm ... yeah. Perhaps you should work on making better products that the market actually wants?
posted by kcds at 12:41 PM on June 14, 2011


OK, I gave it 2 mins. Haven't read the thread, but this guy's video demonstrates he doesn't understand basic mechanics. Oh, and this isn't a new idea. Haven't got Whitt and Wilson's Bicycling Science at my elbow at the moment, but they thoroughly discuss the disadvantages of a lever drive.
posted by normy at 12:59 PM on June 14, 2011


Back in the mid-1990's, I was working at a now-defunct independent bike shop here in Fort Collins. Like a lot of bike shops, we had cashflow trouble during the off-season and tried to diversify by carrying other products. You know, like snow shoes, boomerangs, blow guns and air rifles, right?

Given our iconoclastic inventory choices, it's probably not too surprising that my boss purchased about a hundred or so of the Alenax stepper drive conversion kits described by Sheldon Brown at SyntacticSugar's link here. He was small-time framebuilder and thought there were interesting applications for some of the parts, so when Alenax (predictably) went out of business he bought the kits at a deep discount. They came with these hubs, you see, that had freewheels on both sides. The plan was to scrap the crankarms and keep the unique and intriguing hubs.

I'm not sure if I forgot or was never told what he intended to do with the hubs, but whatever it was, it didn't work out. The shop eventually went under, as most do, though I'm quite sure the Alenax affair had little to do with that.

We did build up one bike with the stepper kit, and I got to ride it a bit. It felt bizarre, cornered horribly, and the design would never allow anything but a 1-speed drivetrain. It was way heavier and more complicated than the light, simple, efficient mechanism it set out to replace. The system in this video looks like a marginal improvement over the Alenax, but I still think it's a terrible solution to a non-existent problem.

Also, "The USCF has approved our design for use in mass-start races." WTF?
posted by richyoung at 2:13 PM on June 14, 2011


Holy cow! Alenax is still in business! And they have a 6-way pedaling motion setup!

This seems beyond terrible. Having both feet in the same position on each side of the crank?
posted by GuyZero at 2:26 PM on June 14, 2011


Remember the Trek Y-Foil? It was legitimately faster due to superior aerodynamics and it looked pretty cool. But it was disqualified from racing, which was enough of a setback to kill the product.

(This stepper thing, on the other hand, sounds like it was invented by a guy who is not a serious rider. If the speed claims are true, why not go set some records?)
posted by ryanrs at 3:40 PM on June 14, 2011


Note to aspiring bicycle innovators! Here are the pros and cons of the existing drivetrain:

Good
* light weight
* efficient

Bad
* finicky adjustment
* dirty, stains clothing

Also bear in mind that these downsides are not very important to most serious cyclists. Your mechanism will have to be genuinely lighter and more efficient than a chain drive to win that market.

On the other hand, if you chose to target the casual cycling market, your design better be simple and clean, and cheaper, too.

And don't forget—the existing design works really, really well.
posted by ryanrs at 3:58 PM on June 14, 2011


The Gates carbon belt drive really does seem to be a hit - it helps that Shimano and SRAM are competing to bring wide-range IGH's into a mere-mortal price range, and NuVinci's second-generation CV-IGH is light enough for more than novelty. Almost all of the major manufacturers have an urban bike with a Gates drive paired with a Shimano Alfine.
posted by Slap*Happy at 5:53 PM on June 14, 2011


Also bear in mind that these downsides are not very important to most serious cyclists racers.

As a serious all-weather commuter, I would kill for a drivetrain that isn't so desperately vulnerable to the elements, with a lower efficiency at converting rain and grit into the most powerful eroding abrasive known to man, with which to destroy itself.

I'm hoping that by the time it's time for my next bike, hermetically-sealed ultra-durable belt-drives will be a viable option. My car needs less cleaning and maintenance than my bike, and it's doing twice the miles!
posted by -harlequin- at 6:03 PM on June 14, 2011


"I am so tired of begging for money to bring my products to the market." 117 days ago.

Not all is well at the Bezerra Corportation , methinks...
posted by markkraft at 8:05 PM on June 14, 2011


* No, not cone bearings. Those are easy once you build a jig to put tension on them,

How should cones be set? My understanding (maybe I just pulled it out of my ass...) is that they should be exactly tight enough that the wheel can't move laterally at all, but loose enough that the wheel will pendulum back and fourth once or twice before coming to a rest when disturbed.

With nice clean parts, I've never found this to be particularly difficult. If you add dirt and rust, it can become a real pain (because the nut/cone you are applying force to isn't always the one that ends up moving). I don't really see how a jig would help much....
posted by Chuckles at 8:12 PM on June 14, 2011


One thing that should be considered by the people who try to invent these weird new modifications to the bicycle is that you're actually losing most of your energy to wind resistance (at least, at any kind of speed.) As such, it's unlikely to make a really 'revolutionary' improvement without addressing that. People have tried to do that, with recumbents, aero bars, and fairings being the obvious examples, but they usually remain niche applications with some pretty serious drawbacks.
posted by Mitrovarr at 8:19 PM on June 14, 2011


I've ridden a bike with a similar mechanism (using a rack and pinion) albeit one that preceded it by around a hundred years and it was really no surprise the design never went anywhere. The bloke in the video talks about the dead zone at 6 & 12 o'clock (err...momentum?) and what a terrible waste it is. Having ridden one there is an obvious and unavoidable problem with all these designs -- you have to bring your feet to a complete standstill with every stroke.
posted by tallus at 10:48 PM on June 14, 2011


My understanding (maybe I just pulled it out of my ass...) is that they should be exactly tight enough that the wheel can't move laterally at all, but loose enough that the wheel will pendulum back and fourth once or twice before coming to a rest when disturbed.

Exactly. More importantly, it shouldn't feel like it's ratcheting at all. However, if you have a quick release axle, you can't set this on the wheelstand, unless you have something to put that compression into the rig while you're setting the cones, or you do it on the bike (if you can get to the cones while it's on the bike.)

I tighten the cones until they *just* start to bind, then back them off about 1/8th of a turn. The trick here is feeling the cones binding when your rotating the wheel by hand.
posted by eriko at 5:44 AM on June 15, 2011


As a serious all-weather commuter, I would kill for a drivetrain that isn't so desperately vulnerable to the elements, with a lower efficiency at converting rain and grit into the most powerful eroding abrasive known to man, with which to destroy itself.

This is a solved problem.
posted by SyntacticSugar at 6:37 AM on June 15, 2011 [1 favorite]


This is a solved problem.

You'd think so, but even though there is no mechanical reason why a shroud can't be sold for dérailleur bikes, no-one does it. The euro style you link too just ditches the gears, which is fine in flat Copenhagen, but useless in hilly Seattle, and the US style (which keeps the gears) isn't interested in making them practical.

It drives me nuts that it's so demonstrably a solved problem, yet no-one has solved it.
posted by -harlequin- at 3:17 AM on June 18, 2011


They have 8-gear internal hubs with the same gearing range as the average 21-speed derailleur bike. Solved.
posted by GuyZero at 8:52 AM on June 18, 2011


I still don't really get it eriko. I mean sure, the quick release adds pressure that tightens the bearings a little.. I've played around with that, but only when I've failed to set the lock nuts with enough torque. Lock nuts properly(?) set, and the added pressure from the quick release is negligable.
(or maybe not, because I have ground up a fair few bearing cones... I do test the wheel when it is on though, and while you can't really feel the ratcheting unless it is terrible, you can certainly confirm that it pendulums freely)
posted by Chuckles at 12:04 PM on June 18, 2011


You'd think so, but even though there is no mechanical reason why a shroud can't be sold for dérailleur bikes, no-one does it. The euro style you link too just ditches the gears, which is fine in flat Copenhagen, but useless in hilly Seattle, and the US style (which keeps the gears) isn't interested in making them practical.

-harlequin-, a guy called Bernhard Rohloff decides to take his bike for a spin on the beach. 200m [meters, not miles] into his ride he has to stop, his gears and cogs are caked in sand, making his bike inoperable.

He decides there must be a solution.

Three years later he has a working prototype, and goes for a 30km bicycle ride on the same beach.

14 non-overlapping gears with the same range as standard 3 top-ring geared bikes.

[I would have copy'n'pasted the above story from his brochure, but it all came out as gobbledegook. Y'gotta read it – it will leave you drooling. Includes a testimonial from a touring cyclist who rode 85,000km from Alaska to Patagonia on the same gear hub.]

Make sure you're sitting down when you see the price.
posted by uncanny hengeman at 8:07 AM on June 19, 2011


The euro style you link too just ditches the gears, which is fine in flat Copenhagen, but useless in hilly Seattle, and the US style (which keeps the gears) isn't interested in making them practical.
Hub gears, maybe you've heard of them?

If you want to run a derailleur then you can use something like the SKS Chainboard, but it provides limited protection at best.
posted by SyntacticSugar at 6:58 AM on June 22, 2011


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