ganchan

Anybody heard of this thing?

3-Speed Gearbox: Alternative to Front Derailleur | lovingthebike.com

CliffordK

It looks like a neat idea. I think I've seen others that needed a custom bottom bracket shell. This one is nice that it retrofits standard shells.

It does compete a bit with other internal gear hubs (Nexus, Alfine, and Rohloff), as well as the Dual Drive systems that have a rear IGH plus cassette.

Are there any sprocket choices? Can the sprocket be replaced?

One of the issues with Planetary Gear systems is increased friction. Once shifted, a front derailleur should have ZERO added friction, and most of the chain friction is similar for an IGH vs a derailler system, with the IGH adding a small amount of friction on top of that.

Andrew R Stewart 

A minor point- I beg to differ. The BB gear box augments any other gear systems. Andy.

Jeff Wills

Shimano made a 5-speed planetary gearbox mounted on the crank, the Shimano FM-5. It was only available on some Miyatas in Japan:
******************************??-5 ( ??? ) - PenPen******************** - Yahoo!???

dsbrantjr

Not sure about other choices, but this movie https://vimeo.com/117609549?from=outro-embed states that it has a 28-40-50 equivalent gearing, and that 1st is 1:1, so the sprocket provided must be 28T (I know I could have just counted them). Looking at the product gallery it appears that the hub will need disassembly to swap the sprocket :-(

CliffordK

I suppose it depends on how one is installing it. For the most part, a triple shifting system (front, rear, and internal) is not needed and would create some horrible redundancies (no easy half step shifting sequence).

However, this would augment a simple internal gearing system. Say 3 front x 8 rear, and no derailleurs. Keep in mind though, there are benefits of eliminating the rear derailleur. But, if one has some kind of intrinsic chain tensioner mechanism, then a front derailleur has essentially no resistance when properly centered.

Yeah, I saw that on their website.

Gearbox | Efneo

I'm not a fan of "compact gearing". It also might knock it out of folding apps.

The Alfine goes + & - on their gearing, but generally uses a fairly large sprocket, although I'm seeing notes that one might be able to squeeze a smaller rear sprocket on the Alfine (13T?). So, perhaps there would be some gearing flexibility with the combo.

smallest sprocket on an alfine?

I still don't see notes on what kind of chainrng they use, and a 28T would wear fairly quickly.

CliffordK

Their website says that they'll deliver the product on August 2015.
It isn't unexpected to be a little late, but I would like to see some kind of update to their schedule.

But, I'm not seeing any notes in English indicating a new anticipated delivery schedule.

fietsbob

There have been some for a Long time ...

They get used on Trikes .. crank turns the sprocket on the End of the hub , another sprocket is attached where you would hook up the spokes
on the hub shell , that in turn thru a second chain drives the rear wheel.. thru another cog ..

You can Buy 6 bolt cogs to replace The Brake disc and use a lot of hubs as transmissions that way..

Iv'e seen Rohloff hubs used as a Mid Drive with the rear wheel on a swing arm.. the cog on the Left end of the rear wheel Hub.. .

elmore leonard

can you use them on fixies?

CliffordK

A fixie that shifts


I don't see any notes on the website about what happens when you stop pedalling, or backpedal. This would apply to both single speed rearends, as well as coaster brake hubs.

Perhaps it is worth sending the company an inquiry. Perhaps they'll add it to their FAQ page.

dabac

Sturmey-Archer has a 3-speed FG hub. Sturmey Archer | S3X Silver

In bikes, whatever you can think of, someone has already built....

Dan Burkhart 

What's so funny about that? My fixie has 3 speeds, a Sturmy Archer S3X.

CliffordK

I always thought of the fixies as a subset of the single speed bikes, with a few having a flip-flop hub to allow a small gearing change as allowed by the dropouts and chain.

That has knocked it out of my interest because I prefer higher gearing that would be difficult to get over some of my hills.

The SA S3X hub does look interesting, and may well be able to meet my needs for moderate hill climbs.

One difference between the SA3X hub and the Efneo gearbox is that the SA3X puts the direct drive (highest efficiency) in the highest gear, where a small change in efficiency would make the most difference for one's top speed, and perhaps overall wattage. On the other hand, the Efneo gearbox puts the direct drive (probably most efficient) into the lowest gear... which may well be one's "escape gear".

elmore leonard

That is interesting. Do you know anyone that puts this 3-speed FG hub on a back wheel and sells it off of the shelf?

Dan Burkhart 

Any custom wheelbuilder, of which I am one, can do that for you.

CliffordK

Reading a couple of the Amazon reviews, some people have had major problems with the SA S3X hub.
Amazon: Sturmey-Archer S3X 3-speed fixie hub

Although, it is weighted by one reviewer posting the same review 3 times.

Reading a bit more, post #12 on this page shows the problem.
Sturmey S3X: any long term users?- Mtbr.com

So, there is a shift locking key that wears off and needs replaced (after 1000 miles???)

There are some complaints of backlash. I've no idea how serious that is, but I assume one can habituate to the issue. And questions on whether the shifting is adequately precise.

Dan Burkhart 

The backlash is to be expected. any gear assembly must have some lash, otherwise, it would bind. Even the slightest amount of lash is amplified by the length of the lever arm (crank)
I have heard of issues with shift keys wearing or breaking, but no problems with mine as yet.
Of course, the miles I ride are shared among a fleet of bikes, so it may last forever.
If you are interested in what makes it work...

tcs

Fair question. Early Schlumpf BB gear sets could NOT be used with fixed gears, but Schlumpf upgraded the product and with recent ones you can.

tcs

Riding in a vacuum, I suppose. The power required to overcome air resistance is ~proportional to the cube of speed.

tcs

FYI: Bicycling magazine's 1907 report on gear systems listed three 3-speed BB gear sets.

...Schlumpf and Patterson BB gearsets, that is, if any of these new Polish ones ever reach the hands of consumers.

For the real answer, see the report beginning on page 3.

700

I wonder why they didn't go all the way and put another "gearbox" on the wheel?

fietsbob

I Dont speak for they, But I put a Schlumpf mountain drive reduction gear crankset in my Brompton M3L bike ..
for a wide range of 6 gear-ratios out of the 2 gears.

CliffordK

.I have no doubt that if Efneo does actually go into production, the cranksets will frequently get paired with multi speed hubs.

The company is producing (or designing) a rear hub with freewheel, probably similar to the powercrank crankset.

If all this is successful, they may plunge into the IGH rear hub market, but one step at a time, and there is already a lot of competition in that market with some BIG players.

The other question is whether, it is better to go with say a 3x3 system rather than an 8x1 or 11x1 or 14x1 system. Sequential gear selection through the entire range of gears would seem to be much preferable to the a two shift system.

And, of course, there is always the flexibility to choose the arrangement the end user desires.

700

That's the thing. It doesn't have to be a HUB. They could just design a gearbox that retrofits on standard(s) wheels. Then, enclose the chain and be maintenance free.

CliffordK

Interesting concept, replace a freewheel with a multispeed planetary gearbox. One could probably get away with a non-keyed axle for gear reduction, but I think a keyed axle may be required for greater than 100% gearing.

Assuming one isn't installing an autoshifter one would still need a shift linkage (or wireless electronic shifting).