another "new" gearbox?

[Dingo2024]

just came across this;

http://www.bikeradar.com/news/article/crank-based-gearbox-in-development-35979/

a little more info...........

http://www.efneo.com/why-to-use-bicycle-front-gearbox/

Ian

 

[Miles]

I'll wish them good luck with that..

Wonder what happened to this one?
http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=19662&p=286826
http://www.endless-sphere.com/forums/viewtopic.php?p=428681#p428681

 

[Hillhater]

Why is it that "cyclists" insist on having a different way of expressing gear ratios to "normal" engineers ?? :x :x
300%..600% . and even the "400 inch" gear ratio !...WTF.. cant they just use normal engineering terms like 3:1 , 6:1

 

[Dauntless]

Ummmm, because they have no clue how engineers talk about these things?

Tonight at the gas station a guy ahead of me asked for 10/60 oil, the guy behind the counter asked me if I knew of that actually existing. I've fixed his coworkers cars on the lot there, so he figured I'd know. So a minute later at most the guy buying the oil walks up to me and asks if it hurt anythng that he accidently started adding the oil to his "Freon." Since I knew that couldn't happen told him I'd look at it and figure out where he REALLY put it and if it was a problem. Oh, on an engine that had already been running, he'd apparently taken the radiator cap off without burning himself and poured some of the oil in there. . . .

400" gear ratio seems pretty tame by comparison.

 

[Miles]

Strictly, 400 gear inches isn't a ratio....

What's wrong with using percentages as a measure of change in ratio?

 

[NeilP]

Ummmm, because they have no clue how engineers talk about these things?

Exactly.. I mean they call the bottom crank bearing and cross shaft a 'bracket'... :wink:

 

[Chalo]

Why is it that "cyclists" insist on having a different way of expressing gear ratios to "normal" engineers ?? :x :x
300%..600% . and even the "400 inch" gear ratio !...WTF.. cant they just use normal engineering terms like 3:1 , 6:1

Ratios don't tell you everything you need to know. Gear inches (or meters development) are proportional to ratio times wheel diameter. That's what you need to know to make relevant comparisons.

Percentage is usually used to describe overall gearing range (high gear divided by low gear) rather than any single gear ratio. I think this latter custom helps distinguish the ratio between top and bottom gear from the ratio between front and rear sprockets.

The term "gear inches" dates to the earliest chain-driven safety bicycles. Unlike high-wheelers, distance covered per revolution of the pedals wasn't a simple function of wheel size, so gear inches were used. A 2:1 gear ratio on the 30" wheel of an early safety bike would yield the same distance per revolution as a high-wheeler with a 60" wheel, therefore 60 gear inches.

Most customary bicycle terms and conventions precede "normal engineers" as we understand them. In fact, we can thank cycling for rapidly advancing mechanical engineering in the late 19th and early 20th centuries.

 

[Hillhater]

Ratios don't tell you everything you need to know. Gear inches (or meters development) are proportional to ratio times wheel diameter. That's what you need to know to make relevant comparisons.

Sorry Chalo,..i respect you but... Gear inches tell you nothing !
Its simply a number to compare with previous numbers.
If you want to alter that number , you have to start thinking in terms of sprocket teeth and "ratios'.
..and how long is it since there was any serious option for wheel diameter on road bikes ?

..Most customary bicycle terms and conventions precede "normal engineers" as we understand them. In fact, we can thank cycling for rapidly advancing mechanical engineering in the late 19th and early 20th centuries.

Again, Beg to differ.....
There was a lot of advanced engineering around before the bicycle or its gearing terminology was concocted.
... I'm thinking Greeks, Romans, clock makers, etc and earlier devices like rope blocks and levers that used "ratio" calculations in their design.

 

[JennyB]

Sorry Chalo,..i respect you but... Gear inches tell you nothing !
Its simply a number to compare with previous numbers.
If you want to alter that number , you have to start thinking in terms of sprocket teeth and "ratios'.
..and how long is it since there was any serious option for wheel diameter on road bikes ?

Actually, gear inches probably work better for ebikes than for road bikes. For a direct drive hub the gearing is the wheel diameter, and for a friction drive it is the diameter of the roller. In either case, 336 rpm gives 1 mph for each inch of gearing. Simple!

 

[speedmd]

I agree that gear inches is seemingly archaic but still find it useful when wondering where all my strength went, picturing my atlas efforts of pedaling against a direct drive 122 inch (10 plus feet) tall wheel / gear.

For motors, (thinking out loud a bit). I think the "ev (rpm/v) number to final wheel size / ratio may be a good baseline for all of us. Would be independent of all the variables in the middle.

 

[Chalo]

Ratios don't tell you everything you need to know. Gear inches (or meters development) are proportional to ratio times wheel diameter. That's what you need to know to make relevant comparisons.

Sorry Chalo,..i respect you but... Gear inches tell you nothing !
Its simply a number to compare with previous numbers.
If you want to alter that number , you have to start thinking in terms of sprocket teeth and "ratios'.
..and how long is it since there was any serious option for wheel diameter on road bikes ?

I've worked on road bikes with ISO 406, 451, 520, 540, 559, 571, 584, 590, 597, 622, and 630 sized rims. Even if you normalize for 700c (ISO 622) wheels, a 700x20 tire doesn't have nearly the same circumference as a 700x60 Big Apple.

Using customary gear ratios won't get you what you want with a bike like this:

But if you know you want a 40 inch low gear, then you'll have a quick idea of what you need to do to accomplish that.

 

[ress]

Hi,

I came across this crakset a couple of months ago and I think it looks really interesting. 3 gears, 179% gear ratio and should fit to most bikes. If I remember correctly it will cost $189 or $160 with the 15% discount.

Homepage: http://www.efneo.com/en/gearbox/

Presentation video: http://vimeo.com/117609549

They're starting a Indiegogo campaign soon and you can get a 15% discount here: http://www.efneo.com/en/gearbox/#pre-ordering Last day for discount is today!

I'm not involved in any way with this company, I just thought you might be interested

 

[cjh]

Wonder if this would work with a Bafang BBS01 and BBS02? It uses the same square taper.

 

[gridlok]

This wouldn't work with the BBS02. The pedal is not attached to the drive train except through the gearbox inside and the chainring bolts to a non-standard 5 hole mounting system (thus the need for a BCD adapter). Nice system though.

Thanks for the link!

Karl

 

[GiantEV]

That's a good price.

 

[Storapa]

Hi Folks,

You may or may not already know about this. It's maybe a more cost effective option to the Schlumpf Drive. It also has the benefit of using a standard square taper BB, so can be set up for different width of BB's.

https://www.indiegogo.com/projects/3-speed-front-bicycle-gearbox-efneo

 

[Drunkskunk]

Looks awesome. Great entry price, too. Too bad it can't handle MTB.

 

[LockH]

https://www.indiegogo.com/projects/3-speed-front-bicycle-gearbox-efneo#/updates

 

[LockH]

Posted yesterday on Faceplant:
https://www.facebook.com/groups/436300886382371/permalink/1461064133906036/

If you have been waiting for this 3 speed Front Chainring replacement to come to market, your patience will soon be rewarded. Expected to start shipping to North America in April the Efneo Gearbox is expected to retail for $495.us. Will it fill a void that the Schlumpf & Patterson drives have missed?

http://www.efneo.com/gearbox/

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