Check out the Trek Lime automatic shifting bicycle
It has been noted time and again that the most efficient means and most popular form of transportation the world over is the bicycle. The bicycle has been with us in one form or another since the 19th century. There have been a few attempts at automating the bicycle shifting mechanism, with a certain degree of success. Something that most, if not all prior attempts of automatic shifting have been mechanical. Until now, that is. With the introduction of the Trek Lime bicycle, Trek brings electronics into the world of the automatic shifting bicycle. Power for the brain comes from a small generator built into the front hub. Interested in knowing more about this creation? Of course you are! Click here for more.
[Source: Trek via Treehugger]
Reader Comments (Page 1 of 1)
Dolan Halbrook 2:59PM (4/06/2007)
Trek didn't really do anything but build a bike around Shimano's "Coasting" group. This is great if it gets more folks on bikes, but personally I find the NuVinci hub and Shimano's own Alfine 8-speed internal hub much more interesting.
Reply
Bill 4:29PM (4/06/2007)
I don't know why people keep looking at the Trek. It looks so boring. The Raleigh uses the same Shimano system, but looks cool, and the pièce de résistance: 6-pack rack with built in bottle opener!
http://www.raleighusa.com/items.asp?deptid=7&itemid=384
--Bill
Reply
MikeW 8:17PM (4/06/2007)
The thing about the NuVinci is that there may be too much reduction in the ratio spread, and not enough overdrive. Is the spread symmetric about unity, say 1:2 reduction and 2:1 overdrive? The traction oil has limits.
Going to the garage, the trek there has 24, 32, 38 on the drive sprockets, and 28,24,21,18,15,13,11 for driven sprockets. So the lowest gear ratio is 24/28, (1.17:1 reduction) but 2nd gear is 24/24, which is where the chain is dead straight. (and the bike has 26" wheels) 38/11 is the max. OD, 3.45:1
http://en.wikipedia.org/wiki/Rohloff_Speedhub
That geared hub has a 1.467:1 reduction gear (perfect for bike/trailer uphill into headwind (at altitude)) and a 3.58:1 maximum overdrive.
My dad just bought a new bicycle (chinese made unfortunately) and has 700mm (28" 'hybrid' wheels) and has 24 theoretical speeds. You have to give up 3 in low range, 3 in high range, and 4 in the middle range, to preserve the chain.
The gearing sucks. WAY too tall. If anyone should have bicycle mastery, shouldn't it be the chinese? 28,38,48 drive, 30,26,23,20,17,15,13,11 driven 4.675:1 total ratio spread. You only use the first three gears in low range.
So maybe that NuVinci will catch on with the AARP crowd.
Reply
Dolan Halbrook 11:46PM (4/06/2007)
MikeW,
Going from this NuVinci review (http://phil.veloblog.ch/post/7/333), the gear range is about equivalent to a Nexus (350%). Nowhere near the Speedhub (500%+), but in the ballpark for hub that will probably be near 1/10th the price. Of course the lower and upper ranges will be dictated by the gearing, but from the tests I've read it holds tight even when geared extremely low with weight. For casual riding and touring, you really only care about the low range -- above a certain amount you're probably going to coast anyways.
That said, I agree the initial release of the NuVinci will be for casual use primarily due to its weight. It's hard to fairly compare it with the Speedhub which has been developed for a much longer time and is considerably more expensive. Provided the design has the claimed longevity, it will still be interesting to see what can be done to make it smaller and lighter, and therefore more appealing to you the likes of you or me.
Reply
MikeW 5:11PM (4/09/2007)
It looks good to get neophytes into bicycling, the little hill/flat icon is perfect for newbies.
Those guys are a bit more advanced than I, weighing components down to grams.
I wonder if that 97% is peak efficiency? Does that occur around 1:1?
I still like banging off 3 quick sequential upshifts, or 4 downshifts in rapid succession, it makes me feel like Schoemaker.
Reply
Ed Carey Sr 6:46AM (4/14/2007)
The "Lime" never needs batteries, because it has a generator in the front wheel hub, that powers the automatic shifter. I have two questions?
1) Where does the electricity go that is not used to shift?
Your not shifting all the time, sure there has to be a little bit used to sense when it needs to actually shift, but that shouldn't use up much and there's no battery on board to store any excess unused electricity.
2) How difficult would it be to put a battery charger in the seat?
There is a mention of storing an Apple Ipod in the seat. Apple sold over 100 million of those and is coming out with an phone. Not to mention every other brand cellphone, portable game, personal organizer, GPS, flashlight, laptop, etc. These all contain batteries that need to be recharged. I'd Co-Market the "Lime" with Apple and anyone else that would pick up half the advertising cost and let 3rd parties sell the chargers. A bike that changes colors, recharges your favorite toy and low maintance, How COOL is that!
Reply
Glenn Aavang 11:17AM (6/14/2007)
My wife is switching from a Trek 720 to a Lime and finds the gearing a little low. She has gotten accustomed to using the taller gears for riding in town to work and on the Lime she is spinning more than she would like. A little smaller rear sprocket would set the range about right. Is this possible?
Reply
john 1:53PM (4/09/2009)
Yes, I changed my gearing. I took off the 20 tooth rear gear and replaced it with a 15 tooth. If you do this, you will also have to adjust the shift points on the cpu thingy. It is easy to do with a screwdriver. You can experiment with what works best. I found that it works when turned all the way to the lowest setting for me.
wilson munari 11:46AM (1/01/2008)
please inform address of makers or distributors of Lime bike.
tks
wilson munari
Reply