Can someone tell me if all the lower 5 gears are an underdrive ratio such that the only way to have high speeds (say 20mph) with reasonable cadence is to have a small rear chain/belt sprocket and a larger front?Revolute Hub 1 is the most appealing hub at the moment. It has 250 Nm torque rate (Rohloff and Kindernay are rated around 160 Nm) so it is more durable, 3.15 maximum internal gear ratio (Kindernay XIV and Rohloff have 1.47 max internal gear ratio and Kindernay VII has 2.1) so it will go faster, it allows to shift under load (Kindernay and Rohloff are hard to shift under load and not really recommended for longevity reasons), it uses standard interface for the brake disk (Rohloff, Kindernay and 3x3 use proprietary brake disk interface and custom brake disks) so you can use any brake system you like and save money.
Revolute
www.revolute.de
2022 - Top 12 Bafang Ultra M620 Ebikes
- Thread starter Ebiker33
- Start date
The internal ratio of the gear hub is "Wheel Turns"/"Rear Cog Turns". It means the amount of turns of the wheel is equal to the amount of turns of the rear cog multiplied on the internal gear ratio of the gear hub at the current speed it is set on.
The derailleur systems have "internal" gear ratio 1 for all cogs. So if you use let's say 14 teeth rear cog with this particular gear hub you will move more than 3 times faster than on a bicycle with derailleur system set at 14 teeth cog speed at the same cadence. And 10-14 teeth rear cogs are usually smallest amount of teeth you can find on derailleur systems. The smallest rear cog gear hubs usually allow to install is maybe 13-14 teeth. Basically this gear hub should allow you to ride about 3 times fasted than any derailleur system you can find on the market if you will use the same front chain ring which is going to be probably around 60-70mph if you can apply enough torque on it to overcome the wind resistance. I believe Bafang m620 has enough power and torque to crank the pedals at such speed. So it theory with this gear hub and Bafang m620 you should be able to keep up with traffic on 60mph highways.
With this particular gear hub you can have almost equal size rear cog and front chainring and it will have almost like regular bicycle with regular derailleur system cadence-speed ratios range. But for electric bicycles you need bigger front chainring and smaller rear cog for a few reasons. The main reason is to keep the chainring to cog ratio big enough to not overcome the maximum torque the gear hub is rated for or you can brake it with motor assistance. Another reason is on an e-bike you want to go fast, you don't want to go slow, that's the purpose of the e-bike and gear hubs designed specifically for e-bikes like this one. And one more reason is the e-bike motor provides assistance and you don't need low gear ratios to move or to start moving.
PS: I actually might be wrong and it might be in Germany they show not the gear ratios but the term "Getriebeübersetzung" which is maybe 1/"internal gear ratio". I just found this page https://fahrrad.fandom.com/de/wiki/Entfaltung and I found they use also term "Entfaltung" which is meters of travel per crank of pedals and now looking on their web page I am not sure this gear hub has maximum gear ratio 3.15, it might have maximum gear ratio 1/0.8 which is 1.25 and it sucks lol. In this case Kindernay VII is the king. Or not, maybe 3x3 is the king depending on what "Übersetzung/Ratio" and "i" mean and how they in Germany count gears (like is the 1st gear the slowest or the fastest gear?)
FAQ - 3X3
Du hast eine brennende Frage zur wartungsfreien 3X3 Nabenschaltung für dein Fahrrad. Hier findest du unsere ehrlichsten Antworten.
www.3x3.bike
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Dengfu just released new carbon fiber frames E55(regular size tires) and E56(fat tires) for m620 motor for DIY guys and the frames look sick, the motor is smoothly integrated and on top of that is it works with huge 52V 20A 1040wh battery. I think at this point the Biktrix Monte Capro Ultra is obsolete
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AHicks
Well-Known Member
- Region
- USA
- City
- Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Not for me, but still a pretty awesome looking design. Motor case tilted up out of the way, and room so you can carry a battery big enough to allow for some hard play using the M620. Nice!
mschwett
Well-Known Member
- Region
- USA
not a chance. you need about 5,000 watts to get anywhere near 60mph on a typical bicycle. the gearing isn’t really the problem, the combination of torque and speed (aka power!) needed to overcome exponential wind resistance is.
if you want to go that fast on two wheels, you either need to focus heavily on the aerodynamics or turn the thing into a motorcycle.
ProphetZarquon
Active Member
- Region
- USA
Based on the rotation rate shown in their videos & animations, last gear is way more than 1.25 wheel rotation per 1 sprocket rotation.
In their default background image, it looks to be in a gear that's around 2:1 output:input?
https://www.3x3.bike/wp-content/uploads/2022/06/220627_HB-Hightech_Web_korr_1050_3MB.mp4
This looks very promising! Any word on price or drag percentile?
(Most hub shifters lose 4-to-10% of input power to drag, noticeably less efficient than a perfectly aligned chainset but more efficient than a gunky or steeply angled chainset. Each of a shift system's gear ratios will have its own lossiness ratio, due to different numbers of teeth & moving parts, for each. Belts are efficient at low torque levels, but become less efficient than chain somewhere around the 50Nm range?)
No Words........Dengfu just released new carbon fiber frames E55(regular size tires) and E56(fat tires) for m620 motor for DIY guys and the frames look sick, the motor is smoothly integrated and on top of that is it works with huge 52V 20A 1040wh battery. I think at this point the Biktrix Monte Capro Ultra is obsolete
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ProphetZarquon
Active Member
- Region
- USA
That Frefat ebike (Firefat? Odd kerning...) has a distinctly different frame than the E56 & E55. Rear shock layout just for starters.
Looks great in orange though!
Is that your new ride? It looks nice enough that I immediately went searching for details, but I didn't find anything resembling it, online. Can you tell us anything more about that beautiful bigfoot?
I'm ah... not a fan, of the Tektro brakes which would come standard on the Biktrix Monte Capro Ultra.
Fat tires aside (these are all full-suspension, after all), the AM1000 v6 from Frey costs about a thousand less, with better components albeit on an aluminum frame, & the 60V×24Ah Frey Beast has a carbon front frame with Rockshox Super Deluxe 205×65mm coilover rear shock & a KS 900i dropper seatpost, for just $732 more than the Monte Capro Ultra.
I am very enticed by the nicer carbon full-suspension m620-compatible frames like Dengfu's E55. I especially like the upward rake given to the motor; no reason it needs to hang down at all. Given just a bit more budget, I would not need much convincing to order a Dengfu frame (even though what I really love is the finish & kinematics of surgical stainless
Assembling thread for the first frame
TQFreak's Dengfu E55 Build Thread
A separate thread for the build of this bike from the main E55/56 thread : https://www.emtbforums.com/threads/dengfu-e55-emtb-and-e56-fat-bike-new-selection-of-diy-frame.31400/ My 17" Dengfu E55 frame is arrived and it looks amazing! The box with the frame Everything is packed very well...
www.emtbforums.com
The main 'benefit' here for most, I think, is their intent to not allow locked in licensing on this frame, avoiding the problems many in the US have on e.g. getting an E10 (Luna) or (forget it's designation, but it's a modified E22 with the diamond mount up front, otherwise an E22) - Monte Capro (Biktrix) or Hydra/Z1 frame to build themselves. Haven't done a deep dive in geo changes, but I expect it to be pretty close to E10 and E22, plus I think it has a larger battery area.
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ElevenAD
Well-Known Member
- Region
- USA
- City
- Ringoes New Jersey
well done, i would like very much to ride that beast!
AHicks
Well-Known Member
- Region
- USA
- City
- Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Not pretending to be an FS expert, or intending to take away from the bike above. Just wondering if you guys have checked out Flex Bikes recently?
They have this bike with an M600 in a standard version, and with the new M610 in their X package - 58 lbs
flx.bike
They have this bike with an M600 in a standard version, and with the new M610 in their X package - 58 lbs
The Weapon X
Take your mountain biking to the next level with the most POWERFUL carbon fiber electric mountain bike of it's class! The best of both worlds—it rallies the trail like a traditional bike on descents but rips back to the top with 750W assist on climbs. Make climbs the best part of your ride...
flx.bike
Stefan Mikes
Gravel e-biker
- Region
- Europe
- City
- Mazovia, PL
Not sure this has been mentioned. Bafang has a new app on Google Play, Bafang Go+. Screenshots show assist programming. It may have just been added today, no reviews and shows today as last time updated. I don't have my QuietKat Rubicon yet, (fantastic price right now) but managed to get the app installed and verified. A little clunky as expected and asks for lots of permissions! I blindly said yes to all but notifications, otherwise it wouldn't run. I hope it works as I ride tight trails and from what little I know, the motor currently lacks control and finesse. Will see when the beast (bike) gets here...
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smorgasbord
Well-Known Member
- Region
- USA
You sure that works with the M620? App description says it connects wirelessly.
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