Why Put 12 Speed Groups On Bafang Ultra Bikes?

[voidedwarranty]

To take the op topic a step further, if the Ultra motor is so powerful and robust and things like Ludacris and Archon X1 exist, what stops someone from converting to a 1 speed belt drive for the pure strength and reliability and simplicity it offers?

 

[scrambler]

I don't know if the ultra could take full throttle action on a single speed (providing reasonable top speed gearing).
May be someone with more knowledge could comment.
I would actually be interested to know if on a single gear with top speed around 30mph, the Ultra could be used like that, using throttle only from zero to 30mph and some decent pickup.

 

[voidedwarranty]

I don't know if the ultra could take full throttle action on a single speed (providing reasonable top speed gearing).
May be someone with more knowledge could comment.
I would actually be interested to know if on a single gear with top speed around 30mph, the Ultra could be used like that, using throttle only from zero to 30mph and some decent pickup.

One could pedal from a stand still to take the edge off the motor. I am assuming it comes down to controller amperage. Something tells me the motor would be fine but a stock controller at maybe 25amps would turn to a molten pile of garbage.

It still remains an interesting thought. I did a little research and found some spec sheets that listed the max rpm of the motor at 170ish if I'm remembering correctly. In that case you wouldn't even need an extreme chainring or rear cog to have a top speed of say 35-40 mph. I used this bike calculator and input for the tire size I have 26x4.9 and with a 42T chain ring and a 14T rear you can be at 45mph by 160rpm.

* Even a 44T chain ring and 18T rear makes for 36mph at 160rpm

Someone with a better understanding of motor strength/controller durability please chime in. Am I crazy? It's ok if I am.

 

[kurt_s]

Look at it this way... no rider that ever won the Tour de France could output 400 watts. You want to put six times that through a bicycle with a one size for all gear? Yeah you could but easing up through gears is going to be a better idea. When I hit the throttle on say 46/14 to go from 15 to 35 mph the first thing I feel is the chain stays and spokes squirm underneath me.

My rear hub is a 32H but now add 40 pounds of cargo on the rack and I am thinking a 40H custom built wheel would be better.

 

[voidedwarranty]

Look at it this way... no rider that ever won the Tour de France could output 400 watts. You want to put six times that through a bicycle with a one size for all gear? Yeah you could but easing up through gears is going to be a better idea. When I hit the throttle on say 46/14 to go from 15 to 35 mph the first thing I feel is the chain stays and spokes squirm underneath me.

My rear hub is a 32H but now add 40 pounds of cargo on the rack and I and thinking a 40H custom built wheel would be better.

I hadn't considered wheel spoke strength. I always hear chains and freewheels breaking. Back to the drawing board.

 

[scrambler]

Spokes are no issue as long as you have the right ones.
MTB like the LMX64 have separate chain rings for the motor and the pedaling, so you can drive at full throttle on a single gear with a 2.5kW motor, and the spokes are not an issue.
Same for the SEM venom and a 4kW motor.

 

[kurt_s]

Not saying they break. Saying the wheel hub moves laterally.

 

[scrambler]

Just saying this has proven to be a non issue on bikes using the full power in a single gear.

 

[reed scott]

OP here: Seems obvious that a good gear spread is necessary to obtain good range ( distance ) out of an ebike. I wonder though why we need 12 cogs? The spread of those cogs yes but so many? Cannot better detailers jump two cogs on request? Don't know. Never had that many on a cassette as I've always had a triple chain ring. I mention the jumping cogs because if you had only 6 or 7 cogs and the same spread as a 12 speed the jump between cogs would be large.

 

[kurt_s]

OP here: Seems obvious that a good gear spread is necessary to obtain good range ( distance ) out of an ebike. I wonder though why we need 12 cogs? The spread of those cogs yes but so many? Cannot better detailers jump two cogs on request? Don't know. Never had that many on a cassette as I've always had a triple chain ring. I mention the jumping cogs because if you had only 6 or 7 cogs and the same spread as a 12 speed the jump between cogs would be large.

Yes exactly. I have electronic derailleur that I have programmed to shift one cog with a touch and three cogs with a longer press of the bottons.

 

[kurt_s]

Whelp, I found the limit at about 300 lbs with 46T Wolftooth and KMC top of the line DLC chain up a super steep grade. I was in 3rd of SRAM 10-50 I think. I was getting to cheeky with it though.

The chain giving way took out the chainring with it. I will go to the KMC ebike specific chain now, put the 44t back on and order another 46T. Doh!

see the chainring tooth and the silly ass load I was grocery load. I deserve this. I gotta get on that covid moss in tge driveway.

 

[voidedwarranty]

Whelp, I found the limit at about 300 lbs with 46T Wolftooth and KMC top of the line DLC chain up a super steep grade. I was in 3rd of SRAM 10-50 I think. I was getting to cheeky with it though.

The chain giving way took out the chainring with it. I will go to the KMC ebike specific chain now, put the 44t back on and order another 46T. Doh!

see the chainring tooth and the silly ass load I was grocery load. I deserve this. I gotta get on that covid moss in tge driveway.

View attachment 76868View attachment 76869

Got a spare Miata by any chance?

 

[kurt_s]

Got a spare Miata by any chance?

Yes I think I do, among other things a man without grounding (aka wife) acquires

 

[TomW]

I kinda agree with you OP, I would probably be more than fine with say a 8 speed set but unfortunatly unless you pick up old/new stock like a unused XT groupset from the late 90's early 2000's then the quality will not be there in the materials.
I run 11 speed atm because it is easy to purchase the higher quality parts and I like the total range 11-42 but I do find myself shifting multiple gears at the same time because they do not need to be as close as they are.
But have concidered dropping to 10 speed because you can still find higher quality parts but decided not to because they are getting harder to find over time.
Also modern wheel spacing etc can restrict choices.
The ebike 7 speed Sram groupset they released a few years ago looked good until I saw the price of the cassette lol.

 

[voidedwarranty]

Yes I think I do, among other things a man without grounding (aka wife) acquires

Just noticed you are on the other side of the country. if you were closer I'd give you an offer for one. Miata Is Always The Answer

 

[smorgasbord]

I kinda agree with you OP, I would probably be more than fine with say a 8 speed set but unfortunatly unless you pick up old/new stock like a unused XT groupset from the late 90's early 2000's then the quality will not be there in the materials.
I run 11 speed atm because it is easy to purchase the higher quality parts and I like the total range 11-42 but I do find myself shifting multiple gears at the same time because they do not need to be as close as they are.
But have concidered dropping to 10 speed because you can still find higher quality parts but decided not to because they are getting harder to find over time.
Also modern wheel spacing etc can restrict choices.
The ebike 7 speed Sram groupset they released a few years ago looked good until I saw the price of the cassette lol.

SRAM makes an eBke specific 8 speed drivetrain.

 

[TomW]

Was it 8 speed, my bad. It was still to expensive tho lol.

 

[CCroft]

For what it's worth...I'm riding a 26" fatbike that I did the BBSHD conversion on back in 2017. I'm an amateur naturalist, and my riding is largely off-road and off-trail in search of interesting flora and fauna--similar conditions/expectations to what some of the "hunting bikes" are aiming at I'd imagine.

When I had a rear wheel built with that lovely/quiet Onyx hub in 2019, I decided to replace the drivetrain too. With the advice of 'AZGuy' over at Luna's forum ebike.com, I bought/installed the following:

-Luna single 36t front chainring (about 8mm offset)
-Sunrace CSMS8 EAZ 11-46 cassette ($75); appears to be popular with more than a few ebikers due to its all-steel cogs, as well as the fact that its design (6 largest cogs on 2 alum spiders) ‘reduces the indents’ and stress on the freehub body, since I’m obviously wanting to protect my expensive Onyx hub
-Shimano Ultegra/XT CN-HG701 11spd chain ($35); set of KMC missing links reusable 11spd links for repair kit
-Shimano XT RD-M8000 long cage derailleur ($85)
-Shimano Deore XT M8000 shifter (SL-M8000-R 11s) ($55)

With my riding (which includes some on-pavement portions when I make loops after biking down and out of some public land areas), I could probably lose the 11 and the 46 and be perfectly happy.

This setup has 100% reliable for me. I'm pushing close to 300lbs with bike, battery, rider and photo gear/other goodies. I'm using the throttle frequently so I can adjust to the changing topography of what I'm riding; 6-7% uphill grade is about as much as I'll ride, but that's off-trail, so pretty good stress on the system. Not infrequently, I'm pushing/pulling the bike up and down areas I can't or shouldn't be riding, schlepping it over barbed wire fences, etc., so it's always getting banged around. I replace the derailleur hanger 2-3 times a year, but the drivetrain has been totally solid. My chainline isn't as straight as I'd like above 32t, but I've never thrown a chain, never broken a link/chain, shifting has always been reliable/solid, and there's little noise even with the non-straight chain (I regularly use the Chain-L lube which I really like...buttery smooth and quiet).

Bottom-line I couldn't be more satisfied with this relatively inexpensive set of components...they've been a good match for my 26" eFatbike with BBSHD and the challenging riding I've thrown at them. At some point I'll probably replace the front chainring with something like the Lekkie 42T to straighten the chainline a bit, but that won't be because my current setup has had any issues...

 

[Chapooski]

Has anyone ever tried Box Components?

Box Two P9 X-Wide Single Shift E-Bike Groupset

Our Box Two tier's mission in life is to deliver performance similar to the Box One but without its exotic (and costly) features. With the Single Shift E-Bike Groupset you still get the Tri-Pack™ Clutch in our derailleur only it isn't adjustable. The cassette's 12-50T range is optimized for...

boxcomponents.com

Box Three P9 X-Wide Single Shift E-Bike Groupset

Our Box Three tier delivers many of the same capabilities of its more famous siblings yet it's built upon a simpler platform. The cassette is E-bike Optimized at 12-50T, adding an extra tooth to each of the three highest gears. The derailleur exploits our Limited Slip clutch technology without...

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[reed scott]

Has anyone ever tried Box Components?

Box Two P9 X-Wide Single Shift E-Bike Groupset

Our Box Two tier's mission in life is to deliver performance similar to the Box One but without its exotic (and costly) features. With the Single Shift E-Bike Groupset you still get the Tri-Pack™ Clutch in our derailleur only it isn't adjustable. The cassette's 12-50T range is optimized for...

boxcomponents.com

Box Three P9 X-Wide Single Shift E-Bike Groupset

Our Box Three tier delivers many of the same capabilities of its more famous siblings yet it's built upon a simpler platform. The cassette is E-bike Optimized at 12-50T, adding an extra tooth to each of the three highest gears. The derailleur exploits our Limited Slip clutch technology without...

boxcomponents.com

'Box' Components. Would love to get some real world feedback on this company.