Bafang Ultra - steel or nylon gear?

explorer

New Member
In the thread "Return of WW "City Commuter" Pushkar mentioned that the M600 will come with stronger nylon gear. Does anybody know if the Ultra- M620 on the Helios will come with the same nylon gear?
 

pushkar

Well-Known Member
Nylon gear will not work at the higher power levels. Ultra used to come with nylon gear but had significant failures. Bafang switched to Metal gears and those are awesome. the tolerances are much better now so motors tend to be quieter as you go beyond 6-7MPH.
 

explorer309

New Member
Thanks Pushkar. On my BBSO2 i have the gear sensor and it really helps save the grinding of the gears especially when climbing hills. Can that be ordered on the Hydra with standard derailleur system and a t what cost?
Also, what is the largest chain ring that can be installed?
 

pushkar

Well-Known Member
We dont install gear sensors - esp with kinderny being Hydraulic, there is no way for a gear sensor to work at all.

You can do 44T with no issues.
 

TForan

Well-Known Member
I have a 2017 Ultra with the nylon gears and I still haven't had a problem. And I do my best to break it every time I ride it.:) Have had the metal gears in my garage for years but I won't swap them until the nylon fails. Zero noise , presently and I like that.
 

pushkar

Well-Known Member
I have a 2017 Ultra with the nylon gears and I still haven't had a problem. And I do my best to break it every time I ride it.:) Have had the metal gears in my garage for years but I won't swap them until the nylon fails. Zero noise , presently and I like that.
That is good to know.

Just Testing on the m600, i know that continuous 120Nm appears to be the upperbound on the original nylon from Bafang.
The new one from Bafang, and the "silent gear" from Luna goes higher.
 

greeno

Active Member
Region
USA
City
San Diego
I have had great luck with the stock nylon drive gear on my BBSHD. Snapped the main rotor gear on a ride and had to push it home. Figured it was the "suspect" nylon gear that gave way but after removing motor and opening up the nylon gear was fine. Everything else was good too. So I got another motor housing part and reassembled and have had zero issues and it's been 2 years or so. Thats why the BBSHD is so quiet and the Ultra makes the whinning noise. Nylon to metal, metal to metal.


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Wald

New Member
I would love to have a more quiet Ultra motor.
Does someone know where you could get a nylon gear for M620/ G510?
I had searched the internet without luck. Also asked pushkar but he couldn't help me either.
 

greeno

Active Member
Region
USA
City
San Diego
I know Luna use to carry them. I think it was $100 for them to swap out the steel gear for the "Peek" nylon composite one. I think they use to sell just the gear if I'm not mistaken. But then again they say they use to carry the Apollo, and Ultra Max Drive. I think Eric (owner) made a video on the sound comparison of the two gears running on a bike with a decimal meter it's on you-tube. Send them an e-mail maybe they have a few laying around on Kyle's desk or something even if they don't list it on their website. I would think it would be pretty easy to install yourself if you have some building chops. Good luck.
 
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JRA

Well-Known Member
As mentioned running high watts seems to be an issue with the nylon gears on any electric motor. Other than the peet ones I guess which are a higher modulus material meant for those applications of high stress and shear.

What I have found to be the death of the two nylon gears I've managed to shred on my TSDZ2 conversions, one even running OSF that is designed to have a softer start, is an abrupt stop with power on. Once I was just getting going on a tight trail and during my initial stroke as the torque assist kicked in the front wheel hit a small stump hiding in some grass on the side of the trail.The other was the other day when I overshifted into the spokes, that I haven't managed in years, just as I was gearing down for a steep climb that locked up the rear wheel and brought things to a quick standstill. However both times I was able to ride home albeit a bit noisily and mostly under throttle as pedaling excasberated the crunching.

Other than that i thihk they are fine for every day riding if you can avoid the above and will keep using them. In fact I'm just getting ready to replace the latest failure today. They are a cheap item and about an hours time to swap out plus at the same time you get to clean out the old grease and add fresh which should be done once in awhile anyway.

I am glad that the M600 for future production will feature a higher modulus gear as that is the system I have in my sights to upgrade to. What is the type of bike that you have under design with it @pushkar?
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
I asked Luna about a nylon gear (or composite, whatever) for the Ultra, and they said they didn't have one. Thier gear was for the BBSxx series only. Somebody here know differently?
 

pushkar

Well-Known Member
As mentioned running high watts seems to be an issue with the nylon gears on any electric motor. Other than the peet ones I guess which are a higher modulus material meant for those applications of high stress and shear.

I am glad that the M600 for future production will feature a higher modulus gear as that is the system I have in my sights to upgrade to. What is the type of bike that you have under design with it @pushkar?
We are re-launching the M600 based city commuter from last year. Potentially up to 750W nominal (depending on testing), so will be fairly awesome performance for the motor.
 

greeno

Active Member
Region
USA
City
San Diego
I went to Luna's website today to check and they carry the "Peek" gear for the BBXXX series as well as the M600 ( listed on the Luna parts section for the M600 ) which is the lower wattage Bafang built in motor that they run on their X1 bikes. Not so much as a sniff as to anything related to the Ultra motor anymore which they used to carry many moons ago. Is it in stock? who knows.
You know if someone had the time to design one for the G510 (Ultra) I bet it would sell. Not sure on the durability of the HD plastic gear I wonder if Bafang corp has any feedback on a replaceable gear?
 
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AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
I'd be happy if somebody would come up with a gear similar/as strong as the original 510 gear. That's all I'd need, as well as many others that will never push that motor anywhere near it's limits....
 

pushkar

Well-Known Member
I'd be happy if somebody would come up with a gear similar/as strong as the original 510 gear. That's all I'd need, as well as many others that will never push that motor anywhere near it's limits....

Curious ...If you are not pushing it that hard, then why not use the m600 ? It already has the nylon gear in it now. With the new controller, the performance is quite nice, and it is within PEEK spec.

May be some material science people can comment on the strength (Tech spec here - https://www.polytechindustrial.com/products/plastic-stock-shapes/peek) . Notice that 8000PSI at 73 C, but with the Ultra goes above that easily. With ultra, at 200Nm+ sustained, PEEK should start to shear.
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
May I answer a question with a question? Why run a motor rated at 160nm to 200nm?

Actually, I'm 300lbs and spend a lot of time riding in a hilly coastal area (thus the need for substantial reserve power). The standard Ultra torque is plenty, confirmed with the previous bike running a MAC 12t hub motor (that uses nylon gears by the way) that does what I need easily. Also I was curious what I could do myself with the controller programming, and to be 100% honest, the price was right for a mid drive with that kind of power available. -Al
 

pushkar

Well-Known Member
May I answer a question with a question? Why run a motor rated at 160nm to 200nm?
Great question.

From a manufacturer perspective, we want to keep a single motor config for all scenarios and torques we make available (140Nm to ~240Nm). That means whichever gear we choose needs to support a wide range of power configs for our bikes (all the way up to 3000W ).

There is also a scenario where a rider may start off with a 1000W motor, but as they get more comfortable, they may want to upgrade to 2300W. We will quickly run into an artificial hardware limitation.
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
That makes a lot of sense. Potential for big power mods would be a perfect explanation for the steel gear scenario. So where is the next weak spot when talking 2500w plus? The cassette?

Anyway, if you happen to run into a nylon gear for a 510, please let me know! As long as it didn't get too crazy, willing to make it worth your trouble to get it pointed in my direction...
 

Ebiker33

Well-Known Member
@pushkar

LUNA just came out with a PEEK gear for the BBSHD, if you run a 52V battery with the standard 30amp controller with it, that is 1560 watts. That motor is also rated for 160nm.
Maybe I am wrong but they just had it for the M600 before.
Link
LUNA PEEK GEAR
If you had the motor limited to the 1000W option this might work, some people might want less noise than power.
A PEEK gear paired with the X1 could be one of the smoothest motors in the industry, you could challenge Brose with this option.