Ultra Chainring Swap?

[il Munduato]

I've ordered Hundreds of things on AliExpress and the Only thing that ever got stopped and checked by Canada Customs was my replacement carbon filter for my RO water filter.

View attachment 183417

The perfect container for shipping drugs.
The activated carbon absorbs VOC's so I bet it sucks up radar too ??

They didn't open it up, so they must have beamed it with X-rays.
I might be drinking radioactive water now?
My Flux capacitor has been acting up too.

Now I need to buy a Geiger counter !!

I feel sick

Ali has a top quality Geiger counter for $0.47 delivered.... Flux capacitors are on sale too!

 

[DDBB]

Ali chainring was poorly machined. Well worth two dollars though!

 

[il Munduato]

Ali chainring was poorly machined. Well worth two dollars though!

Take a pic and point out your concern

 

[DDBB]

LOL.. the garbage man took it today. No great loss. I'm hoping greenbikekit can provide a good steel 48 tooth chainring but I've been waiting awhile. Some of the teeth were higher than others on the ali chainring and no, I'm not confusing narrow/wide for poor machining.

 

[il Munduato]

Dude... What are you doing?!?!
That's the latest innovation. Narrow/Wide/Short/Tall.
Honestly I gave both rings I received a good look over and I couldn't find any defects... tho admittedly I didn't break out the electron microscope.
300mi now between the two I received and I can't tell any difference between them and the stock Bafang ring that came with the motor. I'm not delusional thinking it's the best out there... But it definitely looks the look and works quietly without issue.
I'll keep an eye on it for longevity.

So what's your obsession with steel?
I wouldn't mind getting a better one if that really is the case.. so let me know what GBK comes up with.

 

[DDBB]

Aluminum is too soft. I'm sure these Ali sprockets are some kind of alloy but nothing lasts and holds it's shape like real steel. The difference in teeth on the ali sprocket was visible to the naked eye. Honesty it probably would have worked o.k. but it wasn't quality that's for sure. Maybe they picked mine out of the 99 cent bin

 

[il Munduato]

Aluminum 7075-T6; 7075-T651
General 7075 characteristics and uses (from Alcoa): Very high strength material used for highly stressed structural parts. The T7351 temper offers improved stress-corrosion cracking resistance.
Applications: Aircraft fittings, gears and shafts, fuse parts, meter shafts and gears, missile parts, regulating valve parts, worm gears, keys, aircraft, aerospace and defense applications; bike frames, all terrain vehicle (ATV) sprockets.

Just sayin'. . .
Is 7075-T6 aluminum stronger than steel?
How does the strength of 7075 aluminum compare to steel? While 7075 aluminum is not as strong as some steel alloys, it is stronger than many mild and low-carbon steels. The tensile strength of 7075 aluminum typically ranges from 540 to 590 MPa (78,000 to 86,000 psi), making it stronger than mild and low-carbon steels.
I can guarantee you that the stock Bafang ring is not a high strength steel alloy...
Tho a stainless one would be nice.

As far as Ali... That's the chance you take. Ive gotten some decent stuff from them and then ordered another some time later for it to be not as good. And you have to be careful with your seller selection (check reviews and time in business) and make sure they offer free returns.

 

[Chargeride]

I bought an Ali 32T for my bbshd, 20 quid, I havent run it yet, but with the 8 speed chain on in sounds pretty noisy, I'm hoping a few weeks on the beach should bed it in

 

[SpinningGears]

Surly make a stainless steel chainring that fits, it's a bit too shiny for my liking. I've had the raceface chainring on my ultra for about 3 or 4 years, looks the same as it did the day i put it on.

 

[il Munduato]

I bought an Ali 32T for my bbshd, 20 quid, I havent run it yet, but with the 8 speed chain on in sounds pretty noisy, I'm hoping a few weeks on the beach should bed it in

View attachment 183544

Those stamped steel rings are about as cheap as it gets. The BBS02B is very hard to fit anything else because of the offset so that's what I was stuck with. They do work and never really had an issue but it's far from state of the art. Too bad that they didn't machine a N/W tooth profile into them after stamping

 

[il Munduato]

Surly make a stainless steel chainring that fits, it's a bit too shiny for my liking. I've had the raceface chainring on my ultra for about 3 or 4 years, looks the same as it did the day i put it on.

I agree a black anodized stainless would be more appropriate... tho I like having a chain guard so not much would be visible anywho.

 

[DDBB]

7075 alloy is good stuff, don't know if ali tempers it or even if it's really 7075 to begin with. Hopefully your long term testing will give us some answers. The sprocket I received may very well have worked o.k. but just by looking at it I decided not to use it. I'm sure these things are made in a machine that knocks them out in the thousands. Mine was probably the last one out before the machine got its annual servicing.

 

[Chargeride]

It 'claims' to be 6061Alloy with T6 treatment.
So its gonna wear out fast, but at least I can test its suitability for the bike.

 

[il Munduato]

It 'claims' to be 6061Alloy with T6 treatment.
So its gonna wear out fast, but at least I can test its suitability for the bike.

My reasoning too...
I wanted to be sure of what tooth count I felt comfortable with as the math doesn't always take into account the human factor.
I already have enough >$50 garage ornaments

 

[il Munduato]

I've been in touch w/ greenbikekit and they are going to get me a compatible 48 tooth chainring to replace the 44 tooth. With it I shouldn't have to use 9th gear any longer with it's few teeth prone to stripping w/ prolonged use. The chainrings from aliexpress are junk

Did you ever receive anything from GBK?
I just found this in the most recent Bafang catalog.

 

[DDBB]

Wow, thanks!... I was in contact with Anna Lee from greenbikekit who said she could get me one. I waited a month, emailed her and she said it got lost and she'd order another, that was another month ago.

 

[il Munduato]

Wow, thanks!... I was in contact with Anna Lee from greenbikekit who said she could get me one. I waited a month, emailed her and she said it got lost and she'd order another, that was another month ago.

Surprised.. Anna is typically pretty thorough.
I had an error in my last order and she caught and corrected it while confirming with me.
I paid for slow boat shipping and it went out next day and arrived in less than 30 days.
Go figure.

 

[tomjasz]

An 11 year business relationship with GBK and mixed reviews. My experiences have been very good especially considering how many other Chinese companies fail to provide good service. I love their little 36V GD motors. Very small and stealthy.

 

[DDBB]

The 48 T chainring is for fat tire bike only.. I need 48 T for e-mtb... I guess it's a different offset?

 

[il Munduato]

The 48 T chainring is for fat tire bike only.. I need 48 T for e-mtb... I guess it's a different offset?

If I'm not mistaken the offset is in the spider not the ring. I believe both are 130BCD so I don't see why you couldn't fit the 48t ring on the mtb spider.