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Bafang replacement CRANKARMS

Posted: Jan 06 2016 1:31pm
by Leebolectric
So, the Bafang crank arms are less than awesome, and only offer one length.
What are the best available aftermarket crank arms to replace the stock Bafang cranks with?
The White Industries cranks look like the nicest I've seen in the new market...anyone try them? hows the clearance?

I'm sure there are a lot of good options in the NewOldSale market, something like an old XTR with JIS fitting would be rad.
Anyone have good options researched for lightweight square taper crank arms that have no spider or removable spider?

(searched, but only found references to the WI freewheels...)

Re: Bafang replacement CRANKARMS

Posted: Jan 06 2016 1:46pm
by Speady
What's wrong with these crank arms?
They're available in 170mm and 175mm length at btn-ebike.com

Re: Bafang replacement CRANKARMS

Posted: Jan 06 2016 1:52pm
by Leebolectric
I don't want another heavy turd...the stock ones are crap.
...I would like to find a 165-170mm...lightweight QUALITY crank arm set.

All of the parts on my bikes are quality, I don't like to feel crank arm flex.
The Bafang is already a pig...I'd like to find ways to lighten it up and improve function.

Re: Bafang replacement CRANKARMS

Posted: Jan 06 2016 1:57pm
by Leebolectric
these are in the lead so far...

Image

Re: Bafang replacement CRANKARMS

Posted: Jan 06 2016 2:03pm
by Leebolectric
On this topic...
Freewheeling cranks...for other mid drive kits...
Everyone uses ISIS or JIS...both out of date crappy interfaces...
White Industries makes the front freewheels for SickBikeParts for the Trials Cranks that people make freewheeling cranks from...
White Industries makes their cranks with a splined lockring similar to modern high end cranks like the carbon SRAM...

Why couldn't we get White Industries to make those front freewheels for a splined crank interface?
Wouldn't this cut a lot of weight out of our systems?
The larger axles of outboard cranks makes for a much stiffer and direct power transfer.
Nothing in my experience beats the hollow forging of Shimano high end cranks...want to find a way...somehow...

Wouldn't it be rad if E-Bike parts weren't 10 years behind modern MTB? :roll:

Re: Bafang replacement CRANKARMS

Posted: Jan 06 2016 3:08pm
by WoodlandHills
How about these, are they any good? I don't think it would take long with a hacksaw and belt sander to cleanup the right side arm and they come in colors!

http://www.treefortbikes.com/#navbar=pr ... 642___1336

Re: Bafang replacement CRANKARMS

Posted: Jan 06 2016 3:17pm
by nutnspecial
I don't know much about middrive kits and went with jis on my bike to alter and customize crank tread.
But, doesn't the tangent drive use a hollow bb/crank? There's no combining the two?

Re: Bafang replacement CRANKARMS

Posted: Jan 06 2016 3:35pm
by Leebolectric
the Tangent uses a ISIS BB and Trials Crank with the SBP front freewheel.
It works, and I have no complaints with the function s far.
All of the mid drive freewheel cranks are set up this basic way.

But, in the world of MTB, ISIS was abandoned because the bearings wear out so fast due to being small enough to fit INSIDE the bb.
ISIS interface wears and eventually wobbles...Shimano can be assembled and removed dozens of times without loosing ridgity.
Out board bearings last much longer and spread the load better with a larger axle diameter, larger bearings, and wider spacing.
It would be nice to have a setup in the modern level of technology.

Re: Bafang replacement CRANKARMS

Posted: Jan 06 2016 3:39pm
by Leebolectric
Those road/track cranks are cute...but I doubt they are ready to handle MTB jumps....I don't want pretty, I want strong and light.
I'd like to find something that doesn't take hours of grinding to make work right. Preferably from a quality company.
Removable spiders are not so uncommon...I was hoping someone knew of a good crank with removable spider for the BAfang's spiderless setup.

Re: Bafang replacement CRANKARMS

Posted: Jan 07 2016 12:41am
by tomjasz
MTB jumps with BBSxx? Kidding, right? I'm not intending sarcasm, but the BBS isn't up to it. I mean better cranks arms? If you're flexing the OEM how long is that shaft going to hold out? I wish I was wrong but I can't imagine it.

Tell me more about these jumps and the Bafang.

Re: Bafang replacement CRANKARMS

Posted: Jan 07 2016 1:32am
by Leebolectric
It's a motor...on a bike...and I jump my bikes.
I guess we'll see how bad the axle is too...I'm down for some destructive testing.
If I can't catch air, what's the point? :roll:

Re: Bafang replacement CRANKARMS

Posted: Jan 07 2016 1:44am
by Alan B
Someone said to use unicycle crank arms for the Bafang.

Re: Bafang replacement CRANKARMS

Posted: Jan 07 2016 5:50am
by ginekolog
I do jumps with BBS02, so far made 4000 km in one year. No problems :mrgreen: Jumps up do 0,5 m with my hard tail GT.

I did destroy both bafang crankarms but it was my fault ( I mixed left and right ->pedals fell off). Then i got used Shimano crankarms for free, both left ones. Works good, I made pedals are securely tightened so they don't unscrew.

Re: Bafang replacement CRANKARMS

Posted: Jan 08 2016 6:01pm
by Lurkin
The only time I've had issues with the standard arms is when the non drive side fell off. I didn't tighten it after the first ~100-400km and needed to. Did this with the replacement, no issues since.

As for a lighter weight version.. the weight of those referenced are 655g (http://www.whiteind.com/mountain-cranks/) the standard arms are ~205 -210g each = max of 420g? I realise white industries include chainrings in their weight, I think... not sure of the weight of their actual chainrings, but surely the wouldn't weight 235g?

Image

If thats the case, your better off with the lighter BBS arms. I think some of the older shimano stuff would be lighter, but might be hard to come by these days.

After seeing the size of the bearings inside the crank, I wouldn't be jumping on these, its kinda asking for trouble.

Re: Bafang replacement CRANKARMS

Posted: Jul 07 2016 10:08pm
by Fredorbea
Out of curiosity what does the Bafang axle look like? I presume it has a drive gear and a couple of bearing diameters. Why not just make a new axle with isis interface instead of crappy square taper?

Re: Bafang replacement CRANKARMS

Posted: Jul 07 2016 11:39pm
by Triketech
Schlumpf cranks are a perfect fit. Look up Hostel Shop in Wisconsin they have shorter cranks in stock at a decent price.

Re: Bafang replacement CRANKARMS

Posted: Jul 08 2016 1:37am
by ScooterMan101
Those Befang Crank Arms are light at 205-210 grams,
The extra weight that needs to be shaved off that Mid-Drive , must then be in the
Chainring
and
Heavy square taper bottom bracket and bearings,
and
other parts in motor and/or casing.

What does that stock chainring weigh ?

What does the Befang Mid-Drive Square Taper BB with bearings weigh ?

( the Shimano outer bearings for the Hollowtech II cranksets , weigh between 58-96 grams for both of them )
( shimano BB-UN55 bottom bracket weighs 325 grams with the required crank arm bolts, and the BB-UN55 is lighter than others )
So at least 225 grams to over 300-400 grams of savings , for a modern crankset/bb system like the Shimano Hollowtech II
and at even a little more weight savings with a BB30 / FSA Crankset System.

A modern Crankset / Bearing system , with better chainring, would drop a little over a pound on the BBS02 / HD motors







Lurkin wrote:The only time I've had issues with the standard arms is when the non drive side fell off. I didn't tighten it after the first ~100-400km and needed to. Did this with the replacement, no issues since.

As for a lighter weight version.. the weight of those referenced are 655g (http://www.whiteind.com/mountain-cranks/) the standard arms are ~205 -210g each = max of 420g? I realise white industries include chainrings in their weight, I think... not sure of the weight of their actual chainrings, but surely the wouldn't weight 235g?

Image

If thats the case, your better off with the lighter BBS arms. I think some of the older shimano stuff would be lighter, but might be hard to come by these days.

After seeing the size of the bearings inside the crank, I wouldn't be jumping on these, its kinda asking for trouble.

Re: Bafang replacement CRANKARMS

Posted: Sep 20 2017 9:48am
by ximox
Shimano FC-E6000 Crank Arm

Thats all you need. 22 eur / pair in EU. https://www.bike24.com/ sends in USA but too expensive postage. I am sure you can find them in USA.