Author Topic: ZTTO BB92 BB86 threaded bottom brackets.  (Read 8176 times)

carbonazza

Re: ZTTO BB92 BB86 threaded bottom brackets.
« Reply #15 on: January 15, 2021, 03:00:37 AM »
Is the crank arm that is touching the flange of the BB ?
There is no need of a spacer to make a gap?

It looks like a Hollowtech spindle though.
I've installed a Shimano cranksets with that BB and it was fine.

adriaanm

Re: ZTTO BB92 BB86 threaded bottom brackets.
« Reply #16 on: January 15, 2021, 03:23:46 AM »
changed the steel bearings immediately, with good ones, as they were with metal sleeves.
@carbonazza could you share which bearings you're using exactly? I bought this BB for use with a zrace hardrock crank, which has an aluminum spindle, and now I'm concerned about corrosion (steel bearing shell + aluminum spindle).

(EDIT: I'm asking because I interpreted your post as saying that you didn't like the metal sleeves.)
« Last Edit: January 15, 2021, 03:28:44 AM by adriaanm »

Bajker

Re: ZTTO BB92 BB86 threaded bottom brackets.
« Reply #17 on: January 15, 2021, 03:39:47 AM »
@carbonazza could you share which bearings you're using exactly? I bought this BB for use with a zrace hardrock crank, which has an aluminum spindle, and now I'm concerned about corrosion (steel bearing shell + aluminum spindle).

(EDIT: I'm asking because I interpreted your post as saying that you didn't like the metal sleeves.)

Isn't the axle coated with something that would prevent corrosion or is it raw aluminium?

theirishrider

Re: ZTTO BB92 BB86 threaded bottom brackets.
« Reply #18 on: January 15, 2021, 04:55:57 AM »
What cranksets are you all using with this BB?  I'm using this onehttps://www.aliexpress.com/item/32920639633.html?spm=a2g0s.9042311.0.0.27424c4dq2WAt4  and the spindle is too short to house all the way into the non drive-side crank arm properly, it's about 4mm short. I suspect the thicker flanges on this BB are the problem.

Sorry mate I don't but at the cost of the BB is worth mucking around with and not just getting a full replacement?

Shimano XT 12s boost :) Ah thats frustrating. 4mm is alot. The XT ones fit pretty well.
You're right, it's hardly worth it!
So last night I was boxing my bike for a flight. And I had to remove my power meter and therefore the cranks too. I tried to get the crank shaft out and I wouldn't come out, tapping away (gently) did nothing, I have to unscrew the BB with the driveside crank still attached and the axle in there. The damn top hats. I'm going to replace the bearings with 24mm ID ones. According to this https://www.mtbr.com/threads/ztto-bb92-thread-together-bottom-bracket-for-24mm-shimano.1112783/ I can replace them with these and remove the need for the plastic shim https://wheelsmfg.com/products/bottom-bracket-parts/bb-bearings/enduro-24x37-abec-3-sealed-bearings-bag-of-2.html

adriaanm

Re: ZTTO BB92 BB86 threaded bottom brackets.
« Reply #19 on: January 15, 2021, 08:15:59 AM »
Isn't the axle coated with something that would prevent corrosion or is it raw aluminium?
Good question -- I don't know. It doesn't look coated to me, but I attached a pic in case someone can tell that way.

Bajker

Re: ZTTO BB92 BB86 threaded bottom brackets.
« Reply #20 on: January 15, 2021, 11:26:57 AM »
Good question -- I don't know. It doesn't look coated to me, but I attached a pic in case someone can tell that way.

Almost looks like steel, but yeah most likely not coated with anything.

carbonazza

Re: ZTTO BB92 BB86 threaded bottom brackets.
« Reply #21 on: January 15, 2021, 12:04:33 PM »
@carbonazza could you share which bearings you're using exactly? I bought this BB for use with a zrace hardrock crank, which has an aluminum spindle, and now I'm concerned about corrosion (steel bearing shell + aluminum spindle).

(EDIT: I'm asking because I interpreted your post as saying that you didn't like the metal sleeves.)
I changed the bearing on my bike with the PF30 version of the BB, with 6806 bearings.

The BB86 one comes with 6805 bearings with a ID of 25mm, leaving a space, well maybe too little, for the sleeve.
BBInfinite provides sleeves too for GXP 24/22mm.
Not sure if it is to protect the alloy spindle from the steel of the bearings( PF30 BBs do not seem to care about this).
Or maybe 6805 are just bearings more common in the industry ?


...So last night I was boxing my bike for a flight. And I had to remove my power meter and therefore the cranks too...
Was it explicitly requested by the airlines ?
I never had any issue with rechargeable PM(P2M) on the bike.
With Ryanair and TUI.


Almost looks like steel, but yeah most likely not coated with anything.
I was thinking alloy  ??? Maybe try with a magnet, if it sticks or not

adriaanm

Re: ZTTO BB92 BB86 threaded bottom brackets.
« Reply #22 on: January 15, 2021, 12:07:08 PM »
Yeah it’s definitely not magnetic. First thing I tried  8)

theirishrider

Re: ZTTO BB92 BB86 threaded bottom brackets.
« Reply #23 on: January 16, 2021, 08:38:21 AM »
Was it explicitly requested by the airlines ?
I never had any issue with rechargeable PM(P2M) on the bike.
With Ryanair and TUI.
Nope, but since the chainring would somewhat be loaded in the bike box, i though prudent to remove it. 10 mins work while preventing 300 euros of damage :)

So, just bought new bearings for the ZTTO bb. 19gbp from here:
MR2437 LLB Enduro Bearing Abec 3 - 24x37x7mm
https://www.bearing-king.co.uk/bearing/mr2437-llb-enduro-bearing-abec-3-24x37x7mm/17126
Need to figure out how to get a seal for the outside :)


Schumo

Re: ZTTO BB92 BB86 threaded bottom brackets.
« Reply #24 on: January 25, 2021, 12:11:29 PM »
Need to figure out how to get a seal for the outside :)

I just cutted the old seal, but I'm always open to better solutions

carbonazza

Re: ZTTO BB92 BB86 threaded bottom brackets.
« Reply #25 on: January 25, 2021, 01:18:51 PM »
I think the seal works on two sides.
Preventing too much mud/water to arrive to the bearings.

And a guess, they prevent water ingress at the shaft too.
I find wet mud inside my PF30 one, that kills my bearings from the inside :o

The only option I found is to drill a hole at the very bottom of the BB, when the bike is horizontal.
I had the same issue with a BBInfinite, and against their advice I drilled it at 2.5mm
If water enters, it has a way out other than trough the back of the bearings.

And my bearings last much longer.
Then BB infinite came with these kind of seals.

Probably better to have a trap, or a purge hole already below the frame to do this.
However I did it on my 041 that didn't have any.

adriaanm

Re: ZTTO BB92 BB86 threaded bottom brackets.
« Reply #26 on: January 30, 2021, 02:02:07 AM »
FYI my bottom bracket has a manufacturing defect (pic attached: the notches on one side are not machined properly. My tool fits fine on the other side and on all the other BBs I’ve installed with it). Been going back and forth with the ZTTO Official Store for three days on getting a replacement and I’m running out of patience. They keep suggesting my tool is faulty or that I’m just holding it wrong...

Where did you all buy yours? Any affordable (<50 EUR) alternatives to recommend?

I mean, if I’m truly doing something dumb and the BB is fine, that would be the best outcome — please tell me :-)
« Last Edit: January 30, 2021, 02:05:42 AM by adriaanm »

emu26

Re: ZTTO BB92 BB86 threaded bottom brackets.
« Reply #27 on: January 30, 2021, 04:44:45 AM »
Got mine from the ZTTO official store on Aliexpress and I didn't have that trouble.

theirishrider

Re: ZTTO BB92 BB86 threaded bottom brackets.
« Reply #28 on: January 30, 2021, 07:15:22 AM »
FYI my bottom bracket has a manufacturing defect (pic attached: the notches on one side are not machined properly. My tool fits fine on the other side and on all the other BBs I’ve installed with it). Been going back and forth with the ZTTO Official Store for three days on getting a replacement and I’m running out of patience. They keep suggesting my tool is faulty or that I’m just holding it wrong...

Where did you all buy yours? Any affordable (<50 EUR) alternatives to recommend?

I mean, if I’m truly doing something dumb and the BB is fine, that would be the best outcome — please tell me :-)
Thats such a weird problem! I suggest you just file the notch down, should only take a second - but im sure the BB will give you plenty of life after. If you file it, the tool will still engage on all the notches!

adriaanm

Re: ZTTO BB92 BB86 threaded bottom brackets.
« Reply #29 on: January 30, 2021, 08:29:58 AM »
Yep, just decided to do that as well! ;D Haven’t made up my mind if I’m going to tolerate the imperfection ::) on my midlife crisis bike / 40th bday gift to self (my yoeleo r11 is being painted, should ship out before the lunar new year!)