ZTTO BB92 BB86 threaded bottom brackets.

[emu26]

Does anyone have any experience with the ZTTO threaded BB86 / BB92 bottom brackets, either ceramic or normal?  https://www.aliexpress.com/item/33021799492.html?spm=2114.12010612.8148356.10.551c4f0d8pC56Q

I'm ask because I am wondering if those 4 o-rings used to seal the frame are enough to cause any movement in the bb or if the fact that it is threaded and screws together is enough offset and "squish" the o rings might cause?

TIA

[theirishrider]

I have one on my carbonda FM936 and its really really well made. I can't speak to the bearings quality but the shell is good. The plastic top hats were about 0.01-0.02mm too thick so a little bit of sand paper and it was golden. the top hats space the bearing and the axle.

The 4 o-rings should be good for a little bit of tollerance issue maybe 0.05-0.1mm. I've not actually ridden the bb yet but it went in very nicely.

[emu26]

Thanks. Did you get the ceramic bearing or the "normal"?

I just stumbled across a post on MTBR for them and the OP commented on the bearings being slightly too big and that they came with plastic spacers.  https://forums.mtbr.com/drivetrain-shifters-derailleurs-cranks/ztto-bb92-thread-together-bottom-bracket-24mm-shimano-1112783.html

I might take a punt and replace the bearings with proper ones when the time comes.

[carbonazza]

I did put one on my 062 few months ago, changed the steel bearings immediately, with good ones, as they were with metal sleeves.
No problem so far.
Screwing the two cups together until flush, make the assembly strong.
I did put loctite compound over the last centimeter on each side before pressing.

[Matt_C]

I ordered the standard bb86 version and they sent me ceramic anyway. I am around 300km in and the bb is solid. i just greased it up and screwed it in with no problems. only negative point is how difficult it was to get the drive side crank in, it required a few too many punches to my new carbon frame than i was comfortable with.

[emu26]

I ordered the standard bb86 version and they sent me ceramic anyway. I am around 300km in and the bb is solid. i just greased it up and screwed it in with no problems. only negative point is how difficult it was to get the drive side crank in, it required a few too many punches to my new carbon frame than i was comfortable with.

Next time try a couple of turns of an appropriately sized one of these to clean up the inside of the shell.  https://toolswarehouse.com.au/products/grip-29013-50mm-120-gript-flap-sanding-wheel?variant=21213204185201&currency=AUD&gclid=EAIaIQobChMI2cWckIDT7AIVWcEWBR3QDgtEEAQYBiABEgLc0_D_BwE

and thank you for the feedback.

[theirishrider]

I ordered the standard bb86 version and they sent me ceramic anyway. I am around 300km in and the bb is solid. i just greased it up and screwed it in with no problems. only negative point is how difficult it was to get the drive side crank in, it required a few too many punches to my new carbon frame than i was comfortable with.

I had exactly the same problem, the plastic top-hats are too tight. I used a diamond nail file. Worked well after a couple passes!

[emu26]

I ordered the standard bb86 version and they sent me ceramic anyway. I am around 300km in and the bb is solid. i just greased it up and screwed it in with no problems. only negative point is how difficult it was to get the drive side crank in, it required a few too many punches to my new carbon frame than i was comfortable with.

I had exactly the same problem, the plastic top-hats are too tight. I used a diamond nail file. Worked well after a couple passes!

Apologies Matt_C I misunderstood your post and read it as you had trouble getting the drive side BB into the frame.

theirishrider, if you put the tophat on the crank arm first then put it into the bb would that help or is it simply a case of the top hat section that goes into the bearing is just too thick?

[Matt_C]

I'm sure that sanding wheel would be perfect for taking a fraction of a millimetre off the plastic caps. I'll give that a go next time I have to remove the crankset... Not looking forward to punching it back out though...

[theirishrider]

I'm sure that sanding wheel would be perfect for taking a fraction of a millimetre off the plastic caps. I'll give that a go next time I have to remove the crankset... Not looking forward to punching it back out though...

Yep, it's tight. I could only get one side of the spindle through. When I tried to get it out, it pulled the bearing out. The bearing went back in ok. Its only a fraction of a mm so the sanding is really quick and easy. I don't know why they make it so tight to be honest.

[bremerradkurier]

I'm going to try putting the BB cups in a freezer before my next install-with access to dry ice, you could "cryofit" even further.

[theirishrider]

My cranks have got like 1mm play. I think It's because I ruined the top hat trying to remove it once. Any suggestions about where to find replacement bearings/tophat for 24mm Shimano spindle?

[emu26]

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.

My cranks have got like 1mm play. I think It's because I ruined the top hat trying to remove it once. Any suggestions about where to find replacement bearings/tophat for 24mm Shimano spindle?

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

[carbonazza]

...it's about 4mm short. I suspect the thicker flanges on this BB are the problem.

It depends the width of your frame at the BB shell.
If it is 86/92mm the BB is flush with the frame.
If it is 68/73 the BB protrude to make about the same end width as above.

PF30 spindles have two lengths, and can be too short if coupled with the wrong BB.

That's why I start to like DUB, that works for all frames.
As long as you use the right BB.
Zrace is an Ali brand doing DUB cranks.

[emu26]

I have a SRAM GX DUB crankset and DUB PF BB on order but I was asking specifically about what cranks are being used with this Ztto bottom bracket  being used in a matching frame. I believe the thickness of the screw flanges makes the overall width too wide.