What's wrong with Isis bottom brackets?

[Shenlong]

If you need a 113 ISIS the get a 113 ISIS, like skf mentioned or otherwise.

See post #10 on page 1.

As for lengths.
Grab the spec documents, it's a pdf under documents.
The Overdrive spec pages don't seem to work for me but you can get at them.
I might need to try a different browser.
I'm surprised the BMX/Trials users didn't go for that, but that Spanish spec looks reasonable.

Here's the table snippet.


View attachment 768160

Silly me . I wasn't able to find this spec sheet on the ISIS Drive site. Thanks for sharing it - it's much appreciated

 

[Shenlong]

Fine,I think this has gone as far as it needs to bud,Signing off,
As for ebikes the axle runs through the motor,it may have splines but it aint isis
All the best

Thought "this has gone as far as it needs to" and that you were "signing off".

With respect Kaydee, your contributions to this thread thus far have all been festering with negative energy. Lighten up.

While FluffyChicken and I have differing opinions & experiences - I can appreciate that he is contributing knowledge to this thread.

You can learn a lot from people you disagree with.

This would be a good opportunity for you to make a positive contribution to this thread.

I am very pleased for you Suburban ,but your experience is far from typical and the fact remains that Isis bottom brackets simply don’t last .If they did everyone would be using them….And they arent
glad you;re happy with yours though
.

Fluffychicken I truly admire you for the amount of time you are spending on this guy,theres an old saying
”If one person says you are wrong it’s a difference of opinion,if two people tell you you’re wrong it’s a coincidence,but if three people tell you you’re wrong it’s because you’re Wrong”

You sound vaccinated.



Looking forward to your first positive contribution to this thread.

 

[Woz]

For years I've heard the problem with ISIS and Octalink is small ball bearings. Page 4 and still no one has shown one pulled to bits and said what the actual ball bearing size is to compare.

Cup-n-cone: 6.35 mm (1/4″)
Shimano UNxx sealed unit: 5.556 mm (7/32″)

SKF do not seem to publish the ball bearing size for industrial replaceable cartridge bearings found in bottom brackets

EDIT: Got a crappy knackered FSA square taper thing that uses 6002 bearings that I will try to pull to bits later.

 

[Imlach]

For years I've heard the problem with ISIS and Octalink is small ball bearings. Page 4 and still no one has shown one pulled to bits and said what the actual ball bearing size is to compare.

Cup-n-cone: 6.35 mm (1/4″)
Shimano UNxx sealed unit: 5.556 mm (7/32″)

SKF do not seem to publish the ball bearing size for industrial replaceable cartridge bearings found in bottom brackets

 

[Woz]

Good man @Imlach - a tiny 2.381 mm (3/32″)

Got a crappy knackered FSA square taper thing that uses 6002 bearings that I will try to pull to bits later.

 

[Woz]

Thread should have been called "What is right with ISIS Bottom Brackets" and then it would have fell by the way side with no replies.

 

[Imlach]

Good man @Imlach - a tiny 2.381 mm (3/32″)

Got a crappy knackered FSA square taper thing that uses 6002 bearings that I will try to pull to bits later.

Always trust a Dutchy to get to the point with a video (I think the guy is Dutch)

I've had a few of that one he took apart and all failed quickly

 

[kingoffootball]

I have an old SKF that has been fitted to my SS for at least ten years, and has seen thousands of miles of use. I no longer use it. The bb Is absolutely fine but the ti pedals have seized in the cranks and the bearings are phut...

I was hesitant to use an ISIS bottom bracket, due to the reputed weakness of the smaller bearings. However, I picked up some lovely FRM cranks with an ISIS fitting. I bought a cheap second hand RPM BB ..... and it's still smooth many years and miles later. My bikes tend to not be left wet for a long time, but otherwise it hasn't had that easy time - single speed with a 44T chainring and 13T cog (because I can't spin, but can grind).

I'm not denying the disadvantage of the smaler bearing based on one individual experience .... but that weakness doesn't mean ISIS bottom brackets are unusable.

 

[FluffyChicken]

I think typically ISIS have a thickness of 4-5mm for the case/race and bearings.

Square taper has, well most use 61903/6103 so 6.5mm.

That's for cartridge bearing style.


I know Shimano go bigger because they are not cartridge bearings, hence they (esed to) last forever.



They often use custom-ish bearing for isis as they go ball/rod, double row.. , a mix etc

The SKF ISIS on the other hand do a Shimano, more like the M950.
So use the axle and shell as the bearing races, so they CA get big bearing in there. Don't know the size but I guess somewhere between 4 to 5mm.

As a side
BB-M950 (octalink) bearings are pretty small iirc, can measure, but then that's comparing to BB-M730 square cup/cone that are 6.35mm