Bicycle Mechanics - Octalink v1, Octalink v2, ISIS, power spline, Bottom Bracket differences

Being a new(er) bike mechanic, found a really good pic for differences in bottom brackets, as I could not find solid references with pics on here.

Was replacing my TruVativ power spline 68x113 BB, and was mistakenly told an Octalink v2 would work as a replacement. That was not the case.

Anyways, thought this pic might help other newer mechanics who are learning the trade as they go.

In pic: from left to right is: Square Taper, Octalink v1, Octalink v2, ISIS (or TruVativ calls it Power spline).

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power spline is not the same as isis. power spline requires a square taper crank puller

Ahh... I did not know that.

Is the difference only in type of puller to use?

Or are crank arms interchangeable on ISIS and Power Spline BB's?

no they are different

Kinda makes ya miss the old square taper doesn't it. The new and improved ain't so improved.

The new and improved ain't so improved.
Some were and some weren't. Shimano's Octalink was a questionable improvement in weight and stiffness but at least their bottom brackets were durable and reliable. ISIS varied all over the map in terms of quality. Some were dreadful and some were pretty good.

The newest external cup bottom brackets have some theoretical benefits but how much they really change things for the better is highly debatable.

External BB's are already outdated. Bleeding edge tech is press in bearings to 'cups' molded into frames.

Some were and some weren't. Shimano's Octalink was a questionable improvement in weight and stiffness but at least their bottom brackets were durable and reliable. ISIS varied all over the map in terms of quality. Some were dreadful and some were pretty good.

The newest external cup bottom brackets have some theoretical benefits but how much they really change things for the better is highly debatable.

Increasing the rod into a tube and decreasing the leverage on that tube are damn fine ways to go about getting the same job done with less metal.

The principle is definitely sound; I just hope the industry can settle on a well-sorted, hassle-free standard.

Is there a particular means of securing crankarms associated with BB30, or does it just relate to the bearings and spindle?

I just hope the industry can settle on a well-sorted, hassle-free standard.



I don't see that happening anytime soon. In our shop, we have new bikes with square taper bb's, splined spindle bb's, outboard bearing bb's, BB30 bb's, and Shimano's BB86 bb. As Sheldon said, "the problem with standards is that there are so many of them." :)

All these splined interfaces try to lock you in into the offering of the particular vendor. That's why I made it a firm and unchangeable policy to only purchase square taper BBs and cranks.

Isn't BB30 the best contender for the next default standard?

Isn't BB30 the best contender for the next default standard?I sure as hell hope not. I like my existing frames.

BB30 is Yet Another Attempt from bicycle part industry to get hapless cyclists re-purchase their frames and cranksets. But that's OK; why would I mind that a fool and his money are soon parted.

Since hapless consumers have already had to repurchase their frames to fit the current plethora of integrated, semi-integrated, internal headsets, its a mystery to me why they still stick with the old standard BB shell.
It makes sense to use the std shell with a std headset, but if you are going to break one standard, why keep the other?
Headsets go internal and bottom brackets go external!!

BB30 is Yet Another Attempt from bicycle part industry to get hapless cyclists re-purchase their frames and cranksets. But that's OK; why would I mind that a fool and his money are soon parted.

Seems to me like a perfectly obvious way of lightening and/or strengthening a BB, dude. You know, that whole stiffness versus cross-section thing?

Stuff like this is simply evolution, like threadless steerers; deal with it.

Since hapless consumers have already had to repurchase their frames to fit the current plethora of integrated, semi-integrated, internal headsets, its a mystery to me why they still stick with the old standard BB shell.
It makes sense to use the std shell with a std headset, but if you are going to break one standard, why keep the other?
Only if they actually did jump on Yet Another Buzzwagon and bought into the ingrated and semi-integrated headset fad. And the eternal words again echo forcefully with truth: a fool and his money are soon parted.

Isn't BB30 the best contender for the next default standard?

BB30 is certainly becoming more common on mid level and higher end bikes, but it's got a lot of competition, and I doubt any of them, BB30 included, will become a "default standard." As I said in my earlier post, we have several types of bb's on new bikes in our shop, among them BB30, Shimano's BB86, threaded bb's w/ external bearings, square taper bb's, splined interface bb's (we've got at least one model of new mtb that uses Octalink), etc. On some mountain bikes, there's BB92 I believe, although we don't have any of these in our shop currently, I don't believe.

The highest end new bikes we currently have in our shop are Colnago's, and they have old-fashioned English threaded bb shells, and the bb's have external bearings We have some equipped with all three major component makers (Shimano, Campy, SRAM). We have one new Colnago Master X Light frameset, and it's Italian threaded.

Another thing to consider is that while these newer bb types are becoming more common, there are still SO MANY frames out there with conventional, threaded bb shells that there will always (at least into the foreseeable future) be a huge market for various types of threaded bb's.

Once again, I'll defer to what Sheldon said about "standards," quoted in my above post.

Of course the English threaded standard will persist, but it'd sure be nice if some those new BB standards die off to leave a clear winner.