More BB30 madness

[marciero]

Reading recent posts on BB30 made me feel more comfortable about the BB30 on my Cannondale tandem. But there is some weirdness. The manual lists BB30, and there is also an exploded diagram showing the press-fit bearings. The BB30 logo is also painted on the underside of the boom tube. But the bike clearly has standard FSA threaded outboard mega exo type bearing cups. Indeed, FSA BB7000 documentation was also included. The cranks are FSA Gossamer. BB shell is standard 73mm by my measurement.
Apparently the outboard bearings are screwed into some type of adapter. But then it does not make sense to also have the press-fit bearings (manual lists KB 6180). The frame came new this way. The manual cryptically lists "KP230 BB guide for rear" which I assume is the adapter.

I understand that the use of Praxis and other adapters to convert and use various cranks is common, but why initially spec a bike with BB30 frame only to use an adapter? That does not make sense to me. Am thinking it was design expedience, based on the availabiltiy of parts, etc. Maybe they had the BB30 shells on hand so built frames with those but could not easily and cheaply source tandem BB30 cranks. I will say that tandems seem to be sort of an afterthought for Cannondale. I knew this when I bought the bike based on web presence and other clues. (In fact when I inquired about the axle to crown on the fork, the rep who finally got back to me after two weeks said he did not have/could not find that information!)
I must say that I am okay with the arrangement-I got a screaming deal on it and so far I have not had any creaking or other issues. (From reading other threads I now have a good idea how to address those should they arise).
But I am curious to know exactly what the adapter is, should I need to service it, and if this sort of thing is common.

[hollowgram5]

Before Praxis and others started making conversions, Cannondale worked with FSA to produce a sleeve that is pressed into the BB shell to provide a threaded insert to thread bearings into. This is removable with the right tools. I'll try to find some pictures when I get to my computer.

Additionally, the part spec on the bike can vary between levels offered by Cannondale, but the frames (especially the tandems) are batch built. There could be a more expensive version that has a BB30 crankset installed as OEM. That adapter allows for this, and keeps their total PNs for frames at a minimum.

[marciero]

Before Praxis and others started making conversions, Cannondale worked with FSA to produce a sleeve that is pressed into the BB shell to provide a threaded insert to thread bearings into. This is removable with the right tools. I'll try to find some pictures when I get to my computer.

Additionally, the part spec on the bike can vary between levels offered by Cannondale, but the frames (especially the tandems) are batch built. There could be a more expensive version that has a BB30 crankset installed as OEM. That adapter allows for this, and keeps their total PNs for frames at a minimum.

This sheds some light; thanks. It sounds like there was some thought and design rationale put into this. In fact, a quick check confirms that the T1 (mine is T2) did spec SLK carbon cranks on this bike, though not sure if those are for BB30 or threaded with the same sleeve

[topflightpro]

Before Praxis and others started making conversions, Cannondale worked with FSA to produce a sleeve that is pressed into the BB shell to provide a threaded insert to thread bearings into. This is removable with the right tools. I'll try to find some pictures when I get to my computer.


And that sleeve, if I remember correctly, once installed cannot be removed.

[hollowgram5]

And that sleeve, if I remember correctly, once installed cannot be removed.
It sure can. I even have the tool. Requires a headset press as motivation and it will come out.