External bearing bottom brackets

[Tom Anderson]

Hi,

Shimano's HollowTech II, RaceFace's X-Type, FSA's MegaExo: are they
mutually compatible?

Can i put one in a frame which currently has a square tapered BB (after
taking that out!)?

Are there any downsides compared to a square tapered BB?

Am i right in thinking that the BBs themselves can be had for about 15-30
quid?

Are the cranksets ludicrously expensive?

Are there road or touring cranksets?

Any and all answers gratefully received!

tom

--
102 FX 6 (goblins)

 

[Pete Biggs]

Tom Anderson wrote:

> Can i put one in a frame which currently has a square tapered BB
> (after taking that out!)?

Yes. They are designed for ordinary frames.

I don't know enough about them to properly answer your other questions. I
haven't been interested personally because I don't know of any road triple
ones.

~PB

 

[Tom Tobin]

"Tom Anderson" <[email protected]> wrote in message ...
> Hi,
>
> Shimano's HollowTech II, RaceFace's X-Type, FSA's MegaExo: are they
> mutually compatible?
>
> Can i put one in a frame which currently has a square tapered BB (after
> taking that out!)?
>
You might need new crankarms!;-(
I don't think any of the above do square taper.

> Are there any downsides compared to a square tapered BB?
Fitting can be tricky: you need the right tools.

>
> Am i right in thinking that the BBs themselves can be had for about 15-30
> quid?
You might have to go above your top figure...
Chain Reaction show the HollowTech II @ about £34
http://www.chainreactioncycles.com/Models.aspx?ModelID=27239

>
> Are the cranksets ludicrously expensive?
>
> Are there road or touring cranksets?
>
> Any and all answers gratefully received!
>
Here's a bottom bracket FAQ:
http://www.cyclepowermeters.com/faq-34-c.asp

--
Another Tom.

 

[Jeff]

Tom Anderson wrote:
> Hi,
>
> Shimano's HollowTech II, RaceFace's X-Type, FSA's MegaExo: are they
> mutually compatible?

Yes, I run an LX crankset in a raceface diablous bb.

> Can i put one in a frame which currently has a square tapered BB (after
> taking that out!)?

Yep, just use the right shims (supplied with the BB) depending on what
width your frame is.

> Are there any downsides compared to a square tapered BB?

There are pluses and minuses.. Some claim the bearings are more prone
having the grease washed out. You can service them with care (my old LX
one came apart without too much drama)

> Am i right in thinking that the BBs themselves can be had for about
> 15-30 quid?

Yes
http://www.chainreactioncycles.com/Categories.aspx?CategoryID=145

> Are the cranksets ludicrously expensive?

No, and many come with the bottom bracket as part of the package.

> Are there road or touring cranksets?

Yes.
http://www.chainreactioncycles.com/Categories.aspx?CategoryID=577

> Any and all answers gratefully received!

J

 

[Tom Anderson]

On Wed, 4 Jun 2008, Jeff wrote:

> Tom Anderson wrote:
>
>> Shimano's HollowTech II, RaceFace's X-Type, FSA's MegaExo: are they
>> mutually compatible?
>
> Yes, I run an LX crankset in a raceface diablous bb.
>
>> Can i put one in a frame which currently has a square tapered BB (after
>> taking that out!)?
>
> Yep, just use the right shims (supplied with the BB) depending on what width
> your frame is.

All good news!

>> Are there any downsides compared to a square tapered BB?
>
> There are pluses and minuses.. Some claim the bearings are more prone having
> the grease washed out. You can service them with care (my old LX one came
> apart without too much drama)

Hadn't thought of that. Not too keen on having to re-grease them myself,
and knowing my luck, and propensity for riding in the rain, i would.

>> Are there road or touring cranksets?
>
> Yes.
> http://www.chainreactioncycles.com/Categories.aspx?CategoryID=577

I do like this:

http://www.chainreactioncycles.com/Models.aspx?ModelID=21876

Although the rings are probably slightly too big.

Random rant: i do wish websites selling bike components would organise
their data properly, and then let you search it. If i'm only interested in
triple cranksets to fit a JIS square bottom bracket, i have zero interest
in wading through millions of splined doubles or whatever. I'm sure the
sites would make more sales if they could actually show people products
they want.

tom

--
I had no idea it was going to end in such tragedy

 

[Paul Boyd]

On 04/06/2008 17:10, Tom Anderson said,

>> There are pluses and minuses.. Some claim the bearings are more prone
>> having the grease washed out. You can service them with care (my old
>> LX one came apart without too much drama)
>
> Hadn't thought of that. Not too keen on having to re-grease them myself,
> and knowing my luck, and propensity for riding in the rain, i would.

If you do go to an external bearing BB, you ought to consider getting
the BB shell faced so that the bearings sit absolutely square. It'll
all work perfectly well without facing, but you *might* shorten the
lifespan of the bearings.

--
Paul Boyd
http://www.paul-boyd.co.uk/

 

[Tom Anderson]

On Wed, 4 Jun 2008, Paul Boyd wrote:

> On 04/06/2008 17:10, Tom Anderson said,
>
>>> There are pluses and minuses.. Some claim the bearings are more prone
>>> having the grease washed out. You can service them with care (my old LX
>>> one came apart without too much drama)
>>
>> Hadn't thought of that. Not too keen on having to re-grease them myself,
>> and knowing my luck, and propensity for riding in the rain, i would.
>
> If you do go to an external bearing BB, you ought to consider getting
> the BB shell faced so that the bearings sit absolutely square. It'll
> all work perfectly well without facing, but you *might* shorten the
> lifespan of the bearings.

Okay.

Er, what's 'facing'?

tom

--
only positivistic reason and the forms of philosophy based on it are
universally valid -- Pope Benedict XVI

 

[Pete Biggs]

Tom Anderson wrote:
> On Wed, 4 Jun 2008, Paul Boyd wrote:

>> If you do go to an external bearing BB, you ought to consider getting
>> the BB shell faced so that the bearings sit absolutely square. It'll
>> all work perfectly well without facing, but you *might* shorten the
>> lifespan of the bearings.
>
> Okay.
>
> Er, what's 'facing'?

The outside edges of the frame's bottom bracket shell are resurfaced by
removing some material. The shell should be properly faced to start with by
the frame maker, but sometimes it was never done or not done properly, so
refacing makes sure it is.

It leaves the faces even and square, and can help with some conventional BBs
as well as outboard jobs.

~PB