SKF BRI-600 ISIS Bottom Bracket

App said:

Anyone have an opinion on these as an improvement over older ISIS bb's?

They are using roller bearings on the drive side. Good idea? Issues?

App

http://www.bikemagic.com/news/images/in290705_skfbb_big.jpg

Looks cool to me! Never tried one though....

-n

What takes up the axial load for the axel moving to the right, toward the
chainrings? What is the axel made of and the weight of the unit?

cel

"Llatikcuf" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

App said:

Anyone have an opinion on these as an improvement over older ISIS bb's?

They are using roller bearings on the drive side. Good idea? Issues?

App

http://www.bikemagic.com/news/images/in290705_skfbb_big.jpg

Looks cool to me! Never tried one though....

-n

App said:

Anyone have an opinion on these as an improvement over older ISIS bb's?

They are using roller bearings on the drive side. Good idea? Issues?

I can't offer any specific observations about the BB in question, but
the mechanism is very similar to that of a rear hub I made several
years ago. It used a roller bearing in the freewheel side to allow the
use of a larger axle than could otherwise be accomodated within the
freewheel thread.

The left side cartridge bearing was retained by a cap fixed with a
circle of small screws. I did this so that the axle would not be able
to float out of the left side of the hub if the bearing's press-fit
failed to hold.

The main drawback I have been able to discern over a more conventional
hub is that the roller bearing has some internal clearance which can't
be adjusted away. This results in a small amount of play at the rim,
reminiscent of a loose bearing in a cup & cone hub. I used an
industrial drawn-cup roller bearing and sleeve-type race pressed on to
the axle; if I had been able to specify the bearing clearance with more
precision, I expect that the free play could have been reduced, but
probably not eliminated.

I believe that the BB in question is apt to exhibit some amount of the
same sort of play in the crank.

Using a roller bearing on the right side seems like a generally good
idea, though-- the right side sees the same radial loads from pedaling
as the left side does, but it sees substantially higher radial loads
from chain tension. The radial load capacity of a roller bearing that
will fit within the space available is vastly larger than that of a
ball bearing that will fit in the same space.

Chalo Colina

App said:

Anyone have an opinion on these as an improvement over older ISIS bb's?

They are using roller bearings on the drive side. Good idea? Issues?

I can't offer any specific observations about the BB in question, but
the mechanism is very similar to that of a rear hub I made several
years ago. It used a roller bearing in the freewheel side to allow the
use of a larger axle than could otherwise be accomodated within the
freewheel thread.

The left side cartridge bearing was retained by a cap fixed with a
circle of small screws. I did this so that the axle would not be able
to float out of the left side of the hub if the bearing's press-fit
failed to hold.

The main drawback I have been able to discern over a more conventional
hub is that the roller bearing has some internal clearance which can't
be adjusted away. This results in a small amount of play at the rim,
reminiscent of a loose bearing in a cup & cone hub. I used an
industrial drawn-cup roller bearing and sleeve-type race pressed on to
the axle; if I had been able to specify the bearing clearance with more
precision, I expect that the free play could have been reduced, but
probably not eliminated.

I believe that the BB in question is apt to exhibit some amount of the
same sort of play in the crank.

Using a roller bearing on the right side seems like a generally good
idea, though-- the right side sees the same radial loads from pedaling
as the left side does, but it sees substantially higher radial loads
from chain tension. The radial load capacity of a roller bearing that
will fit within the space available is vastly larger than that of a
ball bearing that will fit in the same space.

Chalo Colina

Quoted message said:

What takes up the axial load for the axel moving to the right, toward the
chainrings?

a ball bearing

Quoted message said:

What is the axel made of

stainless steel (some cheaper axles are plated cromo)

Quoted message said:

and the weight of the unit?

290 grams

SKF says they'll last 15 years, and they know bearings. Production has
just started.

--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

Quoted message said:

I believe that the BB in question is apt to exhibit some amount of the
same sort of play in the crank.

In that case, what about applying a couple of balls towards the outside of
the roller bearing (even building it into the retainer) to run on a tiny
race ground into a small, thin steel insert that fits into the drive-side
cup assembly?

Do you happen to have any quantitative numbers on that vastly high load
capacity for the roller bearing?

--
Phil, Squid-in-Training