Shimano Hollowtech II Bearings.

I recently installed a new crankset onto my bike which is of the
Hollowtech II type where the crank axle is simply pushed through the
bearing cups.

Can someone explain how the bearings 'mate' with the axle to stop it
simply wearing itself away by turning in the bearing cups.

Drinky wrote:
I recently installed a new crankset onto my bike which is of the
Hollowtech II type where the crank axle is simply pushed through the
bearing cups.

Can someone explain how the bearings 'mate' with the axle to stop it
simply wearing itself away by turning in the bearing cups.

Probably, but the trouble is getting the axle to accept the explanation

--
/Marten

info(apestaartje)m-gineering(punt)nl

On 13 Nov, 10:43, Drinky wrote:
I recently installed a new crankset onto my bike which is of the
Hollowtech II type where the crank axle is simply pushed through the
bearing cups.

Can someone explain how the bearings 'mate' with the axle to stop it
simply wearing itself away by turning in the bearing cups.

I had to gently persuade mine to mate using a "soft faced mallet".
Why would the axle turn in the cups if the cups turn easily in the
bearing? OTOH maybe there would be some turning due to precession.

Drinky said the following on 13/11/2007 10:43:

Can someone explain how the bearings 'mate' with the axle to stop it
simply wearing itself away by turning in the bearing cups.

Friction? The axle is a snug fit in the cup, and the friction between
axle and cup with 14st of rider standing on the pedals is going to be a
heck of a lot higher than some nice smooth bearings :-)

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

On 13 Nov, 11:58, Paul Boyd usenet.is.worse@plusnet wrote:
Drinky said the following on 13/11/2007 10:43:

Can someone explain how the bearings 'mate' with the axle to stop it
simply wearing itself away by turning in the bearing cups.

Friction? The axle is a snug fit in the cup, and the friction between
axle and cup with 14st of rider standing on the pedals is going to be a
heck of a lot higher than some nice smooth bearings :-)

--
Paul Boydhttp://www.paul-boyd.co.uk/

Agreed, no need for any special mating techniques

POHB wrote:
On 13 Nov, 10:43, Drinky wrote:
I recently installed a new crankset onto my bike which is of the
Hollowtech II type where the crank axle is simply pushed through the
bearing cups.

Can someone explain how the bearings 'mate' with the axle to stop it
simply wearing itself away by turning in the bearing cups.

I had to gently persuade mine to mate using a "soft faced mallet".
Why would the axle turn in the cups if the cups turn easily in the
bearing? OTOH maybe there would be some turning due to precession.


There will be, especially as the bearings become a bit rough. The inner
ring walking on the axle can wear a nice groove, so the large hammer
will come in handy when you have to take it apart again. Campa cranksets
are the exception with pressfits for the inner ring on the rotating axle

--
/Marten

info(apestaartje)m-gineering(punt)nl

CoyoteBoy said the following on 13/11/2007 21:47:

Agreed, no need for any special mating techniques

We're not back to Vicki B-H again, are we? ;-)

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

On Nov 13, 5:43 am, Drinky wrote:
I recently installed a new crankset onto my bike which is of the
Hollowtech II type where the crank axle is simply pushed through the
bearing cups.

Can someone explain how the bearings 'mate' with the axle to stop it
simply wearing itself away by turning in the bearing cups.

i have heard from some racers (extreme wear) that the BB will not last
one season. so i guess there is just more friction and more pressure
on the outside of the bearings. with us regulars the BB should
probably last 2-3 years
carlos
www.bikingthings.com
ride hard, get fit, be happier, live better