Dura-Ace crank problems?

My bike had developed a strange ticking noise which I finally traced to my
right crank/pedal interface. At 3 O'clock the pedal would get "set" and at
around 11 it would click to "unset" itself--these were imperceptible
movements of the pedal axle in the crank. So I removed the pedal, greased,
and re-installed it.

I also noticed a lot of fretting at the face of the crank arm where it
attaches to the pedal. The last 1/3 of the pedal threads had a lot of fine
metallic powder on them. I suspect that I must have neglected to grease the
pedal when I first installed it.... but all this fretting in only 5000 miles
seems a wee bit scary. I weight less than 195 these days and no one would
call me a strong rider... so what gives?

The cranks on there are 7700 Dura-Ace, and the chainrings also seem to have
a lot of blistering on the surface. Did Shimano change anything for 7701?
Are Ultegra cranks any different, other than about $80 cheaper for 30 grams
heavier?

Cheers, Shawn

PS: I have found one reference to speculation that Ultegra cranks may use a
softer alloy with perhaps less precise teeth cut in the octalink, any
experience with this?

Shawn Amir wrote in message ...
My bike had developed a strange ticking noise which I finally traced to my
right crank/pedal interface. At 3 O'clock the pedal would get "set" and at
around 11 it would click to "unset" itself--these were imperceptible
movements of the pedal axle in the crank. So I removed the pedal, greased,
and re-installed it.

I also noticed a lot of fretting at the face of the crank arm where it
attaches to the pedal. The last 1/3 of the pedal threads had a lot of fine
metallic powder on them. I suspect that I must have neglected to grease
the
pedal when I first installed it.... but all this fretting in only 5000
miles
seems a wee bit scary. I weight less than 195 these days and no one would
call me a strong rider... so what gives?


Install pedal with a pedal spanner. Oil is sufficient for assembly, grease
will slowly migrate from area of high pressure leaving attachment not quite
as tight as envisaged.


Trevor

Shawn Amir wrote in message ...
My bike had developed a strange ticking noise which I finally traced to my
right crank/pedal interface. At 3 O'clock the pedal would get "set" and at
around 11 it would click to "unset" itself--these were imperceptible
movements of the pedal axle in the crank. So I removed the pedal, greased,
and re-installed it.

I also noticed a lot of fretting at the face of the crank arm where it
attaches to the pedal. The last 1/3 of the pedal threads had a lot of fine
metallic powder on them. I suspect that I must have neglected to grease
the
pedal when I first installed it.... but all this fretting in only 5000
miles
seems a wee bit scary. I weight less than 195 these days and no one would
call me a strong rider... so what gives?


Install pedal with a pedal spanner. Oil is sufficient for assembly, grease
will slowly migrate from area of high pressure leaving attachment not quite
as tight as envisaged.


Trevor

Shawn Amir wrote:

I also noticed a lot of fretting at the face of the crank arm where it
attaches to the pedal. The last 1/3 of the pedal threads had a lot of fine
metallic powder on them. I suspect that I must have neglected to grease the
pedal when I first installed it.... but all this fretting in only 5000 miles
seems a wee bit scary. I weight less than 195 these days and no one would
call me a strong rider... so what gives?

They all get chewed up like that (TA recommend the use of a washer
between the pedal and their cranks). The only broken cranks that I've
seen both went at the pedal end.

Shawn Amir wrote:

I also noticed a lot of fretting at the face of the crank arm where it
attaches to the pedal. The last 1/3 of the pedal threads had a lot of fine
metallic powder on them. I suspect that I must have neglected to grease the
pedal when I first installed it.... but all this fretting in only 5000 miles
seems a wee bit scary. I weight less than 195 these days and no one would
call me a strong rider... so what gives?

They all get chewed up like that (TA recommend the use of a washer
between the pedal and their cranks). The only broken cranks that I've
seen both went at the pedal end.

Zog The Undeniable wrote in message 4132d56d.0@entanet...
Shawn Amir wrote:

I also noticed a lot of fretting at the face of the crank arm where it
attaches to the pedal. The last 1/3 of the pedal threads had a lot of
fine
metallic powder on them. I suspect that I must have neglected to grease
the
pedal when I first installed it.... but all this fretting in only 5000
miles
seems a wee bit scary. I weight less than 195 these days and no one
would
call me a strong rider... so what gives?

They all get chewed up like that (TA recommend the use of a washer
between the pedal and their cranks). The only broken cranks that I've
seen both went at the pedal end.

Quality pedals have the thread taper out,leaving a gap between pedal axle
boss and thread so removing the stress raiser which would otherwise exist at
the face of the crank at the pedal eye. A taper on the pedal eye will
reduce the stress raiser.

I wonder when and why TA recommended this practice of fitting washers, it
should have no significance with normal materials. I think it would have a
detrimental effect, because it would be taking the axle thread to the face
of the crank so negating the advantageous thread form of the axle.

Trevor

Zog The Undeniable wrote in message 4132d56d.0@entanet...
Shawn Amir wrote:

I also noticed a lot of fretting at the face of the crank arm where it
attaches to the pedal. The last 1/3 of the pedal threads had a lot of
fine
metallic powder on them. I suspect that I must have neglected to grease
the
pedal when I first installed it.... but all this fretting in only 5000
miles
seems a wee bit scary. I weight less than 195 these days and no one
would
call me a strong rider... so what gives?

They all get chewed up like that (TA recommend the use of a washer
between the pedal and their cranks). The only broken cranks that I've
seen both went at the pedal end.

Quality pedals have the thread taper out,leaving a gap between pedal axle
boss and thread so removing the stress raiser which would otherwise exist at
the face of the crank at the pedal eye. A taper on the pedal eye will
reduce the stress raiser.

I wonder when and why TA recommended this practice of fitting washers, it
should have no significance with normal materials. I think it would have a
detrimental effect, because it would be taking the axle thread to the face
of the crank so negating the advantageous thread form of the axle.

Trevor