play in cranks

I recommend you have it checked out by a competent bike shop
immediately! You should also read this:

http://www.sheldonbrown.com/brandt/installing-cranks.html

I recommend you have it checked out by a competent bike shop
immediately! You should also read this:

http://www.sheldonbrown.com/brandt/installing-cranks.html

Francesco Devittori said:

I just noticed that my cranks have developed some lateral play. It's not
a lot but I can feel/see a movement (while riding I don't feel it).
The bb area is still somewhat mysterious to me, so I don't know if it's
something I can live with or if it's an alarm bell...

The cranks and the bb are Dura-Ace 7410 (the low profile ones that looks
like the 7700), I think it's a square taper.
They are well cared but have seen a lot of kilometers.

Any opinion is welcome!

Francesco

Either one of the cups for the bottom bracket is loose or the BB is worn
out, assuming that one of the crank arms is not loose.

a loose crank can be a "hitch" in power delivery to the spindle when
pedaling on that side-that is you can begin to locate the problem by
only pushing down with one foot.
or the crank spindle can sound like a bull frog!
erk erk erk
this is sometimes cawsed by vandalism cured by filling the hole with
epoxy or goop
or the bolt unscrewed from loctite failure
or it wasn't on tight enoughto begin with
I went through 3 lefts over 15k miles, one vandalism, one unknown, one
probabbbly wear from going off and on.
i recently developed the heebiejeebies with a right erk erk erk and
unfamiliar aluminum CR's using only steel prior.
it was the pedal going erk erk erk
but that right's on tight now!

On Tue, 05 Apr 2005 18:49:00 +0200, Francesco Devittori

frenkatfrenkdtcm said:

I just noticed that my cranks have developed some lateral play. It's not
a lot but I can feel/see a movement (while riding I don't feel it).
The bb area is still somewhat mysterious to me, so I don't know if it's
something I can live with or if it's an alarm bell...

The cranks and the bb are Dura-Ace 7410 (the low profile ones that looks
like the 7700), I think it's a square taper.
They are well cared but have seen a lot of kilometers.

If they move together, it's either a loose BB retainer (unscrewing on
the left), a loose BB (unscrewing on the right), or a worn out BB. Of
these three, a loose retainer and a worn BB would be the two more
likely issues in my opinion. If one crank can be moved without
causing the other to shift, then the problem's on the side that's
moving, and it's most likely a torn up crank at this point. If so, it
won't hurt anything to retorque it and see if it'll get you down the
road a bit more before you have to fix it.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Werehatrack said:

If they move together, it's either a loose BB retainer (unscrewing on
the left), a loose BB (unscrewing on the right), or a worn out BB. Of
these three, a loose retainer and a worn BB would be the two more
likely issues in my opinion. If one crank can be moved without
causing the other to shift, then the problem's on the side that's
moving, and it's most likely a torn up crank at this point. If so, it
won't hurt anything to retorque it and see if it'll get you down the
road a bit more before you have to fix it.

I also think that the BB is worn (moving a crank also shifts the other
one). What's the typical lifespan of these BB (DA 7410 - used in every
kind of weather mostly for training, including a lot of climbing and not
that much sprinting)? I estimate this one has about 50'000 km on it.
What's the worst thing that could happen if I don't fix it immediately?

Thanks everybody for the quick replies!

Francesco

On Thu, 07 Apr 2005 10:36:00 +0200, Francesco Devittori

frenkatfrenkdtcm said:

Werehatrack said:

If they move together, it's either a loose BB retainer (unscrewing on
the left), a loose BB (unscrewing on the right), or a worn out BB.

I also think that the BB is worn (moving a crank also shifts the other
one). What's the typical lifespan of these BB (DA 7410 - used in every
kind of weather mostly for training, including a lot of climbing and not
that much sprinting)? I estimate this one has about 50'000 km on it.

With that much time in service, it's quite likely to be worn out.

Quoted message said:

What's the worst thing that could happen if I don't fix it immediately?

It will slowly get sloppier and will probably become noisy before it
gets to the point where it interferes with shifting. I doubt that you
need to be concerned about a sudden failure, but if the BB is truly
worn out, it's time to replace it.

--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

worn BB?
doesn't sound like it.
but if-one side spindle will rotatate elliptically
or maybe both.
eliptical wear makes tightening the unit down problematic to a varyng
degree untill its shot-
headsets are esp unwelcome here.
the BB insides show more wear on one side than the other in the same
race-the race width varies. I suppose that's normal but it dopes
produce the egg shaped movement out at the end of the spindle.
buy new bearings for every repack!!