Creaky crank question...

My turn to interrogate those with mechanical know-how...

Finally dusted off the duallie (2002 XT-specced Marin) for a weeken
spin and have noticed some awful creaking noises coming from th
crank/bb...

Performed a little test at the lights and discovered that when stoppe
with both brakes locked on, there appears to be some rotational play a
the cranks can be rocked back and forth (ie. as if pedalling) a smal
amount accompanied by an awful lot of creaking.... Any idea what thi
is? Loose cranks? Stuffed bb? Loose chainrings? Some kind of gyps
curse?

Eddie(hoping this won't be expensive)

--
eddiec

eddiec wrote:

My turn to interrogate those with mechanical know-how...

Finally dusted off the duallie (2002 XT-specced Marin) for a weekend
spin and have noticed some awful creaking noises coming from the
crank/bb...

Performed a little test at the lights and discovered that when stopped
with both brakes locked on, there appears to be some rotational play as
the cranks can be rocked back and forth (ie. as if pedalling) a small
amount accompanied by an awful lot of creaking.... Any idea what this
is? Loose cranks? Stuffed bb? Loose chainrings? Some kind of gypsy
curse?

Eddie(hoping this won't be expensive)C

If the play is forward/backward then it seems you need to tighten the
cranks, if you haven't wrecked them already. Can you move the cranks
independently of each other?

Peter
--
Peter McCallum
Mackay Qld AUSTRALIA

Peter McCallum Wrote:


If the play is forward/backward then it seems you need to tighten the
cranks, if you haven't wrecked them already. Can you move the cranks
independently of each other?

Peter
--
Peter McCallum
Mackay Qld AUSTRALIA


Cranks was probably what I suspected, but as they're somewhat of
mystery to me, wasn't sure...

I don't think they're moving independently... But I'll check. I'
hoping they're not stuffed, as the creaking has only just started (an
only really kicks in when you're pushing hard)... I'll have a tighte
and see what that does, and tighten up the chainring bolts while I'm a
it...

Thanks

--
eddiec

eddiec Wrote:
Cranks was probably what I suspected, but as they're somewhat of
mystery to me, wasn't sure...

I don't think they're moving independently... But I'll check. I'
hoping they're not stuffed, as the creaking has only just started (an
only really kicks in when you're pushing hard)... I'll have a tighte
and see what that does, and tighten up the chainring bolts while I'm a
it...

Thanks.

I just had a chainring problem myself!

http://www.cyclingforums.com/t233874...ing-bolts.html

Check those chainring bolts! I was getting terrible creaking whil
under load on my small chainring. It was a reasonating creaking soun
that wasn't exactly in time with my pedalling strokes

--
jazmo

eddiec Wrote:
My turn to interrogate those with mechanical know-how...

Finally dusted off the duallie (2002 XT-specced Marin) for a weeken
spin and have noticed some awful creaking noises coming from th
crank/bb...

Performed a little test at the lights and discovered that when stoppe
with both brakes locked on, there appears to be some rotational play a
the cranks can be rocked back and forth (ie. as if pedalling) a smal
amount accompanied by an awful lot of creaking.... Any idea what thi
is? Loose cranks? Stuffed bb? Loose chainrings? Some kind of gyps
curse?

Eddie(hoping this won't be expensive)C

It doesn't look good, but a cheap scenario is that the bottom bracke
bearings need adjustment. This is if you are using old-school cup an
cone bearings. Many BBs these days use cartridge bearings and aren'
adjustable http://sheldonbrown.com/tooltips/bbadj.html. If you have th
latter type, then crank movement is _bad_ news. Either the BB cartridg
bearing has failed or the crank has loosened (in which case its shap
has irreversibly changed to something that won't ever fit properly o
the spindle again.

If it was just a bit of creaking, but no discernible play, then you'
probably be ok...

Ritc

--
ritcho