Stripped crank

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AndyRM

XOXO
Location
North Shields
So, the last 25km of my ride on Saturday were somewhat hampered by my right pedal coming off.

A closer inspection yesterday evening has revealed that the thread on the pedal is fine, but the crank is totally stripped. This seems rather odd to me and suggests something other than a schoolboy error. Any thoughts on what may have gone wrong? I've changed pedals many times and never had this issue.

Crankset was Campag Centaur and the pedal was an Exustar, though I'm not sure that should make any difference.

One more question - will I need any special tools to get that crankset off my bike? I've got a Campag cup tool so I assume all will be fine?
 
More than likely the pedal was cross threaded when attached to the crank arm ....
Two Allen bolts or a center allen key fixing on the left hand crank arm .. Take of the left hand arm
Take the chain off the ring ... And tap the spindle on the left hand side with a block and hammer the right hand side will become free ..
 

raleighnut

Legendary Member
Campagnolo Centaur has a central 10 mm allen key with a Hirth (radially serrated) coupling if its the same year as mine. There is also a wire clip on the drive side which locates into a groove on the bearing to provide sideways location.
This bolt is very tight and to remove slide a 10 mm ring spanner onto the long arm of an allen key or use the Campagnolo special tool
 
Try to use a Allen key in the back of the spindle of the pedal when attaching it to the crank arm
It will to keep it straight whilst you load the threads in... just be gentle ...
 
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ianrauk

Tattooed Beat Messiah
Location
Rides Ti2
Thanks @tissot, any tips for avoiding cross threading in future? I'm not even sure how I managed it in the first place!


The only tip is to grease the threads and thread easy, taking your time making sure that it's threading on straight. They should be able to do up most of the way by hand, only using a key or spanner for the very last bit of tightening. .
 
OP
OP
AndyRM

AndyRM

XOXO
Location
North Shields
That's the weird/confusing/annoying thing - I do exactly that @ianrauk & @compo and didn't feel anything untoward this time. I'd ridden a good few 100k with absolutely no problems until Saturday. I guess it just took a while to reveal itself as cross threading.

I noticed a weird movement, sort of a dull clicking which I wrongly put down to a loose cleat.

Ho hum, live and learn I suppose! Fortunately I've got a spare crankset I can put on so I'll still be able to do the Cyclone in a couple of weeks.

Thanks for the advice and tips everyone.
 

Smokin Joe

Legendary Member
You can strip a thread without cross-threading it. You've got a steel spindle going into a much softer aluminium crank and it only takes a little bit of overtightening to damage the thread, particularly if you've made a habit of it during several changes.

And a thread can just fail with time anyway if there was a manufacturing or material flaw. It does happen.
 

Matthames

Über Member
Location
East Sussex
You can avoid cross threading by turning the bolt backwards for a turn before you start doing it up.

As for repairing the crank, this can be done by boring out the hole and taping it for a heli-coil.

When putting the pedal on to the crank, make sure you use something like copperslip and remember not to overtighten.
 

gbb

Legendary Member
Location
Peterborough
If you have PowerTorque cranks, you do indeed need special pullers. I have cobbled a solution on the past with a 1/2 drive socket that just sits right on the splines, a 2 leg puller and an alloy plate to protect the back of the cranks...alternatively, buy the expensive tools, borrow them..or let your LBS remove them.
 
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