pedals coming loose!

bennn

My local bike shop fitted new bottom bracket, cranks and chainset to my bike the other day, and re-attached my old pedals.
After 2 miles of riding one of the pedals came loose/ almost fell off so I took it back - on the basis that the pedal cannot have been screwed into the crank correctly by their mechanic.
The guy in the shop tried to tell me that the pedal had come off because, as my pedal was stiff on its bearing that it would loosen on the crank as I pedalled! i.e. my pedal was at fault!

On the plus side, they sorted the problem out on the spot, but I've not had the chance to fully test the pedal.

Before I go and complain to them that they are fobbing me off with nonsense rather than admitting to an error in the refit, can someone confirm that theidea that a stiff pedal can cause it to unscrew off the crank is complete nonsense? I thought that the cranks and pedals were specifically threaded so that they inherently tighten? He even suggested that this was a problem when i was free wheeling, when in fact both crank and pedal are stationary!

Thanks

joshtp

if the pedal really was too stiff, it would actually tighten it into the crank! unless, of cource, you were back pedaling all the time!

.blitz

bennn wrote:

The guy in the shop tried to tell me that the pedal had come off because, as my pedal was stiff on its bearing that it would loosen on the crank as I pedalled!

Obv. your lbs has a well-used copy of The Big Book of Bike Shop Excuses.

Arm yourself with a copy of Bike Tech For Gobby Know-It-Alls next time you go

The Rookie

joshtp/mbukman wrote:

if the pedal really was too stiff, it would actually tighten it into the crank! unless, of cource, you were back pedaling all the time!

No it was the gobby tech in the LBS who sounds like he was back pedaling!

Simon

wordnumb

:oops:
:roll:

ride_whenever

none the less, how did they drop out?

salsarider79

If the pedals are too stiff then they would come undone. To tighten pedals, go anti-clockwise. Lefty loosy, righty tighty....TBH they could have used too much grease which would compound the problem of stiff pedals, as would not doing the pedals up properly. Since you left the shop, I doubt you could prove they did anything wrong.

I work in a bike shop and have to tighten pedals.

The Rookie

salsarider79 wrote:

To tighten pedals, go anti-clockwise. Lefty loosy, righty tighty....

Only on one side right, so if you're going to say that, please do tell us which side that applies to, the other goes the other way usually!

Simon

ride_whenever

the action of pedaling tightens pedals by vibrational procession i think it's called.

Hence the reverse thread on the non-driveside crank. The only way for a properly located pedal to come out, even with stiff bearings is if it has been cross-threaded or for the crank threads to fail. They simply don't just drop out.


And for the record, I too work in a bike shop.

mikeage

I'm pretty sure pedal threads are designed so they unscrew if the bearings sieze. when fitting pedals I just put the spanner on and spin the cranks backwars and it threads in.

May be myth but I thought they were designed this way to prevent broken ankles back in the days of toe straps on race bikes.

*Edit - according to Sheldon this IS a myth, though it is what would happen, it isn't the reason for the design. best go tell me old man he was wrong all them years ago!