Loose crank bolt

[gray198]

Have an Oxygen S Cross.Happy with bike. Suits my needs. However I have a problem with the bolt that holds the left side pedal working loose. Have already had it replaced once but it has started working loose again. I have tried lock thread on it but still happens. It seems like the problem may be caused by the thread being the wrong way round . ie it loosens in the direction of pedalling. Anyone any ideas how to solve.

regards

 

[Andy-Mat]

Have an Oxygen S Cross.Happy with bike. Suits my needs. However I have a problem with the bolt that holds the left side pedal working loose. Have already had it replaced once but it has started working loose again. I have tried lock thread on it but still happens. It seems like the problem may be caused by the thread being the wrong way round . ie it loosens in the direction of pedalling. Anyone any ideas how to solve.

regards

The pedals have a threaded rod (with bearings) in the middle usually, that screws into the end of the crank. One side is a LH thread the other a normal thread.
Are you referring to that threaded part being the bolt?
I may be wrong, but my memory says that the lefthand side should be a normal thread. The Right hand side is the reversed thread.
Can anyone confirm or deny that, as I am now unsure.
I have seen (several times!) where people have forced the wrong pedal on the wrong side, basically cutting a poor quality thread!
A fairly permanent repair, would be to clean up both parts of the thread using methylated spirits, and glue them together, using a quality Epoxy resin, correctly mixed, and give it at least 24 hours to set, no matter what the package says! Do not buy a 5 minute version.....
Someone may have placed the wrong crank on the LH side, if the threads fit normally. Maybe both are reversed?
I got given (sold), two pedals with the damn thread, from a crap bike shop here once. A bit confusing till I noticed......
Best of luck.
Andy

 

[gray198]

The pedals have a threaded rod (with bearings) in the middle usually, that screws into the end of the crank. One side is a LH thread the other a normal thread.
Are you referring to that threaded part being the bolt?
I may be wrong, but my memory says that the lefthand side should be a normal thread. The Right hand side is the reversed thread.
Can anyone confirm or deny that, as I am now unsure.
I have seen (several times!) where people have forced the wrong pedal on the wrong side, basically cutting a poor quality thread!
A fairly permanent repair, would be to clean up both parts of the thread using methylated spirits, and glue them together, using a quality Epoxy resin, correctly mixed, and give it at least 24 hours to set, no matter what the package says! Do not buy a 5 minute version.....
Someone may have placed the wrong crank on the LH side, if the threads fit normally. Maybe both are reversed?
I got given (sold), two pedals with the damn thread, from a crap bike shop here once. A bit confusing till I noticed......
Best of luck.
Andy

Thanks Andy. Might have to try the epoxy route. The cranks are as supplied when bike was new. If you sit on bike it is the left pedal that is affected. It is tightened towards the rear of the bike so when pedalling forward that to me would seem to be undoing the bolt. I have contacted oxygen to see what they say, and will post if I get an answer. Again thanks for your input

regards gray

 

[AndyBike]

Are you sure you just arent tightening it enough ?. Pedal threads are 360 inch-pounds. Thats about 40nm, which is a lot.
ADDS - Because the pedals and the cranks aren't the very best of quality on your bike, I'd not recommend putting that much oomph into it. But still, you need to do it us very tightly.

I use an anti seize on the threads before torquing it on, and plenty of it. You use epoxy you are going to destroy the crank arm threads if you ever need to take the pedal back off. Thats if you can get it back off, so worst case scenario you'd need to replace the crank-set and the pedals.

I may be wrong, but my memory says that the left hand side should be a normal thread. The Right hand side is the reversed thread.

The right hand pedal is a right hand thread and the left hand pedal is a left hand thread.
So to tighten a right side, you turn it clockwise, and to tighten a left side you tighten it counter clockwise

 

[Sturmey]

Left hand pedal normally has left hand thread as explained below.

Everyday Scientist » why is the left bike pedal left-hand threaded?

View attachment 47282

 

[slowcoach]

I got given (sold), two pedals with the damn thread, from a crap bike shop here once

I think I must have gone to that shop and got the other pair!

Don't forget you can get helicoil kit to repair these threads.

 

[gray198]

Thanks guys it would definitely seem to me that it is threaded the wrong way. The left pedal is clockwise to tighten. The opposite way to what Sturmey has shown to be the right way. Probably wrongly assembled at factory or just a way of cutting costs

 

[gray198]

Took to a local bike shop. The threads are the correct way. What he said was that as it is a square shaft it had got damaged and rounded slightly. He has squared it back up again and is sure that it should be ok. Not been able to try it yet