Hey People! Anyone had a similar problem? Shimano cues crankset, just installed, first ride – 30km in i noticed play, upon inspection the whole crank thread gone and pedal in my hand.
Please if possible spare me the cross threading story – pedal went in smoothly by hand, with some antisieze and tightened at the end with wrench.
by Exact-Net6313
23 Comments
Did you put the pedals on the right side? Left on left and right on right? Or did you crossthread while installing? I dont believe this is a problem with the cranks/pedals, but an user error most likely..
No haven’t seen this yet, but this is why warranty exists! Shimano really stands behind their stuff. I guarantee they send a new crank.
Is it possible that you bought pedals with a different thread size? I would check with the producer
Almost definitely not tightened enough, worked loose whilst riding and destroyed the thread. Seen it happen to dozens of cranks
You are supposed to tighten them before riding.
Is that possible that other pedals were installed before these and they were cross threaded? The first pair created new bad threads and those are what you were tightening against?
I’ve had that with a bike-sharing bike and one time with a youth hybrid bike… but both times they had considerable mileage.
on the first ride? no. this has to be sone kind material/machining error. i have never seen a crank arm disintegrate like that in one day.
Happened to me before on a very low quality bike, Are you sure the cranks are original parts?
There are clear signs of overtightening. User error + cheap cranks.
https://preview.redd.it/zgfpfc20sctg1.png?width=1069&format=png&auto=webp&s=95b0dff5fa5abb1fc04b32f2e2940c33f7252d58
From experience most likely two scenarios are that the pedal loosened during the ride and the play destroyed the threads or it was initially overtightened ruining the threads but this only becomes apparent after riding a bit.
The handful of times I’ve seen this is always slightly loose pedal backing out while riding and ripping the threads out as it goes.
It might be a failure of the chainset, but I don’t think it is.
That’s due to over tightening it. Cues are cheap but sturdy AF, I have 1000km on mine and they’re like new.
Are shimano still using a steel insert for the thread or have they cheaped out? Aluminum is crap for threads.
No pedal washer with an aluminum crank arm.
Check out my [post](https://www.reddit.com/r/RedditPHCyclingClub/s/zdDadTzyWW) on my Cues 2x cranks. Seems like they don’t tolerate over-tightening a lot. If you’re willing to risk it, there’s stuff you can buy on shopee or alibaba that you weld onto the crank itself to act as a new thread. I just bought new ones though. Although mine was fucked up by a mechanic who put the pedals sideways and over time ate up my thread.
I was thinking of getting that group set. Changed my mind, thank God.
OP did you begin threading the pedals with an Allen wrench and then finish the job with a pedal wrench?
If you so, you might have inadvertently loosened the pedal while finishing the job with the wrench. Can’t tell you how many times I’ve gotten my direction confused when I switched from the Allen key to the wrench. Just a thought.
Hey Stop for a second – just to set things straight- not looking to blame anyone other than myself – the reason for this post is that i have been changing pedals on bikes since i was a kid, crossthreaded some pedals as well, and i couldnt see where a mistake was made here.
So I know I am the one to blame, but the question is what did i do wrong – cuz from my point of view, pedals were installed by the book.
Peace
People talking about cross threading have clearly never attempted to do that.
This is wat happens when you over or under torque a pedal into the crank. The slightest of play will have the metal pedal eat the aluminium threadding of the crank.
I had the same thing happen a long time ago. Off course it happens on the drive side. Expensive lesson, but learned I bet.
Pedal is on the correct side, very common case:
1. Avoid cheap pedals. They have imprecise threads machining and can cause such damage.
2. Always apply a thin film of lube.
3. Always tighten the pedals fairly firmly.
4. Always ride a little and check for tightening the pedal again.
Car wheel nuts are also recommended to be tightened again after some ride. It’s normal for bolts to settle down after installation and become a bit loose.
Now you have 2 options.
1. Checking for a possibility of installing a thread insert by a professional
2. Replacing the crank. And throw those cast pedals away. Buy a 20-30 dollars machined axle ones.
All cranks are alloy. Pedal axles are steel. If you fit them incorrectly the cranks always come off worse as it’s a softer metal. There’s no way those pedals are better quality than the cranks 😂
Cheap pedals are never a good idea on a decent specced bike. They give you the cheapest set possible just to get you out the door. First thing I would have done is buy some quality pedals to go along with the new bike.
Does the pedal axle still turn freely? Seems unlikely, but if the pedal bearings seized the steel pedal might have chewed into the aluminum crank. I imagine you would have felt a lot of resistance though.
Only failure was when installing pedals I am afraid.
If they are not tightened in properly pedals always work loose and do this just scroll down this sub and you will see many posts similar.