Accidentally stripped crankarm thread

[AliShah2020]

I wanted to thank everyone for your input and views. I was initially quoted circa £200-£400, and told bike my brand new bike would need to be scrapped as it wouldn't be worth repairing due to the cost of the parts. I queried why the stripped threads on the crank arms couldn't just be repaired or replaced and was told it was impossible and I would need an entire new group set!

The attempted con really shocked (and angered me) so I had to reach out to get your views as I am new to biking, but I am a fast learner.

I have a happy ending to this saga: I contacted Lapierre and explained the situation. They said the shops are instructed to put stickers on the LH and RH pedals.They were very sympathetic, and understand that the aluminum is soft, and can accept the wrong pedal almost 70% of the way in before you meet resistance by that time the damage is done.

Lapierre reckon the shop was at fault and sent me a free chainset as a good will gesture. I also got an independent mobile bicycle mechanic to come to my home fit it and he only charged me £10. Massive difference to being quoted £200-£400 for a new group set I did not need (bike was 24 hours old) by a dishonest dodgy shop owner unable to look me in the eye when I asked him about the labour cost, and my gut tells me he was sizing me up and would likely tamper with the bike so something else would go wrong within 20 miles.

I've had a great weekend riding the streets with my children. Thanks for your time, help and advice.

 

[Gunk]

Glad you’ve managed to get it resolved

 

[And]

Lapierre reckon the shop was at fault and sent me a free chainset as a good will gesture.

That is brilliant customer service - kudos to Lapierre

 

[AliShah2020]

That is brilliant customer service - kudos to Lapierre

The chap liked the fact that I was polite, honest and held my hand up and admitted that I had installed the pedals incorrectly. He said most people were too quick to blame the manufacturer and claim "defective for parts" they had damaged themselves.

It always pays to be honest. Lapierre are part of Raleigh. They have a fan for life!

 

[boydj]

I don't think it's that hard to screw left into righthanded/vice versa thread if it's steel (pedal) into alu (crankarm). Alu is no match for steel so clear loser hence no damage to pedal thread and all to crankarm thread. It's probably even possible to cut thread in alu alike tapping without the steel hardened alike real taps.

That's why you should always start threading a pedal by hand until it is well in. If there's any serious resistance and that persists after cleaning out any dirt from the threads, then something is wrong and needs investigating. With clean, uncorroded threads, you should be able to get a pedal all the way in by hand. It's good practice to unscrew pedals and clean up the threads every few months anyway and put a dab of grease on the threads when putting them back on.

 

[rogerzilla]

Every few months!

I left a set of M540s on my commuting bike for...er...9 years (M540s are good; the bearings only had the tiniest slop after all that).

They were challenging to remove!

 

[silva]

That's why you should always start threading a pedal by hand until it is well in. If there's any serious resistance and that persists after cleaning out any dirt from the threads, then something is wrong and needs investigating. With clean, uncorroded threads, you should be able to get a pedal all the way in by hand. It's good practice to unscrew pedals and clean up the threads every few months anyway and put a dab of grease on the threads when putting them back on.

I recently had a similar case.
I wanted to replace the front Magura HS33 brake pads but the left one sat like jammed, removing the lower bolt didn't suffice, the upper pen sat like jammed in the frame mount hole. I decided to also losen the upper bolt that is screwed in that upper pen. I broke before losening.
What turns out to be the cause: Magura doesn't pretap the screwthread in the hole in the pen. The steel bolt has to tap its own thread in the aluminium of the pen.
But the thread is metric, so much finer than a wood screw or so, so strong connection, and a dedicated tap leaves some tolerance, selftapping not.
I find that Magura should have filled the bolt head with something, or a warning, to make clear that should not be attempted to loose the bolt.

 

[boydj]

Every few months!

I left a set of M540s on my commuting bike for...er...9 years (M540s are good; the bearings only had the tiniest slop after all that).

They were challenging to remove!

I've got more bikes than pedal sets, with one set of roadie pedals (Speedplay Zero), and a couple of pairs of mtb/touring pedals (Speedplay Frog). So, depending on where I'm going to go and what bike I'm going to use I'm often changing pedals. It's a five minute job at most. With Speedplays you've got to be injecting grease fairly regularly too, so my pedals do get a bit more tlc than M540s would require.