Thoughts on bits fa...
 

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Thoughts on bits falling off a new bike

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If you say something never happens, it only takes one counter example to prove you wrong.

Are you new here?


 
Posted : 31/07/2023 4:06 pm
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BTW I know the torque I'm using isn't that accurate, but at the very least it's going to be more consistent than me. Which is mostly why I use it. And if I need to; at least if a manufacturer asks me "Did you torque it to spec" I can honestly answer "yes" to that.


 
Posted : 31/07/2023 4:06 pm
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I bought a Nukeproof from a major online retailer, after 6 or 8 rides the rear chainstay bearing bolt had come loose. Maybe a Nukeproof issue?


 
Posted : 31/07/2023 4:55 pm
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It’s obviously wrong that a bike shop could provide something so shoddily built. Especially as there really isn’t any comeback - except shouting their name loudly all over social media and telling as many people as possible how crap they are. (maybe it won’t damage their reputation, but maybe it will remind people to check bikes they’ve had built for them!)

Usually have built my own bikes, but recently purchased off the internet from Leisure Lakes and they did a great job of setting up the bike.

Halfords are the only shop I’ve had a really bad job done by, that was a long time ago, and I know they do decent bike prep courses for staff these days (my son works for em).


 
Posted : 31/07/2023 5:55 pm
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Must have shifted like an absolute dog if the mech was that close to coming off

i dunno, I’ve had a mech work loose, so much so that I thought something had snapped off.
but it still shifted perfectly.
so I wouldn’t use shifting as a guide.


 
Posted : 31/07/2023 6:00 pm
 5lab
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Deore 6100 rear mech? I've had mine come loose despite correct torquing. I suspect the thread isnt quite right on them


 
Posted : 31/07/2023 6:05 pm
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I never use a torque wrench on my bicycle.

I’m with you on this.

“It came lose and fell off”
“Was it done up tight enough?”
“I borrowed an old torque wrench from a friend that he got in a sale a decade ago and tightened it to spec”
“Did you try and tighten it with a multi tool?”
“No, it was tightened to the correct setting … it just came loose and fell of a mile down the road”
“So it wasn’t tight then?”
“The numbers don’t lie”
“The hand doesn’t lie”


 
Posted : 31/07/2023 6:08 pm
fasthaggis reacted
 jedi
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I've had a few mechs come loose especially the sram electronic ones


 
Posted : 31/07/2023 7:12 pm
winston and kelvin reacted
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Well if Deore is so cheap and low end surely it wouldn't cost them much to give you another?

use copaslip on the bolts when reusing old ones

😬

Copper grease is an excellent conductor and a great way to encourage galvanic corrosion. You also have to apply anti-seize correctly ie. to all contact surfaces including under the head.

Tin or zinc is seemingly better where aluminium is concerned.


 
Posted : 31/07/2023 8:11 pm
martinhutch and tjagain reacted
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Copper grease is an excellent conductor and a great way to encourage galvanic corrosion.

I have heard this before and it would seem to make sense - but I have never had a seized bolt that has been coppaslipped.  I thank the great god coppaslip every time I undo one. 🙂


 
Posted : 31/07/2023 10:06 pm
scotroutes reacted
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Salt has a lot to do with it too, I just don't take the chance on anything that doesn't need it now. Plus it clags up something rotten.


 
Posted : 31/07/2023 11:38 pm
fasthaggis reacted
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That is frankly shoddy beyond belief

For all those folks saying they go over a new bike themselves to make sure it’s properly assembled, I assume you are keen home mechanics, or at least know what you are doing

the vast majority of folks just buy bikes and ride them. Certainly when I bought my first bike that’s what I did, and likewise all my mates. I’d say 99% of bikes from Halfords are bought by folks who don’t have a clue about bike maintenance and they (mostly) don’t fall apart. And no bike I’ve ever purchased has ever just fallen apart in a month.

It wouldn’t even occur to me to check all the bolts if I bought from a reputable lbs


 
Posted : 31/07/2023 11:56 pm
scotroutes reacted
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I have never had a seized bolt that has been coppaslipped

Is the correct answer


 
Posted : 01/08/2023 12:06 am
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I have PDI'd hundreds of new bikes. I've also "prepped for hire" hundreds more. The number of loose bolts I've found, I could count on the fingers of one hand. I don't go around checking my own bikes before I ride them, simply down to that low number of potential issues.


 
Posted : 01/08/2023 12:10 am
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Name and shame.


 
Posted : 01/08/2023 12:32 am
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bikes are increasingly complex, but the amount of time the mechanic has to PDI them hasn't increased.


 
Posted : 01/08/2023 1:13 am
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I give my bikes a "shake and rattle" test before riding them.  thats the extent of my pre riding checks


 
Posted : 01/08/2023 6:43 am
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I give my bikes a “shake and rattle” test before riding them. thats the extent of my pre riding checks

I check pretty much every bolt on the DH bikes at least once a week. literally only a 'put allen key in and see if it moves' type thing, but picks up anything that's loose.

And at times, things are fractionally loose and not always the ones you'd think, or even ones you've seen previously..


 
Posted : 01/08/2023 7:01 am
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bikes are increasingly complex, but the amount of time the mechanic has to PDI them hasn’t increased.

Don't worry we've abolished the front mech to keep the bolt count down an save their poor overworked wrists 😉


 
Posted : 01/08/2023 7:05 am
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There's a distinct lack of virtue signallers bleating on about the importance of supporting your LBS 😁


 
Posted : 01/08/2023 10:46 am
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Saw a video on YT where a fella (very experienced, very good mechanic btw) torqued a pedal up to 50Nm! Now call me crazy, but I'd want to check that WOULD come undone!


 
Posted : 01/08/2023 10:51 am
nickc reacted
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Over the course of some new bikes:

YT Decoy

Nukeproof Mega

Privateer 161

Whyte e160

Every one of them has had something that wasn't right.  Some were direct sales, some from shops.  Disappointing, but I now assume that they need checking.


 
Posted : 01/08/2023 10:55 am
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I know you refer to getting it from an actual shop but it does look like you got it 'in the post' as you had to fit bars and wheel.

I think the onus is on you the second you have to put a spanner on it to build it up tbh.  Didnt some manufacturers refuse to do online sales like this (Trek?) in the early days because there was no way of guaranteeing the quality of workmanship from weekend warriors spannering.

You finished off building it.  You got multiple warnings of it not having been put together very well over the first few weeks and i personally would be having a word with my boy for ignoring the way it was shifting with a rear derailleur so out of kilter as it unwound itself.  He needs to let his dad know its not working very well imo.


 
Posted : 01/08/2023 10:55 am
 mert
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Didnt some manufacturers refuse to do online sales like this (Trek?) in the early days because there was no way of guaranteeing the quality of workmanship from weekend warriors spannering.

Specialised did it as well. Shops weren't allowed to do mail order of their bikes for a good chunk of time, they may still not be allowed to, but i haven't bought a specialised in 20+ years.


 
Posted : 01/08/2023 10:58 am
nickc reacted
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desperate bicycle - thats just daft - pedals self tighten by precessional forces.  Mine get copaslipped and done up to finger tight plus a tweak. never had one come loose.  He is not a good mechanic - he is a hamfisted butcher


 
Posted : 01/08/2023 11:02 am
 mert
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Ahhhh, the youtube mechanic, i have a million followers, therefore i'm right.


 
Posted : 01/08/2023 11:08 am
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I assumed this was some sort of right of passage for once burnt twice shy, I picked up a bike which was meant to have had a PDI, the bars rolled forward when going off a drop! Any bike I pick up now for myself or my family I give a full bolt grease and torque to spec nose to tail.


 
Posted : 01/08/2023 12:31 pm
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My general thought on the OP is that it is the shop's responsibility to make sure the bike is put together correctly when they send it out, so they're pretty much responsible.
The shop's response is ridiculous because the average consumer is not qualified to check that all the fasteners on a bike are appropriately tightened. If consumers could do this stuff then loads of shops would be out of business from losing their servicing revenue. I wonder if the owner's manual for the bike reflects their position, or not?
On the other hand the OP has made the situation more complicated by previously rectifying some of the stuff yourself - had they gone back to the physical shop with the loose rear caliper etc then they'd have a much clearer recourse.

This thing about pedals

Mine get copaslipped and done up to finger tight plus a tweak. never had one come loose.

I don't agree with this advice - most manufacturers advise something in the region of 40Nm tightening torque which equates to a firm push ~20kg on a 20cm spanner or long allen key. In my opinion, there is no downside to doing this to guard against things coming undone in the first few hours of use because it always requires more torque to undo the thing after it has self-tightened.
I remember as a teenager one of my pedals coming loose on my MTB because I had not tightened it properly - the trailing leg when landing jumps / descending etc can cause backing out of threads - also if the bearing slips during pedaling rotation this puts a backing off torque on the thread. Fortunately, the lesson was not particularly expensive as the crank thread was just about salvageable and I snapped one of the crank arms in half a couple of months later anyway.


 
Posted : 01/08/2023 2:02 pm
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I do my pedals up a few nm's shy of their recommended torque settings, just nipping them up a little is baffling to me, it wouldn't end well if I did that. they've come undone on me in the past when I used to just use a bog standard Allen key, back when my knowledge and tool collection was minimal.


 
Posted : 01/08/2023 3:01 pm
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Never had one come undone.  A well coppaslipped one done up to say 10nm ( a tweak) is more like 20nm on a dry one in terms of bolt stretch which is the real measure needed.  Pedals self tighten  50nm is just absurd and risks stripping threads,.  Id suggest if they are coming loose you have damaged threads in the crank arm from overtightening.

When using a torque wrench the thread must be dry and clean - maybe a very slight drop of light oil  Use the normal torque setting on a greased bolt you will overtighten it.


 
Posted : 01/08/2023 3:10 pm
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He is not a good mechanic – he is a hamfisted butcher

He's not though - he's amazing. Very experienced - He even dismantles and replaces the parts in EBike motors! (You could probably find him from that info).
I've never used a torque measurement on a pedal, just tweaked so it won't come undone.
Only prblem I've EVER had with pedals is them not coming undone - bought a crank off ebay recently - fact that the guy was selling it with the pedals still attached, I knew they'd be bastards to get off. And sure enough when it turned up... I got it off through use of a big spanner and all my bodyweight. If it had been allen key only pedals I would've had to bin it.. Really it's bonkers to do pedals up too tight. (We all know this but ... yeah 😆


 
Posted : 01/08/2023 3:18 pm
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no dude - he is not. If he is whacking pedals up to 50 nm he is a hamfisted butcher and would never get anywhere near my bikes.  Was he lubing the pedals?  If so 50nm is so far ott its not funny and if not they will seize.


 
Posted : 01/08/2023 3:28 pm
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No he's not. He just goes a bit nuts with torquing up pedals. Don't milk it - look him up on YT


 
Posted : 01/08/2023 3:30 pm
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I stripped and rebuilt an ebike motor unit and I am a decent home mechanic, far from professional.  Overdoing the pedals like that shows a total lack of mechanical sympathy


 
Posted : 01/08/2023 3:40 pm
scotroutes reacted
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Pedals self tighten

Kind of. In normal use by precession (think of a spirograph) they can tighten a wee bit, but if the bearing seized when riding along (as if that happens all of a sudden nowadays) then you would unscrew the pedal from the crank. If they tightened in that scenario, and your shoe was clipped in (spd or strap) then it would try to knacker your ankle instead.

Mind if your pedal was at 50nm then you might knacker your ankle before the pedal starts unscrewing anyway.


 
Posted : 01/08/2023 9:16 pm
twisty reacted
 LAT
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no dude – he is not. If he is whacking pedals up to 50 nm he is a hamfisted butcher and would never get anywhere near my bikes.

not according to shimano

For maximum performance we highly recommend SHIMANO lubricants and maintenance products. When installing the pedals, apply a small amount of grease to the threads to prevent the pedals from sticking. Use a torque wrench to securely tighten the pedals. Tightening torque is 35 - 55 N·m.

https://si.shimano.com › RAFC010
Crankset - Shimano


 
Posted : 02/08/2023 12:54 am
twisty reacted
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I do pedals up quite gently. No more than 15 or 20Nm. Never had one come loose, never had one get stuck either 🙂


 
Posted : 02/08/2023 3:52 am
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I’ve had a pedal come loose, some Shimano PD-500s, bit of anti seize  grease and tightened to prob 20Nm thinking they would self tighten if anything - went to check them a week or so later and one was loose. Bearings were free running etc (they were brand new).

Always do those particular pedals up to 40Nm now. 🤷‍♂️


 
Posted : 02/08/2023 7:58 am
twisty reacted
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I have to confess it has been a while since actually used my torque wrench so got it out to check my pedals.
They appeared to be in the 30-40Nm range. The commuter bike was 40Nm, the others were pretty low mileage since the pedals were last fitted. Measurements are not terribly accurate - the torque wrench is a unidirectional click type.
I suspect I'm actually torquing the pedals up to about 30Nm typically, and not the 40Nm I previously stated.
In any case - I think all this debate around pedals just reinforces the point that the average consumer is not qualified to check that all the fasteners on a bike are appropriately tightened.


 
Posted : 02/08/2023 12:27 pm
 mc
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Generic torque setting for a 9/16-18 (pedals are actually 9/16-20 so slightly finer thread, but finer threads actually allow a higher torque) fastener, is 60-80lb-ft (81-108Nm) for a generic low tensile bolt. For a high tensile bolt, those values are just over doubled.
However if going into alloy, those numbers are typically reduced by a third.

In the case of pedals, they should self tighten due to mechanical precession, but due to non-constant forces, you still need them tight enough to start with to avoid jars/binding causing them to slacken and unwind.

So in short, 50Nm is not excessive.


 
Posted : 02/08/2023 1:03 pm
twisty reacted
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So in short, 50Nm is not excessive

YOu know what... after how this thread has gone, I am in total agreement. Going to check them all now! 😆


 
Posted : 02/08/2023 5:48 pm
twisty reacted
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Hope 35-40nm
Shimano 35-55nm
Unite 35-40nm
Chromag approx min 30nm
Crank bros 34nm
Deity 30-50nm
PNW 35nm.
Personal pref is around 30nm.
50nm seems a touch excessive, exceeding most or hitting the max, little to no room for error in any calibration.


 
Posted : 02/08/2023 7:31 pm
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I don't think a lot of people tighten stuff up enough and it feels like a lot of the manufacturer torque ratings are on the low side for a lot of things. "Just" tight  enough to hold, until used. The only time I actually abide by torque ratings is for suspension internals and carbon bits. Even then suspension top caps are barely tight on recommended torque.

Fingers crossed but never had anything undo on me yet.

John


 
Posted : 02/08/2023 7:52 pm
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