Utter tosh. Pedal falling off is caused by one thing only – mechanic poorly building a bike.

Really?

I’ve clouted a pedal fairly hard on a rock, stripped the threads and fell off/out fairly shortly afterwards.

Also to the people on this thread who regularly tighten your pedals… Are you kidding?

I thought this too. I’ll wager nobody who’s said that everything should be checked before every ride actually does it themselves.

40nm,

Copaslipped and just nipped up for me.

40nm,

Copaslipped and just nipped up for me.

Agreed. Torquing pedals up to 40nm just makes them very difficult to get off when you need to strip the drivetrain. I’ve shredded my knuckles too many times removing semi-seized pedals so just nip them up to about 20nm nowadays. No problems so far.

It seems worth asking here what happens if pedals are over-tightened into the cranks. If the thread starts to yield, will the pedal come loose later. Just asking…

Maybe the mechanic didn’t tighten them correctly. Maybe they were just a shitty £3 set of pedals for demoing bikes, not designed for off road use, and they weren’t built to the same tolerances so worked their way loose. Maybe the OPs girlfriend clipped a rock.

Maybe the mechanic put the pedals on with sufficient force for a good set of pedals but they worked their way loose because they were cheap shit or they took a knock?

In the shop I used to work in we went through hundreds of sets of those pedals as some noobs just won’t accept that an expensive bike DOES NOT come with pedals. We came across duff ones on a fairly regular basis.

I always strongly advised customers against using them off road.

It seems worth asking here what happens if pedals are over-tightened into the cranks. If the thread starts to yield, will the pedal come loose later. Just asking…

Interesting point.

Some cranks have a steel threaded insert, some are soft alloy threads faced with a removable / loose-able steel washer.

Torquing an alloy threaded crank to 40Nm “might” cause it to strip when used.

Undoing pedals is once of the worst knuckle / chainring interface scenario, hence, I just nip them up. I thought that they were threaded as they are, to keep tight while riding, rather than undoing…

Agree with everything said here. Pedals rarely work loose – and then only after lots of use, if the bearings seize, or similar. Certainly if ridden only lightly, checked after six weeks etc, coming loose while riding along – on the balance of probabilities you’d say it was shop error.

If they can’t produce documentation to confirm it was done correctly, you’d think they’d have to accept the blame and cover the cost.

Also cost price on a complete SLX chainset (and as others have said, it’s unlikely to be this level and certainly not any higher if it’s a £1000 RRP bike) is more like half of what you’re being quoted. And given that the shop will be able to keep the bottom bracket, chainrings and left hand crank (assuming stripped thread is in the drive-side crank – if it’s actually in the left hand crank, that’s available as a spare for much less) they’ve got £70 worth of spares they can use/sell right there. So as a gesture of goodwill, if they’re unable to prove conclusively they did their job right, I’d expect them to sort it free of charge. Assuming the facts of the matter are as laid out by the OP, we’d be doing that (and as others have said, would be absolutely mortified and want to make sure we did everything possible to apologise and reassure the customer).

The only situation I’d expect the customer to accept responsibility would be if they had removed and re-fitted the pedals themselves (or if someone else not connected with the shop had done so), or if there had been a substantial length of time or amount of riding (dozens of rides, several months at least) without a competent person checking it over. If that’s the case OP, I think the offer of a reduced-price chainset is a good one (but £140 isn’t reduced, unless it’s at least XT level and even then that’s very nearly RRP including all the bits you won’t need).

Certainly agree that it’s not warranty for either the bike or crank manufacturer, assuming it’s all as the shop and OP are describing, and that threadlock is not the way to go.

Sounds like a well known chain rather than a LBS, is that correct?

Have i missed it, who is the shop as i dont wanna go there? 🙁

Pedal threads only need to be nipped, the pedalling rotation will keep them tight.

I’d say it might be a case of only finger tight and the crap bearings in the cheap pedals have dragged.

But, more it was tight. Too tight and the threads have been damaged. then failed under load.
More likely that this, than not tight enough.

All that said, name and shame. That’s now way to operate. Very poor CS.

to the OP, be aware that “PDI” sheets are generally box-ticking exercises, where mechanics get lazy and just tick all the boxes through. does not prove anything!

as a personal example, I collected a new road bike (Cannondale) on Saturday last week from a well known chain retailer in London.

According to the PDI sheet I received with my “welcome” pack:

-pedals fitted (no pedals were provided, I had to walk 2 miles home as they would not even give me plastic ones from the workshop!)

-saddle level (saddle was tipped back like a dirt jump bike)

-bell fitted (no bell to be seen anywhere)

-headset torqued (headset bearings rocking loose back and forth in head tube)

-brake bolts torqued (left brake pad rubbing on rear rim, with rear brake flopping side to side with finger pressure)

-controls set up (handlebar was rotated forwards in stem clamp so hoods were pointing downwards)

-gears adjusted (front mech rubbing on chainring in large chainring / small cog combo)

It seems worth asking here what happens if pedals are over-tightened into the cranks. If the thread starts to yield, will the pedal come loose later. Just asking…

If the pedal threads start to yield a little, everything’s done up tight so you remove most of the cyclic loading from the threads, so they generally won’t fail later on from fatigue – the only credible way they’d fail would be at the time of fitting (or, yes, when hitting a big rock).

If it’s done up loose, all the cyclic loading goes through the threads and you are quite likely to get a fatigue failure over time.

In this case, if the mileage you are quoting is correct then it’s essentially “less than a big ride”, so it should be replaced as the shop should have checked the crank. Sounds to me like you are being fobbed off, and if necessary you need to take it to trading standards & name and shame – you shouldn’t be going through this stress and hassle from someone elses cock up.

Another ex-workshop and bike shop manager here. If the usage stated by the OP is correct it would have been repaired FoC in my stores. the laughable £140 “good will” offer sounds suspiciously like profiteering from an unsuspecting punter to me too.

the pedalling rotation will keep them tight

Wrong way round there chief.

Rorschach – Member
the pedalling rotation will keep them tight

Wrong way round there chief.

It’s not the drag in the bearings from the pedalling, but the way the forces rotate around the joint that tightens them up (well, doesn’t assist their unwinding).

Oooh, forgot to say, former LBS Saturday mechanic who regularly had the piss taken out of me, but never for not tightening a pedal correctly, and never as much as the boss’s mates had the piss taken out of them.

I’ve had shocking service from 2 Local ish BS over the past 6 Months, their idea of changing pivot bolts is totally different to mine in that it was corroded in, hence the none replacement.

The mechanic tried informing me he had OCD and they were definitely changed :-0

Second to that I bought my son “10 years Old a Spesh hot rock, bought for it paid threw it in the van got home and my son pedalled 3 times and then back pedalled 3 times. Trying not be over zealous I kept asking him to STOP pedalling backwards!

This went on so when he eventually burst into tears he sat down on grass refusing to ride it because the most he could pedal was 3 times without the pedals falling off, as I picked it up the grip came off in my hand and the rear brake blocks were loose digging into the tyre,

I wouldn’t mind but the shop assistant made a right fuss about PDI ing it and torque ing everything up. That cost me a 99 flake ice cream and I had to buy him some bright pink plastic pedals 🙁

Pink FFS!

Any way, I digressed a tad there but feel better for that,,,,,,

Ask your LBS for it in writing that Loctite is sufficient to hold the part in place to prevent harm. That is the least they can do. If they are adamant that CUBE have stated this is sufficient ask them to validate this in writing too.

Rorschach
“the pedalling rotation will keep them tight
Wrong way round there chief”

Really, so the pedalling rotation undoes them then?

Ask the LBS to confirm in writing that the repair is safe and doesn’t put you at risk of injury. Also ask what crankset they are providing in the goodwill gesture and post it on here so we can tell you it’s true cost.

@rorschach and @speshpaul – a bit off-topic, but my understanding for the reverse threading on left crank is not specifically that pedal rotation will then tighten them up, but rather that it prevents the pedals from loosening themselves under normal usage. Small distinction, I know.

EDIT: Here’s a small article about it. Precession is what the sciency types call it.

What he said

crap bearings in the cheap pedals have dragged

I doubt he was referring to precession tbf.

Hi – I’m waiting for the manager to contact me and I also asked this morning for Cube’s contact info. I will let you know how I get on but some more good ideas here so cheers again

No cubes come with pedals so it will be some cheap shite off something else.

As above the amount of people who don’t listen about the stock pedals being called “demo” or “testride” pedals for a reason then come back shouting about the pedal falling apart after 6 months of winter commuting….

BUT I haven’t seen any strip the thread/come loose so would probably give the benefit of the doubt.

Lots of years ago I bought a £2000 bike. The nice chap in the shop included two pairs of pedals, SPDs and Times. On that basis the LBS might have thrown in a better pair for a new rider.

PS it was a t*nd*m, and ISTR the NS rear pedal was threadlocked in.

A customer has the right to expect the pedals provided to be perfectly suitable for extended use. Those who work in shops that intentionally supply shoddy goods, please tell me which shops these are so I know to avoid them.

Cheap plastic pedals might fall to bits quite quickly, but if fitted properly they won’t strip out the crank threads.

A customer has the right to expect the pedals provided to be perfectly suitable for extended use

Not if they are specifically told that the pedals aren’t suitable for extended use.

A customer has the right to expect the pedals provided to be perfectly suitable for extended use.

If the bike doesn’t come with pedals and they don’t want to pay for a proper set, so the lbs do them a favour, throw in a set of ‘demo’ pedals for free but warn the customer they wont last, I don’t see the problem.

A customer has the right to expect the pedals provided to be perfectly suitable for extended use. Those who work in shops that intentionally supply shoddy goods, please tell me which shops these are so I know to avoid them.

As already said I would always advise to purchase some proper pedals even if a bike is supplied with (crap) pedals which the manifacturers specifically state is not for extended use. If they do not want this they can be provided with the ones that other people chose not to have and advised it will be enough to get them home but won’t last long and are not for proper use of the bike…

but as I and bencooper already said, I have seen plenty of pedals fail but usually the bearings collapse and the body comes off the axle never had one take out the threads…

I am slightly worried about the people saying that you only need to nip pedals up a bit because they’re self tightening. Yes, they are, but that only works against rotational forces – the dynamic loading from pedaling could make a not-so-tight pedal work it’s way out.

Pedals spanners are usually pretty long for a reason.

Since the bike shop isn’t being particularly helpful I’d just drop a nice email to cube along the lines of you’ve bought one of there bikes from this dealer and the pedal threads have broken away. Say you’re concerned with their suggested solution using Loctite. It’s prob worth mentioning you’re not happy about the possible bill of £140 so soon after buying a new bike. Hopefully they will sort you out and it might even cause the shop manager a bit of embarrassment.

Whilst you should keep an eye on things and the damage will probably been done while riding with the pedal lose. I agree that a correctly fit pedal shouldn’t come lose. There is a chance that the lad building the bike just screw the pedals in with his hand and planned to nip it up later and never did, or he over-tightened it damaging the threads, or started to cross thread it when fitting damaging the threads before removing and refitting… there are many things the shop could have done wrong but they’re clearly not prepared to acknowledge they could be at fault or seem to have any interest in keeping you as the customer happy!

Desperate to find out what the replacement cranks would be.

Pedals spanners are usually pretty long for a reason.

Cos they do get tight after while?

Just so you know, a £999 Cube hardtail is available with XT cranks: http://www.tredz.co.uk/.Cube-LTD-Race-27-5-Mountain-Bike-2015-Hardtail-MTB_74537.htm

So it’s not necessarily £140 for Alivio cranks, not saying the offer from the shop is very good, but just thought I’d point it out.