pedal perils; can cheap pedals be any good?

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GeekDadZoid
Posts: 96
Joined: 21 Aug 2020, 7:01pm
Location: Stockport

Re: pedal perils; can cheap pedals be any good?

Postby GeekDadZoid » 16 Dec 2020, 4:44pm

Scrap that plan, the left pedal was as stuck as I think it could be, even after an overnight soaking in penetrating oil it managed withstand enough force to break the pedal spanner.

Ended up cutting the axle off and then grinding the stub so I could hammer a 18mm socket onto it, then using a 3ft pole managed to remove it, it looked like it had bonded but had not caused any internal damage on the threads. Greased up and pedals fitted, hopefully get them out for a test tomorrow.

Brucey
Posts: 42162
Joined: 4 Jan 2012, 6:25pm

Re: pedal perils; can cheap pedals be any good?

Postby Brucey » 16 Dec 2020, 6:12pm

a bit late now I know but

a) heat is your friend when getting pedals out of cranks; several heat/cool cycles and much use of oil helps release the pedal. If the oil starts to burn, you know the crank is too hot.

b) if the pedal is disassembled the spindle flats can normally be gripped in a bench vice (using spacers if necessary) and you can get considerably more serious with it.

c) if the spindle still won't come out, an in-situ pedal rebuild is always possible. A few commutes with the pedal being a bit fractious won't have caused catastrophic wear, so restoring some kind of functionality is usually possible, even if you only have to use it temporarily. [You could have used the balls etc from the new pedals if you didn't have any to hand...?]

FWIW I am always a bit leery of using massive force to remove pedals, because all too often the pedal wrings the life out of the thread in the crank as it comes out.

Needless to say removing the pedals once a year and applying more lube (eg copper ease) to the pedal and crank threads will stop them from getting seized in place, but hindsight is (as ever) wonderful...

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

GeekDadZoid
Posts: 96
Joined: 21 Aug 2020, 7:01pm
Location: Stockport

Re: pedal perils; can cheap pedals be any good?

Postby GeekDadZoid » 16 Dec 2020, 6:30pm

Thanks for the advice as always. I was worried about applying too much pressure. I did think about heat, I really need to get myself a small blowtorch.

My commute has dropped in the last week from 9 miles to under 2 so it's no real issue, but being able to work from home knowing I can be in the office in minutes is the perfect solution at the moment.

pwa
Posts: 13648
Joined: 2 Oct 2011, 8:55pm

Re: pedal perils; can cheap pedals be any good?

Postby pwa » 18 Dec 2020, 7:21am

Why do people buy questionable pedals to save money? Good pedals are not expensive. At £30 these Shimano pedals (SPD) make buying an even cheaper alternative look to me like a false economy, when you take into account the long life expectancy Shimano pedals have:
https://spacycles.co.uk/m17b0s86p283/SHIMANO-PD-M520

Brucey
Posts: 42162
Joined: 4 Jan 2012, 6:25pm

Re: pedal perils; can cheap pedals be any good?

Postby Brucey » 18 Dec 2020, 9:30am

PD-M520 are good pedals but they are SPD pedals. I like them but not everyone wants or needs SPD pedals. You can buy shimano flat pedals with the same bearings inside them and not only are the same bearings arguably less well suited to flat pedal use, but such pedals cost about double, too. And good though they are, the bearings in those pedals still need maintenance in hard use. Also, price is no indicator of true quality here; folk are seduced by talk of 'sealed bearings' in other pedals, (which could mean practically anything) so "cheap" and "cheaply made" are often two entirely different things.

Being one of the three contact points with the bike, folk are understandably fussy about what the pedals looks like and feel like; to work properly pedals are likely to vary in shape and appearance at least as much as the shoes that worn when riding bikes, and bearings are often a secondary consideration. Pedals are also easily damaged in minor prangs, so are effectively a consumable item for some cyclists.

The whole point of this thread was to point out that many cheap pedals have "pretty good" bearings in them and conversely many expensive pedals have bearings that are "fundamentally no better" or even "pretty hopeless" inside them. It isn't a question of 'saving money by buying cheap pedals'; it is often a case that finding a pedal shape that is comfy underfoot and then choosing between pedal models with that shape, price and different bearings being the main factors.

Different bearings feel different when they are new, and come with different maintenance requirements. But first impressions are often misleading (i.e. the pedals which feel roughest when they are new may have the lowest friction once run-in and the longest life ahead of them) and even the least well-sealed bearings need not be that difficult or tiresome to maintain.

For example IME a set of fairly inexpensive pedals with (poorly sealed) cup and cone bearings can last very well, provided the bearings are fitted with a lube port, and/or are given a squirt of lube whenever the chain is attended to. I wouldn't have guessed that this was possible unless I had seen it with my own eyes.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

Cowsham
Posts: 971
Joined: 4 Nov 2019, 1:33pm

Re: pedal perils; can cheap pedals be any good?

Postby Cowsham » 18 Dec 2020, 9:35am

Brucey wrote:a bit late now I know but

a) heat is your friend when getting pedals out of cranks; several heat/cool cycles and much use of oil helps release the pedal. If the oil starts to burn, you know the crank is too hot.

b) if the pedal is disassembled the spindle flats can normally be gripped in a bench vice (using spacers if necessary) and you can get considerably more serious with it.

c) if the spindle still won't come out, an in-situ pedal rebuild is always possible. A few commutes with the pedal being a bit fractious won't have caused catastrophic wear, so restoring some kind of functionality is usually possible, even if you only have to use it temporarily. [You could have used the balls etc from the new pedals if you didn't have any to hand...?]

FWIW I am always a bit leery of using massive force to remove pedals, because all too often the pedal wrings the life out of the thread in the crank as it comes out.

Needless to say removing the pedals once a year and applying more lube (eg copper ease) to the pedal and crank threads will stop them from getting seized in place, but hindsight is (as ever) wonderful...

cheers


Would it be a good idea to wrap some ptf plumbers tape ( not the gas stuff as it's a bit too thick ) around the threads before winding them onto the cranks ?

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: pedal perils; can cheap pedals be any good?

Postby Brucey » 18 Dec 2020, 9:53am

yes that could help. But it may also be the case that even the most tightly wound PTFE tape will be lost from the end of the pedal spindle by the time it is wound into the crank. This may vary with the state of the crank and pedal threads.

I guess it is also possible that the PTFE tape could have an unexpected effect on precession in the pedal threads, especially if it is unevenly distributed. I have never tried it so I can't really comment further.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

Cowsham
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Joined: 4 Nov 2019, 1:33pm

Re: pedal perils; can cheap pedals be any good?

Postby Cowsham » 18 Dec 2020, 10:04am

Just that it seems to preserve lots of outdoor fittings at my work place.

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: pedal perils; can cheap pedals be any good?

Postby Brucey » 18 Dec 2020, 10:30am

Cowsham wrote:Just that it seems to preserve lots of outdoor fittings at my work place.


yes indeed. But I would hazard a guess that they are more conventional uses of a screw thread; by contrast a pedal is a design which has 'evolved' to be the way it is and one that few engineers would choose to design that way. To say that it works 'unconventionally' (for a screw-threaded part) is something of an understatement.

It is not clear to me that the PTFE tape will be evenly distributed (and NB corrosion can attack a pedal thread from both ends) or that the effects of precession will always be the same even with PTFE tape in the joint. I guess the only thing to do is to try it...?

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

Cowsham
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Re: pedal perils; can cheap pedals be any good?

Postby Cowsham » 19 Dec 2020, 8:11am

Got the cheap pedals yesterday -- on first inspection the bearings feel a bit tight but some of that may be down to that rubber seal around the inner bearing -- if that's an issue it'll get dumped -- will dismantle the pedals to get a good look later.

Cowsham
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Re: pedal perils; can cheap pedals be any good?

Postby Cowsham » 20 Dec 2020, 3:43pm

20201219_140416.jpg


They are as you said they'd be and like you said and like hitler with one ball missing on each race.

I put them together again with better industrial grease and replaced that daft seal with an o ring -- won't keep all the dirt out but will be better than nothing.

Cowsham
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Joined: 4 Nov 2019, 1:33pm

Re: pedal perils; can cheap pedals be any good?

Postby Cowsham » 20 Dec 2020, 3:47pm

After adjustment and o rings put in
20201219_150720.jpg

Cowsham
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Re: pedal perils; can cheap pedals be any good?

Postby Cowsham » 20 Dec 2020, 3:50pm

The Rockbros pedals I had on the bike were not dear pedals either but a plain bearing on one end and a sealed bearing on the wee end.
20201220_143405.jpg


A bit draggy -- also the black ones with ball bearings both inner and outer are a little smaller which I like cos then you don't have to stop pedaling at even the shallowest of turns.

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: pedal perils; can cheap pedals be any good?

Postby Brucey » 20 Dec 2020, 4:48pm

FWIW some pedal spindles running with smaller bearings have downsized cone/locknut threads. Instead of M8 threading on the end of the spindle they can have M6 or M5. Shimano SPD pedals nearly all use 5mm cone/locknut threads with a non-standard extra-fine pitch; mostly they seem to get away with it (better quality steel in the spindles?) but even they have had some failures.

Smaller threads in other, less expensive pedals seem to be a potential weak spot; I have seen several pedals where the spindle broke, just inboard of the cone. In many cases there are two issues; they have used a smaller diameter spindle and they have used a short spindle too, such that the outboard bearing takes the lion's share of the load, being closer to the centre of the pedal. This is asking for trouble.

Overall, In less expensive pedals I suspect it is safest to stick with 8mm cone/locknut threads if you can do so. Cowsham's pedals appear to have M6 cone threading, but at least the spindle is long and the load well-shared between the inboard and outboard bearings.

FWIW I have a set of resin-bodied pedals on my carrier bike. I suspect they are lasting fairly well in good part because I don't ride out of the saddle on that bike, so I'm less likely to overload the pedal bodies. That said, not all plastic is made the same and nor is it made the same thickness around the bearing cups, either.

BTW I may have mentioned this upthread, but there are some cheap pedals which look as if they ought to have cup and cone bearings inside them, and even have spindles which are designed that way, complete with cone and locknut fitted, but the pedals bodies just have a plain bore inside them. No cups, no balls, just the pedal body running direct on the pedal spindle as an oversized plain journal bearing. Needless to say when I first encountered this arrangement I was rather confused; I tried to adjust them (to no avail) and then I wondered how the cups and balls had escaped, before finally concluding there never had been any to start with... :shock: :shock: . :lol:

cheers
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willcee
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Re: pedal perils; can cheap pedals be any good?

Postby willcee » 20 Dec 2020, 8:29pm

Interesting contris,I still use rattraps & toestraps mainly campag and nearly every pair of pedals has come to me either via cycle jumbles when I trailed over to the mainland or donations from someone who had gone spd or look or some other fancy rig..one thing I always do whether new or used is remove the dust cap cover plug or whatever hides the end bearing and load them with oil until it runs through then I fill them with waterproof grease until its seeps out when I recover the brg... and i haven't had many problems . one younger friend bought fancy shin gougers ''rock bros'' and appeared to have them fitted. and was totally amazed when I unscrewed the caps of both pedals and did my usual trick on them ..protesting all the while'' but they're new Willie'' when he came back 2 years later his machine had sweet running big flat spiked ally pedals.. which he donated to me when he went spd... and tried to convert me as well... will