pedal washers

[pliptrot]

should you use pedal washers? I never have, but a friend insists these are essential to prevent untimely crank expiration. I wonder what others experiences are......

[Valbrona]

You would only use pedal washers to increase Q factor. And then they are a bad fix - better to use pedals with higher Q, like Time which allow the switching between a low and high Q factor.

Not sure what you friend means by 'untimely crank expiration'.

[gaz]

I have them fitted on one bike. They are a left over from a set of TA Zephyr cranks that suffered an "untimely crank expiration" of the type that a pedal washer could not possibly prevent.

[Brucey]

You would only use pedal washers to increase Q factor.

-nonsense I'm afraid.

Not sure what you friend means by 'untimely crank expiration'.

uh-huh.... there speaks someone who has never broken a crank....

Some pedals in some cranks are a very bad fit and will indeed cause the crank to be more likely to fail.

Some cranksets (TA, Gipiemme etc IRRC) used to be supplied with pedal washers and where this is the case you should use them unless you have a very good reason not to. Any crank with a narrow top eye is going to be vulnerable to cracking in this area. Any crank with a flat counterbore in the pedal eye is most likely meant to have a washer fitted. Carbon cranks almost invariably need pedal washers.

But the real villain of the piece is often the pedals. Quite a lot of pedals have flats which extend as far as the shoulder that bears against the crank. Sometimes there are even burrs facing inwards as well. These burrs/sharp edges will gouge into the cranks. The gouges can be nice (corrosion assisted) crack starters and can even prevent the pedal from self-tightening in use through precession. The latter can cause the crank threads to strip.

Some pedals fit so poorly to the crank that there is a gap and water can get into the first few turns of the pedal threads and cause corrosion. Any corrosion will accelerate the growth rate of any cracks there might be. So however much copper-ease you might put on pedals with a complete shoulder on the spindle, you should put more on with pedals that have extended flats.

In practice most modern cranks have rather overbuilt pedal eyes and such failures are comparatively uncommon. But if you use these;

http://www.sjscycles.co.uk/wheels-manufacturing-stainless-steel-pedal-washers-per-pair-prod16976/

it won't hurt and nor will it hurt if you use pedals with a full spindle shoulder; you should certainly choose these if you have a choice of otherwise similar pedals.

BTW Jobst Brandt has proposed a tapered pedal interface in place of the flat one we have at present. I think he is horribly wrong about this and that in UK conditions it would greatly increase the instances of SCC assisted pedal eye cracking.

cheers

[531colin]

You would only use pedal washers to increase Q factor. And then they are a bad fix - better to use pedals with higher Q, like Time which allow the switching between a low and high Q factor.

Not sure what you friend means by 'untimely crank expiration'.

Get about 1.5mm extra pedal spacing, at a guess.......http://www.spacycles.co.uk/products.php?mode=search
Its just a flat washer to stop pedals with shoulders on the spindle from scoring up the crank, not a "kneesaver" http://www.sjscycles.co.uk/kneesavers-pedal-adaptors-prod14725/

I only used pedal washers when a pair came with TA Cyclotourist chainset, which inevitable failed at the square socket on the left crank.

[Valbrona]

Nope. Never broke a crank and never knowingly used a crankset that has required the use of pedal washers. Never come across any instructions to use pedal washers with the carbon cranksets I have used - these have used a threaded aluminium insert. For me, pedal washers will always be something to increase Q factor.

Don't think I would want to keep a crankset if it came with a pair of pedal washers.

[Brucey]

SRAM, FSA and truvativ recommend the use of pedal washers on their carbon cranks, esp if the pedal spindle is rough where it bears against the crank (eg extended flats...) or it bears against a part of the crank away from the Al insert (large flange on the pedal spindle).

Maybe you don't always 'need them' with these cranks (it'll vary with your pedals...) but if you fit them they are unlikely to cause any trouble if you don't need them but you can't say the converse applies...

cheers

[ANTONISH]

I use pedal washers on all my bikes. I'm not sure of the long term damage but it goes against the grain to see the pedal spindle gouging the crank.
Perhaps the washer may also help to prevent seizure of the pedal in the crank?

[Valbrona]

I like the idea of a pedal engaging as much of the threads as possible.

[tatanab]

I like the idea of a pedal engaging as much of the threads as possible.

The washer makes a difference of 0.5mm or less. Like you I did not use washers in 45 years of club riding and innumerable machines, but I did know about them and the reason for them. I have one set in use these days, on a set of Campag Record aluminium cranks I bought in 2006 and decided I wanted to preserve as best I can.

[The Mechanic]

I have not used them in the past but do so now on my FSA carbon cranks at the instance of the instructions that came with the cranks.

[foxyrider]

SRAM, FSA and truvativ recommend the use of pedal washers on their carbon cranks, esp if the pedal spindle is rough where it bears against the crank (eg extended flats...) or it bears against a part of the crank away from the Al insert (large flange on the pedal spindle).

Maybe you don't always 'need them' with these cranks (it'll vary with your pedals...) but if you fit them they are unlikely to cause any trouble if you don't need them but you can't say the converse applies...

cheers

Campagnolo specifically forbid their use on the carbon cranks and I'm sure I've seen Shimano instructions explicitly telling you not to use them even on the aluminium cranks - just saying

[firedfromthecircus]

Doesn't this suggest a fault with pedals that have extended flats?

[Brucey]

I guess so. But then again some quite good pedals (eg MKS sylvan) have had this design for years and it seems to work for them.

Campag and shimano don't make pedals like that; I suspect that if you were to fit them to their cranks they would sooner that they were fitted with pedal washers than without, despite what their service instructions say.

cheers

[Dafydd17]

So however much copper-ease you might put on pedals

Why on earth would you use copper-ease to keep water out of threads? (I assume you mean Copaslip or similar; the tin's a bit of a giveaway - it says "High Temperature Anti-seize compound" or similar. So if you're trying to keep high-temperature steam pipe flanges, or diesel exhaust bolts, from seizing, it's quite good stuff; not bad on vehicle brakes, either).

I'm rather baffled by the number of people who seem to think it's good as a lubricant for a whole variety of uses it's not designed for. For example, to keep bicycle threads that are exposed to road salt/spray etc in good condition, surely a water-resistant grease is ideal, or better still a salt-water resistant grease, such as Castrol SW2 (I think they've renamed it recently, just to confuse). I've used this on threaded fittings that were reglarly drenched/submerged in sea-water for months, and still been able to unscrew them. If you used Copaslip in the same application, you'd need the burning gear...