Dawes-man

The Lyotard 460D has been my favourite pedal for several years now, so much so that I have them on 8 of my 9 bikes. The 9th has a pair of Lyotard Marcel Berthets. As well as the simple, and to me very attractive, design, I find them just about the easiest to use with toeclips - you can ride the underside and the serrations make it dead easy to flip the pedal and slip the foot in.

However, the other evening I was riding my Peugeot PX60 and being in a hurry was standing on the pedals as I sprinted away from the lights, up a slight incline, when the left pedal snapped clean off the crank. I think I was lucky for 2 reasons - my right testicle didn't get caught as I came crashing down on the top tube and I didn't come off in the path of the traffic I was in. I do have a nasty bruise in my right groin, though. I won't post a photo of that, though. Instead, here is the pedal:

[IMG]
Lyotard 460D - spindle snapped while sprinting uphill by Dawes-man, on Flickr[/IMG]

And what's left in the crank:

[IMG]
What's left of the spindle - 1975 Peugeot PX60 by Dawes-man, on Flickr[/IMG]

You could dismiss it as a one-off except that this is the 3rd time it's happened to me. As I said, I have these pedals on all but 1 of my bikes... the other 2 broke at slow speed on my Chesini Pista and the effect was more comical than anything else - 'Whoah there... what's with the sudden lightness?' kind of thing. This time it was life-threatening. The other 2 pedals:

[IMG]
Lyotard 460D, left & right - spindles snapped at slow speed, both within a week. by Dawes-man, on Flickr[/IMG]

You can tell the spindles snapped at low-speed from the small amount of deformation of the end-plates and how much the spindle tubes have come out of them. In all 3 pedals, the spindles have snapped at the exact same point.

Now, I'm not one to panic. I could even be described at times as stupidly unconcerned about risks. However, this has grabbed my attention.

What to do? Mikashima (MKS) do a 460D copy, called the Sylvan Touring, which you can buy for around $30 a pair here. They have a very good reputation as a fine working pedal. The side plates are very similar to the 460D's but that's all:

[IMG]
MKS Sylvan Touring by Dawes-man, on Flickr[/IMG]

MKS' 2 end-plates and spindle-tube are a single cast alloy part. While that cleans up the space in the pedal by doing away with the 460D's central strut, the effect is much more visually heavy. A friend has suggested that maybe I'll get lucky and find the Mikashima spindle will fit in the Lyotard. I've ordered a pair to check it out.

I wonder how many people here use the 460Ds and if anyone else has had one break? Does anyone know if the Sylvan Touring spindle will fit the 460D?

Capecodder

The MKS Touring Pedals are AWESOME...... That's the only pedal I use on all my bikes.

beech333

Mikashima Uniques are the way to go for me. Quality is on par with Suntour Superbe and the price is generally lower.

aixaix 

I'm guessing the problem isn't the axle. It looks like the housing isn't rigid enough to maintain the bearings parallel to each other, which is what equalizes the load across the pedal. If the housing flexes, the axle will too, breaking eventually. The MKS pedal (like the Campy Record & many others) uses a single casting to house the bearing cups. The Lyotard 460d does not, having an aluminum tube pressed into the steel bearing housings. It relies on the aluminum cage plates to deal with the considerable bending load the pedal takes. They flex, the hammered joints get loose and any time they hit the ground or anything else, the blow can easily misalign the bearing cup holders. The Marcel Berthet model doesn't seem to have this problem, perhaps because the barrel and platform are steel and don't flex much.

I hope you hear from users. It looks a lot like a design flaw to me, but I'm just guessing: I've never owned any.

I have a pair of Berthet Lyotards that have been in use since the 1960s on the bike I ride the most, by the way. They are my favorite pedals.

auchencrow

I'm not a metallurgist by training, but those surely look like hydrogen embrittlement failures to me.

High strength steels - (and especially zinc plated high strength steels) are susceptible to having hydrogen ions permeate into the metal, causing abrupt, catastrophic failures, even after many years of service. Timely, proper heat treating per ASTM guidelines serves to reduce the potential for such failures.

In the US, the steel and heat treating industry has taken this quite seriously for a long long time. I would not vouch that this was the case for manufacturers outside the US - even today.

H.E. is a pretty insidious thing, and it is plausible that failures will not show up at all until late in the service life of a part.

Drillium Dude 

If not the first time, the second time would surely have grabbed my attention

Are the spindle's breaking points roughly the same? If so, that might indicate a design flaw, however, if they are breaking at different areas on the spindle perhaps it was a crappy run of spindles.

And to think I'd only ever heard of Campy's early commercially-pure titanium pedal spindles breaking. I wonder how common pedal spindle breaks are - across the board.

Anybody else have this happen to them?

DD

Dawes-man

Thanks for the guess. The first 2 to snap were a pair - the right went, then the left and the both snapped in exactly the same place. I don't understand the mechanics and I've always assumed that the pedal is there merely to make it comfortable on the foot and that you could just have a spindle sticking out, turning under your foot. According to this view, it would all be down to the strength of the spindle.

However, the fact that they both snapped in the same place suggests that either the metal was coincidentally weak in exactly the same place or, as you propose, the design ensured that the stress would be concentrated in exactly the same spot. Here's a photo showing the breakage points:

[IMG]
IMG_5311 by Dawes-man, on Flickr[/IMG]

It's interesting, maybe, that the 2 on the left, from the same pair, are the same colour while the one on the right, from the pedal that failed the day before yesterday, is a different colour and has snapped in a different place.

Dawes-man

Thank you for your input. That's what I assumed about the 1st 2 to snap but (see above) now the idea of design fault seems to me more likely. In case there are metallurgists reading this, here is a photo of the ends:

[IMG]
IMG_5312 by Dawes-man, on Flickr[/IMG]

Dawes-man

Yeah, maybe it should have but they were a pair I'd bought NOS and I just figured they were from a bad casting.

As I wrote above, the 1st 2 broke in exactly the same place but the last, seemingly made from a different material, broke a little further away from the crank arm.

unterhausen

That shows all evidence of a typical fatigue failure. I'm not sure that there is anything to suggest hydrogen embrittlement. I think they may have case hardened the spindle so the bearing surfaces didn't wear out too quickly. I'd be interested in seeing the other half of the axle to see if there is some obvious reason for the failure there, but this is probably just the point of maximum bending. Lyotard pedals were very inexpensive, I'm actually not surprised to see this.

auchencrow

I've seen a lot of bolts fail from hydrogen embrittlement. It is a brittle fracture. Fatigue fractures usually show striation from crack propagation. Like this

Dawes-man

I'm beginning to grasp this. Thank you for your input. The fact that the spindles are 'stepped' and that they haven't broken at a weaker point, seems to me to support what you say. Do these help?

[IMG]
IMG_5315 by Dawes-man, on Flickr[/IMG]

[IMG]
IMG_5314 by Dawes-man, on Flickr[/IMG]

Dawes-man

Well, this doesn't look like that so it suggests this is a... brittle fracture, caused by hydrogen embrittlement?

Could it be that you, auchencrow and aixaix are all right? The metal was brittle, the design caused stress to be placed on the spindle and it broke at the most flexed part?

[IMG]
IMG_5316 by Dawes-man, on Flickr[/IMG]

auchencrow

^ Hydrogen Embrittlement fracture.

auchencrow

Anyway, go with those MKS touring pedals.
I have a few pairs, and they haven't broken on me. . . . Yet!

Dawes-man

I was just about to answer Capecodder and beech333 that I don't doubt their quality but one of the attractions of the Lyotards is that they look the part on my four 1950s English machines.

Hey ho! If the MKS spindles fit the Lyotard pedals I will try that. If not... not sure yet.

Capecodder

I would be much less concerned with the looks of the pedals vs the quality. If I were you (which I'm not) I would not be sporting those Lyotard"s on my bike ever again. You have had a few close calls, do go for broke.

Road Fan

I suspect the flexibility of the aluminum tube design on the old Lyotards is a problem, compared to the larger casting of Mikashima. Joining aluminum to steel is always a problem. Partly it's the fact that the two metals do not bond readily, and partly its that they have very different rates of thermal expansion and contraction. Over time mechanical joints get worked against each other by temperature change, and these stresses can have a long term effect.

The Berthet has a steel body, but it's still built up of parts crimped together rather than a single casting. It's probably not as stable as a cast pedal, but due the steel and the shorter spindle (compared to the 460) it is probably more stable than the 460. If you like the 2-sided design of the 460, change to the Mikashimas. If you like the design of the Berthet (I do!) then get them. I find the GR-9 is not as easy to tip into than is a Berthet. Despite its more modern engineering I prefer the Berthet.

You might also like the Campagnolo Chorus or C-record platform racing pedals.

I can't really tell if the spindles had a step at the point of fracture. The changes in cross-section are points where stress is concentrated compared to a straight rod. Such places are candidates for failure in any kind of part, especially if they have sharp corners rather than radiused transitions.

ftwelder

I also have another set of those Lyotards if you want to continue testing.

Chombi

Uhmmmm....French "junK'....I guess.....
I remember having Lyotard rat traps on my PH10S when I got it in the early 80's. Really liked those pedals but I replaced them with quills before I got that many miles on them. I think they were the first things I modded on the bike. Although I thought they looked like they would last forever......

Chombi

rootboy 

whew...interesting thread. And kind of scary too. I'm going to be much more cautious now when standing on the pedals on my Gitane. Sorry about your failures. Sounds a bit dangerous too.

Dawes-man

I'm not sure about the role the pedal has in the stresses exerted on the spindle. You and aixaix might well be right but I would have thought that the pedal sort of 'hung' on the spindle with the spindle taking the load. After all, it's the spindle that is attached to the crank arm, not the pedal body. When I first saw a Mikashima pedal I assumed they had cast the pedal body for reasons of economy rather than strength. Indeed, in the Classic Lightweights article on the history of Lyotard pedals - https://www.classiclightweights.co.uk...s/lyotard.html - they mention the plates loosening and riders having to hammer them together again, which doesn't suggest the pedal bodies were regarded as stressed members. The same article goes on to say, "However, there was one exception the final 460 had reinforced axles at the crank end a response no doubt to complaints about breakages." so perhaps this is a recognised problem with the 460D spindles.

Michael Angelo 

Terrible metal alloy and manufacturing, I'm sorry if I hurt anyone's feels. But, if they were made out of better metal alloy, Forged and then machined and heat treated, they wouldn't break as easy. Then again were talking bicycle pedals. I'm also using MKS pedals on most of my bikes these days.

Mike

Dawes-man

As I said earlier in the thread, the first 2 pedals broke at walking speed. At the time I thought that maybe my neglecting to disassemble them (they were NOS from the 70s or later) and grease the bearings had been a factor. However, the latest breakage is with an older pedal that I did service so that probably was not a factor.

Another thing about this is that I have another 7 bikes with the same pedals which haven't broken. The pair on my Dawes are so worn the serrations on one side have almost completely worn away (due to the PO using toeclips I guess) so they can go for thousands of miles without problem. I've done a lot of searching for info but there doesn't seem to be anything on these pedals commonly breaking.

Naturally, though, it's your choice. I will probably be less violent in my sprinting.

MrEss

You seem really attached to these pedals... maybe you could find a local machinist that could make some new spindles out of a better, modern steel?