Mtn Pedals - spindle strength question

[eolson124]

Is a stainless steel spindle much stronger than a chromoly spindle?

[Cicli]

I dont think its much of a concern. I have seen one broken spindle and it was one of those aftermarket Ti ones.

[ofcounsel]

I agree. I wouldn't think one is much stronger than the other. The only ones that usually have weight limits and what not are titanium spindles.

[Louis]

When it comes down to giving an engineering answer, "stronger" is a loaded term. There's fatigue strength, static strength, stiffness, etc, etc

I would assume that if a pedal is made by a reputable manufacturer and if it doesn't have a weight limit, then strength shouldn't be a issue unless you abusing it by constantly doing monster jumps or if you weigh 275 lbs.

However, pedals have been known to fail, and you also have to do some basic maintenance, if only to check to make sure that everything spins freely and the fasteners are snug. You shouldn't just put them on there and forget about them for 20 years. (Although the Look Delta cleat pedals on my daily driver sure have been doing great over the years.)

[clyde the point]

I've broken several Look spindles.
Never an mtb though, and always use Shimano.

[11.4]

It's more a matter of which version of stainless or chrome moly, or whether the steel is even a chrome moly alloy. And of course a matter of how they're machined and to which dimensions. All this has to do with which brand you get.
Stainless can be tougher than a non-stainless steel, or can be brittle and break on a small crash. I'd choose pedals within a brand rather than within a steel type. I'd trust any Shimano pedal, and would buy the stainless axles simply because the rest of the pedal is better made. I hardly ever see a broken Shimano road or MTB pedal (downhill is of course something different for every brand), but I see broken Time, Look, and Crank pedals regularly. And I've seen plenty of broken Speedplays but because of design issues -- like grooving of the pedal axle by the cleat when the cleat wears. I've almost never seen a recent Campy pedal break, though old ones from the 70's had a tendency to snap.

When it comes down to it, I just get Shimano and don't worry. If you are worried about pedal integrity, I'd suggest you do the same.

[peanutgallery]

unless you're doing giant tail whips...you'll blow out many other things first

stick to shimano and keep em serviced, you will never have an issue

[Peter P.]

Tensile strength of 4130 chromoly is 81,200psi.(annealed).
Tensile strength of stainless steel (Type 302, 304, 305) is 75,000psi. (annealed).

I only picked an annealed alloy so the comparison would be more equal.

In the above case I'm not sure it would matter which you chose, if braking pedal spindles was a problem for you. I would presume both are strong enough and breaking spindles would be more a design flaw rather than a material choice.

I broke a Shimano SPD pedal spindle once, and I weigh only 130lbs. I think it was a freak thing. It broke somewhere near the outboard bearing.

[93legendti]

Les Gold from Hardcore Pawn came in when I was still working part time at Performance. He had just broken his 2nd Forte mtb pedal at the spindle. Same pedal each time-the right one. He said he had it set up at home, not sure what kind of bike. Convinced him to try the lowest price Shimano spd.

He is not a big guy and he said he used them 4x/week for an hour. I was surprised he broke two. Must have been a manufacture defect, but never heard of anyone else breaking a Forte spindle.

[11.4]

Tensile strength of 4130 chromoly is 81,200psi.(annealed).
Tensile strength of stainless steel (Type 302, 304, 305) is 75,000psi. (annealed).

I only picked an annealed alloy so the comparison would be more equal.

In the above case I'm not sure it would matter which you chose, if braking pedal spindles was a problem for you. I would presume both are strong enough and breaking spindles would be more a design flaw rather than a material choice.

I broke a Shimano SPD pedal spindle once, and I weigh only 130lbs. I think it was a freak thing. It broke somewhere near the outboard bearing.

But the problem is that one brand's axle can be hardened to numbers much higher (more than twice). And with hardening can come brittleness, which is the real issue in pedal axle breakage.