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-   -   Titanium Axle on an Shimano PD-M424 Pedal (https://www.bikeforums.net/bicycle-mechanics/1230167-titanium-axle-shimano-pd-m424-pedal.html)

Skolbiker 05-10-21 04:50 AM

Titanium Axle on an Shimano PD-M424 Pedal
 
Hi
Anyone know if it is possible to buy/fit a titanium axle to a Shimano PD-M424 pedal? This is the pedal with flats both sides and mtb cleat system also both sides. It's sort of a do it all commuter pedal. There doesn't seem to be a lighter pedal option with all these features, so I'd like to make mine lighter by modding the axle.

Crankycrank 05-10-21 08:32 AM

I doubt anyone makes a Ti spindle for a pedal in that price range. But, not to be an idea killer if you do find something try to avoid the cheapy versions usually from China on Ali Express or similar. IME Cheap Ti is almost always guaranteed be poorly machined with rough bearing surfaces and sloppy threads. Also if you're planning on using these some of the time with soft-soled non-cycling shoes they won't be very comfortable with the small cage and cleat device protruding above the cage.

Skolbiker 05-10-21 08:54 AM


Originally Posted by Crankycrank (Post 22052884)
I doubt anyone makes a Ti spindle for a pedal in that price range. But, not to be an idea killer if you do find something try to avoid the cheapy versions usually from China on Ali Express or similar. IME Cheap Ti is almost always guaranteed be poorly machined with rough bearing surfaces and sloppy threads. Also if you're planning on using these some of the time with soft-soled non-cycling shoes they won't be very comfortable with the small cage and cleat device protruding above the cage.

Thanks for the advice. I have been using these pedal for years (on my third set) and they are not very comfy with non-cycling shoes but good enough for a short hop to the shops. I guess I should have asked if anyone new if these pedals had the same axle as any other pedals in the Shimano range. The other pedals are more likely to be listed in replacement axle specifications.

ClydeClydeson 05-10-21 09:56 AM

Bad idea. Ti is not as strong per cross sectional area as steel, so a part designed to be made from steel but then Ti is swapped in will result in a significantly weaker part. If you are a very lightweight person then it might be OK, but for the absolute minimal improvement it's not worth the trouble - any trouble.

dsbrantjr 05-10-21 11:28 AM

Titanium is not a miracle material, it has definite downsides and weaknesses and needs to be designed to an application, not just substituted for steel.

davidad 05-10-21 11:46 AM

Are you trying to save a half an ounce? Why?

Skolbiker 05-13-21 04:27 AM


Originally Posted by ClydeClydeson (Post 22053070)
Bad idea. Ti is not as strong per cross sectional area as steel, so a part designed to be made from steel but then Ti is swapped in will result in a significantly weaker part. If you are a very lightweight person then it might be OK, but for the absolute minimal improvement it's not worth the trouble - any trouble.

Thanks - I'll probably not pursue this any further.

HillRider 05-13-21 07:10 AM

These things weigh about 475 grams a pair which over 100 grams more than Shimano's regular MTB pedals, the PD-M520 and PD-M8100. If you want to save significant weight, get another pedal style.

WizardOfBoz 05-13-21 09:42 AM


Originally Posted by ClydeClydeson (Post 22053070)
Bad idea. Ti is not as strong per cross sectional area as steel, so a part designed to be made from steel but then Ti is swapped in will result in a significantly weaker part. If you are a very lightweight person then it might be OK, but for the absolute minimal improvement it's not worth the trouble - any trouble.

Pure Ti and some of the less rigorously controlled (Tofu-grade) Ti stock from China are not as strong as steel. But some Ti alloys (Ti-6Al-4V - Grade 5, is at 1100 MPa, or 160,000 psi yield strength) are stronger than some steels (e.g. 4030 chrome-moly, 470 MPa or 68200 psi yield strength). In further support of ClydeClydeson's point, Ti is less stiff than steel. Which is why the Ti pedal axles you see are much thicker than steel axles. There's limited space inside the pedal (and you have to be able to slide the inboard bearing over the length of the spindle) and I think that this is why Ti spindles are more rare.

Getting a part made from a good quality alloy (and being certain that it's good stuff) will be expensive. The paperwork alone to certify that Ti stock is Ti-6Al-4V (Grade 5) would probably be a few hundred bucks. But it is machinable. From my viewpoint, not worth the effort. But if this sounds fun to you, don't let us naysayers get your down.

Skolbiker 05-14-21 04:38 AM


Originally Posted by HillRider (Post 22057507)
These things weigh about 475 grams a pair which over 100 grams more than Shimano's regular MTB pedals, the PD-M520 and PD-M8100. If you want to save significant weight, get another pedal style.

I'd buy these pedals if they had the same features as the PD-M424s but unfortunately they don't. Maybe I'll try titanium cleat bolts and plates to save a few weight-weenie grams but I don't fancy the bolt fittings rounding out as they are small and usually hex/Allen head not Torx. Manufacturer often don't say if they are the stronger grade 5 titanium either. The only pedal I'm aware of that is both double-sided flat and double-sided clip-in is the PD- M424.

WizardOfBoz 05-14-21 08:00 AM

A quick review of pedals offered by Shimano confirms that their SPD offerings seem not to include Ti spindles. Their SPD spindles (even the XTR trim level) are about the same weight as what the OP has now. These pedals weight about one pound. If you want to go lower and stick with SPD, you can get a non-flat pedal like the Wellgo W-01 which weighs about a half a pound. If you want, there's a proprietary pedal where pedia and clip together weigh 138g - a bit more than a quarter pound. But everything I see with Ti axles is just the clip - no pedaling flat surfaces.

If this is a bike for racing, perhaps its worth shaving grams. If this is for general riding, commuting, and enjoyment, well.... Spending hundreds* to shave 4 ounces off the bike wouldn't be my choice.

*I'm guessing finding and having a machine shop do this will be hard and expensive. But you WOULD be the only guy with Ti axles.


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