Feedback on Cheap Ti spindles for Crank Brothers Eggbeater

Started by carbonazza, June 14, 2016, 04:55:44 PM

Previous topic - Next topic

SportingGoods

Hi cmh! Agreed that my statement means nothing :D "Strong" is not a physical property (my teachers would have not accepted "strong" as a proper answer) but that's what people understand in real life :)

The relevant parameter here is "shear strength". It is the best one to describe what could happen to the spindle if it was to brake. Again, depending on the grade, Ti alloy will have higher or lower shear strength then Steel alloy.
A basic page with relevant numbers: http://www.tikore.com/titanium-facts/

Carbon_Dude

#16
Quote from: cmh on June 21, 2016, 05:35:38 AM
No. Got a degree in mechanical engineering and was into bikes when I went to school so was particularly interested in the materials aspect.

Me too!

Here is some good reading on Ti as it relates to bicycle parts:
http://www.ibiscycles.com/support/technical_articles/metallurgy_for_cyclists/the_titanium_advantage/
2019 Stumpjumper Expert 29/27.5+
2017 Santa Cruz Stigmata
2017 Trek Stache 9.8 (29+)
2016 Specialized Stumpjumper FSR Carbon Comp 6Fattie (27.5+) (Sold)
2016 Trek Stache 9 (29+) w/upgrades (Sold)
2014 -036 Full Suspension Chiner (Sold)
2013 -057 Hardtail Carbon Chiner (Sold)
Atlanta, GA

SportingGoods

#17
OK, I found a better reference available online:
https://www.ti64.com/v/vspfiles/assets/docs/fasteners%20101.pdf

cmh is right, the "strongest" steel alloy is "stronger" then the "strongest" Ti alloy. But steel alloy will rust. So you want stainless steel. Then, most Ti Alloy are "stronger" then stainless steel, except low grades of Ti alloy.

EDIT: in an effort to provide clarity (and simplicity), I would rank the materials as follows.
Low grade of Ti < Stainless Steel < High grade of Ti = regular grade of Steel < high grade of Steel

cmh

Don't get me wrong, Ti is wonderful stuff. I've got a Ti road bike sitting right behind me as I type this that has given me tons of good miles since 2002 and will continue to do so as long as I can foresee. I've run Ti bolts, Ti saddle rails, all manner of Ti parts. It's wonderful stuff.

All I'm saying is if you're a big person, Ti spindles are not a good idea. It's just too small of a diameter to capitalize on the strengths of Ti. Hell, even Grace has had a Ti spindle fail on her eggbeaters, but that was several years back and the design was pretty rife with stress risers. She's been on full Ti Egg 11s for a while now, and they've been fine.

Also, I've had several pedals with non-stainless spindles. Sure, it can rust, if you're not paying any attention to your components. Otherwise, grease keeps that from happening.  ;D

VisionTim

You guys are rough. I've been riding the same pair for 10 years!
http://visionmtb.com
Long Island NY Mountain Biking

carbonazza


carbonazza

After blowing again another pair of Crank Brothers pedals(lasted may be 10 months), I give up on that brand.

There was a relatively good deal on an online shop for a pair of Mavic Crossmax SL Ti ATAC.
They look like a copy of the Time Atac XC12.

While waiting them to arrive, I looked if there was cleats available on aliexpress.
And found these pedals ( another copy obviously )
Not sure why but the page and its explanations looks somehow good to me.

Anyone tried these pedals?

SportingGoods

They are copy of the Time XC12. If they are just relabeled from the factory it is a VERY good deal, they cost about 200€.
http://www.probikeshop.fr/time-pedales-atac-xcaa2-ti-carbon-noir/81438.html

I use the XC8 for years now (same as XC12 but axle is not Ti) and love them. They are perfect to me. I would try the Chinese copy but have no plan to change my pedals for now.
They are solid, no specific maintenance, shed mud nicely, light and provide a wide float. This is very nice for MTB as you can really freely move around the bike without unclipping.


carbonazza

I couldn't resist to my curiosity yesterday, and ordered a pair.
If they arrive fast( unlikely, but sometimes it happen ) and look good/solid,... I'll return the Mavic.

SportingGoods

#24
Actually I could buy a pair for my road bike  ::)
It's a bit of a pain to swap them between MTB and road bike. Let me know how it goes and I might order as well.

Thanks!

EDIT: thinking twice about it I might just buy yours if you consider they are good quality but come in too late to return the Mavic. Well, that's if you want to sell them, that leaves you options!

carbonazza


SportingGoods

Looking further into this vendor I see he has the same pedals for Road (Time Titanium road pedals). Same price.
https://fr.aliexpress.com/store/product/Time-Xpresso-12-Titan-Carbon-Pedals-Road-Bike-Pedals/106197_1970117445.html?isOrigTitle=true

I'm really tempted to give those a try...

I see only positive feedback, people even say they are identical to original. Looks like 2 weeks delivery lead time.


SportingGoods

And again 4.5$ cheaper. Yes, 65.5 USD for a pair of Titanium/Carbon road pedals that cost about 220€ in France. That was so low that I've just ordered them!
https://fr.aliexpress.com/item/discount-sale-costelo-Xpresso-12-Titan-Carbon-Pedals-Road-Bike-Pedals-Road-Bicycle-Parts-Pedal-lock/32666399964.html?detailNewVersion=&categoryId=122204

Sorry Carbonazza I will finally not take your pedals, but I think that you'll probably just keep them! If I was you I would return the Mavic/Time pedals even if the Chinese ones don't arrive on time.

carbonazza

Quote from: SportingGoods on November 16, 2016, 02:25:27 PM...If I was you I would return the Mavic/Time pedals even if the Chinese ones don't arrive on time.

That's probably what is going to happen