|M&M Mars and the Shimano connection...||Ahimsa|
Oct 11, 2001 5:45 PM
|If you add caramel to a 3 Musketeers it becomes a Milky Way, add peanuts and it is a Snickers. Swap peanuts for almonds and you get a Mars bar.
Seems the same with Shimano road cranks...Sora plus one aluminum ring begats Tiagra. All aluminum rings + hollowtech becomes 105. Slighlty more hollow and you get Ultegra...ad infintum, ad nauseum.
My question: Does the idea of hollow crank arms concern anyone but me? Does the durability of a hollow aluminum crank sound dubious? No doubt ridden many miles by many of you; how have they held up? Any broken arms (crank or flesh) due to heavy use?
I am wary of less durable components, but my commuter needs a drivetrain update and Shimano looks like a good deal. It occurs to me that to alay my fears, I might wish to build up a Tiagra triple with Ultegra rings and hardware to get a non-hollow, all aluminum setup that weighs in around a mere 60 to 80 grams more than Ultegra triples. Is this do-able? Any tech flaws in this? Anyone wish to claim that my durability issues are ludicrous and sell me on the 105 hollows? I prefer tough parts with tried and true designs.
Speak up. Comments are appreciated.
|re: M&M Mars and the Shimano connection...||TJeanloz|
Oct 12, 2001 7:30 AM
|It is true that the cranks are hollow- but they are really durable. I have a Dura-Ace crank that was bent 90 degrees in a bike/auto mishap, no cracks, just a nice bend. Where most crankarms fail is right at the bb spindle. And in the case of Tiagra, you'd be using a UN52 (square taper) bottom bracket, which I think is probably more likely to cause failure than the splined type (pure speculation).
Historically, not being hollow hasn't kept crankarms from cracking- Shimano and Campy both have had recall issues with their lower-end solid cranksets (Alivio/Acera from Shimano and Mirage/Veloce from Campy).
Personally, I would be more confident in the higher-end 105 crankset's durability than the Tiagras. You also would use the 'better' (in my opinion) splined bottom bracket design. And you might find that buying a Tiagra crankset and putting Ultegra rings on could cost more than a whole Ultegra crankset.
Oct 12, 2001 8:16 AM
|...I've been running HollowTech cranks on my mountain bike for two years with no problems. I'm not a very good mountain biker, so I really bang the hell out of them (hit rocks, roots, trail markers, anything out there to hit).
I also agree with splined, cartridge-type bottom brackets. easy to install, last forever without real maintenance, strong connection...
|re: Mars vs. Almond Joy||Chen2|
Oct 12, 2001 10:47 AM
|I think the differences in cranks goes beyond hollow vs. solid. I think the alloys are different (but I can't back it up with data). I do know that the upper-end cranks are less likely to corrode from sweat than the cheaper ones.
|hollow is good, and no problems, aside from cost.||jw25|
Oct 12, 2001 12:01 PM
|Put another way, would you rather ride a frame made of tubes, or of solid bars? More materials doesn't correlate to more strength, it's more dependent on where the materials are placed. |
Aside from 1 story of cracking Dura-Ace arms (from a shop monkey, and not substantiated - "A friend saw..."), I've yet to see any problems from the hollow design. I use 2 sets of splined cranks on my mtb's, and while I don't notice more or less flex than square-taper BB's, the splines make replacing the cranks easier and more reliable (as does a torque wrench).
For the commuter, I'd look around for a deal on a 105 triple crank. All aluminum rings, splined BB, and less than upgrading Tiagra to alloy rings.
Then again, it's a commuter, so any decent triple would work (steel inner rings also last longer), and I've seen a few solid-arm designs that use a splined BB. FSA sells the Gossamer, and CODA made a triple - might be tough to find, though.
As always, my first choice would be Ebay and a bit of patience. Chances are something will pop up, and I've saved more money there...
|Good advice from all of you, thanks. I'll try the 105 triple. nm||Ahimsa|
Oct 12, 2001 3:58 PM