# hollowgram crank strength?



## framesti (Jan 26, 2009)

I know its stiff but have read about and seen breaks in the crank. Is the design bad? 
Someone said near it tore? near the pins, and I saw a break near the pedal hole. It is hollow. Isn't solid aluminum or hollow steel better strengthwise?


----------



## latman (Apr 24, 2004)

I have had hollow shimano alloy cranks for AGES and never had ANY problems ever. Im sure solid alloy or hollow steel would be stronger (and heavier too) assuming the welds on the hollow steel didn't sap any strength that is!


----------



## Clevor (Sep 8, 2005)

framesti said:


> I know its stiff but have read about and seen breaks in the crank. Is the design bad?
> Someone said near it tore? near the pins, and I saw a break near the pedal hole. It is hollow. Isn't solid aluminum or hollow steel better strengthwise?


The Shimano hollowgram cranks are plenty stiff. In fact the DA 7800/7803 cranks were the standard for stiffness for quite a while, and are still probably stiffer than 95% of the cranks out there, e.g., the SRAM stuff. Maybe the latest $500-$700 nanocarbon cranks from Zip, Easton, and FSA claim to be stiffer. The DA cranks are hollow aluminum forgings, which only Shimano figured out how to do. A hollow forged crankarm is probably stiffer than a solid aluminum piece that is not forged.

On my beater bike, I just installed an R-700 Ultegra compact I got for $94 from JensenUSA. It replaced an FSA MegaExo carbon that came with my bike. When I stand with all my weight on either pedal (I weigh 177 lbs) I see no flex on the arms of either crank.


----------



## Quixote (Aug 26, 2008)

The crank arms seem fine, but a 130lb friend of mine just folded the chainring. Granted he is a strong climber, but still...


----------

