The question we get is, "Which of the high-end compact double cranks should I put on my new bike?" Since we've been long-time fans of the Sugino Alpina crank and now we make what is seen by many as a competing crank, the Grand Cru 110, it's a question we must often address. The Alpina is regarded by many as the best compact double available today, the successor to the discontinued TA Zephyr. How to choose? I'll try to be objective about this and do a point by point comparison.
This is the most obvious difference between the two cranks. The Alpina is a modern design while the Grand Cru could have been designed in the 1960s. Since this is strictly a matter of taste neither crank has an advantage.
The Crand Cru double has a q-factor of about 140mm; the Alpina's is 159mm. Both use 110mm square taper BBs. So the Grand Cru has significantly lower tread, which some cyclist believe results in less knee pain and a higher power output.
A 172.5mm Alpina crankset weighs 702g. The Grand Cru 172.5mm crankset weighs 683g.
Both cranks have very well made 110bcd CNC cut chain rings made of 7075 alloy. These have superior wear characteristics compared to the chain rings found on lower cost cranks like the Sugino XD and regular VO cranks. Shifting is great with either, perhaps a touch faster with the Grand Cru. Both are 6-10 speed compatible.
Note that the Grand Cru is also available as a triple, while the Alpina is only a double.
Both cranks have arms that are cold forged and polished. The slightly wider width of the Alpina means that it's probably a little stiffer.
Note that each size Grand Cru crank has different crank arm length, while the various sizes of the Alpina cranks all have the same arm length, but with the pedal hole drilled in a different place. Look at the first photo in the post to see what this means.
The close up photos below show the differences better that I can explain; click on them to enlarge. The fit is clearly tighter on the Grand Cru cranks. This is most evident where the the chain rings meet the spider. I'd judge the Grand Cru's polish to be a little shinier, while the Alpina has more of a satin finish.
The Alpina currently costs $175. The Grand Cru runs $190.
So there you have it. The biggest differences are style and Q-factor, but these are very significant for many cyclists. If you need a much lower Q or like the classic style, the Grand Cru is the obvious choice. If Q is unimportant and you like the more modern look, or want to save a few dollars, the Sugino is a very fine alternative. It's hard to go wrong.