VO Grand Cru Cranks

Yesterday, one of my favorite online bike shops, Velo Orange, announced the arrival of their line of cranks. Among them are two very nice 110/74 bcd cranks, one set up as a 46/36/26 triple and another as a wide-range double 46/30 with the outer position taken by a chainguard (one of these is already on order for my wife’s upcoming Betty Foy build). More exciting is their top-of-the-line classic Grand Cru 50.4 bcd crankset (pictured above) similar to the much-revered TA Pro Vis-5.

I’ve always really liked wide-range doubles and in the past had toyed with the idea of putting together one similar to the 46/30 + chainguard that VO is now offering for my Rambouillet. Instead, I opted for a NOS set of the TA Pro Vis-5 cranks and 46/26 rings. I wrote a blog post about those cranks on The Joke Is Up last year.

In that post I playfully said I had a “secret source” for the TA cranks. That source was Spa Cycles in the UK. They now appear to be out of the crank arms, and are selling the bolts at 30 quid a set. Ouch. Well, there’s no need to pine over rare, out-of-production cranks at exorbitant prices now as these 50.4 VO cranks appear to be a much better design.

Having ridden the TAs for a year, I can say that I really like them but have one big gripe – the shifting is not great. While part of that is due to the huge 20-tooth difference, the tricky front derailleur setup doesn’t help. The low tread of the crank arms leaves little clearance.

At times the chain simply won’t be able to get to the large chainring. At other times, the chain will over shift and, because the crank tread is so narrow, get stuck between the crank arm and the outer chainring then become further lodged in by the chainring bolt heads. When this happens, I need to pull over and manually tug the chain out.

Peter White of Peter White Cycles has these criticisms of the old TA cranks so I know I’m not completely alone in my frustrations:

…while they may have some value to users of vintage bikes, they aren’t a sensible choice for use on modern bicycles. The gap between the outer chainring and the crank arm is very narrow, and the outer plates of modern front derailleurs are simply too wide to allow using the larger chainring without hitting the crank on the derailleur.

Also, the bolt circle is tiny, even for the outer chainring. This allows the outer ring to flex easily to the outside during upshifts, and in time, the gap between the ring and the arm becomes even smaller. As the gap between the outer and middle ring increases, the chain ends up falling between the two. When I was installing the Pro 5 Vis regularly on high end touring bikes in the 1970s, I rarely used outer rings larger than 46 teeth for that reason. [source]

I’ve tried various front derailleurs – a Shimano 600 (as pictured), Shimano Dura Ace 7400, an IRD CD (specifically designed for compact cranksets), and currently a modern narrow Campagnolo derailleur. I’ve had the best luck with the Campy one, but it still isn’t satisfactory.

The VO crank seems to address this. It features “3mm more room between outer ring and crank arm (compared to classic TA) for easier front derailleur setup” and “shifting pins on chain rings for faster shifts compared to classic rings”. The improved shifting is huge and that little bit extra clearance, in addition to helping derailleur adjustment, should hopefully prevent the stuck chain problem.

Other improvements they list include:

• Thicker chain rings for less flex than TA or other classic cranks.
• 7051 7075-alloy CNC cut rings for super durability.
• All-stainless hardware. All bolts/nuts are Allen head (the TAs use hex headed bolts made of inferior metal that break easily)
• Standard extractor/dust cap thread, standard ISO pedal threads. (the TAs require a non-standard crank extractor, and older versions have French pedal threads)

The VO Grand Cru crank should be a worthy successor to the TA Pro-Vis 5, combining the best of old and new bike technology. While I probably won’t get an entire crankset for myself to replace my TA crank, I will likely eventually replace the chainrings and hardware with VO equipment.

Tags: velo orange