Cranksets and Cassettes…its a ratio thing.


Dear Rouleurs,

I’ve been obsessing over gear ratios, drive trains and hill climbing.  As a 102 Kg Clydesdale, doing sportives this year, these things matter.  I’m riding the  60Km version of the Ballarat Classic in February and that course contains some serious gradient.  Certainly more than I’m used on my local Beach Road ride.

So I started out looking at triple chain ring. Straight away, I encountered two significant snags.  First, Campagnolo phased triple chain rings on their lower end groupsets, hence I wouldn’t be able to source a Veloce component.  Second, even if I had sourced an older Veloce triple, it would have meant changing over the front and rear derailleurs as well.  Essentially, that’s 3 out of 4 bits of drive train.  Given its Campag, that would be a costly trip to a bike shop.

Instead, I read a few blogs and landed on fitting a compact chain ring with a smaller 50/34t ratio and higher ratio 13-29t cassette.  Originally, I had 11-23t which I upgraded as part of Zonda rim package to 11-25t.  For everything I’ve done thus far 11-23/25t has fine.  I tend to do most of riding on the outer ring anyway.  The theory being I should be able to keep my cadence fairly high and not have to stand on the pedals to exert brute force.  So I’m swapping out the 11-25mm for the 13-29mm.

 11-25mm  To  13-29mm
 20160114-campy-veloce-cassette-10-speed-11-25  20160114-campy-veloce-cassette-10-speed-13-29

The compact chain ring is an interesting beast. Depending on what online cycling magazines Its being described as the ‘killer’ of the tripleset chain ring. Mainly because of its ability to provide similar ratios to the tripleset, whilst enabling manufacturers to avoiding extra tooling and production costs. Most likely, this is why Campagnolo doesn’t offer triples on the cheaper groupsets.

So these were the alternatives:

53-39 – Race -> I have one of these already
52-36 – Semi-compact –> the one I’m not sure about
50-34 – Compact -> the one I’ve decided on.

53-39t has been the standard chain ring for some time now. It’s used in races that are mainly flat and in timetrials, where the more powerful riders are using a 53 to 11 ratio to achieve maximum speed.

50-34t Compact crankset has been around since 2002 and has been used by the Pros to travel through mountain stages. The primary idea being that a smaller front chain ring allows a higher cadence which should reduce muscle fatigue. It also allows less powerful riders access to lower ration gears without ‘crossing’ the chain. Crossing the chain creates more friction and increases wear and tear on the drive train.

52-36t Semi-compact is the new kid on the block. Its reason d’etre is that it provides the best of both worlds means a 52-tooth chainring for attacking descents and sprints, while maintaining a smooth chain line from the big ring when riding on flat roads, and a 36-tooth inner ring which, of course, offers a lower gear for climbing than a 39-tooth ring.

My decision on which crankset was made easier…again…sigh…by Campagnolo not having Veloce 52-36 crankset. So I’m swapping this 53-39 for this 50-34.

 53-39t  To  50-34t
 20160114-campy-veloce-crankset-53-39  20160114-campy-veloce-crankset-50-34

So circling back to where I started, in about 2 weeks I’ll find out how all of this tinkering in my drive train worked. The Cadel Evans Peoples ride is fairly flat with the exception of a couple nasty little hills on the back end of the course. Hopefully this will all ‘gel’ together and provide a really efficient ‘gearbox’ for my 46 year old legs.

Until next time


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