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Monday, 9 July 2012

Rotor 3D+ and Q ring review

3 weeks after getting them installed, I thought it a good time to write a short review on the Rotor cranks and Q rings I have on my Parlee.

There are loads of options, and there is one thing that’s very important to understand:
Rotor sell their system as a module. So you can choose individual components or the complete package;

Crank arms
Q rings (or normal round rings)

So you can get Rotor crank arms with normal rings, OR you can put Q rings on your existing chainset. Or you can be a hitter like me and get the full system.

This review will be mainly about the Q rings as I don’t have a great deal to say about the crank arms (I have the 3D+ version which is for BB30 frames, but you can also get 3D for normal 24mm BBs).
I don’t mean this in a bad way – its simply that crank arms to me should be like stems or seatposts. If you don’t notice them they are doing their job.
The 3D+ does look cool which its machined finish, and its certainly light and stiff but I would love it if they brought out a stealth one that had less garish decals…..

The Q rings have been a huge success. There has been a real trend towards Ossytmeric rings recently (though Mechanic Matt is old enough to remember the ill-fated Shimano biopace system). Recently however Rotor have had huge success with Carlos Sastre winning the Tour and this year Ryder Hysdeal won the Giro on them. Bradley Wiggins is on a different system (with an even more aggressive shape) but the principle is the same….

And what is the principle? Well its quite simple; a round ring is round (doh!)  so a 53 tooth stays a 53 tooth throughout the stroke, whereas the Q ring is ossyemnetirc in shape, and  when you are in the power phase (around  2 o’clock to 5 oc’lock) the teeth become an effective 55. Then in the recovery phase the teeth become an effective 50.

So you are pushing a bigger gear when you are strong, and a smaller gear in the recovery phase (so you get to the next power phase quicker).   Genius….

In reality they do seem to work – I felt a real snappiness on the recovery phase – almost like you were pedalling ever so slightly downhill….

I have not done a threshold test and cannot quantify if they are more powerful but they feel they are, and that is often half the battle…..
I know guys who have done tests and say their numbers are up 3-5%. Not massive, but at 300 watts that’s c15 watts, and every bit helps!

People say that the biggest difference is when you go back to normal round rings. You then feel all the imperfections in your stroke…

The other big advantage is the choice of chainrings you can have. In the Giro there was a real trend towards what is termed ‘mid-compacts’. In English this means 52-36, so straddling standard (53/39) and compact (50/34). Now the Pros used this because the Giro climbs are so ridiculously steep, but for me I thought it would be perfect for the Alps.
A 52 is plenty big enough for me (especially using an 11) and a 36 allows you to spin up far more than on a 39. But I also think 36 is much more useful than a 34, as often you are in the 34 and then its too small so you go to the 50 and its too big!

However chainring versatility is something that the other big boy will soon share, as SRAM, Shimano and Campag either have, or will have, 52/36 chainring options.

This is not a universal downside, rather a personal peeve as at present I cannot use my Dura Ace SRM with them (you can use Dura Ace cranks just not SRMs because of the extra machining), and I am really missing knowing my numbers for training and racing. For instance on QBH I would have loved to see where my power went from hours 1-2, 3-4 and 5-6.

The other downside (and this is the major one) is that you will make Matt unhappy. Because of their shape setting up the front mech can be an issue (as teeth are never at the same height throughout a revolution). Likewise shifting is good, but there can be a tiny pause vs normal rings (especially compared to my Di2 shifting).

Many people like a uniform groupset, and its true the big 3 spend a fortune on R&D ensuring that their chainrings are designed to work perfectly with their chains and cassettes. Obviously you don’t get that with using Rotor….

How popular will Q rings get? Its hard to tell – they are certainly not the easiest sell to those who have not already read the science behind them For example I got all sorts of banter from my friends saying that my chainrings had melted in the Spanish sun…
And I can imagine if you were new to cycling and you were unlucky and your chain fell off, or you miss-shifted, Q rings would be the first to be blamed and off the bike. So they are not an easy sell, but I certainly think they are worth a very serious consideration by anyone who takes their cycling seriously. 

1 comment:

Anonymous said...

These are the best thing going, have been using them for the past four years and have them on 4 bikes. You will find that they only work if all your bikes are set up with them. I´m having problems for the first time after putting Sram Red on one bike and the front der is not shifting as it should compared to the quickness as Campa on my other bikes but have been told to try with a Shimano front der.