Wolf Tooth Components Elliptical 110-BCD Chainring

This elliptical 110-BCD 40T chainring from Wolf Tooth Components (WTC) enables you to create a gearing system option otherwise not available. It's well made, and a variety of sizes, shapes and fitments are available. I'm not totally sold on the oval shape for my needs – a round option is also available – but some will like it.

What with wider tyres, disc brakes, gravel bikes and 1x11-speed transmissions being among the recent trends to take hold, it is an interesting time in cycling with a lot of very capable bikes out there. There is a lot of crossover and mixing and matching going on, with products from the worlds of road and mountain biking that previously were separated by much clearer lines beginning to come together in various forms.

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If you are the kind of rider who likes to build your own and experiment, and might have a variety of road, mountain bike and cyclo-cross bike pieces lying around, you may have found yourself just one or two pieces of the puzzle away from building something new and interesting. It's quite often the case with groupsets that manufacturers will make their products as complete systems for a specific purpose, but smaller specialist companies will often come along and see an opportunity to produce a component that allows one system to play with another.

I came across this WTC chainring for exactly that reason, since it is one of a small number of smaller companies offering a huge range of rings in just about any size, shape and fitment you might want, to allow you to find the right solution.

I selected this 40-tooth ring to complete a build that would allow a Shimano XTR rear derailleur on an 11-40 cassette to pair with a Dura-Ace 9000 crankset, along with Shimano's R785 disc brakes and STI levers, to create a 1x11 system for an 'adventure' drop bar bike with a good spread of ratios. This is something not possible with standard XTR or Dura-Ace transmissions, since the single ring mountain bike systems go to a maximum chainring size of 36T, and the road based transmissions do not have a single ring chain-retaining option or a clutch on the rear mech.

> Beginner's guide: understanding gears

I also then fitted it to an Ultegra 6800 crankset in place of the compact 50/34, paired with an 11-28 cassette for use on and off-road with a standard Ultegra Di2 derailleur.

WTC offers this 110mm BCD (bolt circle diameter), asymmetric, 4-bolt ring in round sizes of 36, 38, 40, 42 and 44 teeth, and this elliptical shape in 38, 40 and 42T. All are offset to correct for a single ring chainline and all feature WTC's 'Dropstop' chain-retaining tooth design, which is very similar in form and function to any other type of tooth design using narrow and wide teeth to retain the chain, though seemingly different enough to have its own patent application.

The whole range also includes rings to fit Race Face, S-Works, Cannondale and SRAM direct mount, as well as symmetric 4-bolt rings in 110, 120 and 130mm BCD, and a whole host of mountain bike sizes too.

On the bike, the chainline works very nicely, with smooth pedalling across the extremities of rear ratios and no hook-up on teeth. With the standard Ultegra mech I have not dropped the chain once despite the absence of a clutch, and despite riding that has wandered well into the mountain biking end of gravel at times. Quality of finish is also very good.

Elliptically speaking…

What is left to talk about really then is whether to go elliptical or not. Personally, after this experience I am still somewhat ambivalent on the matter. The general theory behind elliptical rings is fairly simple – our legs are mainly good at pressing pedals downwards, not so quite so good at pulling up on them or pushing them forwards and backwards. What elliptical chainrings do is effectively give the user a smaller diameter ring and hence an easier gear near the positions at 'top dead centre' and 'bottom dead centre positions'. Advocates say this eliminates the dead spots in these parts of the pedal strokes.

WTC produces its elliptical rings with 10% ovality which it says gives the feel of two teeth fewer in the weaker part of the stroke and two teeth more in the stronger part of the stroke. The timing is given as 112 degrees after top dead centre, which means that the ring is producing its biggest gearing effect a little way (22 degrees in fact) after the crank arm is parallel to the ground – or around 3:45 for clock fans. This timing is based on roughly where we tend to be applying the maximum force to the pedals, and the fact that there is often some momentum in the pedal stroke which clocks the whole dead spot effect around a bit.

In reality our legs are a compound system of levers and links, and we as riders are all different shapes and sizes so the oval shape is still something of an approximation. You will often see more complex shapes on pros' time trial machines as they can be matched to the exact torque profile of the rider and their riding position, but that of course is bespoke and very expensive.

Since the shape is a smooth and regular ellipse then the oval effect increases smoothly to a peak before reducing in the same manner to a minimum, and so on, so the actual ramping up and ramping down of the force required on each individual pedal stroke is barely noticeable through the stroke, but the overall effect is felt.

At a lower cadence the benefit of the easier trip through the dead spot is more detectable and the result is a feeling that the gear is a little easier to push than its average size would suggest. When cadence increases, though, power becomes less dependent on the force delivered in each pedal stroke and more dependent on cadence itself and the rate at which you can move the chain. This is going to be governed by the overall number of teeth, as with any other ring, but for a given force the cranks may vary in their speed throughout the stroke, which tends to mess about with your timing. The result is that spinning feels a little awkward while you get used to it and your muscle timing adjusts.

This is part of the source of my ambivalence about oval rings – that one might have to re-adjust a spinning technique that might have been finely honed over many years of cycling. If you've ever ridden a fixed gear at speed down a hill or taken part in goldsprints you can appreciate subtleties of technique and the muscle timing it takes to move your legs in circles at a high rate.

> Read more road.cc reviews of chainsets and chainrings here

The other part of my ambivalence is that the oval shape is presented as a solution to an inherent asymmetry in the function of our legs – but if we make the weaker part of the pedal stroke easier then this is only going to promote the increase as we are loading and hence training our legs more at the point at which they are strongest. It's rather like avoiding hills because you are no good at climbing.

On balance I think an elliptical ring has certain benefits in certain situations, and in that way is like a tool designed to do a specific job – it has its place in the tool box and used correctly can be highly effective, but it doesn't make all other tools redundant.

For me the boon of this offering from WTC is that it provides a compatibility that is otherwise not available, and makes the gear ratios I am looking for possible with some of my favourite transmission components.

Verdict

Well made and useful size; elliptical rings have benefits in certain conditions but it's not one ring to rule them all