26 Jan 2016


There are many benefits to running a single ring at the front, but with the revolutionary MegaTooth design, not all of them are obvious.

Clearly you’re going to drop plenty of weight – removing the front shifter, mech, cable and extra rings will ditch around half a kilogram (1lb) – but you’ll also benefit from some clever new design.

As there’s no need to derail the chain onto another ring, the MegaTooth can be designed for fantastic chain security. Very long, asymmetric teeth in a thick-thin alternation create a tremendously quiet, secure engagement.

On a mountain bike this creates further weight savings, as it also removes the need for a heavy chain device.
How easy are they to fit? Surprisingly easy, so long as you note a few important details – as follows.

Chainring Bolt Circle Diameter
First, you must make sure you get a chainring with the correct Bolt Circle Diameter (BCD) for your cranks. The BCD describes the spacing of the mounting holes in the ring, and determines if they’ll align with the spider on your crank.

To find your BCD, check the existing rings – they probably have it stamped on them. If not, either try the crank manufacturer’s product page, or measure center-to-center across opposing bolts (not adjacent bolts).
MegaTooth rings are available in five BCDs, with the common 104mm option bracketed by standards from 76mm to 110mm.

Get your gearing right
Second, the correct gearing is very important – and it’s very personal too. Fitness, bike weight and terrain play a huge role.

If your climbs are typically steep and demanding you’ll want a small ring, such as a 26T (tooth) or 28T. Also, if your descents are typical too rough and steep for pedaling, there’s little need for the taller gears a larger ring would give – you may as well benefit from an easy climbing gear.

If you’re always on the pedals, however, and ride with high average speeds, you’ll need a larger chainring to give the necessary top end. The largest rings, at the 48T end of the spectrum, will suit fit XC racers and road riders.

If you’re running 10-speed on a mountain bike, it can pay to combine your new single-front ring with a 40T ‘extender ring’ on the back. This gives an extra-low climbing gear at the expense of the 11T ring, but as it widens the ratios to a 28-tooth spread from a maximum of 25T (11-36T), it can be combined with a larger front ring. This means you get a good top end and a workable hard-climbing gear at the same time.

MegaTooth rings come in 11 different teeth-counts, from 26T to 48T. Be aware that the smallest rings physically won’t fit on the larger BCDs.

Third, you may need shorter chainring fixings: 6mm bolts and 5mm nuts. If your existing ones are significantly longer, they won’t cinch tight.

Lastly, now’s the time to check your chain is not worn or stretched beyond its service life – if it is, it’ll wear your new chainring excessively. It’s also best to degrease and lube it properly while you’re at it!

*Compatible also with 1×10