Leonardi Factory Racing Track Ring

Eccentric, oval, Rotor, whatever you want to call them, elliptical chainrings are nothing new in cycling and XC, but elliptical chainrings on a mountain bike for aggressive riding? That’s exactly what Leonardi Factory Racing seems to be thinking with their Corona Single Oval Track chainrings. Available in either a 34 or 36 tooth configuration, the chain rings have two mounting positions the affect how each ring performs.

Now, as these are single rings and we’re talking mountain bikes and not XX1 (though that technology would be a good use for this), the chain would simply go slack and fall off while bouncing through the forest. In order to use these bad boys on your MTB, you’re going to need a specially designed chain guide.

See it, after the break.

Leonardi Factory Racing Track Ring Chain Guide

This is Leonardi’s own chainguide that will work with their Track oval chain rings. Apparently, the guide was designed specifically for use with the Corona single oval Track chain rings, and according to I-MTB, works quite well. The guide bolts on to frames with an ISCG OLD 05 standard, and is compatible their 34 and 36 tooth Track oval chainrings or standard 32-38t single rings. Built with Delrin guides, a silver anodized aluminum frame and a Polyzene taco, the guide comes in at 175g.

What do you think? If you’re a fan of oval rings on the road, would you try it on the MTB?



  1. Rotor has been producing oval rings for mtb’s for years now. I have been using them as a triple for 4 years. One of the first things I noticed was the feeling of better traction on steep, technical climbs and smoother power to the tire in rock gardens.

    We have also noticed less anterior knee pain, and decreased heart rate through FTP testing. 2 down sides is the cost, and increased chance of chainsuck.

  2. Rotor is offering oval chain rings for a while now. I use one one my single speed. The chain tension doesn’t change as the ring rotates. No chain guide needed. I don’t see why these would be any different.

    • I should have made it clear that I was referring to more aggressive mountain biking. Fully aware of Biopace, and other MTB rings on the market.

  3. I’ve used the Rotors on my 29er, and saw the benefits stated on comments above. The cost is the only impediment to continued use for me. I believe I was faster on them.

  4. This won’t affect clutch derailleurs. As NinerRider said, you can even use it on a single speed since chain tension won’t (appreciably) change.

  5. Rotor rings have treated me well for years on my mountain bikes. I am riding a triple but plan to go XX this year. As for the Biopace comment: Rotor Rings may be oval but that is the only thing they have in common w/ biopace, Totally different concept. I’m sold and Ned Overend wouldn’t ride without them.

  6. To elaborate, the chain will wrap a little more than half the ring, give or take one or two teeth. The change in tension is pretty minor.

  7. “Biopace was the opposite or this current crop of rings. I wonder if they could have just rotated them 90 deg.

    I do like Rotor chainring for granny gear. Not so much for middle.

  8. Rotor works fine with clutch (runing an XTR). … some wattage spent (I imagine minor though) moving the lower pulley arm .. oh well… get stronger and disable for long climbs … or racing if you want … but I just love that silent feeling on the downhill and no more chain drops …

  9. I Love my Rotor rings and I run them on my Road Bike and Single Speed. Truth be told I thought I got rip off when I first road them. 20 miles in a hit a long climb and half way up I could not believe how “GOOD I flet!” These rings really woke up on the climb. My SS I changed the ring at the LBS before I ever rode her. I am currently testing a 38 tooth on my XTR crank for this race season. Rotor dosen’t make one for that XTR Race cank. I am using a standard 104mm patern and seeing what happens. So far so good but we will see how the front shifting goes when I put them to the test with a heavy load in a week or so.
    These rings shown in the photo have a much more aggressive oval than Rotor so I am would like to see what the power curve is on these?

What do you think?