In this article I’m going to delve into the best mountain bike chainring replacements.
I’m going to replace the entire drivetrain for my Cannondale Killer V. Both to refresh the worn components and to have a setup that better suits my riding-style.
I know the BCD or bolt-circle-diameter I’m looking for, which is 104 (I found out Shimano calls it PCD or pitch-circle-diameter). And I also know the size of the chainring based on my bicycle gear ratio research, which is 36 teeth.
But as soon as you start looking for a suitable chainring, you’re swamped with options. So let’s do a bit of research and come up with the best mountain bike chainring replacement for my bike.
Single setup vs dual and triple cranksets
A lot of mountain bikes come with a single front chainring nowadays. Those chainrings are different than chainrings meant for dual or triple cranksets, since they don’t have to aid shifting.
For many decades, chainrings did not have ramps and pins, and yet they shifted fine. Ramps and pins serve only as “insurance” against bad shifts that occur when the rider doesn’t push the lever far enough, or when they forget to let up on the pedals during the shift.renehersecycles.com
A lot of chainring providers specifically state that their chainring is meant for a single setup. Since I run a triple I’ll be needing a mountain bike chainring replacement for a triple crankset. That means this article will feature dual and triple compatible chainrings only.
A word of caution about changing chainrings
Running different brands and/or type chainrings on the same crank does mean you increase the risk of lowering your shifting performance. There are a number of reasons however I feel this will still work:
- I’m changing the entire drivetrain setup. Enabling the chain to run the middle cog predominantly, so I need less shifting in the front.
- The change concerns the middle ring, so no issues with the chain dragging on the front derailleur cage.
- The font chainring will be a 36T, making the jump to the outer ring less high and easier.
- I hardly ever use the inner ring. So the risk of downshifting issues with the chain drop being too big (36 to 22 instead of 32 to 22) and the chain traveling past the smallest chainring is almost zero. I have to say I did sometimes experience issues with a 44 to 29 drop (15 teeth difference).
Time will tell if the new setup will work. If it doesn’t I’ll probably swap out the outer ring and/or inner ring as well.
Shimano Deore XT M770 Hollowtech 2
I currently run a Shimano Deore XT M770 Hollowtech 2 crankset, which came out around 2008. That crank only came with one middle ring option, which was a 32. The most obvious choice would be to find a Shimano Deore XT chainring.
A 36-teeth Deore XT chainring does exist, but not for my crank. That chainring has a 94 BCD while I need a 104.
It’s a shame because the crankset has a certain look-and-feel that’s also incorporated into the chainrings. But it means I need to be looking somewhere else instead for the right chainring.
The original 32-teeth chainring has a plastic ring attached to it. Initially I thought it was a ramp that helped change gears. It’s not. It’s a seal that means to protect the bottom bracket from mud being sprayed onto it from the front wheel.
When looking for a mountain bike chainring replacement Shimano offers more than just Deore XT components. A quick search uncovers that a Deore FC-M590 104BCD 36-teeth version exists.
Strangely enough the teeth from the picture already look worn to me. But they come in both black and silver, are very reasonably priced and are meant for a 9-speed triple crankset.
The difference between the Deore and XT chainrings is that the Deore are made of steel. Since Deore XT is the more premium version using a carbon/steel composite middle chainring, I assume those are better and longer lasting.
The inner ring is also made of steel, with the outer being made from aluminum. I’ve looked it up and it seems the reasoning behind an aluminum outer ring is because it needs to be able to endure more force.
Blackspire Nuvi and Super Pro MTB chainrings
I came across the Canadian Blackspire brand who are very adamant about their non-offshoring production with high-grade materials.
They are a bicycle parts manufacturer only with chainrings being the first item in their main navigation.
It seems for a non-downhill mountain bike chainring replacement for a 4-bolt 9-speed 104BCD 36T setup, you need to look at the Blackspire Nuvi chainrings or the more expensive Blackspire Super Pro MTB chainrings.
Chainrings are made from 6061 T-6 for the Nuvi and the stronger 7075 T-6 aluminum for the Super Pro series.
They are not cheap.
Spécialités T.A. Chinook chainrings
I bought two Spécialités T.A. chainrings. It was on of the few 32 and 44 teeth options for a 94 BCD and together they looked the part on my CODA crankset.
They’re designed and produced in France, made from aluminum and pretty premium. In typical French fashion, their website doesn’t offer a translated version.
They offer a beautiful 104BCD, 36T chainring called the Chinook, made for replacing the middle chainring on triple cranksets running 9-speed transmissions.
Chainrings are also made from 7075 T-6 aluminum.
I think I found what I’m looking for.
You might also like
There are a number of reasons why you should put bullhorn bars on mountain bikes, and in this article I’m going to give them. I’ve