30T Andersen’s Machine Chainring…

29 10 2012

Extralite 30T ring on left and Anderesen’s 30T ring on right…

On a few of my bikes I am already running 1 x 8/11 drivetrains with an IGH. Typically the smallest chainring you can get for 104mm BCD cranks is 32T which limits the lower end of your gear range on this common crank type. So I was interested to try out the two 30T rings I found for 104mm BCD cranks. Extralite.com makes the one on the left and Andersen’s Machine makes the one on the right.

Extralite ring on the left is much thinner and lighter…

I decided to install the Andersen’s ring on my Nomad turning it into a 1×9 with a 30T x 11-34T cassette. The only reason I selected the Andersen’s ring is it looked more robust than the Extralite ring. I don’t care about weight on my Nomad, but it gets abused a lot so beefy is good. I should be able to flip the 30T ring around once it’s worn and wear it out going the other way to double its service life.

Filing of the crank arms is required…

The reason 30T rings are not common is that you get physical interference between the chain and crank on such a small ring. The solution is to file away a bit of the ring’s arms to create the needed clearance. This only takes a few seconds with a flat file. Don’t get carried away!

Clearance achieved!

The 30T ring bolts up in seconds and you are ready to rock.

Shimano 28T inner ring and Andersen’s Machine 30T ring mounted…

Shimano sells a 28T inner ring which can also be used to move your single ring drivetrain’s gear range around as required. Having a 28T/30T double is probably pointless as there isn’t enough difference between the rings to bother. The 30T ring is also spaced inwards a bit more than normal to help with chain clearance. This buggers up your indexed shifting setup with a granny.

30T ring installed on SLX cranks with bashguard…

Once installed on my Nomad the 30T ring provides a very useful low gear with a 34T cog on the cassette. Low enough to climb just about anything while still providing a reasonable high gear. With the uber wide range 11-36T cassettes available a 30T front ring makes a single ring drivetrain feasible for a lot of MTBers.

1×9 and loving it!

For my needs there is no reason not to go with a 1 x 8/9/10. Ultra low gearing results in too much torque which spins the rear wheel on techy climbs and the gear inches are too low to get me over the gnar in the one to three power strokes my puny legs have. By using a higher low end gear I can maintain speed as I approach some tech, I can’t break the back wheel free as easily and I can usually power over the tech before I lose steam.

I never need a big ring on my MTB. I’m riding fairly steep terrain so when I point the bike downhill I’m not looking to go any faster than gravity is powering me!

Funny thing is that 5yrs ago I would have told you that not having a triple on a mountain bike was crazy! 3yrs ago I would have said the same thing about a double ring setup. 😉



6 responses

29 10 2012

Good stuff. I’m running a 3×9 right now and it’s totally overkill. I had a guy that was riding behind me comment on how little I shift. I’ve been giving serious consideration to dropping it to a 1×9, then building a single speed rear wheel for when I really want to simplify. That last paragraph was helpful for my decision making. I often over-plan beyond my real needs.

29 10 2012
Fat Bob

Being in Central TX, Andersen’s stuff is a natural (I have one of his excellent bash rings, with a second on the way). Neat to see his stuff up your way.

13 06 2013

Thanks for the review, I’m quite surprised to see this.
I’m running a 12-36 and 32T front. But I’m suffering on steep climbs. So I need to lower my gear, but like the 1 x 10 setup and don’t have dough for XX1. (I’m a shimano bitch anyway).

So if I get it, I can buy one of those rings, and run it single ring, with a guide, as a ‘middle ring’. (On the 104BCD middle gear)?
If so, I’m definitly in.

13 06 2013

@Greg – that sounds like it should work just fine.

1 07 2013

Awesome, I am thinking about grabbing one of these for my wife’s Transition Bandit and setting her up with 1×10. She is currently running a 38/24T combo with a 11-36 cassette.

While I’d like to try and get her on a 28T up front I think the 30T is the easiest option without switching cranks. We’ll start there and if she still can’t spin the uphills I’ll look into some spiderless cranks.

9 02 2014
vikapproved | Nomad 30T Ring + New Chain

[…] using wide range gearing. I can almost keep up, but I thought this was a good opportunity to put the 30T ring I got from Andersen’s Machine back on the Nomad. It’s paid for and that might be the little bit extra help I need to keep […]

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