Mountain Double – 36/22

Ring count conversions have become quite popular — like going from 3X to 2X, or from 2X to 1X, or even from 3X to 1X !  The best part is they’re easy, and in most cases do NOT require getting a new crank.

Regardless of the kind of conversion you want to do, some accommodation must be made for the chainring (or rings) you remove. You’ve got a few options, some or all may apply depending on your situation. What you choose to use is totally up to you.

Many chainrings are made to fit the crank you probably have. A standard mountain bike crank with 4 arms and holes at 104 mm BCD / or a standard Cyclocross crank with 4 or 5 arms and holes at 110 mm BCD. These can be treated essentially the same as far as the process of conversion is concerned.

Read below, compare your current crank, then follow the instructions for purchasing the right parts.

Mounting The New Big Ring (or Single for 1X)

The new chainring will mount to the inside of the crank spider. (Inside meaning side closest to the bike frame.) See the images. If the crank was made to mount another ring on the outside using the same bolt holes (sandwich mounting, most common), you will need something to take up the space where the other chainring (the one you’re removing) used to use. Here are three options:

1. Conversion Spacer Tabs Conversion Spacer tabs act as place holders for where the outside ring used to be, allowing you to use the same hardware. They also blend the shape of the crank so it does not leave a gap where the other ring was. For this option, use Standard Chainring Bolts, and the appropriate number of Spacer Tabs.
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2. Bash Guards can be used in place of the other chainring too. They’re a lot like conversion spacer tabs in that they fill the space originally taken by the outer ring, and they also act as an excellent guide to assure the chain cannot jump or be bumped off the outside. For this option, you’ll need a Bash Guard and a set of Standard Chainring Bolts — 4 or 5 depending on your conversion.
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3. Short Chainring Bolts, or ‘shorties’ as we like to call them, are just long enough to mount a single chainring to the spider, negating the need for a spacer (or bash guard). This option also works well — the only down side being it is, perhaps, not as aesthetic. For this option, you’ll need an appropriate set of Short Chainring Bolts for your crank.
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The Small Ring Spot

For most conversions to 1X, there is no need to worry about other mounting. If, however, your new 1X ring mounts at the smaller BCD (like on a crank made for a triple, use the male end of Standard Chainring Bolts to mount it.

In the case of triple to double conversion, the small ring is mounted just the same as previous. If you need new bolts, order them Here.

Any of the above options are acceptable and will work well — it really depends on your preferences and the crank configuration. Just make sure you check the crank carefully to be sure you’re ordering the right parts.

For step by step video instruction you can visit our Quick Fix reference library.

Note that some cranks won’t accommodate these instructions because of their configuration. The SRAM 2×10 style mountain crank is one of those. Others also exist.