How to Replace a Double Bike Crank With a Triple

Replacing a double bike crank with a triple is a common upgrade for people living in hilly areas. You can upgrade by replacing the double crank with a triple or attaching a tripleizer, a triple chainring adapter, to your existing double crank.

Instructions

Difficulty: Moderately Challenging

Things You’ll Need:

• Socket wrench
• Crank puller, sized to your bike crank
• Tripleizer chainring
• New bottom bracket spindle
• New shifters
• New derailleur

1. Adjust your bottom bracket spindle according to the brand of tripleizer chainring you will use. Call the manufacturer of the chainring and tell them what cranks you'll attach the tripleizer to and they can tell you how much to adjust the spindle. Usually the adjustment is between 5 and 9 mm when replacing the double crank.
2. Exchange the bottom bracket spindle entirely if you have a cup-in-one bottom bracket. If you have a cartridge bottom bracket, you may be able to get a new spindle installed.
3. Rejoice if you have bar-end or down-tube shifters or if you use Campagnolo shifters because all you have to do is adjust them for the front derailleur.
4. Look for someone who can sell you just the left control level if you use Shimano STI. If you can't find just the left unit, you'll have to buy a new pair of triple specific controls.
5. Decide if you need to change the front derailleur. Some are designed for double chainrings and can shift between the smallest and largest chainrings, however others can't handle the upgrade. Triple-compatible front derailleurs are probably best and will go a few teeth higher without a problem.
6. Get a long cage rear derailleur. You don't have to, but you really should when upgrading from a double to a triple crank. You can use an MTB or Road style long cage rear derailleur, but the Road style tends to shift over clusters better with only small jumps between sprockets.

Tips & Warnings

• It isn't necessary to purchase a special "road triple" crank because it's possible to use a standard 110/74 mm bcd triple crank, which is usually more affordable.
• You may need a new front derailleur if the existing derailleur doesn't have the range to shift to the outer or inner rings or if the chain drags on the derailleur when it is in the small ring.