Cranks play a huge part when putting the power down to the ground, so there is no surprise why there is so much technology being created year by year. After the change from a basic "square taper" bottom bracket, to ISIS drive, now we are using outboard bearing, with 2 piece cranks. Everyone is making an outboard set up these days and the crew an Shimano has been at it for a while now. I just got my paws on a set of 2008 Shimano XT cranks and wanted to show you what it took to install and set them up right for my application.Recently I decided that I was going to strap down, and take the time to install a set of new cranks. Now, to a lot of us it was super simple for a long time. As long as the bottom bracket fit, the crank arms would fit. However, now that you have the option of external bearings for your bottom bracket, it makes things a little more complicated. Another part that makes it even more exciting (add time here) is if you are running a chain guide, with an ISCG mounting bracket. So I am here to explain to you how I, with some help from Tyler, figured out how to install the new Shimano Deore XT cranks on my trusty steed.
First off I started by reading the instructions (ok Tyler told me to do that as I was gonna wing it). I have learned from experience that if you read the instructions first off, you save yourself a lot of pain in the end-thanks Tyler. After figuring out the correct amount of spacers I would require to install these cranks properly on my bike I was off to the races.
After removing my old cranks, I was starting with a clean slate. With my bottom bracket shell cleaned, and ready for the new cranks, I was ready to begin my journey. So, first off, I made sure I had the required tools.
White Grease, Bottom Bracket Installer, and 4mm Allen Key
Once I had those in hand, I started by greasing my bottom bracket shell. By greasing this, I ensure there is lube applied to the threads, compared to applying it to the threads of the bottom bracket cups , where It would be pushed off once I tightened it down.
Clean, and prepped.
I was now ready to install my drive side bearing assembly. I equipped the bottom bracket cup with my required 2mm spacer, and the ISCG mounting plate, and tightened it down. Shimano's installation instructions advise the user to tension the drive side cup down to 35-50 N-m. Here's a helpful hint. To safe yourself trouble later, make sure the upper ISCG mounting hole is at the 1 o'clock position if you use a ISCG mounting plate. This will ensure your chain guide has enough adjustment to be utilized correctly, without having to adjust it at a later date.
Ready for the guide
After that was correctly installed I was ready to install the non-drive side bottom bracket cup. Tighten the cup down until it bottoms on the spacer that is installed when you install the drive side cup. Torque the cup down to 35-50 N-m. Now you are ready to install your guide. I was taught to leave about a centimeter or less of space between the chain guides bottom roller and my swing arm, however, this spacing is different for all bikes, and you may have to fiddle with it to get it correct.
With my chain guide installed I was ready to install the non-drive side crank arm. The non-drive side crank arm only has 1 way it will go on, so this will ensure correct installation. With the crank arm on the spindle, take the Park TL-FC16 tool, and install the end cap down. This ensures that the drive side arm is tight on the assembly, and can not come out. Tighten the cap down to 0.7 - 1.5 N-m.
Once that is tightened down do NOT tighten the crank bolts. First off, you have to push the stopper plate in. What the heck is a stopper plate you say? The stopper plate consists of a small hook, that connects the non-drive side crank arm to the spindle. The easiest way I found to do this is with a small allen key, and just push it in. It should be effortless. Once the stopper plate is in place, you are able to tighten down the non-drive side crank bolts down to 12-15 N-m.
Your new Shimano Deore XT cranks are now installed and ready to go. Double check your bolts to ensure they are tight, throw some pedals on them, and go for a rip.
Complete and ready to go
All in all I was very surprised by how simple this assembly was (once I read the instructions). After you have figured out the correct spacing for your guide with these cranks, the installation should only take about 15+ minutes. My first ride impression was a very pleasant one! Fresh cranks just feel stiffer to me and these new XT cranks look great too. I'm sure they will be rolling on my bike for a very, very long time!
For more information on the Deore XT cranks, or other products from Shimano, please check out there website at www.Shimano.com