Being that we're always testing new products, our bike is equipped with somewhat of a Frankenstein build.

Being that we're always testing new products, our bike is equipped with somewhat of a Frankenstein build (click to enlarge).​

Last week we visited the Ibis factory in Santa Cruz to have Mary Moncorge, the Ibis EWS Team Manager, swap out the original rear end on our Mojo HD3 with the new boost model designed to accommodate plus sized tires.

We also recommend hosing your bike off before putting it in the stand. Starting off with a clean bike helps simplify things.

We also recommend hosing your bike off before putting it in the stand. Starting off with a clean bike helps simplify things (click to enlarge).​

Step one of the process is to remove the wheels and derailleurs.

Right about now would be a good time to consider converting to a 1x drivetrain.

Right about now would be a good time to consider converting to a 1x drivetrain (click to enlarge).​

If you're running a front derailleur, you'll also need to remove the mounting plate.

To 2x or not to 2x, that is the question.

To 2x or not to 2x, that is the question (click to enlarge).​

Continue to page 2 for more steps »

Once you've reached this step, you need to take a long hard look at your reasons for staying on a 2x or 3x drivetrain. The main reason we bring this up is that boost spacing increases your axle spacing from 142mm to 148mm, which also pushes the cassette out by 3mm. In order to keep a proper chain line with a boost rear end, you will need a boost specific crankset that shifts the chainrings outwards.

Don't want to spend the money on a new crankset? If you decide to ditch your front derailleur in favor of a narrow wide chainring and monster cassette, you can either shim your chainring outward, or purchase a boost spaced chainring. Wolf Tooth has a good explanation of the how and why on their website here.

Take your time here to avoid doing any unnecessary work.

Take your time here to avoid doing any unnecessary work (click to enlarge).​

The new rear end will come with the links preinstalled, so you only have to remove the bolts holding the links onto the front triangle. Mary recommends by starting with the lower link.

Our favorite trick for removing air from the shock is to use the back of the valve cover.

Our favorite trick for removing air from the shock is to use the back of the valve cover (click to enlarge).​

Before moving on to the top links, remove the air from the shock. This will allow you to lift the rear end to help ease the removal of the upper link.

Halfway there.

Halfway there (click to enlarge).​

Once you remove the bolts on each of the top link, the rear end should come away easily. Although be prepared to do some gentle wiggling.

If you're using a portable stand, you may want to be careful at this point to ensure everything is still balanced.

If you're using a portable stand, you may want to be careful at this point to ensure everything is still balanced (click to enlarge).​

Once you've removed the rear end, you should have something that looks like this.

bis Mojo HD3 torque specs and thread treatment recommendations.

bis Mojo HD3 torque specs and thread treatment recommendations (click to enlarge).​

Before installing the new rear end, it's important to treat the threads per the instructions in the owner's manual. While most shops and home mechanics will have regular blue loctite on their shelves, Ibis recommends using the 243 compound. According to Casey Devonshire, the Ibis Demo Coordinator and top wrench, 242 tends to break down over time and less tolerant of surface contaminants like oil or grease.

The new boost specific mounting plate is easily identifiable due to the laser etching.

The new boost specific mounting plate is easily identifiable due to the laser etching (click to enlarge).​

Despite loads of heckling, Francis insisted on keeping front derailleur on the Mojo. We're not sure if it's because he's getting old or because he's having a hard time keeping up with the kids on the highschool XC MTB team he coaches. Either way, if you too decide on keeping your front derailleur, you'll need to install a new mounting plate that pushes the front derailleur outwards 3mm.

Double and triple check that you have the upper link mounted in the correct position before continuing on.

Double and triple check that you have the upper link mounted in the correct position before continuing on (click to enlarge).​

Continue to page 3 for more steps »

Mounting the new rear end is a straightforward process, but you will want to be careful and pay close attention to detail. The link needs to be spread slightly which requires a little force. You'll also want to ensure that the link is positioned correctly before proceeding (please see image above), or you will have to redo this step. Once the top link is in position, you can try lifting the rear end to help guide the bolts in.

The bottom link.

The bottom link (click to enlarge).​

The lower link uses a thru axle which should go right in.

It's best to use a torque wrench to ensure all hardware has been properly tightened.

It's best to use a torque wrench to ensure all hardware has been properly tightened (click to enlarge).​

The upper link bolts should be tightened to 10 Nm. The lower links should be tightened to 15 Nm. You can always refer back to your owner's manual for the full list of torque specs.

Might as well through in new cable if you're this deep into a rebuild.

Might as well through in new cable if you're this deep into a rebuild (click to enlarge).​

While the Mojo does not have internal tubes for their cable routing, the large ports help make fishing new cables through the frame less challenging.

Almost done!

Almost done! (click to enlarge)​

Once you've remounted the cranks and derailleurs, it's time to turn your attention to boosting your wheelset.

The Boostinator conversion kit is manufactured in the United States by Lindarets.

The Boostinator conversion kit is manufactured in the United States by Lindarets (click to enlarge).​

Rather than mounting a new wheelset, Ibis helped us future proof the of their ultra 741 wheels with a Boostinator kit from Lindarets.

The Boostinator kit for the rear wheel retails for $40, which is a hell of a lot cheaper than a a new rear wheel.

The Boostinator kit for the rear wheel retails for $40, which is a hell of a lot cheaper than a a new rear wheel (click to enlarge).​

The kit includes a hub specific axle spacer to shift the hub away from the drive side, a machined rotor spacer to push the disc brake outwards, and longer bolts to tighten everything up.

If you don't feel comfortable dishing your rear wheel, you should contact your local bike shop.

If you don't feel comfortable dishing your rear wheel, you should contact your local bike shop (click to enlarge).​

Continue to page 4 for more steps »

Once you've pressed the new axle spacer on and re-installed the disc brake using the spacer, you'll have redish the wheelset over by loosening the drive side and tightening the non-drive spokes. If you don't feel comfortable dishing your wheels, you should contact your local bike shop.

Tire pressure is critical for optimal performance.

Tire pressure is critical for optimal performance (click to enlarge).​

According to Ibis founder Scott Nicol, having the right tire pressure is critical for optimal performance on a plus sized bike. In our Post your Plus sized tire pressure forum we've found users run everything from 8-16 PSI, but Scott recommends starting out around 16.5 PSI and adjusting from there. He also suggests using a digital pressure gauge to ensure the accuracy of your pump.

Done!

Done! (click to enlarge)​

Once you're done with your conversion, there are a few things you should double check before riding.


While Ibis has spent hundreds of hours testing the plus version of the HD3, we recommend checking to see that there is still plenty of clearance at bottom out with your rim and tire and combo.

Ibis Mojo HD3 Boost Rear End Conversion

It's also very important to double check that there is clearance at bottom out for the top crown of your fork. Fox recommends have 6mm of clearance between the tire and crown at bottom out. WIth this 2.8" Schwalbe Nobby Nick mounted on an Ibis 741 rim we only have 5.8mm…..

Ibis Mojo HD3 Boost Rear End Conversion

The last step is setting up suspension. According to the engineering staff at Ibis, tire rebound happens at a much faster rate than suspension. With plus tires, you'll want to set your rebound just like you normally would, then ad an extra couple clicks to help account for the rebound of your tires.