Thursday, January 16, 2020

Canyon Endurace: Deore XT MT800 Disc Brake Rotors

As I have a second gravel wheelset for gravel riding, this second wheelset also needs to have its own tires, cassette and brake rotors. By having a completely separate set, it is easy and convenient to swap the wheelsets, without adjusting any other components.

The final pieces of the puzzle are the brake rotors, where I decided to get something different. On the Reynolds road wheelset and Fabike C3, I used the Dura-Ace RT900 Ice-Tech rotors, which look really good on road bikes.

However, on this gravel wheelset, I decided to change the image, to make it look more like an off-road wheelset. That is why I decided to use the MTB disc brake rotors, which has quite a different appearance.

I could have chosen the XTR MT900 rotors, but the black cooling fins would make it look too much like the Dura-Ace RT900 rotors. Therefore, I chose the Deore XT MT800 rotors instead, which looks exactly the same as the XTR, except that the cooling fins are silver coloured (raw finish) instead of black colour.

Deore XT MT800 disc brake rotor, with a diameter of 160 mm. As you can see, the appearance is quite different from the RT900 or RT800 rotors.

Rear of the aluminium 4 arm spider is hollowed out to save weight.

Close up look at the cooling fin and cutouts.

160 mm rotor weighs 106 grams without lock ring.

160 mm rotor plus lock ring weighs 114 grams, which is actually quite a bit lighter than the RT900 (125 grams) and RT800 (133 grams) rotors.

I will be using two of these MT800 rotors, for the front and rear of the Canyon Endurace.

Appearance comparison between Ultegra RT800 (left) and Deore XT MT800 (right) rotors.

The design of the aluminium 4 arm spider, cooling fins and cutouts are quite different.

One potential problem with swapping wheelsets on the same bike is that the disc rotor position might not be exactly the same on the two wheelsets. This means that even if you set the brake pads to have clearance with the brake rotor on one wheelset, the brake pads may touch the rotor on the second wheelset.

If this is the case, the rotor position on one of the wheelsets should be adjusted, so that they are exactly the same, to ensure no brake pad touching for both wheelsets. For this purpose, I found that there are Centerlock rotor shims, which can be used to adjust the position of the rotor outwards.

Each of this shim has a thickness of 0.25 mm, which should be thin enough to offset the rotor properly. If the shims are thinner, it might break or buckle too easily. If you need more offset, just stack the shims, but ensure that there is sufficient lock ring thread engagement and also spline engagement.

Silver shim of 0.25 mm thickness can be seen just behind the Centerlock splines. The shim has a split end to allow it to fit over the splines.

The shim will rest between the hub and the rotor, to push the rotor outwards by 0.25 mm.

The shim can only be used to offset the rotor position outwards, therefore if any adjustment needs to be done, the shim needs to be installed on the wheelset which has the rotor at the more inward position.

Luckily for me, the rotor positions were equal on both wheelsets that I didn't need to use the shims at all. Swapping the wheelsets and tightening the thru axles did not cause the rotor to rub on the brake pads, which is really awesome.

MT800 rotors installed on the DT Swiss G 1800 wheelset!

MT800 rotor on the front wheel

Looks pretty good in my opinion!

Rear rotor is also 160 mm in diameter, same as the front rotor.

The gravel setup is complete! With 11-34T cassette, MT800 rotors and GRX rear derailleur.

I am pleased with the MT800 rotors as no adjustments were needed at all, when swapping between the road and gravel wheelsets. The rotors also matches the gravel wheelset and bike setup for a good appearance. Finally, these MT800 rotors are even more lightweight than the Dura-Ace RT900 and Ultegra MT800 rotors! For ultimate weight weenies, a smaller 140 mm diameter MT800 rotor will save even more weight.

3 comments:

  1. Replies
    1. https://novemberbicycles.com/products/centerlock-hub-rotor-shim-pack-of-4

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  2. really cool article. Thanks for sharing!

    ReplyDelete

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