So Im finally making some big changes on my 36er. The old frame was too wide and I would catch my legs on the crown while riding and I did not trust the cotterless cranks after destroying a pair over a year ago.
With a new KH frame I am fitting a disc brake. Due to the fact the tyre is a heavy coker one, I am thinking of using a big rotor rather than my usual 160. Does anyone think there would be any problems or have any experience using a 200m rotor on spirits?
No problem for me
I tried that combo (KH Frame, Spirits & 200mm Tektro Rotor) and it was a flawless setup.
I must say that I found it to be exagerated and heavy, so I switched back to a 160mm rotor (Ashima ARO-08) and I’m very happy with it now 
I Use 160mm rotor on (almost) any of my unis and never had an issue, but in fact I’m not an heavy rider 
Cheers.
The reason I want to go for a 200mm rotor is that I want to use a (at least 1/2) drag brake setup. i figured that the bigger rotor would handle the additional heating better than a smaller rotor.
Id do the drag brake with a frictionless shifter drilled to take brake cable…
drag brake?
Sounds like it should work. I have a 180mm disc on my 36 and a 185 on my 26, both with Spirit cranks.
And yeah, the bigger disc will be much better at heat dissipation.
Just curious: I think I understand the idea with the drag brake, but is that for a long descent where you just want to be easier on your legs or something else. To me it seems like if you have a big enough disc then you can just hold the handle (I did 2000m of vertical descent each day last weekend on some really steep stuff, so 4000m vertical in days, and had no problems pushing the brake lever or with overheating: ok, that was on my 26 with a 185mm, but a 36 with 200 shouldn’t be much worse).
The reason I am going for a drag brake is that I use aero bars on a 36er. This means that my most common riding position is resting my hands on the elbow pads. I use inverted bar ends for when I need to pull up and the aero bars at speed.
While I would like an actual lever with the bar ends, for the other hand positions I want to be able to set and forget the brakes for longer periods and not be forced into one position for braking.
Disc brakes on a 36er will be a new one for me. Mine came with some nasty V brakes that caught very easily so I didn’t really try to use them.
I have ordered a rotor so hopefully it will be here Monday :p.