Rotor size monster cross 140/160

[parfumisme]

hey guys,

I thought to drop this one on the fat tire section.

I'm building a ti monster cross bike* and i'm in doubt about the matter of rotor size. The trp spyre mechanical dual piston disc set i'm after is available in 140 and 160. My mind tells me to take 140 for softer modulation on the road/gravel but my mates (who are more keen off-road cyclists) tell me the bigger the better, especially when the road slopes downward. I'll be using said bike on and off road with 30 mm (slick/road) or 50mm (nobby/adventure mode) tires for said use. I realize that the tire contact patch may make a big difference in the way the brakes bite. The marginal difference in weight is no concern to me.

So my question in fact is: Do I run the risk of overpowered braking when choosing for the 160 set? Alternatively, what about 160F/140R?






*build thread is in the road section:
viewtopic.php?f=23&t=283815

 

[thesurfbus]

I have used the 160F/140R combo on my cross bike, recently went to 160F/160R and didn't notice any real difference.
I have an XTR 140mm CL rotor, and 2x 160 and 1x 140 6 Bolt Alligator rotors if interested.

 

[parfumisme]

I have used the 160F/140R combo on my cross bike, recently went to 160F/160R and didn't notice any real difference.
I have an XTR 140mm CL rotor, and 2x 160 and 1x 140 6 Bolt Alligator rotors if interested.

Thanks for the tip. I'll go with the TRP Spyre slc 160/160 and see how i get along with it. They're supplied with rotors but if i'm looking to change ill surely let you know.

 

[thesurfbus]

Let us know how you get on with the TRP Spyre brakes, they look like an interesting alternative to BB5/7s.

 

[parfumisme]

Let us know how you get on with the TRP Spyre brakes, they look like an interesting alternative to BB5/7s.

Will do. I ordered the 140mm SPYRE SLC in the end, simple because these where the only ones available from the suplier. I will immediately replace the front rotor with the venerable avid HSX 160mm , to gain some much needed power and modulation on the road. In my opinion (perhaps because of their 2-piece design) they are very resistant to overheating and thus warping, which is a thing that bugs me most with disc brakes. This is also one of the reasons why I went for the spyres, since I could set them up once (let's see ) and adjust it on the fly (since the two pads move perpendicular) with an inline adjuster. This way its also easy to monitor wear and eliminate rub. Lastly I appreciate that they take standard Deore brake pads, which are the most easily available (and consistently good) brake pads on the market.

All of this is of course theory. I will receive them within ten days, by which time I will be able to finish the bike. For updates please see the build thread on the road forum.

 

[thesurfbus]