Alright so I’m getting a bit of a headache trying to figure out if what adapter I could use. I’m building up a kona sutra ltd frame, which has a flat mount frame and fork. I’m going to use it pretty heavily loaded since I’ll be cycling from Japan to Europe. I still have some Trp spyres laying around that I want to use, but they are post mount. I’d prefer to run a 203mm front rotor and 180mm in the back, and although there are some flat to post mount adapters I’m not sure which ones I can use.
Also not sure if it’s even smart to go up to 203mm because of the added force on the fork, so I’d be okay with 180mm in the front too. I think the frame is designed around 180mm rotors if that helps.
Would the ones by Trp I added in the pictures work, since the bike is already based around the 180mm?
Edit: Alright so 203 in the front is not going to happen, I’ll get a 180.
by 04MimmiM40
5 Comments
There’s some weird thinking going on here. I have never seen the need for bigger than 160 rotors on regular road bikes, so it’s kind of insane that you’re looking for 203mm rotors instead of seeing the advantages of getting hydraulic brakes. I see the Sutra normally specs 180, so just go for that and flat mount hydraulics, you’ll be thanking yourself for not having to fiddle with adaptors – and not having to use manual force to stop a heavily loaded bike with mech disks
I don’t believe Kona recommends going higher than 180 for the front rotor. You’d probably be fine, but your warranty will definitely be voided. With that being said, if you use good rotors and pads, 180 should be plenty for loaded touring.
With that all being said, I’ve found brake adapters to be an extremely fiddly thing in my experience. Last time I used them, I just ordered a handful of different models off of amazon and returned the ones I didn’t use.
Why don’t you sell those calipers and buy flat mount ones?
You typically have to size up one size from the native rotor size to get flat to post adapters to work. Some frames have rear triangle clearance issues and won’t work because of this.
Twist. Sell those and get a $40 set of Zoom HB 100 hydro calipers. I took a flyer and did it with my old 105 cross bike because I was sick of the Spyres. No looking back. They are OEM quality and work 100% better and smoother.