Upgraded rotors 203/180

[ryukenden73]

Stock rotors were tektro 160/160

had a scary braking issue while riding on a main road

while going downhill around 31 mph ... a car jumped into my lane on my right... idiot had a stop sign .... so I squeezed on the brakes and the bike wasn’t scrubbing speed fast enough... good thing that the car kept on going or I would have hit the driver side tire and flipped over the hood......”wheeeeee... I can fly!!”

checked the stock rotors and you can smell burnt brake pads.

I’m 220 lbs and the bike weighs 61lbs. I matched the same OEM setup I have on my analog bike - 2010 specialized FSRXc

 

[OG in SD]

Stock rotors were tektro 160/160

had a scary braking issue while riding on a main road

while going downhill around 31 mph ... a car jumped into my lane on my right... idiot had a stop sign .... so I squeezed on the brakes and the bike wasn’t scrubbing speed fast enough... good thing that the car kept on going or I would have hit the driver side tire and flipped over the hood......”wheeeeee... I can fly!!”

checked the stock rotors and you can smell burnt brake pads.

I’m 220 lbs and the bike weighs 61lbs. I matched the same OEM setup I have on my analog bike - 2010 specialized FSRXc

View attachment 71781View attachment 71782

Same thing happened to me today, but on a steep rocky decline ⛰ . I stopped at the bottom to check if it was the motor, and burned my finger on the rotor. An upgrade is definitely in the works for me as well. Any link to the rotors you installed?

 

[ryukenden73]

got everything from Amazon ...went with RT66 shimano rotors .. the brake adaptor depends on what you have for your fork and rear .. I had post mount to post mount front for 203mm rotor and international standard to pm rear for 180mm rotors

 

[ryukenden73]

Did some panic stops on my new rotor setup going 28 mph.. and I feel confident on the initial bite and stopping distance

 

[Luto]

Not criticizing here, AT ALL, but surprised you did not go for the RT88 with the Icetech feature. I understand they are better at dissipating heat, but they do sometimes slightly warp due to the difference in metals. Brake fade is real. Love the scene in the movie, Ford v Ferrari when it happens.

 

[ryukenden73]

Not criticizing here, AT ALL, but surprised you did not go for the RT88 with the Icetech feature. I understand they are better at dissipating heat, but they do sometimes slightly warp due to the difference in metals. Brake fade is real. Love the scene in the movie, Ford v Ferrari when it happens.

I’m cheap. 60 bucks for one rotor for the RT88 and 30 for both rotors for RT66

 

[Lectric Bill]

My Como 5.0 front 180 mm rotor is about done (thickness =1.57 mm). I'm thinking about going with a 203 mm rotor.

What's confusing me is that the Shimano Deore XT M8000 brake is post mounted to the fork, but already has an adaptor in place. Why? Was the fork designed for a 160 mm disc??

I was about to order a Shimano F203P/Pm Disc Brake Adaptor to go from 180 mm to 203 mm, but now I'm not sure that would work. And not sure what WOULD work.
Any input from the Como whizzes?

 

[Lectric Bill]

OK, I'll answer!
I called the tech support folks at Jenson and found that the Como has a native 160 mm fork, hence the adapter for the OEM 180 mm rotor.
What I need is a Shimano SM-MA-F203P/P adapter.
BTW, I chose the RT66 rotor, not the ICE technology one, after reading on Amazon reviews about lots of those rotors arriving warped.

 

[ryukenden73]

OK, I'll answer!
I called the tech support folks at Jenson and found that the Como has a native 160 mm fork, hence the adapter for the OEM 180 mm rotor.
What I need is a Shimano SM-MA-F203P/P adapter.
BTW, I chose the RT66 rotor, not the ICE technology one, after reading on Amazon reviews about lots of those rotors arriving warped.

I got a 203 and 180 from Amazon for $30...(but it looks like the prices went up). the rt86 still retails for $60 and for one rotor only.

 

[Lectric Bill]

Everything went smoothly with the exception that the original caliper mounting bolts were too long when used on the SM-MA-F203 P/P adapter. I cut then down.
I can't say that I notice a huge increase in braking power in going form 180 mm to 203 mm... maybe a little. The big gain for me was that the new rotor will handle metallic pads and the OEM was for resin only.

A reference for others who want to tweak a mid 2018 Specialized Turbo Como 5.0:

• Brake calipers OEM: Shimano Deore XT BR-M8020
• Rotor upgrade: SHIMANO RT66 6-BOLT DISC BRAKE ROTOR 203MM, RT66L
• Replacement caliper adapter: SM-MA-F 203PPA adapter (replaces OEM adapter for 180 mm rotor on 160mm native fork)
• Brake pads: Shimano H03C Metallic Finned (after upgrading the OEM resin-only rotor)
• Alternative brake pads (could find nowhere in stock!): Koolstop KS-D640S metal, or KS-D640K finned metal/resin mix

Torque values and wrench sizes:

 

[Marcela]

I installed the 203mm rotors front and back on both Vado and Como 5's. I have not want for braking power. Search my name and brake, I did a write up on the parts. The front adapter is reversed for the rear to use the 203mm rotors.

I've had a couple times where the brakes were a blessing. I ride the sidewalks sometimes and crossing streets can get exciting. I've never heard anyone complain about too much braking power. . cheers and be careful.

When I do ride the Sequoia with it's 160mm rotors there is a big difference in braking. Maybe someday I'll change those too.

I also still use the resin pads. Be patient and they will improve. Put a few heat cycles through them to transfer the pad material to the discs and let them cool, they'll get better each time.

 

[Lectric Bill]

I agree: I've never complained about too much braking power. (I clearly remember the puckering horrors from applying old, hard rubber pads on rim brakes in the rain!)

I'm certainly not averse to resin pads in general; it's just that in my use case, I was going through them a little too frequently for my liking. Lots of hills where I ride, and some require higher speeds to not be overrun by car traffic. There's one particularly long and steep hill with a busy intersection at the bottom; I certainly want to eliminate any brake fade at that red light!

This was my first time bedding in new pads as I learned about that procedure on the many YouTube videos. During the course of 20 or so gentle applications, I could really hear the contact surfaces getting smoother and the bite becoming more effective.