Which brake adapter ?

[hellmansam]

Far as I can tell these two do the same thing, in a slightly different way

https://r2-bike.com/Shimano-adapter-pm-203_1

https://r2-bike.com/SHIMANO-Adapter-PM-PM-23-mm-for-203-mm-Disc

The bike has 180mm versions of the second one front and rear, I want to go 203mm rotors front and rear.
The second one looks a bit tidier, the first one looks to get the extra radius by moving tangenitally as well as out.Is there some other difference I've missed ?

 

[BT180]

The first one appears to be for 160mm and the 2nd for 180mm (as you say).

 

[hellmansam]

The first one appears to be for 160mm and the 2nd for 180mm (as you say).

nup it's clearly marked 203mm, might not be easy to see on a phone tho

 

[BT180]

Nah, link one says:

Brake disc size front: 203 mm
Rear brake disc size: 203 mm
mount fork: Postmount (160 mm)
mount rear: post mount (160 mm)

Link 2 says:

Brake Disc Size Front: 203 mm
Brake disc size Rear: 203
mount fork: Post Mount 180 mm
mount rear: Post Mount 180 mm

 

[Flow-Rider]

nup it's clearly marked 203mm, might not be easy to see on a phone tho

It depends on what frame you have, in these days and mixed with the past made frames there's so many different combinations brake sizes and mount designs on frames. Your frame and fork will have been made to suit a certain size brake rotor, depending on the age of your frame you can run them without an adaptor, eg Direct Mount or a (0 mm) height adaptor. So if you want to increase the brake rotor size you then need to change the adaptors to space your calipers out.

Say my frame & fork was made for 160mm rotors and it was currently running 180mm rotors, I will have on the bike adaptors for post mounts of 160mm but to suit 180mm rotors, say now I want to change to 203mm rotors I will need adaptors for post mounts of 160mm to suit 203mm rotors.

I hope this helps.

 

[urallwrong]

If your bike has adapters to run 180mm, it means you have 160mm post mount frame and fork. The second link provided steps a frame/fork that runs 180mm "without" adapters to 203. The former is to convert 160mm post mount to 203mm.

 

[Dales Cannon]

As above.

 

[hellmansam]

Ok thanks fellas, now I get that it's the 160 to 203 I need