Can anyone confirm which brake adapter this is?

B

bgarry

Likes Bikes
Nautonier said:
I need a brake adapter like this to run a 180mm rotor with Sram Guide RSCs (on the same bike as this):

View attachment 333676

Is it an Avid 20mm post mount like this?

http://www.ebay.com.au/sch/i.html?_...er.TRS0&_nkw=sram+20mm+brake+adapter&_sacat=0

The labelling of which adapters work with what bikes/brakes is somewhat confusing.
Click to expand...

Hey mate,
I have a Range with the same brakes, the rear on the Range is already a 160mm Post Mount so you just need a 20mm Post Adaptor & bolts (Standard - Non CPS).
You can use a 20mm Post Spacer or 20mm Post Bracket. I'm using the 20mm Post Bracket per image. Probably best to use the SRAM/AVID ones as the shape of some brakes are different.

TF-BR2032-2.jpg

SRAM have a document that covers all the combinations - https://www.sram.com/service/techdo...iper-mounting-and-spacer-configurations-rev-b

Brendan.
 
Nautonier

Nautonier

Eats Squid
bgarry said:
Hey mate,
I have a Range with the same brakes, the rear on the Range is already a 160mm Post Mount so you just need a 20mm Post Adaptor & bolts (Standard - Non CPS).
You can use a 20mm Post Spacer or 20mm Post Bracket. I'm using the 20mm Post Bracket per image. Probably best to use the SRAM/AVID ones as the shape of some brakes are different.

View attachment 333680

SRAM have a document that covers all the combinations - https://www.sram.com/service/techdo...iper-mounting-and-spacer-configurations-rev-b

Brendan.
Click to expand...
Thanks for the replies, sounds like the 20mm Post adapter is the correct choice, although the "20mm" labelling is very confusing at it's neither 20mm and is a different height at both ends.

When you say you can also use a 20mm spacer, that's what I've got at the moment I think, but on both ends - so what's happening is that the callipers are not quite aligned correctly with the rotor at one end. I can see from the wear on the rotor that on the rearward end of the calliper the rotor is leaving a gap of about 1.5mm. This is strange as I used the same spacers that came off my previous frame, which aligned the calliper perfectly (also 160mm PM).
 
S

shmity

Likes Bikes and Dirt
The Duckmeister said:
Pretty daft calling it a 20mm adaptor when it's only 10mm.....
Click to expand...
True, but when we measure rotor diameter rather than radius it makes more sense to equate the adapter with the rotor size jump its meant for rather than the actual offset the adapter provides.
 
B

bgarry

Likes Bikes
The spacer you have doesn't sound right. I have a spare 20mm bracket and measured it, It's approx. 9mm on one end and 14mm on the other.

The SRAM Document and pictures I've seen for the spacers indicate 17.5mm one end + conical washer and 12.5mm the other end + conical waher
Post Spacer2.jpg

Brendan



Nautonier said:
Thanks for the replies, sounds like the 20mm Post adapter is the correct choice, although the "20mm" labelling is very confusing at it's neither 20mm and is a different height at both ends.

When you say you can also use a 20mm spacer, that's what I've got at the moment I think, but on both ends - so what's happening is that the callipers are not quite aligned correctly with the rotor at one end. I can see from the wear on the rotor that on the rearward end of the calliper the rotor is leaving a gap of about 1.5mm. This is strange as I used the same spacers that came off my previous frame, which aligned the calliper perfectly (also 160mm PM).
Click to expand...
 

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Nautonier

Nautonier

Eats Squid
bgarry said:
The spacer you have doesn't sound right. I have a spare 20mm bracket and measured it, It's approx. 9mm on one end and 14mm on the other.

The SRAM Document and pictures I've seen for the spacers indicate 17.5mm one end + conical washer and 12.5mm the other end + conical waher
View attachment 333682

Brendan
Click to expand...
The spacers I have have "20mm" printed on them and are both 12.5mm. Looking at the diagram, why would the spacers be different to the adapter? If using spacers, surely they would need to be 9mm and 14mm?

# edit: I guess the washers space the 7.5/12.5 out exactly that.
 
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B

bgarry

Likes Bikes
Nautonier said:
The spacers I have have "20mm" printed on them and are both 12.5mm. Looking at the diagram, why would the spacers be different to the adapter? If using spacers, surely they would need to be 9mm and 14mm?
Click to expand...

I believe they will be the same.
With the spacers there is also an additional conical washer used and may not be covered by the measurements printed on the spacer.

Brendan


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