Shimano 160mm brake adapter fitting

garfy117

Currently fitting some rs785 shifters/calipers, replacing a rival 1 setup. I’ve got a 160mm adapter for the rear (SM-MA-R160DDA), but a bit confused about the fitting. The adapter attaches to the caliper with those funny little pin-ended bolts, and here’s where I got confused…
On the front, putting those in resulted in a satisfying “click” when in place…no such sound here, despite being torqued-up.

The instructions also seem to suggest using the same type of bolt (and some washers), to attach adapter to frame…but as far as I can see these are regular threads with no place for the pin to go. I assume I’m being a humpty somewhere but not quite seeing where atm…

pilot_pete

This may help:

https://si.shimano.com/pdfs/si/SI-8NU0A-001-00-ENG.pdf

As you can see, the adapter is for a flat mount frame/ caliper. The RS785 is post mount so I think you have the wrong adapter.

If your frame is flat mount you need a SM-MA-R160P/D to fit a post mount caliper such as the RS785 I think.

https://si.shimano.com/pdfs/si/SI-MAR0A-001-00-ENG.pdf

PP

garfy117

Thanks, appreciated. I think I have the flatmount version (805 rather than 505 caliper?), and the fork mounts ok. Think maybe I need some extra short versions of the bolt...which appear to be sold at about £6 each!

pilot_pete

This is an RS785 caliper;

https://www.bike-discount.de/en/buy/shimano-disc-brake-caliper-br-rs785-front-rear-213310

So I am now guessing you only have ST-R785 levers, coupled to BR-RS805 brake calipers?

https://bike.shimano.com/en-EU/product/component/ultegra-6800/BR-RS805-R.html

The dealer manual shows you how to fit, including how to determine what length bolts you require;

https://si.shimano.com/pdfs/dm/DM-BR0004-05-ENG.pdf

timothyw

garfy117 wrote:

Thanks, appreciated. I think I have the flatmount version (805 rather than 505 caliper?), and the fork mounts ok. Think maybe I need some extra short versions of the bolt...which appear to be sold at about £6 each!

Or you can do what I did and bung a load of washers between the bolt and frame.

Haven't died yet.

Third option is hacksaw/dremel the bolts a bit shorter - but not too much!