Shimano shifter/brake/hose compatibility

[mtb_frk]

So Im building up my first Di2 system, and trying to do it somewhat on a tight budget. As such I went with the ST-785 road levers/post mount brakes to save some money. I was looking at the 105 level 7070 calipers that are flat mount to avoid using adapters. The 785 stuff uses the BH59 shimano hose, and the 105 brakes use the BH90 hose.

Would the 105 brakes work? Would I have to get the BH90 hose and fittings instead of using the BH59?

I know the cheapest answer is to just get some flat mount to post caliper adapters. But just wondering what my options are.

[eippo1]

From what have heard from Shimano on this, that should be fine. You just need to match the hose with the lever and make sure the fittings on each end match correctly. Was looking into putting Di2 on my warbird which is post mount only. So in my case, I would keep my existing calipers and change the hose and match the levers.

Google Shimano match hose to shifter to bring up their compatibility chart. Can't link it because it's a pdf.

Sent from my SM-G973U using Tapatalk

[2000CSI]

This, Shimano's policy is to match the line with the levers

[mtb_frk]

Looking at the compatibility chart it looks I would have use bh90 hoses, if I’m reading that right...