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Mixing Shimano components

Hi,
I've had my Shimano ST-RS505 shifters for a few years and they've recently given up on me. I've got a question about which Shimano components play nicely together.
What I had was ST-RS505 > SM-BH59 > BR-RS785 but the shifters died. I've got a replacement set (ST-R7020 > SM-BH90 > BR-R7070) but have a few problems. I tried simply switching over the old shifter with the new (including a new olive, barb and larger flanged nut) but it doesn't seem to hold pressure. I also found that I can't use the calipers as they're flat mount and I have posts.
So, to my question - is there any combination of my components which will work?
If not then are there any recommendations you could make to get me going again?
Thanks

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5 comments

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Mathemagician | 4 years ago
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Look up Shimano compatibility, gives you all combinations that work and tells you what doesn't.

https://productinfo.shimano.com/#/com?cid=C-453&acid=C-454

Have to say though, that shifter/hose/caliper combination really should work - you sure you're installing everything correctly? I just installed a pair of BR-RS785 calipers with 7020 shifters and BH90 hose and had no problems.

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renMike replied to Mathemagician | 4 years ago
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It's good to hear that it should be possible to get a working set up and I haven't seen the compatibility chart you linked to, so thanks for that. The chart seems to imply (no direct link between them) that the shifter and caliper are not compatible so I'd welcome your view on their combination from a riding perspective.

I think I need to bite the bullet and switch out the hose too in my set up as I still have the older hose in use. I have the compatible olives and barbs but didn't want the extra hastle.

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Mathemagician replied to renMike | 4 years ago
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ST7020 and BR-RS785 are definitely compatible, see image. Not sure if the leakage problem you suffered is because you're using BH59 barbs in BH90 hoses? My understanding is that BH59 hose diameter is 2.1 mm and BH90 is 2.3 mm. I think the smaller dia barbs are gold, and the larger dia silver? Might be the other way around.

Incidentally, do you know if/where you can buy BH90 hose in bulk? I bought front and rear sets, with barb/olive/compression bolts included but you do pay through the nose that way. 

 

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renMike replied to Mathemagician | 4 years ago
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It's the other way around, I'm using the silver barbs in the BH59 hose. This might still be an issue but is less likely. I can't see any leaks from the caliper so it must be under the tape (note to self - don't retape until fully happy with shifter position/connections).
I also bought the BH90 in 1000 and 1200 mm packs with bits. Sorry no idea if it can be bought in bulk.
Think I'll give it a go tomorrow at switching over the hose to BH90 to see if that makes any difference.

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renMike replied to renMike | 4 years ago
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After one day on the new setup (ST-R7020 > SM-BH90 > BR-RS785) and the verdict is uncertain. The rear brake does work a bit better than the previous setup (SM-BH59) but doesn't feel as solid as the original set up (ST-RS505 > SM-BH59 > BR-RS785) which I still have on the front. It could just be the better 'modulation' as mentioned elsewhere, hence I'll defer my verdict for another week or two.

One top tip from my switch of the hose yesterday is, when pushing fluid from the caliper to the cup - make sure you take the plunger out the cup first.

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