Topic starter
I need to fit a longer hose to my xt 785 brake. The shop has BH 59, the brake came with 90. I understand the different barbs but what I would like to know is, will there be a drop in performance from using the 59?
thanks in advance for your assistance.
Posted : 08/04/2019 4:50 pm
will there be a drop in performance from using the 59?
Yes, a bit. Whether that matters is totally down to you.
Posted : 08/04/2019 4:54 pm
Yes the difference is precisely 31...
Posted : 08/04/2019 5:05 pm
Topic starter
Yes the difference is precisely 31
I was hoping that one of the maths geniuses would be in to put it in numbers 
A little I could probably live with.
Posted : 08/04/2019 5:14 pm
Topic starter
This site is hard to use from an iPhone
Posted : 08/04/2019 5:16 pm
This is the very first result on google.co.uk, you did google didn't you?
The Newer BH90 hose is actually SMALLER in internal diameter, giving better braking performance. (You lose less pressure from liquid compression.) The BH59 and BH90 Olives are identical, the barbs however are different, because of the different internal diameter of the tubing. They are not interchangeable.
Posted : 08/04/2019 5:24 pm
Topic starter
I did google but I was hoping for some real world feed back. I do however appreciate your efforts. Thanks
Posted : 08/04/2019 5:27 pm
Topic starter
Not trying to come across like a penis in my replies. Daily events keep pulling my attention from what’s really important, alleviating my fear of ruining my brakes!
Posted : 08/04/2019 6:01 pm
I’ve just gone the other way from BH59 to BH90. I upgraded a leaking set of 2-pot calipers with 59 hoses to the new deore 4-pots which should in theory be paired with BH90s. I started off using the 59s that I already had with the new calipers and they seemed fine but had a little dead travel. Just swapped them for the 90s and can barely tell the difference, probably not more than 5% in it. Id say the 59s will be fine.
Posted : 08/04/2019 6:56 pm
Topic starter
Thanks, Blitz.
Posted : 08/04/2019 8:51 pm
Ive used BH90 and BH59 hoses on my road bikes and not noticed any difference in braking performance
Even used the BH90 barbs in a BH59 hose and visa versa with no issues
Posted : 09/04/2019 7:43 am
Never really noticed any difference between the two..... How well they are bled has much more of an impact on lever feel and travel.
Posted : 09/04/2019 7:55 am
Topic starter
That’s encouraging news, as the hose is now in my garage.
Cheers
Posted : 09/04/2019 5:06 pm
