alias5000

Hi,
is there a way to make the BR-M446 work well with the Tiagra Brifters (ST-4725-R/L)? Would be good to know before buying parts.
Most notably, the BR-M446 calipers are not the shimano one-way bleeding system, if that matters.

Thanks,
alias5000

lasauge 

AFAIK there's no reason why they wouldn't work together. I looked up both components and Shimano specifies the same hose and connectors for both, and with some searching online I see that plenty of people report that the piston diameter is the same in all of Shimano's 2-bolt calipers and have had success with similarly mixed road/mountain setups. The newer 'one way' bleeding procedure only changes how you remove air bubbles from the caliper end of the system, so as long as you follow the older procedure specified for those calipers you shouldn't have any issues.

alias5000

My main hesitation is coming from the difference in bleeding procedures. I'm not sure if there could be anything that makes that bleeding procedure fail with those components combined. I assume, I would simply put the funnel on the lever and fill it up with oil to replicate the oil bath that's in the standard levers for M446 brakes. Right?

lasauge 

Actually, I was assuming they weren't, but those M446 calipers are a one way model as well. If they weren't you would have simply followed the old procedure that required pushing mineral oil through the caliper with a syringe, but you can just use the one way bleeding procedure.

https://bike.shimano.com/en-EU/produ...0/BR-M446.html

alias5000

Oh, indeed! My bad, I'm sorry to have taken your time there and thank you for double checking this! I'm glad this is looking promising.