Troul 

Has anyone swapped out the 105 flat mount 2 piston calipers for 4 piston?
if so, what did you end up going with & would you have gone with different knowing what you know now?

For those that have knowledge but have not done such a change, feel free to recommend a 4 piston hydraulic caliper that does mount to the stock flat mount bracket.

mattcalifornia

Not exactly on point, but I just swapped out my 2-piston SRAM Rival calipers for Hope RX4+ 4-piston calipers on my gravel bike yesterday. I haven't had a chance to go for a long ride yet, but just test riding it around the neighborhood, it feels 100x better. I'll try to report back once I've had time to put some miles on them. But my swap is more of a comment about how bad the SRAM Rival brakes are -- especially for gravel biking in the mountains. They were really terrible, to the point where my hands were cramping. What's wrong with your 105 brakes? I've always heard Shimano hydraulic brakes were good - esp. for road biking.

Troul 

I looked at the Hope option, but i was not seeing much options for pad material options.
Most if not all 4 piston calipers I viewed use the banjo bolt method, it's not a deal breaker, but i'd rather not have that & also use a coupler

The 105 stuff works, but it can become fussy when it isn't behaving as it should. Also, when the pads wear down to a certain point, the lever action suffers (at least from my experiences)
I could live with 105, but if other products are available I'd be fine trying out alt options... it's a hobby after all.

Polaris OBark

If you need some flat to post adaptors, I unfortunately have some.

Canker

Magura is another option that plays well with shimano levers.

Troul 

just scored the hope for under 40.00. Hope it comes thru!

Troul 

Did a few rides [about 100+ miles] in various conditions [dry, wet, mucky] on different kinds of road surfaces [mainly broken asphalt, some smooth pavement] in temps ranging from 50s up to 92.
I'm thinking the change from the hydraulic 105 2 piston to the Hope 4 piston using 160mm rotor achieved the targeted goal of greatly reducing the brake shuddering effect.
as a secondary goal, I'm almost certain that it has reduced the dragging pad syndrome.
what I have also noticed is that the expected brake squeal during the wet conditions hasn't been a thing. It might be premature for this last part, but if it does happen, then I'll try updating this thread.
Only changed the front caliper, as the rear has not been an issue.

The Hope caliper does grab harder if you want it to, but doesn't seem to impact lever modulation. Only hard sudden tight squeezing of the lever may result in an over the bar experience.

chaadster

WTF did you say? You bought Hope RX4+ calipers for less than $40?? For the pair?? Doesn’t matter; even apiece that’s a smashing deal…deal of the decade. How is that even possible…

I use DOT fluid variant RX4+ with SRAM Force brifters, and like mine as well. I didn’t have any issues with the Force calipers other than that they were kinda boring to look at, and the purple Hopes took care of that. My only complaint with Hope calipers is minor: all the machining grooves take extra work to clean out after dirty rides.

Troul 

was only one. If i did both, idk, I might have spiced it up with a color change. For now, black, to blend in with the rear non Hope.

I agree with the nooks & crannies being all extra extra during a cleaning. PITA!

I

Calsun

This may provide benefits in braking with a heavy mountain bike going down a trail at speed or on a tandem bike with two riders but it is not going to be beneficial on a single person road bike. Extra clamping power makes it more likely you will accidentally lock the front wheel and take a header.

Troul 

it's unfortunate that you find this thread of no benefit to you. Maybe another thread exists that will gain a more positive side of your attention.

enjoy the rest of your day.

matt92037

Absolutely false. That is unless you are a complete idiot and pull the lever as hard as you can.

mattcalifornia

May I ask where you found that? That's insane. The cheapest price I saw was about $120 per caliper.

mattcalifornia

Sorry, that's just wrong. As long as there is good modulation and the rider is not clueless, nobody is going over the bars. The extra braking power is very welcome for some of the long and steep downhills around here.