How are they getting on? I wanted to ask, do they handle a gravity bleed ok or do they need more elaborate techniques with syringes?
I found a good 11.11 price for the Zrace version of the R2X4, which after spending the afternoon trying to get a TRP Slate calliper with stubborn sticky pistons to function properly is looking tempting.
https://www.aliexpress.com/item/1005009315025990.html
On my 29er hardtail, the rear brake is still marginal, at best. I recently rode my full suspension 29er that has the IIIPros E4s installed and those brakes work as one would expect.
I have a IIIPro brake lever and E4 caliper taken apart. I have measured and examined the E4 caliper apart, and they appear to be very very close in design to the Hope Tech E3 calipers. I can't see anything in the calipers that would lead to poor stopping power, other than air bubbles that somehow one can't easily purge.
The IIIpro Lever, could be the problem. I haven't had time to measure and calculate the reservoir size compared to the amount of fluid that is required in the hydraulic piston area of the lever.
I am looking into purchasing either Magura or Hope brakes for the bike I keep having braking problems with.
My gut feel (Not based on real data yet) is that the IIIPro lever is where my rear brake problem is coming from. To date, I haven't figured out anything definitive.
Above being written, Perhaps the lever hydraulic and reservoir design of the Zrace, or R2X4 or Frog Wake is better than the IIIPro levers. Since I haven't purchased this style of brake lever assembly, I can't comment or recommend on the Zrace design.
(
Perhaps someone is running one of these and can start a new thread about those specific brakes.)I made the decision to purchase different brakes for my 29er Carbon hardtail that I use for my extreme terrain Bikepacking events. I will keep the IIIPros on 2 of my lesser-ridden bikes until they exhibit the same problems.