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Re: Tubeless tape alternative
How do you cut the 3M tape to the proper widths? Thanks in advance. The answer is easier than you think. You buy it in the correct widths that you need.  June 29, 2025, 09:11:38 PM |
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Re: Continuation: IIIPRO E4 4-Piston Hydraulic MTB Brakes - Are they to be trusted?
In general, for the past 10+ years I have been trying to avoid purchasing from Shimano, SRAM and Campy. I know that if I have to I can purchase Shimano, except I have typically preferred to not to spent my money on their products. My brother, tried the IIIPro E4s. After about 6 month of usage he mailed them to me said they were garbage and now uses Magura brakes. He says he loves them. Several years ago when I first purchased the IIIPro E4s, I thought they were fantastic! after 6 months of usage I loved my first set. I purchased 3 more sets for other bikes I was building. For a while, they all worked well. then they didn't. I have 3 sets in operation, and the 4th set has become "spares". I feel invested in them and want to make them work. ---- This morning I removed the soft levered front brake assembly and put it on the bench. Took some pictures of the caliper right off the bike, dirt and all, and looked for leaks. No leaks! I want to note that the front brake assembly, as received, are factory assembled, and on this front brake, other than replacing the pads once, I have never exchanged mineral oil, or bled them. This particular front set of brakes has always worked/stopped really well. 1000+ hard miles. Then yesterday, they didn't work! I clamped the lever assembly in place with the bleed port facing the top and level, removed the brake pads, cleaned the caliper and installed a brake block. when I pulled on the lever it was still soft, and pulled all the way, I couldn't even see the pistons pushing out onto the brake block. I removed the bleed port and the reservoir was full. I very carefully and very slowly pulled the lever all the way until it stopped, about 2/3 of the way pulled, some fluid was flowing out the bleed port so I gradually released the lever, then all of the sudden, the rest of the fluid in the reservoir sucked back in and the reservoir looked almost empty. WTF! I added drops of mineral oil until the reservoir was full. (Quite a few drops) I put the bleed plug back in and pulled the lever a few times and I could see and feel some motion on the caliper pistons. I pulled the lever numerous times, and the resistance on the lever gradually improved. I removed the bleed port and the reservoir took a few more drops of brake fluid. When I replace the bleed screw and pulled on the lever, it was felt firm and responsive. I put the pads back in and installed the assembly back on the bike. Braking action feels right back to how it felt before yesterday's ride. What is driving me crazy, is how can a closed hydraulic system, that has no leaks, and worked well for a long long time, all of the sudden stop working and develop a "void" inside such that pulling the lever doesn't move any fluid to the caliper. And, that this happened without any warning over time, it suddenly stopped working*! *Note: The 3 rear brake problems where the back brake stopped working, all started giving me symptoms before they stopped working gradually failing during the ride. September 08, 2025, 01:14:31 PM |
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Re: Continuation: IIIPRO E4 4-Piston Hydraulic MTB Brakes - Are they to be trusted?
I did a little research today and took apart one of my E4 levers and took a few images. - I am impressed with how good of quality and how good the CNC machining of the housing looks. - The internals match up well with generic cross sections of lever hydraulic cross sections one can find on the web. (No weird or unique design features. - About what I expected to find.) I believe that I might have discovered why the hydraulic assembly could be difficult to get all of the bubbles out. In the second and third attached images, I focused on what appears to be almost a bladder, or some sort of flexible pressure equalization/control insert. When I took my assembly apart, the indented area of the insert was facing downward. I think that this indentation, when oriented horizontally, could trap air and not allow the air to escape. These bubbles could relocate from where they are trapped into another area of the reservoir when the bike is oriented in a direction that the bubbles would move to another area in the reservoir. If the air bubble migrates to the small hole drilled between the reservoir and piston assembly, then air could directly be sucked into the piston area. (Perhaps why, a good working brake would get a spongy lever if the bike is hung on a wall, or flipped upside down for a period of time.) This could also help explain when I bleed the brake assembly off the bike versus on the bike, I was able to get a firm feel on the lever very quickly becasue I was rotating the assembly 360 degrees as I pumped the lever. - This may be reaching a bit, but to me it is one possible explanation. When I reinstalled the bladder thingy, I rotated it so that the indentations are vertically oriented. When I eventually try to put this lever assembly back in service, I'll find out this works, or not. September 14, 2025, 12:01:30 PM |
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