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TheKaiser Added a comment about press release Downhill Mountain Bike Legend Aaron Gwin and Kubota Tractor Corporation Announce Equipment Partnership and Sponsorship
5/24/2024 7:46am
Is Dak affiliated with Kubota too?
This press release has 5 comments.
TheKaiser Added a reply to Nerding out on Brakes shall we? Not another tech deraliment
5/22/2024 6:32pm That is an awesome thought experiment, and much credit to you for basing it on some potentially realistic numbers! Like you, I had assumed fluid stiffness was a trivially low component of the overall picture, and was mainly concerned with using a vacuum to help remove entrained micro-bubbles. If your numbers are even close to accurate, it does really give...
dberndt Liked a reply to forum topic Nerding out on Brakes shall we? Not another tech deraliment
5/22/2024 6:23pm
I find this all interesting, and I'm learning some stuff/doing more reading. So please correct me when I go off the rails here. Degassing should/could do two things. 1) Reduce the amount of entrained air that might appear in future (depending upon how well sealed the system is over long periods of time). This seems boring. Entrained gas follows Boyle's law and is very bad for brake feel/performance. It's what we should all be fighting, probably. 2) The more interesting discussion at the moment. Dissolved gases. These do not follow Boyle's law and do not have a big impact on...
This forum topic has 2859 replies.
Slavid666 Liked a reply to forum topic Nerding out on Brakes shall we? Not another tech deraliment
5/22/2024 6:23pm
Glycol ether (primary component of dot 4 and 5.1 brake fluid) contains approximately 19% dissolved atmosphere at STP. Most liquids contain some percentage of dissolved atm with alcohols typically containing more. Short of sparging with helium, vacuum degassing is the most effective method of dissolved gas removal. The soda bottle is somewhat different because it is supersaturated with co2 as a method of generating fizzy bubbles. Yes as the pressure is released the gas content decreases but once it’s done or reached is pressure equilibrium there is still 10 percent dissolved atmosphere in the liquid (approx, just guessing on this)...
This forum topic has 2859 replies.
TheKaiser Added a reply to Nerding out on Brakes shall we? Not another tech deraliment
5/22/2024 6:17pm Do you know what the transparent portion of the bars are for the Bionol and Gold oil on the left side of the comparison chart? Its similar to the way that Radic displays a wet/dry temp for DOT 5.1 on the right, but moisture shouldn't really be a factor for the oils. I'd thought it might have something to do...
TheKaiser Added a reply to Nerding out on Brakes shall we? Not another tech deraliment
5/22/2024 6:19pm The lowest numbers I typically see for mineral oils, just from browsing around, are around 150 Celsius for a flash point, and in the high 200s Celsius for a boiling point, so that Putoline must have some particularly volatile components added to have such a low flash (87) and perhaps boiling (some undetermined number north of 180). Not saying that...
TheKaiser Added a reply to Nerding out on Brakes shall we? Not another tech deraliment
5/21/2024 12:05pm How do you go about degassing it? Are you just talking about pulling a quick vacuum in a high quality syringe, or do you have some other apparatus and do it for longer? I have heard surprising claims about the amount of dissolved air contained in mineral oil (not sure if this would apply to DOT fluid too) and have...
TheKaiser Added a reply to Nerding out on Brakes shall we? Not another tech deraliment
5/21/2024 11:58am That is an interesting take on things. I have heard that there is a surprising amount of dissolved air in mineral oil, right out of the bottle, so it makes sense that one could dissolve more into it if kept under pressure, and the bubbles (assuming a decent bleed in the first place) would be such a trivial amount that...
TheKaiser Added a reply to Nerding out on Brakes shall we? Not another tech deraliment
5/20/2024 2:27pm Are you saying that the flexed piston seals, which would normally roll back the pistons when the lever is released after a short pull, will slowly creep back along the piston under a long sustained pull as is done by strapping the lever down for an extended period? So it is kind of like advancing the pistons by squeezing the...
TheKaiser Added a reply to Nerding out on Brakes shall we? Not another tech deraliment
5/20/2024 2:20pm I have heard that rational before regarding keeping the system pressurized helping rid it of bubbles, and I just don't get how that would be helpful. In my experience, the opposite is what you want, as with a vacuum bleed the bubbles expand hugely and therefore have greater buoyancy. Going up/down in pressure rapidly could maybe help, as can vibrating...
TheKaiser Added a reply to Nerding out on Brakes shall we? Not another tech deraliment
5/3/2024 11:36pm Thank you for posting that master cylinder bore info! Companies frequently publish and even tout their caliper piston sizes as a feature but I haven't ever seen the equivalent for master cylinders leaving a big "?" when it comes to determining actual hydraulic leverage.
TheKaiser Added a reply to Smithage Hybrid Girderfork/Telefork dual suspension
5/3/2024 11:27pm Wow man, I've just been catching up on this thread, great work on your fork! From the vids the newest revision looks to be working beautifully. I remember the twin shock Cannondale DH bike that had a similar "travel envelope" that was measured in square inches rather than linear inches, and it always seemed like a neat idea even if...
TheKaiser Added a reply to Nerding out on Brakes shall we? Not another tech deraliment
4/26/2024 1:07pm Do any of you peeps know if those Lewis brakes, that Intense is now using, have the same cylinder sizes in the lever and calipers as the Trickstuffs they are copying? I am curious if they have the same hydraulic leverage, or did they just copy the look while going for different mechanical advantage?
hamncheez2003 Liked a reply to forum topic What do you prioritize from an e-bike?
11/27/2023 12:30am
So I have two frames, one is a chinese open mold, and boy have those come a long way in the last few years. Geometry is close enough, and they seem well built. However, its still chinese open mold, so internal headset routing (I can't express how much I hate this now that I own one), no UDH, terrible internal cable routing, bolts keep coming loose even with locktite, not enough rear shock clearance, etc. However, when its working it rides excellent. Here is a good place to start on building your own: https://www.emtbforums.com/threads/m820-bafang-cef50-frame-lightweight… My other frame is a ebike-version...
This forum topic has 61 replies.
TheKaiser Added a reply to What do you prioritize from an e-bike?
11/21/2023 1:28am Hey Ham, Your Bafang build sounds really interesting. I've mostly seen their hub motors, but recently came across their mid-drive motor on the new Vitus MTBs, and I dug the promised serviceability and lower entry cost, although that Vitus is somewhat of a tank. From what you're describing though, it sounds like you built yours up from scratch, using an...
