My recent design was basically this, but a little more basic. I brazed a spacer on the face of the dropout plate to get the depth, then a friend with a CNC bored the hole more precisely. They work great so far. I think it would be possible to make this design with only laser cut parts and hand finishing (for about $12).
The next iteration closer to what you show, with a shouldered piece brazed into the dropout plate, and I’m also going to recess the UDH 2.5mm into the plate.
I really like the potential standardization of the UDH, but it is clunky and obviously designed for plastic bikes where the whole body could be absorbed into the stays.
It would probably make sense to start a UDH dropout thread, I’d like to see what else people are doing. From my past research I only found on one model in the Long Shen catalog the one Paragon option. I’m guessing those of you who build for customers need to offer a UDH option once SRAM releases their direct-mount system and everyone will want the new direct-mount AXS.
I’ve used the Reynolds and they’re nice but I don’t like the plug diameters, the Moots is for normal tubing not tapered Reynolds stays. Very pricey too but do save time.
The Lichen machined drops are great but too small a hood IMO. And expensive to fabricate and buy. Doesn’t sound like he’s making the Ti version anymore because of material costs.
I really like Daniel’s printed modular design for hooded dropouts. If that is available I’ll switch to that from using paragon Bobi snap rings since would be less work and I prefer hooded dropouts.
I’m pretty obsessed with sliders. I sketched a FM180 insert for the sliders that I get from strato. my concern is they will add a pretty good amount of leverage. a trick i used to get dimensions is I used the dropout insert from paragon. I then pivoted the face of the flat mount around the center of the axle until it was in the position I wanted.
Glad you like them Whit. Fun for me to read what I wrote several years ago. That was a fun and challenging project because we stepped into something we really didn’t know how to optimize the technology. I went to Birmingham, UK to meet the team to better understand things and in 2 days we had some prototypes going that were the second step to the finished product. The first was too much like a CNC part and didn’t take advantage of the process.
I was considering this approach with a completely round dropout. Simple machined(or cast) elements with mass are economical compared to 3D printing. The 3D printed components should be limited to complex parts or assemblies with time consuming setups.
@liberationfab you should definitely use the RASA dropouts if they’ll work for you! It was always my goal to offer them to frame builders and I would be honored if you used them!
I think you could easily design a flat plate that accommodates the insert to reduce cost. If you need some inspo check out the T-Lab Bikes system.
Another great low cost option are these Tange ones from Metal Guru. I actually think they look really good! I know Pratt/Nice use these on the NDS and Paragon Snapring DS for a super clean super and light set up.
@Daniel_Y I actually designed our dropouts about 5 years ago based on the Kavik Dropouts. Funny timing that Long Shen came out with a similar style around the same time.
Also, if you haven’t seen Rick Hunter’s Flat mount design check it. It’s one of my absolute favorites. A similar design could be extremely cost effective especially if you’re using send cut send.
A small distinction - we actually do our own NDS dropouts for Nice bikes, they’re 3D printed and match the angle and taper of the chainstays as well as matching the profile of the drive-side paragon dropout. They’ve worked out really well, though going forward I think we’re just going to go full FM160 for better clearance between the caliper and seatstay. Those ones from Carl look like a good option though, especially if you don’t want to be making your own all the time.
My favourite flat mount dropouts go in the trash because flat mount sucks and I refuse to build around it. I’d rather swap a flat mount caliper for a post-mount.
It’s a dumb standard implemented by Shimano for purely aesthetic reasons. There isn’t anything wrong with ISO and post-mount, and those calipers can be matched to hydraulic brifters without any issues. I never have to face my ISO or post-mounts after welding / brazing, even with paint on them.
I also have a huge stack of nightmare memories from working on flat mount bikes in a bicycle shop setting.
I never understood why flat mount starts at a 140mm rotor. Who the heck rides 140mm rotors unless you’re like 60lbs?
I mean, what’s the point of flat-mount other than it being more compact? Is that really a benefit? Some of my resilience to flat-mount is seeing it get rolled out in shops and really not seeing any benefit for the end user. I feel like we’re forced into flat-mount now because post-mount has been demonized by SRAM and Shimano for some reason.
This! It’s a standard that designed was for carbon road bikes because it’s easy to implement there and looks cleaner than a seat stay mounted brake if you’re transitioning from rim brakes. That’s fine but it’s a worse option on a steel bike that sees proper use (abuse?).
It is purely a carbon production standard. Easier to make in cabon than making bits hanging off stays and forks. Its not a dumb standard in that respect.
It is a pain to chop into metal tubes though, which is why I use the front flat mount specification in the rear of my road/gravel bikes. Much less intrusive though fiddly as feck.
Your point is valid re: carbon but I still think it’s a dumb standard. It doesn’t make a better bike, it just makes it cheaper for the companies to produce (see press-fit). If the goal is for big companies to be able to manufacture cheaper, but at the cost of a new standard and substandard finished products, then it is a stupid standard.
What really grinds my gears, is flat mount emerging on cheap mountain bikes. Rocky Mountain does this on lower end models of their Growler model. How does that person upgrade their brakes if they want 4 piston? And now the front is PM but the back is FM? Why??
I would define a new standard being smart as: it solves problems, the implementation isn’t solely to pad margins of capitalist corporations, it is genuinely useful and improves upon an existing standard, or evolves it. Does flat mount achieve any of that?
I hear you man, but the bike industry is geared to punching them out cookie cutter style in the tens of thousands per brand. What we do is the opposite. I know for sure it was the big companies pushing on Shimano to come up with this as they look to make their frames even cheaper, while putting retail up.
Agree with FM on mtb. Thats just dumb and while I’m a fan of Rocky I was pretty disappointed. Not that my opinion matters to them.
FM140 for road and gravel is good for those that just can’t learn to modulate their rear brake. Having said that I spotted a pro roadie racing the Cadel Evens road race with 140 on the front as well.
In the end we adopt the specifications we want to use. They won’t be stopping PM anytime soon so just keep making IS and PM mounts. If you customer asks for FM just have your reply ready telling why you won’t do it.
Took me awhile to get back to this, but I do like your conclusions! It’s difficult to make stainless for cheap, but our round dropouts and individual flat-mount bosses do pretty well, particularly the Snap-Ring versions. It’s the old trade off, does the builder prefer to do more labor and save money, or spend more money to do less work? Meanwhile, we’re moving forward with our integrated version.
