You can get a dummy udh insert here
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Thank you, that site has a few more bits and bobs I still needed to find!
It’s funny how that site looks exactly like the biketubing site.
Holy crap this went way smoother than I had expected. I’m really really happy with how the design for my neo-retro socket style UDH dropout turned out!
I’m just waiting until I receive my chainstays so I can measure the width and taper where I’ll need to cut so I can remove the right amount of material from the inside of the chainstay socket to fit the chainstay.
This part is going to be 3D printed in 316L.
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The non drive side ended up a bit heavier with the offset for the hub and the flat mount built in but generally still happy. Hope it has enough clearance for a caliper in there because it looks pretty tight. I’m also not sure if the insertion angle of the wheel into the dropouts is going to cause problems with the location of the caliper.
Approximate weight for the set would be 300g, 100g driveside and 200g non drive.
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plus one for duanedr’s reply above.
first few I did I read the paterek manual (google for a pdf) , made BB-ST, HT-DT, CS-DO subassemblies, and then made a “hockey stick jig”; something like this but without the back plate ( sorry im digging photos out from over a degade ago now) ; a small aluminium box section with an “axle” ( threaded rod) which clamped to the headtube, and seat tube, and held the axle in place.
I used home made wooden tube blocks on the HT and ST with matched outside dimensions to keep the “jig” parallel to the centreline of the frame. hot tip at the time was make that outside dimension 68mm and you can use the bb flat on the table, and the 25mm box would still fit inside the dropout faces of a 120mm “axle” and just need a 1mm washer
but also, if you want to lay it all out flat, the jig can be can be simple offcuts of 4x2 wood with a well cut V at the right center height (100mm goes fine); something like these;
Considering the effort you’ve put in to model the dropouts ya mad not to model a caliper to check clearance. Looks great by the way. Love the mix of old school looks with new tech.
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This is essentially what the Alex Meade surface fixture is. His are made from steel but same idea.
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Thanks, combining my favourite things from old and new is something I’ve been wanting to do ever since I restomodded my first classic bike.
You’re right, I really have to check clearance. Lucky for me I just found a TRP Spyre 3D model on grabcad! I’ll check it tomorrow. Man… would be a big headache if it doesn’t fit.
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Eureka I’ve figured out a way to have integrated bearings in my lugs in a way that’s lightweight and looks really clean!
This idea popped up in my head last night while I was taking the train home, I damn nearly missed my stop because my head was so deep in bike design land!
I’ve figured out that I can integrate bearing races into my lugs and keep it clean and light.
Instead of using a 36mm head tube with a 1.1mm wall thickness for a 34mm pressfit headset, I want to use a 0.9mm thick section of a 38mm downtube. Correct me if I’m wrong but I believe the 1.1mm wall thickness is a bit overkill if you’re using lugs, so 0.9 seems fine since I won’t be needing to ream any out of it and the lugs will be spreading most of the forces.
Total system weight will be either a break-even or possibly a few grams lighter because of the slightly thinner wall headtube and omission of bearing cups.
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Those head lugs look sharp, I like it! Especially with the matching crown. Bulged head lugs with drop in bearing races were very common, even “standard” in the 1920s-'30s. Here’s an example on a Pop Brennan, built in New Jersey.
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Oh cool I’ve never seen that! Why did they disappear? Also do you think I could go any thinner than 0.9mm on my head tube wall thickness with the lugs taking/spreading the forces?
I think old Bianchis and a few others were like this too. It’s a clever design.
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I think you could, but I don’t think you should. 0.9 is nice and thin for a headtube.
It’s your first frame, and there’s very little to gain, especially on a lugged, disc, through-axle steel frame.
if you’re that worried about weight, find a local “learn to tig weld” night class and bank it for frame #2
integrated bearing lugs looking nice, don’t forget you’ll need that IS41/IS42 reamer, and once you buy it, you’ll have heaps of friends.
I don’t mean to go FULL curmudgeon, BUT ( you knew that but was coming…) I’d also caution you not to undercook the wall thickness on your lugs/bearing cups, I would point you in the direction of @photon 's posts in this thread: Metal 3D Printing and Framebuilding - #46 by photon
every good (not even great) frame you’ve ever heard of, wasn’t a first pass; someone built something cool and safe enough to have survived it, and then used their experience from that process to figure out how to do it better.
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Haha don’t worry I already knew I’ll need people to be skeptical of my plans to keep me from doing stupid stuff.
I think I’ve looked at that thread before but I’ll go through it again in detail now that I’m further in my design process. And then once more once I’m testing pieces. And then twice more when I’m ordering my final parts for this frame.
Probably best if I keep plenty of safety factor anything “experimental” indeed. I do like having teeth.
My current strategy is to always stay at least at 2x the wall thickness of any tube that’s being held by a printed part. For example the downtube lug which touches the 0.8mm downtube has a minimum wall thickness of 1.6mm. I also try to use the smoothest shapes and biggest radii I can to minimise stress concentrations, the radii and taper of the head lugs add a lot of meat where stresses should be biggest. Dropouts… I don’t know just pretty thick, not unlike an aluminium part as he recommends.
One thing I’m really split on is the fork crown. I designed a lovely smooth fork crown that fits bigger blades and nicely continues into my head lugs but it scares me a bit because that’s a really cruicial part. Currently have that drawn up with a wall thickness of 2.5mm. reasoning being it’s more than twice the wall thickness of a unicrown fork blade and unicrown fork blades should in theory have more stress concentrations at the welds than this smoothly shaped crown would but I don’t know how that translates to reality.
Received a few tubes yesterday, I ordered a chainstay, the seat tube and another bigger Tange chainstay I want to use as fork blades.
Sheesh… I had hoped on a nicer elleptical shape on the Tange chainstay. Guess I’ll have to draw out that shape based on an imported photo and fine tune by testing fitment with plastic 3D printed parts.
It’s pretty chunky but I think with a nice smooth plug-style crown and a metallic or candy paint it’ll fit right in with a 35mm downtube and 38mm headtube.
Small end is heavier than I expected, but that’s fine, just more confidence that the forces of the disc brake won’t be an issue.
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Seat tube is also one of the first tubes I ordered for the design process because I’ll be ovalising the bottom section for extra stiffness under power. Will ovalize, then measure up and make little pieces to test fit so I can design the lugged BB to fit around it nice and snug.
Not sure yet how heavily I want to ovalize but I’d like to go pretty heavy on the ovalisation.
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That is going to be very heavy and ride like crap for a little 65kg-er. Part of the benefit of a steal bike is the flex and shock absorption. Don’t ‘engineer’ that out.
Weight should be okay, just under 1kg so bit lighter than my Surly Straggler’s disc fork.
But ride quality, yeah… I’m a bit split on that one. With disc brakes I’ll be having to use heavier stiffer fork blades than traditional forks either way.
Maybe I’d be better off using a carbon fork after all… I’m just a bit worried that the front will get too light compared to the rear with one of those.
Bicycle weight balance is not a thing I have ever heard anyone design for. I can’t see how it would affect anything unless you are getting massive air and even then, relative to rider body weight, the difference would be immaterial.
Go with the carbon fork. That also ensures you get appropriate clearance between the crown and the tire. Less than about 8-10mm of clearance is a recipe for catching rocks/sticks/debris in there and landing on your head. IMO, there’s no good reason for less than 12mm if you’re using discs. If you are on the track, that’s a different matter but for all-road/gravel etc, getting a stick caught in there could be bad.
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