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Re: Unreadable Topic: "VeloBuild Headset Play Issue" Hi all, I think I might be able to help with solution to maintain preload. I have been working with the different internal headset routing systems for a while and have been running on my personal bikes a hybrid system using the Deda compression ring and a custom dust cover to mate to the FSA split spacer and ACR / SMR system. Some photos if what I have been working on are below.  I have also been working a generic fitment as well as one specific to the -17 Kalloy uno. All of those designs were designed to reduce stack and are electronic group only as cable housings can't make the tight bends required, but that doesn't have to be the case if more / different spacers are used.

I could adjust the skirt length and thickness of the dust cover to provide a better fit to bikes that do not use a countersunk dust cover, though the system would not have a seal other than what is on the bearing. I would also be willing to make an FSA ACR to Velobuild one piece handlebar adapter plate assuming that most of the frames use the same spacer stack and interface. I would need help getting some measurements of one of the spacers that fits into the bottom of the handlebar or send one to me (and be willing to try out a dust cover and adapter to make sure they fit)

I was previously on the Velobuild forums (2009-2011ish?) and you can find me on a few bike discords as well. This is also a hobby for me and I would price everything at cost + taxes. I will probably eventually open an etsy store or something and these would be about 30USD + shipping with everything MJF printed using Pa12GB + you would need to buy either the Deda headset or the compression ring.
June 04, 2023, 02:34:20 PM 		1
Re: Yishunbike R1058-D I generally like the geometry of this one. However, I would like it better if there was higher offset fork option or even better if they made the fork with multiple inserts so the could vary the offset/rake across the size range from 45-50mm
June 04, 2023, 02:50:02 PM 		1
Re: Jockey wheels that fit 688-rs bearings? I would prefer 12t.

I want to be able to press in a few different bearings and see how they stand up to use / pressure washing etc, and 688 is a nice common size with options from the very expensive (e.g., enduro xd-15) down to the very cheap. So far, I have learned that ZTTO seems to use the 689 size.

I messaged a few aliexpress sellers i found using the the search terms you suggested. Thanks!
June 10, 2023, 02:44:16 PM 		1
Re: Unreadable Topic: "VeloBuild Headset Play Issue" Just want to point out that a headset that cannot maintain preload is not a minor issue.

Riding a loose headset is the cause of the “ring of death” phenomena found on carbon steerers. In most cases, it’s a result of neglect and a lack of maintenance. In this case, this is a critical safety issue caused by poor design.
June 11, 2023, 12:12:38 AM 		2
Re: Light Bicycle AR/WR wheelset alternatives? (30-32mm wide wheels) Nextie ARX are another option worth looking into. They are front and rear specific profiles which is kind of interesting. There is a 49 / 54 and a newer and wider 60 / 65

I personally really like the WR50 from LB (i have had the flyweight version for as I weigh like 55-56kg) and have kept a pair over the course of a few years as many other wheels have come and gone. Not sure that build though fits OPs budget.

One thing to think about is that wheels sort of became a commodity for a while as everyone settled more or less settled on NACA profiles. I don't think that has been the case for several years and the brands pouring in the R&D are making better products. For example my Ascent Polaris 69mm deep wheels are significantly more predictable in crosswinds and faster than than my LB WR50. On the other side, I think my Roval CLX50 were faster wheels than my LB WR50s are; though they were hell for me to ride in crosswinds which is why the WR50 stayed and those went.
July 04, 2023, 03:39:49 PM 		1
Re: Sava Dream Maker As far as I can tell the only bar is 42cm across all the sizes which tells you all you need to know about the thought put into the details around performance and fit. This is really a design showpiece more than a high performance aero design.

Regardless of the data being something that's easy or hard to interpret, i think pulling back the curtain a little and showing that a product was actually engineered with CFD and then that CFD was validated in a wind tunnel is critical to telling a believable story for a high performance aero bike. I think the Elilee Blize (the base version) is in the same price range and has done that whereas Sava has not.
August 17, 2023, 06:51:11 PM 		1
Re: ventum ns1 2022 frame clearance To answer the question: 30mm tires are the official spec. I've seen 32mm tires on some but i think that's probably it.

I also think people don't realize that Ventum has done pretty well on the Tri (Z and One) and Gravel (GS1) side and are bigger than a lot of people think. Their frames are definitely not open molds. Are they equivalent to the best brands? Probably not. How much of their engineering is in house vs. outsourced? No idea. But there are a few shops near me that build and sell them and their riders seem mostly happy with what they have.
August 21, 2023, 10:37:40 AM 		1
Re: Adjustable offset carbon gravel fork? I think its this one. https://www.speedercycling.com/Carbon-Adventure-Bikepacking-Disc-Fork-SC-ADV09-_p375.html

There is also a newer fork from them that has less tire clearance but might be a better fit as i think the dynamo wiring is cleaner: https://www.speedercycling.com/Carbon-Gravel-Adventure-Fork-SC-GXR19-_p417.html
August 21, 2023, 09:09:06 PM 		1
Re: 3d printed stem spacers??? I am really sorry if this comes off as rude, but I think it might be worth taking a step back on this project and clarifying your assumptions about the current design and limitations before proceeding. There are a lot of assumptions about how this will perform relative to the original design that could have serious safety implications.

1. Spacer stack height. 50mm is a lot of spacers to put under a carbon stem. 70mm is playing with fire IMO. Depending on manufacturer that's right at the upper limit of what would be recommended. Most like Trek and Specialized are in the 40mm range for the max amount of spacers. Cannondale is the exception where I think on some models they have said no more than 55mm of spacers. An extra long compression plug like the 90mm ones sold by Origin 8 might help, but the idea of that many spacers is already pushing the limit on designs in an industry that arguably is already playing with thin safety factors.
2. Design. Having a single, rigid, piece will help limit the steerer from bending but this is going to be dependent on getting a great fit to the steerer tube and the cone spacer under it. A split spacer will make that much harder to achieve.
3. Production method. Given the 50mm-70mm of spacers and the use of FDM maintaining preload may be a challenge. Depending on your layer thickness and assuming you have the orientation controlled to prevent shearing, even a 100% infill part is likely 80% as strong as the equivalent injection molded part. It may even be less as it will be hard to get a part that size made without voids.
4. Load on the fork. I don't think there is an issue here with the overall load on the fork with that many spacers, but that will depend on how close to the limit you are pushing things with total system weight, fit, and stem length. Certainly worth checking.
5. Material. I don't know what Velobuild uses for their spacers, but most of this type of stem spacer claim to be nylon or nylon/carbon. UV isn't an issue as most use stabilizers and the end product is considered UV stable. This is also true for many MJF and SLS PA12 based nylons.

The price of failure here can be high as the resulting bending moment can cause the fork to snap above the headset bearing.
August 31, 2023, 07:33:28 PM 		1
Re: 3d printed stem spacers??? A couple of thoughts.

This paper is comparing short fiber reinforced polymers, not the materials you have proposed using, there is some discussion in other papers about whether or not 3d printing can actually help you gain directional strength because of the ability to control fiber orientation.

The caution i am expressing regarding FDM vs. production quality injection molded parts is also what you will hear if you contact production experts at places like Xometry that work on rapid prototyping with all of these technologies and is what most engineers who work with these technologies will tell you. For example, when HP says "MJF produces a part with anisotropic differences that vary between 95% and 90% of an injection molded part" they are, like these papers, assuming the same formulation of material. Unfortunately even for something like "standard" PA12 there are fairly significant differences between the materials themselves that would be used for different production processes including FDM, SLS, MFJ and injection molding. You can pull the data sheets from Stratasys, HP, etc and see for yourself.

Of course this stuff continues to change and today we see 3d printed parts being used for small production parts and on race bikes at highest levels. That would have not been the case only a few years ago.

Obviously the risk is yours to take and it very well may work fine, but this project is pushing the limits of both the materials and the design envelope for most carbon bikes in multiple ways. Good luck!
September 01, 2023, 11:38:31 AM 		2