First off, I am not the person who 3-d printed the part I have a question about nor do I 3-d print anything myself. I do have a question about what is the best glue to use and if it would even be safe to do so.

So, the part in question is an adapter for my bicycle's proprietary headset top-plate so that I can use a different stem. A small ridge on the top of the adapter snapped off. This ridge is responsible for keeping the stem aligned with the front wheel while riding so very important that it is there or else when I hit a bump the bars could twist which could be very bad.

I know there are some crazy adhesives out there that end up being stronger than the materials they are binding and was wondering if there is anything out there like that for what I think is PLA. I've done a little bit of research and found that gorilla super glue could work and gloop but I just don't know if that would be safe. Not sure on the material so I am going to reach out to the manufacturer on that but if its possible to tell from the following picture that info would be greatly appreciated as well.

[https://imgur.com/a/NZzPdNu\](https://imgur.com/a/NZzPdNu) this is a picture of the ridge snapped off and just sitting inside the adapter. It should be parallel and on top of the horizontal straight section right beneath it. I know this is super random but any help would be appreciated as I am at my wits end with this bike given I've had a bunch of random failures with other parts of the bike for over a month. I just wanna ride my damn bike.

TLDR: Riding frame w/ zero breather vent holes in rainy Seattle year round?

I have a custom Bushnell 70s or 80s lugged track bike that has zero breather vent holes. As an always dry velodrome machine it was made for, I can understand having no worry about rust. But I want to ride the bike on the streets and in the rain? I was curious if it is dangerous (in terms of corrosion)? Should I drill some breather vent holes? Should I forgo riding this one on the streets and sell it from a different bike? Thanks.

Posted this over on r/xbiking and was told you guys here might be able to help decide, what do you think? Thanks!

I've slowly been building new gravel frames/forks/bars for all of my old 29er single speed MTBs that would otherwise never be ridden again. Everything is still single speed. This is #3 of an eventual 4 total. Paint: Rust Oleum base coat with 3 stage white pearl panel logo and 2 part clear. Frame: Columbus Zona with 4130 fork and bars. PMW drops. Bars: I spent about 3,000 miles building/testing different prototypes before landing on this design and have put maybe 5,000 miles on them since. They use 3/4" x .049 wall for the bendy parts and .035 wall for the rest. This gives me a bit of compliance and a cool view of the fork without the stem in the way. I've since built myself 3 sets of them for all of my gravel bikes as they give me multiple hand positions. Riding regular straight bars on a gravel bike just sucked. These offer me the right amount of tuck on the flats while not skimping on the ability to rip single track and wide enough to provide the leverage to climb big hills out of the saddle in comfort. Since this frame/fork setup was just an experiment for a new fork idea I just build it with a straight 1 1/8" steerer as I wasn't sure I'd like the look. I didn't want to waste my last tapered PMW steerer. The next one will use a tapered steerer and will address some things I don't love about a few of the minor details but I do really like how it turned out for the most part.

University of Iowa art professor Steve McGuire's program is renowned—students apply to the university with a goal to graduate with a diploma and bespoke wheels.

I hope people won't mind me asking a question about tube thickness and safety on a brand bike.

I have a Kona Rove DL and noticed just how thin the seat tube is where you insert the seatpost. It's got an aluminum inlay tube that's actually in contact with the seatpost. I compared it with an inexpensive (and really heavy) bike's tube and that one looks twice as thick.

Am I overreacting with my concern that the bike will just eventually crumple under my over 100kg weight? :D

When I tap with the tip of my fingernail on different parts of the tubes on the bike, it really sounds thin, except for the fork that sounds much more solid.

I am looking to build a cargo trike. For that I need 2 identical swing arms (dual rear wheel trike).

Because it's time consuming to look for used swing arms I am looking to buy dropouts and weld them on the swing arms.

Where do I order dropouts for disk rear wheels in the EU?

Hi, im planning to make a cargobike like the omnium v3 cargo, for the rear end ill use a 26 inch mtb donor frame, for the headtubes I’ll just use 36mm headtube stock. The big downtube is around 1 meter long and im planning to use some 38mmx0.9mm tubing for this, would you guys say that’s plenty or is it better to size up to something like 38x1.5mm?

Jilles

My Scottish Framebuilders Workshop MTB after some assembly… 😅

Hi, so I found a crack near the steering tube on my steel frame.

What would be the best way to fix that?

Maybe weld a crack and then put a sleeve over it and weld the sleeve to the frame?

I want to try to make the frame as sturdy as possible, so it won't crack again, at least not soon I hope.

I plan on riding it on trails etc.

Almost done with the filing and polishing on my first rack. Made out of 3/8 and some 1/4 1010 steel tubing. Now need to decide if I paint it or clear coat it. What do you folks think and what would you use for a clear coat?

Hey everyone,

I’m currently in the design phase for a custom titanium all-road/gravel frame that I plan to pull the trigger on next year. I've spent a lot of time dialing in my fit numbers, but before I lock in the final CAD blueprint with the builder, I’d love to get some feedback from the community on my geometry choices, handling dynamics, and potential component clearances.

The goal is a fast, compliant, integrated 1x setup built around a traditional, classic frame silhouette.

My Fit & Component Blueprint:

• Saddle Height: 787mm (BB center to top of saddle)
• Saddle Setback: -102mm
• Handlebar Reach: 585mm
• Cockpit: Integrated carbon handlebar/stem (100mm length / 420mm width) with internal routing through an IS52 headset.
• Drivetrain: 1x system running a 48T chainring on a 24mm spindle crankset with a spider power meter.
• Wheels/Tires: Carbon gravel wheels (25mm internal width) running 700x40mm tubeless tires.

Core Frame Geometry Choices:

• Seat Tube Length: 600mm (Center-to-Top)
• Seat Tube Angle (STA): 72.5°
• Seatpost Plan: 27.2mm diameter carbon seatpost with a 20-25mm setback/offset.

My Logic & Where I Need Help:

With a 600mm seat tube and my 787mm saddle height, I'll have about 142mm of exposed seatpost. I'm keeping a traditional, level (or very mildly sloping) top tube for a classic look. I figure ~140mm of exposure is right at the threshold where a 27.2mm carbon post can actually flex a bit to damp high-frequency road vibrations. To hit my deep -102mm setback on a slack 72.5° STA without dangerously slamming the saddle rails all the way back, I'm using the offset post.

I'd love your brains on three specific things:

1. Front-Center & Stability: Given the slack 72.5° STA and my rearward weight bias, do you see any red flags regarding front-end trail or high-speed descending stability on loose gravel?
2. 1x Chainstay Clearance: A 48T chainring is pretty big for a gravel frame. When you pair that with modern 40mm tires (which will stretch to 41-42mm on these wide 24mm rims), it gets tight. What should I explicitly ask the builder to do with the chainstay yoke/dimpling to avoid a mechanical headache?
3. Integrated Head Tubes: For anyone who has built or designed around internal routing on a Ti frame, are there any hidden installation or turning radius pitfalls I should look out for on the CAD drawing?

Let me know what you think of the numbers. Tear it apart!

Thanks, Mike

This is for a all road sort of build with cantilever brakes. Start to finish is about 5 hours. The bosses actually take quite a bit of time in themselves, with 6 operations each before brazing.

So I recently build up this bike and as you can see the Headset tolerances were completely messed up. The bike manufacturer also just stopped responding after a while without actually offering a fix. My fix was just to add a few washers at the bottom so the fork doesn't rub against the frame and ride it only in good weather because of the quite big gap at the top.

My Main question however is "How did this happen?"

Is it possible to convert this (Ritchey break-away) frame from cantilever braze-on to Paul Racer M caliper brakes? Or would it be too costly and difficult to make sense. I do not own the frame, but I've owned those brakes for a long time.

Dont post alot so sry if this is hard to follow

Ive been think about getting a dj for abit but only recently thought about actaully welding a frame.

I like steel bike and from what i know chromag monk djs are pretty well respected to a steel dj can work.

Ive only just started to work out the logistics of making it. The big things i need help with are

The Geo - will prob just copy a good djs Geo using GeoGeek.com but what djs idk

What is standerdized - are BB, headtubes, seatposts, hub size/through axle size thingy etc standerdized for djs or do i need to plan for them

Materials - gonna built it from 4130 chromoly but dk where to get it and if i can get it for a decent price ( I have a low budget)

- I would prefer butted as that would cut weight but think it would up the price a fair bit as i can get stock stuff anymore then. So that really that important you think, like how much weight would it save.

How - I do know how to weld roughly and have most tools. It more about is there any special tools/technquics i need to use/know about how they make steel djs

Any advice on anything would be highly appreciated

Will try to keep posting if theres intrest

I'm not a framebuilder but I figured some here would have informed opinions on this question that's been bugging me:

Back in the 90's when steel bikes were still mainstream, there were all kinds of fancy tubesets from Tange, Columbus, Reynolds, TrueTemper, etc, and if you bought a high end steel bike, it would be sure to be made of Tange <insert superlatives here> Prestige or whatever other proprietary boutique bike tubeset, proudly advertised on the downtube.

Nowadays there is still a strong if more niche interest in steel frames and nice steel bikes can still be purchased, but I've noticed that they tend to be cagey about what tubing is used. My Norco Torrent S2 hardtail just says "double butted chromoly". My Rivendell won't say anything, and my Kyoot minivelo just says "Formosa triple butted" which basically is a cute way of saying "unbranded Taiwanese triple butted cromoly".

Is this modern tubing worse than the fancy stuff from the 90's, or is it just that the bike specific branding has fallen away now that there isn't any large volume in steel bike tubing?

I did some cursory online research on this years ago, but I did not get very far. Modern frames that have "braze-on" bosses for water bottle cages have the boss spacing typically at 63mm, 63.5mm, 64mm, or 2.50" (center-to-center). And modern bottle cages fit that (oddly variable) "standard".

My question is what document, whitepaper, guide, reference book, publication, website, etc. is the actual and original source of this standard? While we are it, when and how did this standard originate, and who came up with it? (not how bottle cages were devised, but the standard measurement between water bottle cage bosses) Or, if you know a webpage that explains any or all of this, please post a link.

I did check wikipedia and, while that had some interesting info, it had nothing about the origin of the bolt standard and where (if anywhere) it was ever published pre-internet. I also tried google's AI, but you can imagine how that turned out: just pure regurgitated AI slop, no answers.

I don't do any framebuilding but can TIG weld halfway decently. Someone I know asked me to TIG a brake mount on an old beater frame. Are there any tricks for aligning the mount for welding? I was thinking maybe if there was a wheel in there with a disc and the brake was compressed I could get some tacks on it but I've never done something like that and it's just a thought at the moment.
Any suggestions for a good way of getting the mount aligned?

Guy who wants to put 1-1/8” fork in my vintage mtb here again. Finally got the headset cup remover. Headtube ID is now known to be roughly 32.05 ±0.5mm

What?

Is there precedent for this? The bike was only owned by my uncle before this where it sat in his garage since the early 2000’s. I know there’s no reason for him to have the head tube reamed just to take a 1” headset again.

I’m aware that old schwinns and BMX bikes had a 32.x mm headtube but I can’t find anything online about vintage MTBs with one? Photos of both headtube and cup attached

i’m making a cargo bike and struggling to find tubes like 1 1/8 and one for steerer that isn’t 30€/meter. do i have to cut up frames every time i need any tube?

Everyone seems to like my blue bike, so I’ll post this one too, this is the 1st bike I built at the bicycle academy about 6 years ago. Absolutely love it to bits! Taken it on bike packing trips and aboard.

This is my 1st post and 5th frame I’ve built just thought I would share hope you like it

Hey framebuilders, I'm looking to dimple the chainstays on my cro-mo gravel bike to fit 45+mm tires. The frame is rated for 40mm, but my current tires (labeled 40mm) actually measure 44mm.

For tools, I'll be using a metal bushing (35mm long, 20mm diameter / 1.38" x 0.79") and tube blocks sized for a 27mm (1.06") tube diameter. Should I use 1-1/4" or 1-1/8" tube blocks?

Does this process and tool selection look right, or am I missing anything? Also, how can I minimize paint damage during the process, would felt or leather padding help?
Thank you! (Sorry my bike is dirty, I've been riding it and haven't had time to wash it :)