Head Tube Rings?

[liberationfab]

I feel like this discussion has been hashed out in the MTBR archives, but I’m failing to find it right now. I’m looking to build with a EC34/44 head tube and picked the Columbus Spirit tapered one to experiment with since the PMW ones are a touch pricier and fixed length. It’s right on the edge of what I’d personally think of needing a reinforcement ring (1.1mm wall thickness), but I was curious what other builders thought.

[project12]

@liberationfab

been hashed out in the MTBR archives, but I’m failing to find it right now. I’m looking to build with a EC34/44 head tube and picked the Columbus Spirit tapered one to experiment with since the PMW ones are a touch pricier and fixed length. It’s right on the edge of what I’d personally think of needing a reinforcement ring (1.1mm wall thickness), but I was curious what other builders thought.

I agree. I’ve built a couple of frames with the 46mm version ( CYRG18600 and XCRX18250) and always used rings as I felt 1.1mm after reaming will be too thin for my liking.

[Dan_Chambers]

Rings here too, for the 1mm finished wall headtubes.

All the best
Dan Chambers

[WHilgenberg]

I’m going with a shameless re-post here for me.

You can find my method on my website

Headtube wall thickness

Waltworks waltzing in here with the definitive answer. Chapeau! I personally add reinforcing rings to all headtubes for a few reasons; It cleans up the transition from the headtube to the headset cup Adding ~30g to the headtube isn’t as noticed in the overall frame weight while a headtube failure is definitely noticed Additional reinforcement at the edges helps to keep the headtube round when brazing or welding to it which is very helpful especially when starting out I never want the failure…

Hope this helps!

[jimg]

When adding head tube rings to a frame that’s going to be fillet brazed, do you overlap the fillet onto the head tube ring, or do you leave enough clearance so the head tube ring is completely outside/above/below the corresponding fillet?

Thanks!
-Jim G

[Brad]

I remember a Paul Brodie video addressing this. I think he overlapped them but had a trick to make the joint look good.

I’ll try to find it today

[jimg]

Now that you mention it – that does ring a bell! But I just dug back through Paul’s videos and couldn’t find it.

-Jim G

[jsudar]

I would definitely use a ring. When the wall thickness is that small, the head tube can act as a punch on an aluminum headset cup. Especially when running cheap chinesium eBay headsets like I did on my kids bikes.
In those cases, I did the rings for extra surface area.

[Brad]

I looked and cannot find it. I think it was on his gravel bike build because it’s HT has a machined step.

[JoeNation]

Generally speaking (for road/gravel/XC) what’s the minimum HT thickness you’d want to have, to avoid using rings? And if you had a butted/relieved tube, how long would you want the butts to be?

[Daniel_Y]

@JoeNation

Generally speaking (for road/gravel/XC) what’s the minimum HT thickness you’d want to have, to avoid using rings?

Road, gravel, and XC are such a wide spectrum. For road and gravel, 1.1 seems to be the standard with no issue. For mountain bikes, people seem to have issues with ovalized headtubes without reinforcement.

@JoeNation

if you had a butted/relieved tube, how long would you want the butts to be?

Are you talking about top and downtubes? Or headtubes? For top and downtubes 40mm is the minimum butt length required by Columbus, so that is a good baseline. I have not seen a butted headtube.

Keep in mind you are removing .05-.1mm of material when you ream the headtube.

[Duanedr]

@JoeNation

minimum HT thickness

I almost always use rings on any kind of bike OR I use Paragon’s which have extra meat for the headset interface. Rings look better and make the frame stronger with minimal extra weight and work.

[LiquidBicycles]

I know it’s an old conversation, but I am just getting into framebuilding and have come upon this question since I am trying to avoid spending $30-40 per machined HT.

I got a Columbus 46mm HT that I can cut to length and once I opened it up I realized it looked like a bad idea to put a headset directly into such a thin wall, and so I stumbled upon this thread.

With reinforcement rings, is it best practice to silver solder them since there’s not much of a gap?
Also, not too sure if anyone ended up finding the Paul Brodie video showing the fillet braze over the ring, but it sounds like that is a good practice?

Thanks,

Xavier

[manzanitacycles]

I braze on the rings with 56% silver.

[Duanedr]

I add them as the final step generally.

If you use silver, and then fillet braze tubes near them, you could disrupt the silver and contaminate the fillet which is bad. Probably not the end of the world but, not good. Because Paul uses nickel silver, it’s not a concern. Ni-AG melts at a higher temp.

Measure how much length of the HT the rings take (5-7mm) and then make sure you have another 10-15mm or so beyond that where the TT or DT meets the HT so you have room for the fillet. Then when you’ve finished brazing the TT and DT to the HT, you can add the rings. You may find that the rings don’t fit the HT which means you distorted your HT. it’s important to control your heat and have tight miters all the way around, top and bottom. This is probably the most critical part for alignment and distortion.

Good luck and post up some pics!

[LiquidBicycles]

In which order of the process to attach them was going to be my very next question, so thank you for thinking of it!

I’m only one frame in and it’s TIG’d together, so it’ll be a learning curve with the brazing, but so far it’s more fun.

I’ll try my best to keep distortion down and post some pics