Butted tubes for short frames

General Discussion
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Hi, wondering if anyone has any good ideas for options of short tubes for small road bikes? Im building my gf a new road frame, and its fairly small. I have always had trouble sourcing tubes for her bikes, in particular road bikes, because i run out of room with the butts.

Her top tube mitre to mitre distance is 460mm and down tube is 550, In the past i have squeezed some columbus tubes in there as they fall just within the recommended distance to the butt ends, but i would prefer to source a set of tubes that work a bit better. Does anyone have any good options?

I’ve scoured all the obvious catalogues, columbus/deda/reynolds, possibly ive missed something though. Reynolds has a few but I can source columbus a bit more readily so would prefer that if possible.

Cheers

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Columbus Spirit Keirin top tube - 25.4 dia. - .8/.5/.8 - length = 580

4

For the top tube of a smaller frame, sometimes I use a tube intended to be a seat tube.

I’ve used this one as a top tube on a couple smaller frames: Columbus Life seat tube 28.6 dia .8/.6/1 - 520mm – Framebuilder Supply

The way I see it, it’s just steel. There’s no rule that says this tube must be a seat tube. Use it wherever it makes sense!

1 Like
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And if you’re going oversize, there’s this one: Columbus seat tube 31.7 dia .7/.5/.9 ext. butted 520mm – Framebuilder Supply

A little larger diameter, with thinner walls and longer butts. And it’s very slightly lighter.

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I’ve always wondered about using a 7/8” 0.028 (aka 0.7mm) straight gauge top tube for a smaller rider. 1” top tubes seem so oversized for a smaller road frame.

2 Likes
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That, or some Tange has 250mm thin section but those cant be find anywhere but Taiwan pretty much

8

Thanks for the info guys! I had thought about the tange stuff but its quite hard to get as you say. I like the idea of the seat tube, that seems like a good shout!

The spirit kieren stuff is also appealing but i need 28.6 :frowning:

9

28.6mm is a huge top tube for a tiny bike. What’s forcing that size vs 25.4?

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Aesthetics!

1 Like
11

Have you tried https://www.tracksupermarket.com/tube-sets-lugs-frame-building.html?

12

I have used 7/8” top tube for a kids bike. I think the answer here is more traditional tubing sizes (1” top tube etc.).

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That’s a bad reason. “A bike the rider likes to ride” is what you’re aiming for. 28.6 is too stiff (even thin walled).

14

I disagree

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You’re not gonna like this one, her MTB has a 31.8mm top tube.

:0

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Frame is done now, no escape in sight for this top tube, thanks for the advise everyone.

PXL_20260303_102411713
PXL_20260303_1024117133000Ă—4000 2.36 MB

PXL_20260303_102431376
PXL_20260303_1024313763000Ă—4000 2.33 MB

4 Likes
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Yeah, like I said, a good a bike is one the rider wants to ride. People ride all sorts of bikes and love them.

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Nice work!

Out of curiosity, which tube did you end up using? Do you feel like there was enough butt left after you cut it to length?

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I used Velospec AC28090609-630 :slight_smile:

It has really long butts! It’s heavier wall than I would have liked to use but otherwise it suited the frame nicely, also I was able to get it fast as I had to build the frame this week, leaving my workshop for a while sadly!

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Nice welding!