What are people using for tube gauge for bars?
Bull moose bars churning in my head- see @Daniel_Y’s build log (how do I link to another thread?)
Thanks!
Minimum .049" but if you’re welding anything on (ie stem/bar or something) go .058" or even .065".
And yes, your bars are going to be super heavy. Better than a trip to the hospital. There is a whole universe of lightweight production handlebars that are safe to ride out there if you want something light.
-Walt
5 Likes
My understanding is Mone and Doom use mostly 049.
I use .058 since it bends better on my 3.5” clr die haha
2 Likes
I’ve been using .058, I’ve thought about going .049 on bars with a crossbar.
1 Like
@Swood and I made some Bullmoose bars out of 4130 .035 that I have been really happy with, though i think they’re a little flexy for a bar that I would want to sell to someone, I’ve been beating them up on my touring/gravel/faafo bike and theyve been plenty strong and supple as heck. If we make any of these Bullmoose bars for people not me I would rather use .049, though that does bump weight up, its not out of this world. for reference, the .035 bars are 593g including stem bolts, and a .049 version would be ~800g. The alloy bar and thomson stem I loosely based this bar design around was 511g with all hardware.
For reference, I have a pair of Mone Meal Replacement Bars that are around a kilogram, that I would describe as VERY COOL boat anchors, wall thickness around 0.74 on my calipers.
Sanded the mill scale off and a quick and crappy coat of clear enamel
My back of napkin sketch in fusion to figure out the miter cuts.
This was basically enough fixturing to tack, @Swood drove the Tig welder and did an excellent job.
If we were making a bunch of these a better fixturing setup would be required.
This project, and being friends/neighbors with @VatFot and @Swood has really brought back my framebuilding aspirations, though I want to spend some time in the handlebar world first.
Curious about others thoughts on wall thickness for handlebars that are reinforced by a crossbar or the triangulated struts of a bullmoose. Thinner cause you’ve got less unsupported span that can flex? Or thicker cause youre welding/brazing onto it?
5 Likes
Stress risers and fatigue are your enemies, and welding or brazing (or clamping) anything on is going to create a stress riser.
I would not personally ride .035" wall bars, and (if I sold handlebars) I sure as heck wouldn’t sell them to a customer. Again, there are lots of excellent off the shelf options in a wild variety of configurations if you’re looking for a smooth riding/light bar.
Remember also that steel is way stiffer than aluminum for the same diameter of tube, so it’s actually a sort of crappy material for a handlebar unless you step down below the 7/8" standard and come up with a way to adapt your controls/grips.
Custom bars are super cool to make and can allow you to create something that has a ton more style than another generic Easton riser bar. But like stems, the goal is fashion here, not function, and if you try to play the light/cushy game you’re running a huge risk IMO.
-Walt
9 Likes
The bars I make, the ‘Oyster Bars’ are .049" .
Initially, I made myself a pair from .035". I’m about 150lbs and I put what I’d consider typical trail or enduro level stresses on them, riding drops and stuff but nothing regularly in the full on ‘downhill’ realm. my .035" bars held up fine after about a year. However a friend of mine who weighs 200+ lbs, riding in similar fashion said he noticed what looked like the powder coat cracking at the bends from flex in the bars.
So personally I would never sell an .035" bar , but feel comfortable using .049". And I think a lot depends on bar width, rider weight, application etc.
Dan
5 Likes
Thanks for sharing your experiences.
Just thinking out loud, has anyone considered developing a butted 22.2 tube for handlebars? It would be the opposite thickness of the main tubes use: .9/1.3/.9
Not sure if the mandrel can draw a tube that way? Assuming they can, the MOQ is probably reasonable for bar production.
Walt makes a great point about not chasing grams for strength, so I can see an argument not to pursue the route. But the stress is almost certainly concentrated at the clamp, so it makes sense you don’t need the full wall thickness. It would not be too hard to build a drop test rig:
Sorry, it’s time for me to bail on the forum.
2 Likes
1 Like
4 Likes
Sorry, it’s time for me to bail on the forum.
3 Likes
@Daniel_Y It’s easy to get the butting that way. They do it like forkblades. That is, swage the tube to the smaller diameter. If you want the wall thickness to be consistent, or thicker in the big diameter you have to start with a butted tube.
Hahn
1 Like
I’ve built a these for myself and a buddy. Neither of us are clearing doubles and trying to post KOM’s. Ive tried two different benders and both wrinkled my tubing. So I said screw it and designed something without bending. Grip section is .035 and the main section is .049. I figured with this pierced design even if the joint was compromised the grip section wasn’t going to snap off.
55 degree backsweep
720mm wide
They offer multiple hand positions and exactly what I wanted. Not my finest brazing but only had some flux coated rod and just tossed them on to see how they felt.
7 Likes