# Bottle cage bosses



## adarn (Aug 11, 2009)

Hey, so I have some questions on bottle cage bosses:

When do you put them on? Before or after the tube is welded? 

How do you do it if you don't use a jig?

Has anyone made their own jig? 

I brazed them Into my ST before the frame was done on this last build (#2) and it seems like it may have cause some distortion, also, they're not 100% Straight. Any advice? 
Thanks


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## jgerhardt (Aug 31, 2009)

I normally put them in close to the very end of the process, after I have done all of the alignment checks.
In a more production environment you would probably do them before the the tube is welded/brazed however I still am not confident enough for that yet.

I am always paranoid something like this might happen...








Taken from PVD's site here


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## unterhausen (Sep 28, 2008)

not sure that was really related to the bottle cage, more related to the amount of displacement being asked for. I'm pretty sure there are pictures out there of buckled tubes w/o holes. In any event, I would finish the job before assembling. 

I have always done braze ons last. I think it's pretty evenly split, but the people who do it before assembling the frame are more vocal about it. It's tricky to drill a bottle cage hole after the frame is assembled, no doubt about that. 

Not sure I understand the other questions in the OP. There are jigs to measure the holes, but I've always just used a water bottle cage to mark them out and a centering punch to locate the holes. I do hold them in place when brazing, it doesn't take much of a tool to do that.


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## adarn (Aug 11, 2009)

Well, I am pretty sure that nova sells a jig for like $120 or something crazy for drilling the holes (Not exactly sure what it does TBH)
I'm just curious how other people go about doing this. Especially the getting them aligned part.


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## G-reg (Jan 12, 2004)

Not an expert opinion.... But it's something I haven't totally F'd up in the whole 1.5 yrs I've been doing this stuff. I scribe the centerline on the front of the seat tube, top of down tube. Rough miter the front triangle so I can hold some cages/bottles up and get a visual of where things really need to be. Mark holes on centerline and drill. I braze the bosses before brazing the frame.... Hell, I suck, so I don't finish my miters until I'm done heating unbutted portions of tubing with braze-ns.


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## unterhausen (Sep 28, 2008)

the Nova jig gets the holes on the same line on the tube at the proper spacing. You still have to put that on the centerline of the frame. BITD it was easier because the DT and ST were the same diameter, so you could just put a straight edge across the two tubes and measure over 9/16"


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## swift (Apr 3, 2007)

I drill/braze after frame is constructed. As mentioned above, one of the first steps I undertake is marking centerlines on all tubes for reference. These "sharpie" lines remain after brazing the front triangle and I utilize them to locate the bottle bosses. I simply use a bottle cage and spring-loaded center punch (doesn't dent tube) to mark the holes. I use a right-angle drill attachment to drill the holes out, starting with a small bit and working up to the correct size, slightly relocating hole along the way if necessary.

On personal bikes, I stopped installing at all because frame-mounted water bottles are lame.


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## Feldybikes (Feb 17, 2004)

[unrelated note: there are two new internets acronyms I was able to piece together without using gizoogle in this thread: BITD, TBH]

I drill the holes before putting the frame together, do the actual braze-ons last. Skipping some (well, many) steps:

1: seat tube is mitered and attached to BB
2: DT is mitered up along with the rest of the frame. This will help you position the bottles so they don't run into each other (assuming you didn't do this on the drawing) -- locate the holes along the circumference of the tube with a marker.
3: drill holes for bosses in seat tube -- you can use the bottom bracket and a drill press to make sure it's square
4. drill holes for bosses in DT. use another BB held against the mitered tube to help with making sure this tube is also square.

Alternately to 3 & 4, it's not actually *that* hard to sight along the tube and freehand make a couple of marks along the length of the tube that are in-line with each other by looking at the reflection of an overhead light on the tube. The reflection will be perfectly straight. You just need to move your head until it lines up with the 12 o'clock position. Now you have a cross of marks that you can punch or just start drilling if you're talented enough (I'm usually not).

Getting the spacing right is dead easy compared to most things with framebuilding -- it's 2.5" and with most cages the holes are elongated so there's lots of room for slop.


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## VenMod (Mar 12, 2006)

Here is a really easy jig to make.

just need a piece of angle stock. I used alum, but you could do it with steel too.










Got some drill bushings from Enco and put it together in an evening.

I usually drill and braze the bosses in before welding the front triangle, except when I forget too.

Paul


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## JaquesN (Sep 14, 2009)

As others have said, it's pretty easy to get the placement correct. Just use an existing water bottle cage and make sure that if you have two, the bottles won't hit each other or anything else. 

I do the braze-ons before building the frame, in general. Braze-ons will distort a tube, introducing a bit of stress if the frame is already built. I'm not sure if it matters. One downside to doing them first is it makes it a bit harder to hold the tube if it's already got something sticking out of it. An upside is that if you are a complete noob who might destroy a frame by brazing or tigging something badly, you might want to make that mistake on a single tube rather than on your whole frame.


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