Seatstay Bottles

Or: making a braze-on fixture with Alex

My buddy wanted to put some bottle cages on his old On One frame in preparation for riding the Oregon Outback route next week. He came upon the idea of sticking some mounts on the seatstays rather than on the underside of the downtube as is more traditional. The logic here is that if you're tired and lifting the frame over a log or something, it's nice not to have to lift up that extra two inches to clear a bottle.

So I machined a little fixture. Normally a bottle cage mount doesn't need to be fixtured, since you can drill the tube fairly accurately. The bottle bosses auto-fixtures inside the hole. But since I was using spools, I thought a it might be nice to try and keep the bosses in plane with each other.


That handy little magnetic stand (named Mr. Helpful) is a cheapo dial indicator holder. A dial indicator is a little gauge that machinists use to take relative measurements of different sides or sections of a workpiece. They make magnetic holders like this so that you can position your indicator wherever you want it by clamping on to a 3/8"ø shaft. Conveniently, 3/8"ø aluminum rod is readily available and super easy to machine. I've got a bunch of little tips I made for Mr. Helpful, mostly to aid in sticking on braze-ons. The little knob loosens the whole arm assembly which can then be positioned wherever, and fixed by re-tightening the knob.


We decided to go with spool braze-ons here since it's an area that can see a lot of bumping. I find that spools, as opposed to bottle bosses or other threaded bosses, are more robust due to greater surface area for brazing.


It's a pretty cool place to mount some bottles in what is otherwise wasted space on most frames. Unless it's a super stiff road touring bike, front loads usually feel way better than rear loads. People are finally catching on to that with the rise in popularity of bikepacking style cargo bags, and so we're seeing fewer and fewer frames running rear pannier setups these days (finally). I think this setup could really be great for a lot of riders. You know, it's always nice to have extra water.