zze86

I'm going to try my hand at brazing together a couple of racks. I figure it will be a good to get comfortable with some of the techniques for eventually building up a frame. Any suggestions on tubing to use? I'm thinking either Al or stainless so I don't have to mess with a finish at this point. Would a simple pipe bender be OK for this type of work? Any other tools that are recommended (other than a torch and brazing materials, lol)?

Also any place I can look up custom bike racks to get ideas of other people's works? A google search of "custom bicycle rack" nets me a bunch of bicycle parking racks...

David Tollefson

Well, since you'll be brazing, that takes aluminum out of consideration. Stainless works, though you'll need to use something like 56% silver or Fillet Pro for your filler. And it uses a different flux. I use a simple pipe bender (similar to the image below) for 1/2"x.035" tubing (4130), so finding one for the particular diameter you need shouldn't be difficult.

unterhausen

I would look on flickr for examples. Search on google for site:flickr.com rear bicycle racks
also randonneur bicycle racks, lowrider bicycle racks, front bicycle racks.

I dont' know why there are so many pictures of bike storage racks on flickr, I think a lot of it is just spam or marketing.

You really want a tubing bender. Pipe benders are the wrong size.

I suggest going on ebay and finding a ridgid, Parker, or swagelok ($) bender the right size. I have never liked the imperial Eastman benders, the bend is usually ugly in my experience.

I usually build with stainless and 45% silver. 4130 is better tubing, and I built one for my commuter where I didn't care if it rusted. I have thought about painting with rustoleum

Andrew R Stewart 

Before I get to the suggestions that sometimes seem like critics I'll just say bravo! You will learn a lot, some of it will transfer over to frame building even.

I would advice away from SS or AL. As David said, AL isn't brazing friendly (for the most part). SS also has it's challenges, the biggest IMO is that silver filler must be used (for the most part) and the strength/set up/temp control/flux life of SS joints are harder to all achieve. I do suggest cro moly as it's very strong, available in many dimensions, easy to braze with both silvers and bronzes, not too expensive and rather tolerant of bending with out cracking.

1/2" x .035" walls is a very robust rack tube. 3/8" is more common and racks of old used AL rod of 5/16" or even less. The few racks I've done have all been bent with a simple bender similar to the pictured. Controlling the radius and ending of the bend can be hard at first. Aligning couple of bends along the single stretch of tubing is challenging enough so some will have more brazed unions to simplify the set up and better ensure the "squareness" of the rack. As you get better at bending doing three or four bends on one stretch of tubing will quicken the construction.

Last is that the comment about wanting a nice finish (hence the consideration of AL or SS) is cute but reflects a view I question. The thought that this first rack will be a forever one, one that is in use for years. That part way through making it you won't have that "the next time I'll do that instead" moment (that I've had with each on my 40+ frames...) Andy

zze86

Thanks for the opinions all and recommended tools.

As for the tubing choice, I will definitely take up the advice for cromoly as starting material. I certainly don't expect my first product to be perfect but I do know that I will prefer to have the racks done in stainless once I gain proficiency. Just figured it'd be best to work with the material of choice and get to know it's peculiarities but I suppose knowing the "base" steels would also be handy later on as well.

unterhausen

if you get 4130, you can make them with bronze, so they will be cheaper

I suggest you get some extra tubing to practice with first

wsteve464

Since this will be your first attempt and assuming you have to purchase the tubing, I would recommend using welded steel tubing rather than 4130, about a 1/3 of the price. https://www.mcmaster.com/#metal-tubing/=1dtr7aw

I can almost guarantee if you use stainless you will have to refinish it as the joints will discolor and need a lot of time with scotch brite wheels, pads and polish. Also with silver used for joining the SS tubing you will not be able to make fillet joints if wanted.

All in my own beginner opinion.

Good luck it is a lot of fun and feels really good when you can look at something and say holy cow that looks pretty nice and I made it.

unterhausen

Cycle designs fillet pro (or most likely any cadmium free 45 percent silver) will build fillets very well. That's what I have used on my stainless racks. I wouldn't build a fillet brazed frame with it, although many have. Nickle silver works well on stainless, but I would never suggest that to a beginner. I haven't been using it because I don't want to spend the time filing it. With silver I don't feel the need to bother most of the time.

I fillet brazed some fixturing for racks, I should take a picture. I stole the idea off of flickr though. I think fixturing is a great place to practice brazing. Most of it isn't safety critical. If it is, you're doing ti wrong.

gugie 

As others have suggested, use CrMo, brass braze it. A lot more forgiving than silver. Powder coat after you're done and it'll be real durable.

Be careful, however. Building your own racks has been know to be a gateway drug to full on framebuilding.

gugie 

I've got one of these tubing benders from Harbor Freight. It's cheap. It works on the 3 sizes of tubing I use for racks. It hasn't broken yet, and if it did, I already got my money's worth out of it.