Portlandjim

I just finished making the handlebar bag rack for my 1978 Merz touring bike. I have been procrastinating on this task for a long time! I just need to send the parts out to get chrome plated. The rack is made from 1/4" 4130 CrMo aircraft tubing, the rack is stiff and very light.

jdawginsc 

Very cool. I like the brushes look as is but that’s probably a rust magnet...I like the double clamp on the fork thingy. Do you have little protective pads under there? I guess at the level of finishment, you wouldn’t need it...

Bianchigirll 

Looks great. Kinda weird I just saw another Merz with a similar setup somewhere....

Portlandjim

Chrome plating is not easy or cheap these days, but it's what I used for most all of my racks. Proven, and I like the way it looks. The clamps fit directly over the paint. They fit perfectly, each clamp is made for the exact fitment. Again, proven over time.

bulgie 

Super sanitary! What's the brazing filler? Looks silvery, is it silver (Fillet Pro?) or maybe nickel-silver?

I like how it carries the bag as low and as close to the steering axis as possible. I see some people making their custom racks, giving up lots of clearance there for no good reason. I'm pretty sure I can tell the difference in handling, between cargo close to the steerer and cargo further out. Unless I'm fooling myself! No, I think it's universally agreed, H-bar bags should be as far back as practical for best handling.
I also love how the top of the bag comes right to the top of the bars. I can't achieve that, bars too high, no one makes a bag that tall (and I wouldn't want it if they did). Your way, the bag helps keep your fingers warm, when they're on the bar tops, "drafting" behind the bag — bonus!

Kabuki12

Very nice work, as I would expect! Looks at home there.

bulgie 

Oh yeah and what's the blue button visible in one of the pics? Is that a locking feature on the decaleur, push button to release the bag?
You don't have to reveal all your secrets if you don't want, I'm just curious...

rccardr 

That’s really slick! There’s a receiver for the decaleur on the bag?

Portlandjim

Good eye on the brazing! I have a stash of Allstate 11, nickel-silver. I used this filler for all my Merz racks, never had one fail! I had the bag custom made for this bike, by the master bag maker Philip Woosley.

The blue button is a Button Handle Quick-Release Pin. I modifed one like shown in this photo. Very clean way to make sure the bag doesn't come flying off when you're going down some bumpy downhill! This decaleur is difficult to make, but I must admit it's the best design I've every seen.

mpetry912 

and you machined a longer brake center bolt to account for the thickness of the rack mount strap ?

/markp

bulgie 

I made a lugless frame once ('70s), all brazed with Allstate #11. Hey, I was young and stupid (I'm old and stupid now). I wouldn't recommend nickel for main triangle joints, not if you want to file and smooth the fillets — brass (aka bronze) is better for that — but the stuff is godlike for racks, I agree. Strength of a TIG weld, but much cleaner looking, and fast to do.

Have you tried the flux Cycle Designs sells specifically for nickel-silver? I haven't, but I hear good things.

romperrr 

Great work, I especially love the details. Thanks for sharing!

Portlandjim

I made the hardware for the brakes from titanium, the central pivot was sized for this rack.

merziac

Fantastic!

Great work all the way around, so glad you shared this with us.

daka

@bulgie, I always wince when you equate brass with bronze. In the sailboat world we think of them very differently - if you use a brass (copper/zinc) item below the waterline the zinc in it will disappear thanks to galvanic corrosion and stray current electrolysis leaving the part reddish, porous and weak (see photo in attached link). Bronze (copper/tin) is very much preferred for longevity. Most boats that sink do so in their marina slips - more often it is often a failed hose attached to a thru-hull fitting left open, but the thru-hulls and valves themselves have been known to fail too.

https://www.passagemaker.com/technic...ow-your-alloys

icemilkcoffee 

Awesome work! How do you bend that hollow tubing without it buckling?

Portlandjim

The tubing is 0.035" wall thickness, it's not prone to buckling when bent with a tubing bending die. I made the dies, 2 different radiuses on this rack. I used the HB bag rack on my Singer as a guide, no sense re-inventing the wheel!

bulgie 

I am acutely aware of the alloying elements in brass and bronze. That's why I call the brazing filler brass, despite the entire welding industry and much of the bike industry calling it bronze. The stuff they call bronze is principally copper and zinc, which is the dictionary definition of brass. Example:
https://catalog.gasflux.com/viewitem...er-zinc-alloys
Note, they call them copper-zinc alloys, then in the descriptions below they call them bronze. Except for the one they call silver, which has zero silver in it. (So much for the accuracy of welding-industry terminology...)

AFAIK there is no brazing filler that is principally copper-tin. Glad to be corrected if you know of one, but the stuff we braze bike frames with is copper-zinc.

I got tired of being corrected when I call it brass (even tho it is!), so I use both terms expressly to avoid that. Now I get corrected for "equating" them. It's the welding industry that equates them, not me!

I guess I could just give in and call it bronze, but I am stubborn. Been calling it brass for 50 years now and I'm not likely to change.

bulgie 

In 1/4", even 0.028" wall can be bent with a standard tube-bender like the common Ridgid 394, usually available under $40 used on ebay, example here That's all you need to get started if you want to DIY in your garage.

Downside of the cheap Ridgid is only one radius available, you can't make and swap in your own dies. And if you want to bend say 5/16" tube, then you have to buy a whole 'nuther bender. But they're so cheap, just buy more benders if you want to use different tube diameters. A real bender like a Di-Acro with a selection of tube diameters and bend radiuses will set you back a couple grand.

Don't get the super-cheap Ridgid #456 bender that bends 3 different tube diameters — it's for aluminum, brass and other soft materials, not strong enough for Cr-Mo steel.

I used a bender when I worked at Rodriguez, but that was way before Futurama, so I didn't make that connection until just this second. I hope they have a picture of Bender Rodriguez on the bender in the Rodriguez shop (R+E Cycles).

Kabuki12

In the tool room at the aerospace company I served my apprenticeship in , we had a very nice bending jig with different dies for different radii. Some dies were for flat metal , some for cylindrical work. I used it to make stuff a lot when I was living on my sailboat , even stainless steel of larger diameters was easily formed . It still takes practice and talent to make stuff , even with nice tools. My first few attempts were marginal at best. We had a rack of remnants and end cuts of various metals for G-jobs , I took full advantage of that material . I spent a lot of my lunch breaks making stuff with the help of some really nice lathes and mills . Jim is an artist who took it to the next level for bicycle widgets.

mpetry912 

the picture below shows the workshop at Ets Alex Singer 45 Rue Victor Hugo Levallois.

that thing above the workbench is the bending jig for rack tubing.

/markp

SurferRosa

Oh man, that looks good.

El Chaba

….and the racks are still being made at Cycles Alex Singer, now with Olivier at the bench instead of Ernest…

daka

Thanks for clearing that up - I'm ignorant of the terminology used in the welding/brazing industry obviously. What I interpreted as you "equating" them is actually quite the opposite!

georges1

outstanding job Jim thanks forsharing with us