Rack Eyelets and Frame Alignment Gauges

rack_w_tabs

It’s encouraging to see that handbuilt bicycles have made such a resurgence in recent years. Building a frame by hand is a labor-intensive process, but done right, the result is a bike that rides better and is more versatile than any mass-produced machine. The best bikes today have custom-made racks that are designed to fit the bike, so they do not need sliding adjustments and thus are lighter, stiffer and unlikely to rattle loose.

Making a good rack is a lot of work, especially if you use small tabs to attach the rack to the fork or frame. Compared to tubes or other attachments, the thin tabs put less torque on the bolt, and so the rack is less likely to loosen due to the vibrations of the road. If you file these tabs by hand, you’ll spend about 20 minutes per tab. And the rack shown above has six of them, so that is two hours of filing tabs! (How do I know? I made the tabs for the rack above.)

framebuilding_rack_tabs

To make rack-building a little easier, Compass Bicycles now offers rack tabs. There are two versions:

  • Version 1 (top) is for the ends of rack tubes, so it has a 5 mm hole and a tab at the end that goes into the rack tube.
  • Version 2 (bottom) is intended as a frame braze-on, so it has a 4.2 mm hole that is ready for M5 threading.

The tabs are laser-cut from 2.5 mm-thick steel and dimensioned for 1/4″, 7 mm or 8 mm rack tubing. More details are here.

frame_alignment_tool

Also new are these nifty frame alignment gauges. Developed by Bicycle Quarterly contributors Alex Wetmore and Hahn Rossman, they greatly facilitate checking the alignment of the frame during and after the build process. There are two versions, one for bikes with 130 – 142 mm rear spacing (top), and one for bikes with 120 – 135 mm spacing (bottom). More details are here.

These new products complement our existing range of fork crowns, fork blades, centerpull brake pivots and other framebuilding supplies. Click here for more information about our framebuilding supplies.

About Jan Heine, Editor, Bicycle Quarterly

I love cycling and bicycles, especially those that take us off the beaten path. I edit Bicycle Quarterly magazine, and occasionally write for other publications. One of our companies, Bicycle Quarterly Press publishes cycling books, while Compass Bicycles Ltd. makes and distributes high-quality bicycle components for real-world riders.
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20 Responses to Rack Eyelets and Frame Alignment Gauges

  1. Xavier says:

    Having fitted a few racks and fenders with lots of sliders and washers I can relate to the joy of a solid, light, monobloc,custom, perfectly fitting rack.

    Whey you say:
    “Building a frame by hand is a labor-intensive process, but done right, the result is a bike that rides better and is more versatile than any mass-produced machine. The best bikes today have custom-made racks that are designed to fit the bike, so they do not need sliding adjustments and thus are lighter, stiffer and unlikely to rattle loose.”

    Handbuild frames are a joy, but I see no reason why mass-produced bikes could not come with custom-to-the-bike racks. I really hope that the path you and framebuilders are showing will lead to major bike makers taking note and offering joyful bikes too.

    • I see no reason why mass-produced bikes could not come with custom-to-the-bike racks.

      There is no reason why it couldn’t be done, but the fact is that no mass producer is doing it (yet?). I hope it’ll happen eventually…

      • I think that Velo Orange attempted this sort of thing with their Randonneur production frame: the rando rack was designed to go on that frame, though it is adaptable to others. It’s by no means perfect, but it’s pretty good–no slots or sliding connections.

      • I am glad that Velo-Orange is offering frame and rack to go together. The Velo-Orange rack has squeezed tube ends instead of tabs. It’s a simple and inexpensive way of doing it…

  2. Twenty minutes seems like a longish time. I usually tack a few together to make it go a little faster. The ones I bought from AW back in 2009 were 0.124″ and 0.96″ thick. The front rack supplied with the Mercian had tabs that were only 0.062″ thick (after rechroming). Lately, I’ve been using 0.08″ 4130 with no problems even on porteur racks.

    Nonetheless, I’m happy to see them offered by Compass and I’ve already placed my order.

    • If you make a lot, you may get quicker than I am… but when you actually time yourself, you realize how long things take. It often happens that the evening is here, and I’ve spent the day in the shop on just a few little things that I thought would take an hour or two at most.

      The old French racks, like that on your Mercian, often had very thin tabs. We made ours a bit thicker, knowing that it’s what most builders prefer these days. They still are very light, because they are so small.

  3. jimmythefly says:

    Non-adjustable racks from the factory has happened in a few instances that I can recall. Salsa Casseroll 2012, Raleigh Port Townsend, Raleigh One-Way 2011 (also low-trail!), Specialized Globe Live 3 2009 (fork crown mounts! Low trail!), Trek Belleville 2010, Electra Ticino 20D 2010(reviewed in BQ, I believe?)

    I remembered the models, but had to look up the year offered. Disappointing to see that the Port Townsend is the only one current.

    In most of those cases there are things that compromise the design, though the Ticino rack looks pretty good.

    • Frank B. says:

      The small Ticino rando rack fits perfectly on a Rawland Stag (see my site).
      I think there was a time when racks were made in the same factory as the rest of a bicycle and then the rack often was built with a certain model in mind. This typically was so on mass-prodcued utility bicycles. Building adjustable parts in this context would be more expensive then building parts that Just Fit. I think, many Dutch roadsters had non-adjustable racks as did the equivalent bicycles from German bicycle giants like Winora. Today it’s different: Companies have special subbrands for accessoires and components, like Trek with Bontrager or Winora with XLC over here in Germany.

      • Frank B. says:

        Forgot to say: The Ticino Rack fits only, if you drill out the fork: It uses a recessed bolt. But after that it does fit “perfectly” …

    • Charlie says:

      You’re not gonna like the 2015 Port Townsend, then.

  4. jimmythefly says:

    Oh -also there are some 80’s bikes that came with aluminum non-adjustable front racks that mounted to the dropout eyelets and the fork crown. I know a few Treks came with a Blackburn model that wrapped around behind the fork crown. Also some Schwinns (and others) had a similar design that just sandwiched behind the caliper brake.

    I know I’m digressing a bit, but interesting to note these older designs.

  5. rodneyAB says:

    . . been thinking about the rack options, not many beyond the GB M13 for cantilevers. . .been thinking about the GB 53mm fork crown and the Kaisei ‘Toei’ blades, and some previous post about cantilever brakes generating twisting torque on delicate fork blades. If GB makes one rack to fit their bicycles with cantilevers, Do they utilize the delicate Kaisei fork blades?, and not worry about twisting torque?
    . . the above rack looks mighty cool to me, but that’d be two to three times the price of a GB M13, so although I very much like the above rack, it seems a more practicable approach would be the GB M13, coupled to cantilever bosses on Kaisei ‘Toei Special’ fork blades, and not think about the torque applied by braking with cantilevers.
    . . do Mafac Raids have the same braze on dimension as do Weinmann or Dia-Comps?, this center pull braze-on bug has just hit

    • The fork blade twist with cantis is real. You notice it when braking hard – the brake action is not linear, since the brake pads change their orientation to the rim. As you mention, centerpull brakes are better, since they attach closer to the fork crown, where the blades are supported much better.

      The Kaisei fork blades are super-slim only at the bottom, so that doesn’t affect the twist. However, the “Imperial Oval” cross-section, which is longer and narrower than the more common “Continental Oval” probably does not resist twisting quite as well. Ideally, you’d have a round fork blade for cantis… or even better, centerpulls.

  6. David Pearce says:

    Interesting how the in photo of your eight tabs, you have arranged them all so they have a little “hook” on the lower right corner of each. Is this intentional–is it used in the braising to position or tack the tab–or just a vagary of your cutting machine?

  7. David Pearce says:

    To me, a small weak point on the rack might be the attachment to the fork blades. Right now, the receiving tabs are attached perpendicular to the fork. I wonder if it would make any sense to cut the mounting surfaces of these tabs on an angle, so when are braised on, they continue the angle of the rack support legs into the fork blades?

  8. Erik says:

    If you make a custom rack, why would you use tabs? The strongest and lightest way to attach a rack is to braze it to the frame. Mount the two top supports on top of the fork crown, so the don’t disturb taking of the brakes, and braze the lower supports on to the fork blades. You’re always raving about integrated design so why not ?

    • Brazing a rack to the frame was popular in the 1930s. We don’t know why it fell from favor. I suspect it was because if you bend the rack in a fall, it’s harder to fix. Or perhaps it was because it’s hard to chrome-plate a complex shape like a rack in the first place, but once you attach a fork (or frame for a rear rack), it becomes nigh on impossible to get good coverage on every tube. And painted racks will wear down to bare metal in no time at all. The four little screws and six tabs add almost no weight at all, nor do they detract from the stiffness of the rack. And well-designed racks don’t come loose, either.

      Still, if you want to braze your rack to the frame or fork, I’d say go for it. You wouldn’t be able to attach the rack to the centerpull pivots, but you could attach the top to the sides of the fork crown.

    • Alex Wetmore says:

      BQ reviewed a Tout Terrain a few years ago that had a brazed on rear rack. The rack was dented (cosmetically, not structurally) in shipping. That becomes an expensive repair since replacing the dented tube also requires repainting the whole frame. Shipping that bike was also complicated by the longer length that came with the brazed on rack.

      In contrast a custom rack can be rebuilt and replaced without replacing the entire frame. Racks on heavily used bikes do seem to get damaged with greater frequency than the bikes that they are attached to.

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