Will it rattle, that is the question.
I recently acquired a new bicycle for my main mode of transportation. It’s a Kogswell frame, you could reference the Spring 2010 issue of Bicycle Quarterly to get the specifics for its frame geometry and front-end angles and characteristics, as it is the 700c test bike that they used to do a side-by-side comparison of the handling differences between 26″, 650b, and 700c wheels in different tires sizes. I migrated many parts from my previous bike to this one when I built it up, including my main cargo carrier, the Cetma Rack and Swift Industries Pelican bag. The Cetma Rack is a great product for what it is, a versatile cargo rack capable of hauling large amounts of weight and able to be attached to virtually any bicycle ever made without modification. However, it is lacking in a couple of areas, mainly stiffness and aesthetics. The P-clamps that attach the struts to the platform are not secure enough and the rack has a lot of play. I originally got it because it was a massive improvement over my dishwasher crate tied to a cheap aluminum front rack, and I am once again ready for an upgrade.
The Kogswell has Fork Crown, Mid fork, and 6mm upper dropout braze-ons, and it’s a shame to be using a rack that doesn’t take advantage of any of these. This is great beginning project for foray into the world of brazing, but the first task is to design. I, like usual, am trying to make something different. The rack I want to build is a multi-use, convertible piece of equipment, capable of carrying my Swift bag and also loosing some weight and supporting a smaller lighter bag for longer rides where I’m not carrying 30 pounds of groceries. The basic idea I’m working off here is that there will be a small randonneur style rack as a base (13cmx21cm), built from slightly heavier tubing than typical. It will anchor to the fork crown mounts and either the cantilever posts, or the mid-fork braze-ons (still thinking about that one). On top of that will be a removable 30cm square platform that will anchor to the smaller rack via sleeves, or bolts, or something else bearing a remarkable resemblance to magic. I sketched something out in Solidworks this afternoon, which I think is a decent looking proto-type. I’m still unsure about the cantilevered weight and not having support directly below the load.
Attachment is through the two sleeves on the rear corners of the base and one m6 bolt on the front.
Detail on the right sleeve attachment
Detail on the front bolt attachment
Hi there,
I’m kind of in the same boat with the Kogswell and the fancy fork, and I’m wondering how this project is coming along. I like the idea of a convertible randonneur rack. Rivendell did something like that recently. It’s a little clunky:
http://www.rivbike.com/products/show/nitto-platrack/20-203
I did notice that the Cetma halfrack is welded rather than clamped. I emailed Lane at Cetma, and he seemed interested in designing a bracket to attach to those eyelets on the forks. It’ll cost a little extra, but I thought it might be worth it. He also stated that in his estimation an attachment at the lowrider mount (that one on the fork blade) would decrease the load-bearing capacity of the rack.
So my current strategy (not feeling like I should learn to braze anytime soon) is to get him a sketchup model, contact Swift and ask about the stability of a possible halfrack strapping system, and go from there. I’m guessing I’ll either end up asking for a small rail along the back of the halfrack so that the bag can strap to it higher up or go with four low straps on the bag.
Tim,
Regarding the status of the project, it is functional. Not perfection, due to the fact that it is now functional and I use it every day. I swear it would be easier now to make a whole new one the way I want it, instead of taking this one off the bike and modifying it and having to deal with living without it. What ended up being made wasn’t actually the same as any of my sketchup’s. It does use the sleeve idea and is a pull-apart. I’m pretty sure there is at least decent documentation of it higher up in the blog.
The Rivendell rack is clunky, and does something that I was trying to avoid, have the larger take-away platform run legs down to the dropout braze-on’s. It makes the platform, when taken off, very cumbersome, and adds an additional two bolts to remove to be able to remove the platform. Lane is right about the decreased load bearing capacity by using the mid-fork braze-ons instead of the ones on the fork, as the load is more highly cantilevered. Using the eyelets at the dropout the main load bearing support is almost directly below the load. Speaking from experience with this rack however, I have carried 40 pounds with relative comfort with it and was not worried about the rack. Use good cromoly steel and it shouldn’t much of an issue within the bounds of reason. I’ve considered making other addons for a bigger platform that would having legs to the dropout, or low-riders for panniers.
Like this: http://www.boxdogbikes.com/blog/wp-content/uploads/2008/06/dsc02477.JPG
Hey, just saw that you have a 700C Kogswell P/R. Is yours serial number CB70W0090?
You are correct, sir. How did you guess? I got it from Matthew through Jan Hein. It’s the 700c test bike used for the Bicycle Quarterly article on wheel size vs. handling characteristics.
I have a 700C P/R as well. When I bought the frame, Matthew sent me frame #CB70W0090 first, but I was unhappy with some defects on it (notably the crooked dimpling in one of the chainstays, and the poor alignment of the rear triangle) so he sent me another frame (#CB70W0093) and then later asked me to send the first one to Jan Heine for the magazine testing. I always wondered what happened to that bike! Glad it’s getting ridden!
Mine can be seen at http://www.flickr.com/photos/jimg/sets/72157603962290528/