Monday, May 13, 2013

Gravel Mutt Project: An Introduction

Trek 520 frame
Saturday I mentioned the "Gravel Mutt Project", the concept and the reasons for doing it. Here I will introduce the bits I am using and working on currently.

The frame and fork are early 90's vintage lugged Trek steel and made in Waterloo, Wisconsin. The original finish is a version of "Trek Green", which Trek must have had semi truck loads of back in the 90's. I can't count how many Trek bicycles were some version of this color, or this color and purple.

Although the frame was made with lugs, Trek had an assembly line set up where all the lugs were joined to True Temper tubes by machines which expedited the process of making lugged frames. So, it is not a "hand made" in the truest sense of the word, but these frames do have a good reputation for ride quality and handling.

Previous attempts at customization
The previous owner was the original purchaser of the frame, and he put something like 40,000 plus miles on this. Over the years, he made attempts at touching up certain scratches, oxidation, and paint chips by applying his own gold and green paint. So, the frame and fork were well on their way to "mutt bike" status before I got ahold of it!

The main area of concern for me was an oval patch of rust pitting that showed through the paint on the top tube. I immediately attacked this spot and sanded it down to determine if I was dealing with a frame in need of further repair, or just a surface irregularity. While the pitting was bad, it did sand out and I feel I will be just fine with a paint job and rebuilding of the bike.

So, there is another reason to pursue the "mutt bike" status. The original paint job has basically been destroyed by the previous owner and myself. Now for an appropriate paint job to reflect the "true mutt bike" soul of this project.

Wheels that came with it...
The original wheels would certainly have been laced up with some Matrix branded box section rim, but the bike came to me with some oddball aero section rims laced to the original DX level Shimano hubs. The smart money would be on the rebuild of the excellent DX hubs and shoeing the rims with appropriate gravel gobbling tires. However; these aero rims are extremely narrow and heavy. I am opting to use a set of rim brake wheels I have in reserve that are XTR hubs laced to Salsa Delgado rims.

At some point I will cut out the DX hubs and relace them to an appropriate rim as back up wheels. The XTR set are much lighter, more durable, smoother, and the Delgado rims sport a much wider inner rim dimension that is perfectly suited to the mounting and use of gravel appropriate rubber. The frame can handle some pretty beefy tires, so I'll likely go with something in the 38mm-42mm range on tires here.

7 speeds!
The drive train the bike came with, a seven speed DX group with a bar end shifter set up, will mostly be retained. I'll likely go with a single ring up front and only the rear bar end shifter with the seven speed rear end. The drive ring will be a 40T ring which should get me a good enough low gear to crawl up most hills around here. I'll likely swap out the crank to an old Sante' crank which I have that is powder coated black. The serviceable bottom bracket in the bike is perfectly fine, but I may go with a Shimano UN series cartridge since they are pretty much impervious to dust and grime.

The bike has a 1" steer tube, threaded headset, which is a Shimano 600 cartridge unit, and that will stay on the bike. The old bars were Modolo Anatomics, and I will ditch those in favor of a new set of Cowbell 2's. Of course, that'll mean something will have to be done about the stem to get the 31.8mm Cowbells to work. I haven't settled on a solution to that yet.

Stay tuned....Gravel Mutt Project will be ongoing for a bit.

1 comment:

Gexton said...

that is a great explanation. keep up the good work with your guitar

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