Wednesday, August 14, 2019

Trek 420 Refurb: Tear Down


I got the Trek 420 in the Stand on Sunday so I could work on tearing it down to the frame this week.  Man is this thing dirty, just standing next to it makes me need to was my hands lol.


I hadn't really intended to do more than a clean up, refurb, and replace the consumables but this ridiculous corncob cassette forced my hand.  For a race bike it would be fine but for a touring bike, even a sport tourer like the 420 with a triple it totally defeats the purpose, so I ordered a Shimano 12-32 7 speed cassette which makes much more sense and will give the 420 a nice wide range of gears for hilly Seattle.


On Monday I was just looking to get started; stem, seat post, derailleurs and wheels got removed that and tossing the old chain.  No issues so far but it's early yet.....



Three of 4 bolts holding the rack to the frame came out fine, but the worthless 3 mm allen cap head bolt had rounded making it impossible to get out with an allen head wrench.   People use a 4 or better yet 5 mm head but never a $%^ing  3 mm.  Sigh.


So I thought I will just use my hack saw to create a groove so I can use a screw driver to get it out.




Here's a tip when you are trying to use a large screw driver on a half assed groove you just cut in a allen head bolt don't position your hand where it will be in the way when inevitably the screw driver slips.  Literally a self inflicted wound..sigh.




Eventually I got the little bugger out with only minor scrapping on the rack.


And the rack joined the growing pile of parts in the box.  On to the crank which I removed the pedals from a while ago thinking I might need to loan them to someone.


Bolt covers are intact on both sides which is nice.


Here's a pro tip remove the crank bolt nuts BEFORE you try to use the crank extractor, it makes the job much easier, ask me how I know.  No idea how I skipped that step.


With the nuts removed I am ready to try again and..


wow it is much easier this time around.  So far besides a rounded allen head bolt I am mostly getting in my own way.




The headset came out fine and I secured all the parts in order with a zip tie to keep them together.  The picture will also help me to remember the order of the spacers.



I had intended to remove the headset cups too as they are easier to clean that way but for the first time ever my cup removal tool failed, it couldn't get purchase on the lip of the cup inside the head tube for some reason, not the end of the world and I could use other methods but for now they will stay in.





The bb didn't offer any issues, I didn't even have to use through bolt method to loosen up the fixed cup.




And so we are down to a frame and fork.  I think the paint is mostly good but there are number of what I think are tar spots I hope the Goof off will remedy and then there are some scrapes that went down to the metal and rusted so a Naval jelly session will need to happen. I will need to try to find some nail polish that is close to the color to cover the metal once the rust is gone.  And while I am at it I will frame saver the inside of the tubes.


Ride. Try and stay out of your own way. Smile. Repeat.

2 comments:

  1. Wow, always impressed that you strip a bike to the frame and rebuild. I once tried to extract the crank without first removing the nut - so you're not the only one! My LBS set me straight - fortunately, only ruined the tool.

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    1. Thanks Annie, it seems like a lot of work but imho it makes cleaning the bike easier and quicker, especially since I can use the sonic cleaner for most parts, and it gives me a chance to look over parts and discover any issues I might not see if it was still hanging on the bike. And waxing the frame when its bare is pretty straightforward. YMMV

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