Sunday, May 5, 2019

Project Lazarus: Turns out he was only Mostly Dead

Pre Crash Sept 2018
As I mentioned earlier I found that the replacement fork from a 1986 Schwinn Passage had a longer steer tube than the Cresta fork and I didn't have enough threading on the fork to snug up the headset.  I had called a local frame builder to ask about adding threads and was told it was not often successful and when they did do it they charged $200.  I was disappointed but the bike forums community encouraged me to keep trying and a couple even offered their die cutting tools if I wanted to try it myself, and I got more shop and builder suggestions.


I tried 3 more recommended shops/builders and got the polite brush off each time except for the shop that didn't even respond.  The last one, however, made a suggestion I hadn't thought of, a shop that used to be local to me but had moved to a cheaper neighborhood, Aaron's Bike Shop.  The owner is a bit of character and not everyone's cup of tea, but say what you will he is a master mechanic.  I reached out and got a positive response that yes they could add threads and it would cost $25.  Sold!  I stopped by after work last week and was in and out in 5 minutes.  Amazing what you can do with the correct tools and know how.  You can see the slightly shinier new threads above.


I had to check and see if it worked of course, even though I had marked it carefully before taking it the shop, and viola the headset snugged right up.  I might need some spacers for the extra length but one problem at a time.


I had decided that I wanted to ride the bike with both forks back to back to really test how it felt.  To that end I dug deep in my parts bin and discovered some XT cantis I had from about 5 years ago when I parted out an early 90s MTB for a friend.  To speed the swapping fork process I mounted them to the Passage fork and tested that they would work.


The original re-bent fork went back in and I measured the threads that were showing after I threaded on the top race - 1 cm.


The Cresta was ready to go with the rescued fork and immediately it confirmed my original feeling -twitchy especially at low speeds.  In my 2.5 mile test ride I really felt the need to grip the handlebars securely,  It rode fine but just felt different, exactly what I had experienced when I first rode it after the fork was fixed.


With the passage fork I had 3 cm of threads showing for a 2 cm delta between forks.   The spacers I bought when I upgraded the Cresta headset are about to come in handy.


The spacers allowed me to get everything snugged up without showing any threads,  The rubber seal is a bit askew but its fine for test purposes.


All ready to go, having the extra brakes mounted helped but of course I still had to fiddle with them to get them dialed in.   And in the first few pedal strokes up the slight incline I could feel it... not twitchy!  I think this might work.  And I as I rode on over the same route it seemed like the bike adsorbed the bumps and ruts better, the increased fork rake or just my imagination?   Anyway I liked the replacement fork and was very glad I actually got to use it.

A progression of shots in roughly the same place


Sept 2018 pre crash


May 2019 Post crash after forks were fixed


May 2019 The Crest-age

For one short ride I am happy with result and in my normal rush ahead fashion I am thinking of how I could paint the fork white when I am house sitting next weekend and also how I could get the steer tube trimmed by 1 cm, BUT, I want to ride it more and do more than 2.5 miles before I go down that path.  It looks a bit odd with the mismatched blue but its not hideous and it has, I think, got back its stately ride.


Ride. Don't accept the No's. Smile. Repeat.

4 comments:

  1. Ryan,

    I commend you for your tenacity! The back to back testing was a brilliant move to solidify your direction.

    It's difficult to tell what the trail is on the Passage vs Cresta post-crash fork. Too bad you don't have numbers on what the pre-crash fork was. That would be good to know.

    Are there double eyelets on the Passage fork?

    Last, I'm curious the process/technique that Aaron's Bike Shop used to extend the fork threads. Care to share?

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  2. Hey Josh, Thanks and yes the Passage for has double eyelets but no mid fork eyelets.

    So Aaron had a tool that looked like a circle with handles, The cutting teeth being in the circle, He started the teeth in the existing threads and rotated the tool down to the blank steerer tube, he sprayed lubricant on the tube and then rotated the tool with handles, and would occasionally spray more lubricant as he used the handle to rotate the teeth cutting new threads. Based on the blue knobs on the handles I would guess it was a Park tool for 1 inch steerer tubes. He said the trick was to keep the cutting teeth sharp. I am sure there was more going on but it looked pretty straight forward.

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  3. Interesting. i remember cutting threads on steerer tubes back in my shop rat days. We had a Hozan die & handle. The trick i learnt was use plenty of oil- PLENTY of oil, and about every 3/4 turn in to reverse the tool about 1/2 turn & clear the chips with a generous shot of WD40 and a blast from the compressor, then re-oil the tool and slowly cut a bit more.
    i recently had a fork that i took in to have more threads cut, but -i hate to say it- they didn't do such a good job... live & learn. If i had the tool, i'd do it myself, but it's an expensive proposition for something i'd use maybe once.
    A builder explained to me that most steerer threads are "rolled", not cut, and many of those steerers are very slightly oversized,and that makes die cutting dicey. YMMV.
    Congrats on the resurrection!

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    Replies
    1. Thanks Mike, I was lucky I had a mechanic who had the tools and knowledge to do it right and he was generous with the liquid while cutting the new threads. Happy with the results, not a job I had to tools or knowledge to tackle.

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