Bontrager Race Lite rebuild, interesting history...

pw_pw_la

Senior Retro Guru
So many amazing Bontrager projects on the go on here at the moment!

I love it.

Following along with interest/admiration/jealousy!
 

Elfman

Bontrager Fan
Well, while I'm waiting for the frame to come back from the powder coat shop (sounds like it will be ready Tuesday!!), I'm starting on refurbishing the Mag 21 SL Ti that will sit on this frame. It's got the typical leg cancer, which I plan on remedying by figuring out how to refinish the gold lacquer. You can see that it is in need of some love...

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Upon disassembly, I discovered that the prior owner did not fully disclose its condition to me in the ebay sale (big surprise!)....the crown bolts are not Ti (as I said before, I used to own one of these and I recall all bolts being Ti), and both of the threaded holes in the right fork leg were stripped at one point, and the previous owner used some sort of epoxy or lock tite to secure the brake post and bolt into the leg (and the bolt was chromed steel and not Ti as well, although the post was still Ti).

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I think this is some sort of epoxy and not locktite, as you can see the hardened gray "glue" that had oozed out of the fork leg once upon a time. The other result is that the bolt hole through the brace was cracked. Not sure if I will try to fix this or buy another brace from somewhere.

IMG_20220116_151126_8.jpg

The oil definitely needs replacement, but the legs appeared to hold air. I am trying to assemble rebuild parts for this, including possibly a long travel kit (again, had this once upon a time and liked the added capability, and I used the bonty with it on tight single track in North Carolina without any handling issues despite the slight changed in geometry).
 

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Elfman

Bontrager Fan
The fork leg refinishing will deserve special attention and study. My plans first are to remove the existing finish and decals, either chemically or by gentle mechanical means. I tried doing this 15+ years ago with the original Mag 21 SL I owned, and I found that I could gently remove the lacquer with a gentle brush attachment on a drill press. After removal, I'll try polishing and buffing the legs if the oxidation doesn't prevent that. If corrosion is too severe, I'm going to try to find a chromed spray I can apply. The goal here is to get a highly polished mirror like finish, either with the native magnesium or with the chromed application, and then coat that with a gold laquer. I'm thinking one of the more brass-like tints from Nikolas, who makes lacquers for brass instrument refinishing and such, might work. Then I'll apply the new decals and do a clear lacquer over that for extra depth and shine.

I may experiment first with a gold spray paint, like Montana Cans Goldchrome or Design Master Gold Enamel, but my experience with these simple spray applications is that they always fall way short of actually looking like gold, or the gold lacquer that was stock on these forks. Jassa Bikes (Marcelo) in Brazil has given me some hints, but none of his products are available in the States, so I either have to find U.S. analogs, or try other methods, like described above.

Wish me luck and as always, I'll post my progress.
 

Elfman

Bontrager Fan
While I'm waiting for the frame (not done yet), and sourcing parts for the fork, anyone have opinions on black versus silver bottom bracket cups? Components will be a mix of black and silver based on what I have, but more of it will be black, including headset, stem, seatpost, and cranks.
 

Elev12k

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Orange is nice. I do remember them from the magazines. With 1600 DM the Race was relatively affordable compared to other steel offerings imo.
 

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Elfman

Bontrager Fan
OK, well the original powder coat was pretty thick, so it's taking more chemical stripping than anticipated, and the painter had to order more "just orange". So, looks like the frame won't be ready until early next week. But that gives me time to keep working on the mag 21s, which of I've hit with Jasco's stripper to get the old lacquer off. Will attempt to polish this weekend if the stripper succeeds. IMG_20220122_130533_2.jpg
 

Elfman

Bontrager Fan
Stripper has succeeded. But, the worm-trace cancer and oxidation remains on the legs, albeit without any trace of the lacquer. So, I got out the fine-grit sandpaper and started hand sanding, starting with 320 grit. Now magnesium is quite soft, so starting with 320 worked well to remove the remnants of cancer and oxidation. You can see below part of the leg (mid section) has been sanded, while the dropout is unsanded. IMG_20220122_152130_2.jpg
A fully sanded leg with 320 brings back the native silver tones, but leaves a slightly dull surface with scratch marks from the grit:
IMG_20220122_152638_3.jpg
Proceeding up to 600 grit, and starting to sand circumferentially instead of lengthwise along the leg:IMG_20220122_153352_9.jpg

And then moving up to 2000 grit and rub down with a dry rag gives a pretty damn nice polish, but not quite mirror finish:
IMG_20220122_154755_8.jpg

Tomorrow I'll break out the buffing compound and polishing wheels on the bench top grinder and try to work towards a chromed finish. And because I was able to achieve this high polish on the raw magnesium, I'll try to source a gold-tinted lacquer to apply next.
 
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