Refinishing a crank arm
07-30-22, 07:22 PM
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Refinishing a crank arm
Recently picked up a 1989 Centurion Ironman Expert. I believe the
crank arm is a SuntourGPX.. Both crank arms have a worn matte finish
in the same spot. I'm wondering if I'd better off just trying to strip the
finish completely off to the bare metal instead of trying to match the matte finish.
crank arm is a SuntourGPX.. Both crank arms have a worn matte finish
in the same spot. I'm wondering if I'd better off just trying to strip the
finish completely off to the bare metal instead of trying to match the matte finish.
07-30-22, 08:59 PM
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Looks like a painted or powder coated silver finish. Really no way to touch it up with anything durable. You could have the whole crank powder coated.
I’m assuming high-polish is not the right look in this case. Twer me, I’d strip and wet sand to a duller polish. Then I’d probably try steel wool to make it look more unpolished and more like matte silver.
I’m assuming high-polish is not the right look in this case. Twer me, I’d strip and wet sand to a duller polish. Then I’d probably try steel wool to make it look more unpolished and more like matte silver.
07-31-22, 12:54 AM
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FWIW, the bike would originally have had Shimano 105.
07-31-22, 11:39 AM
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I have a '89 Master and I recall when looking the '89 Expert they dropped the 105 and went to Suntour's new GPX group, crank, FD and RD, etc. If an '89 yours is white as shown but with beautiful (to me) smoked blue on the fork, HS area and the stays which I would rather have had than the smoked grey I got. The above advice is spot on for powder coating.
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07-31-22, 11:48 AM
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I have a '89 Master and I recall when looking the '89 Expert they dropped the 105 and went to Suntour's new GPX group, crank, FD and RD, etc. If an '89 yours is white as shown but with beautiful (to me) smoked blue on the fork, HS area and the stays which I would rather have had than the smoked grey I got. The above advice is spot on for powder coating.
07-31-22, 12:44 PM
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When I get cranks with wear like that, I tend to strip the finish. At that point, you will have to polish it, repeatedly.
I am becoming a bigger fan of patina. That wear has no impact on functionality.
I am becoming a bigger fan of patina. That wear has no impact on functionality.
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07-31-22, 02:48 PM
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08-01-22, 08:43 AM
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Did just that on a Suntour set for my Univega. This is sanded ruff, I would need to take it down and do finer grit to get a better finish
These were a battleship color when I started.
These were a battleship color when I started.
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08-01-22, 04:29 PM
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Full on coating, a PITA, warrants some kind of scorched earth stripping, stripper, drain cleaner, etc. Fast, effective, nasty.
Anodized can often be sanded some with a sanding sponge that will conform to the shape better, and then scrubbed with Scotchbrite and maybe rust/corrosion/cleaner.
I can usually get an acceptable happy medium. The trick is to stop before you make a too nice spot and have to keep going.
Elbow grease is quickly becoming harder to come by.
Anodized can often be sanded some with a sanding sponge that will conform to the shape better, and then scrubbed with Scotchbrite and maybe rust/corrosion/cleaner.
I can usually get an acceptable happy medium. The trick is to stop before you make a too nice spot and have to keep going.
Elbow grease is quickly becoming harder to come by.
