Plainsman

I’m trying to clean up the cranks on a commercial grade spin bike, and I have two questions:

1. Does the extractor need the magnetic fitting to make its base wider, or use it without?

2. Other than steel wool, any good advice for getting rust out of the nooks and crannies? Any soaks, applications helpful? I plan to prime and repaint once rust is gone.

Thanks for any advice!



With adapter on

Without adapter

Need to clean up this crustiness.

Andrew R Stewart 

I believe the BB and arms are of the "power spline" design and will need the "traditional" smaller extractor end. BTW keep these cranks tight on the BB axle, we've seen far more fall off the spindles then the number in use would suggest.

A popular rust remover solution is Best Rust Remover | Remove Rust Quickly with Evapo-Rust® (evapo-rust.com) I would try it on an out of sight spot before coating the hole part, just to be sure you're good with the results. Andy

Troul 

scrub with CLR, wash off with WD-40. Repeat as needed.

Plainsman

I guess I should have added, since the arms have a lot of rust, I’m looking to strip the paint as well.

Trevtassie

Hit the cranks with paint stripper. Afterwards soak in a citric acid solution (maybe 10 tablespoons in a quart of warm water) until the rust is gone, rinse immediately and dry and prime asap.

Iride01 

That's not a lot of rust. Put some primer on it, paint it and be done. If you are using automotive type paints and a primer with zinc, then no issue whatsoever.

Plainsman

I was thinking this amount of rust merited stripping and refinishing - do you still disagree?

02Giant 

I wouldn't paint over that without stripping the old finish first.

Trevtassie

What he said, exercise bikes cop a lot of very salty sweat...

Troul 

being an inside use only equipment, I'd rough it up & apply an epoxy coating such as chassis saver on it.

Geepig

Presumably it depends on how smart a finish that you want - some people would be satisfied with something like Hammerite slapped over it, others would want something like new.

Only you can answer that.

We just blindly grope in the dark, hoping you tell us more before we blunder too badly...

Troul 

this touches the point in general.

We can give you the tips, but in the end, you're doing the work.

Plainsman

Looks like evapo rust is available at home depot for less than $10. Seems like a good opportunity to try something news. I’m cleaning this up to sell, no more room in the house. It works fine, but is unsightly and will hurt resale. I could by a replacement crankset for $70, but would rather go the elbow grease route I suppose, esp if I don’t want to take a bigger loss on the sale. Thanks for all of the tips!

Troul 

For future knowledge, this would have been very critical in the initial post.

Iride01 

If you do a really fine perfect paint job that will last forever, you'll probably spend more on the paint job than you'd have gotten if you just spray some paint on it and be done.

If you are selling it used, then the people buying it should expect it to be used.

Plainsman

I’m not sure I understand why though. I want them to look nice and hold up, regardless of whether or not they are for me or for someone else. My refinish plan would be pretty much the same either way I think. If refinishing cost more than replacing, I would wind up just replacing them - same again either way. I do appreciate the good advice - I feel like the tips have been invaluable.

Troul 

cost effective responses would have ensued first.

Plainsman

- that’s fair, good point. I guess I really wasn’t thinking about there being a difference. Lesson learned. I always appreciate the advice I get from this forum.