I picked up a spray bottle of pre-mixed Oxalyic Acid solution from Home Depot the other day. It worked a charm! I found it in the plumbing department in a white spray bottle, with an orange label and sprayer under a brand name like Rust-b-Gone (or something, it's down in the garage). I went specifically looking for Oxalyic Acid, and they didn't have 'wood bleach' or anything like it, so I went hunting. I found this stuff, tried it and took a heap of rust off an old Haro. Not done yet, but certainly underway! I think the spray bottle type is great for surface rust on chrome bikes especially. It's easy to use, and the bottle was like $5, so minimal investment. Check it out.