I have placed six orders in eight years to bikepartsusa.com and have had mixed results, mostly bad. They offer good prices on their "house" brand (Pyramid) which they appear to import themselves. This is a cheap line of Chinese bike parts, which work fine for cheap Chinese bikes. No revelation here! I wouldn't DREAM of using them for anything critical, or for anything I need in less than a month.
Their website is truly gruesome. The descriptions are extremely sparse, inaccurate, and use jargon that is understood only by its writer. The pictures are the size of postage stamps, and can be completely wrong, or, at best, useless. If you can cross reference the part number, this is usually the only way to determine if the part will work for you. Alternately, if you are an expert or very familiar with the part, you probably won't need accurate pictures or text. But this is all obvious, except to bikepartsusa, apparently.
I try to be forgiving, and after not ordering for almost two years, I decided to give them a try again. Companies do change, sometimes. I placed a small, non-critical order by phone, and because of troubles with their funky "Smart Post" shipping, requested it be sent Fedex. No problem, the order arrived as expected. So two weeks later, I decided to place a larger order for items I really needed within two weeks. I specified Fedex shipping and offered to pay any extra amount for it, just like on the previous order, and I did this by filling in a form on their website, and also by calling them on the phone, TWICE, once before placing the order, and again when they said the order was "on their loading dock." Well, they lied to me. They shipped the order by worthless "Smart Post" again, and true to form, it has not shown up for three weeks.
The last time this happened, I had to wait two months for a refund, for which I had to spend a great deal of time calling AGAIN AND AGAIN requesting. After three full months, and after I had cajoled a refund out of them by screaming and threatening with the help of my credit card provider, the order finally arrived. Being an honest person, I called them to arrange return of the items, because, naturally, I no longer wanted them, and hadnt paid for them. They tried to get me to ship the product back at my expense, but I insisted, rightly I believe, that they should pay for return shipping because of the delay. They said they would send a call tag. After two more requests for a call tag were ignored, I gave the items to a local charity and forgot about the affair.
So I cant tell if bikepartsusa is merely a scam, if they are just incredibly shoddy, or if they are pathological liars. I certainly would not recommend them to anyone. Unless you are absolutely sure there is no other source, I strongly suggest you shop elsewhere unless you like stress and conflict.