Good morning! I'm new to this forum, I'm from Brazil and this bicycle came to me, it's a USA GT Mach-I pro-series PMX 26-inch wheel. I want to restore it, but I haven't found any information about it on any Brazilian website. Could someone help me? I noticed that the pedals are no longer original, as they are from a Caloi Cross. I would like to know if there is anything else different about it that needs to be corrected. Thank you in advance!!

It looks like an early GT. Looptail was common then. I'm that that knowledgeable on BMX, perhaps others can add more details.

Interesting to note that at this point in their frame design the seat stays end at the seat tube rather than the more forward to land on the top tube. It also looks like it has a derailleurs front and rear. Hmm.

Early GT's and BMX 26" wheel bikes had either a coaster brake or single speed freewheel, not derailleurs. The brakes and headset look lower end. GT's during the BMX period had better quality components. I am wondering if this was a bike from a period when the GT name was sold and the new owner many have cashed in on the GT name with a more affordable bike.

It does have the GT top tube that extends beyond the seat tube. I'm hoping someone else has better answers than my lame observations.

looks like very early GT, I don't think I ever saw one this "Vintage" before, but as noted it may be a "budget model" or just how they built them BITD.

I suggest to take the pix and make a new thread in this "BMX" forum"
https://www.bikeforums.net/bmx/

Could be you have a real collector's item here, but I sure don't know

that is an interesting frame

17 pages of Mach I's on https://www.bikeforums.net/bmx/ , Seems to cover the years they were offered? didn't see one that looked like yours?

Seems like most older graphics used "one" rather than "1" like on your bike?

If you figure it out, check back in and tell us what you found.

Here's 211 pages of GT bikes. I got to the mid '80s and saw nothing like yours. https://bmxmuseum.com/bikes/search?y...mpany%5B%5D=40

Aside from all the other odd aspects, the head badge decal looks fake. I'd put some money on the bike being a non-US-made knockoff.

Edit: after another look, the head badge appears to be painted on, and with obvious orange peel from a bad paint job.

If the components work reasonably well and the bike isn't otherwise damaged, it's probably worth replacing parts as needed to keep it running. But given that it appears to be a fake GT, I wouldn't bother trying to restore it to resemble a genuine US-made GT.

Thanks for the link gearbasher . Looking through the pictures, I have to revise my statement. While many BMX bike, most notably Mongoose, used a looptail rear triangle, GT used straight tubes. They did extend the top tube beyond the seat tube, but the seat stays attached to the top tube aft of the seat tube.

This one has me scratching my head a bit. Some things, like the headtube graphics, the configuration of the rear triangle and what looks like a skinny (and maybe flattened) down tube don't look like typical GT frame styles.

I'm with Trakhak though, rather than trying to identify exactly what you got, ride it if you like it and upgrade what you don't like or keep an eye out for something else. I rarely, if ever see a 26" bike from the BMX era. It is interesting to note that Bike Boom bikes can be easily found, but BMX bikes from a decade later are rare.