It may be hard to read, but the serial number for the 1987 Dyno Detour on the left is and the serial number for the 1988 Dyno Compe on the right is. From the bend at the top of the rear tubes above where the rear brake mounts, is an entire inch different between the '87 and '88. The difference in the rear of the frames are illustrated here. On the 1988 Compe it's one solid piece bent back on itself with two holes drilled out for brake cables. You can also see in this picture that the support plates around the seat tube on the 1987 Detour are completely open (basically two separate 'Dyno' stamped plates, one turned upside-down and welded opposite, hence the logo on the bottom side too). You can see that the blue frame is about an inch higher in the back tubing as this was changed from '87 to '88. To prove these are structurally different frames, I illustrate in this next picture where I've laid the smaller 1987 frame over top of the 1988 frame. These are both factory original and have not ever been repainted or redecaled. I have an original 1987 Dyno Detour and a 1988 Dyno Compe. Then I went to my storage shed and pulled out two old Dyno frames I've had for a while, and the same debate continues on these as well. Dyno switched decaling in 1991 as well, with 'Dyno' and 'Compe' literally switching places on the bars. I know there are those who will say you can see this type of drop out in the '89 Catalog, but as far as hitting the showrooms, I don't think these appeared in their Production bikes until the 90s. Is it then really a 1989 model as he states? Or a 1991 because of the '91'? I know Dyno didn't switch to the cutout/flare-back drop out (and again to the straight forks) until the 90s which would make this a 1990 at the earliest. When I looked at the serial number in the picture, is where I started to get really confused. Upon looking at his pictures, I could instantly tell that it appeared to actually be a '90' model instead because of the decal set and the straight forks Dyno went to beginning in 1990. I happened to see this bike on eBay a bit ago and the seller had it advertised as an '89 Dyno Compe Survivor' based on the serial number on the dropout he was able to read.

Bmx serial number decoder