Chicago Al 

Here's a random group of GPX parts I somehow ended up with. What was I thinking I would do with them, it's a mystery.
Anyway, as you see, we have:
Shifters
F and R derailleurs
Front Brake
I've done nothing with them, as you see, and they're definitely user grade, but for the right 80s bike project maybe they're just what you need.
$MAKE ME AN OFFER!

Chicago Al 

BUMP with lowered price, in fact just about anything you offer will be accepted.

RCMoeur 

EF / EG = manufactured summer 1988.

Is the rear shifter Accushift, and if so, how many speeds?

Chicago Al 

An excellent question, and one that I don’t have an answer for from experience. However, Velobase does: yes, it’s Accushift! Can’t tell how many speeds though.


https://www.velobase.com/ViewCompone...108&AbsPos=674

billytwosheds 

My guess is 7spd and it would probably shift well across a Shimano 7spd cassette too.

Great little kit for a rider.

Chicago Al 

7 sounds right for the time. Come to think of it I may have a pair of shifters that would work with it, not GPX but Sprint maybe.

RCMoeur 

As I recall, it should say how many speeds on the shifter body itself.

canklecat

Same group that came with my 1989 Centurion Ironman. Very good group, comparable to the Shimano 600 of that era. In fact, I've used both groups on that same Ironman, along with various other shifters, just out of curiosity. And I always return to the GPX group because it works well.

Yup, the right/rear lever is indexed (left/front is friction only). Index mode/Accushift works best. While it has optional friction shifting it's nowhere near the smoothness and overall touch of a good dedicated shifters -- I've also used a Shimano SL-422 light action downtube shifter set, technically from a 6-speed but will cover a 7-speed freewheel, no problem. The SL-422 works so smoothly I've considered making a permanent switch to it for my Ironman, mostly to eliminate any need to tweak my rear derailleur cable when swapping wheels with different freewheels. But the GPX index shifting is so convenient I keep going back to it. I think I've also used a Dura Ace 7-speed shifter set on that bike and still prefer the GPX. The Dura Ace had a bit of slack in an odd lever position that wasn't intuitive for me.

One trick to getting the best from Accushift with the GPX group is to install a SunRace freewheel and KMC chain. I've used them for years, mostly the 7-speed 13-25 and 13-28 on my Ironman, but also a 14-28 on my comfort hybrid/errand bike. The chromed 7-speed SunRace freewheels have been perfectly compatible with my Suntour and Shimano shifters and derailleurs and shift more crisply than Suntour or Shimano freewheels. That's due in part to the carefully shaped teeth, and the chromed finish. Combine that with the midpriced KMC Z72 chains and it'll perform perfectly.

With the Suntour chains and freewheels of that era (I have the 13-24 and 13-26) the chain will tend to hang for a split second on the non-beveled teeth and slingshot loudly onto the next cog. It was so noticeable friends used to comment on it in group rides. Switching to KMC chains and SunRace freewheels made for crisp, positive and quiet shifts. The Suntour freewheels are pretty good, but their chains from that era were terrible, very crudely made. I've saved the original Suntour chain from my Ironman, cleaned and waxed it, in a ziplock bag for posterity but not to be used.

The front derailleur works really well too when properly adjusted. I prefer it angled very slightly inward at the front, rather than eyeballing the cage to be parallel with the chainrings. There's a knuckle impressed in the FD cage that nudges the chain for shifts, and I get better results with the FD cage very slightly askew. Once that's set it's very rare to drop the chain on front shifts.

I also replaced the original tension and guide wheels/pulleys with Tacx sealed bearing wheels. Much smoother than the original sintered barrel bearing wheels. Alas those inexpensive but excellent Tacx pulleys are no longer available. They were basically like the classic Bullseye pulleys but with delrin toothed cogs rather than aluminum. Quieter than the Bullseye too -- I have and use a set of the old anodized red Bullseyes. Too bad Tacx discontinued those, I think I paid only $15 a set back around 2018 and bought three or four sets, and gave one set to a friend.

Chicago Al 

I'm back home and able to look more closely at the gear. It was the shifter you were asking about, not the RD, sorry for my mistake there. The shifter does not have a number that I can see. What it has is 3 modes you can switch between: UL, RE, and a barely visible mark in the middle. UL and RE apparently refer to the type of freewheel, Suntour's ULtra 7 speed, and REgular width 7 speed freewheels. In between is friction, though from what I'm reading in an old thread here, it's not Suntour's ratcheting Power shifting.
I gleaned most of that from this old thread:
SunTour GPX shifter questions
GPX would seem to have a lot of fans here, perhaps because it is not just good stuff, but was standard on some Centurion Ironman models.

smontanaro 

Chicago Al I don't suppose you still have this stuff, do you? If so, I could probably take it off your hands...