gbalke

There should be a set of letters and numbers stamped into the seat tube near the top; two letters followed by 6 digits, such as NC123456. The letters indicate where the frame was made frame. The first number should indicate the year it was made.

More information can be found on the following web sites:

https://www.sheldonbrown.com/retroraleighs/

If you check out the 1976 catalog page found on the link below, you'll see that year's model. Compare the decals shown to those on your bike. 1976 was the last year the Grand Prix came with cottered cranks, such as your bike has. Cotterless cranks were introduced in 1977. Based on this, your bike was made prior to 1977.

https://www.sheldonbrown.com/retroral...rand-prix.html

This following page deals with the various manufacturing date codes. Some what confusing.

https://www.sheldonbrown.com/retroraleighs/dating.html

Another site for Raleigh serial numbers:

https://www.jaysmarine.com/TH_raleigh_serials.html

Have fun researching your bike's history.

Grim

Welcome to the C&V forum. I recently found a Grandprix in the trash and dragged it home. The frame is really not that heavy considering the vintage. The lug works is really interesting. As somebody else mentioned "try to find a set of quality alloy wheels" and it will take quite a bit of weight off the bike.

I have been trying to get and exact date on mine and it seems to be equipped almost identical to yours. My best guess is a 73. The Simplex prestige Derailleur seemed to fade after that. It was the first year that I could match the paint color and parts mine has.

I was going to try to do a correct restore on mine but that Simplex is a problem. They just don't last and mine is bent up quite badly. For the short term I think I will convert mine to a single speed.

The cranks may be a problem. cottered cranks are notorious for being sloppy. The threading is not common to anything new. Swapping out the Cottered shaft to a square shaft is the easiest thing to do as you can still retain the original bearing cups. This is detailed in the links posted above for Sheldon's (RIP) web site.

Yard sales and thrift stores would be a good place to find a parts bike. just make sure you don't get into that hole a lot of us seem to dig...the parts bikes end up being projects and it never ends.

TruF 

Two sets of BRK10s. Got it. Thank you!

TruF 

I will have fun with that! Thanks!! I'll look more closely later, but there is a bike license decal for the City of Turlock, 74-75. So I'm guessing the bike is a 73 or 74. BTW: Suggestions for removing the license decal without compromising the paint underneath?

TruF 

Congratulations on your Grand Prix, Grim! And thanks for the advice on the cottered cranks. I need to get out my bike repair book and really start learning the names of each part. I need a bike parts poster!

Grim

Sheldon has an excellent glossary on his site. https://www.sheldonbrown.com/

gbalke

Use a hair dryer to soften up the adhesive on the back of the decal. Then take an old credit card to gently scrape off the decal. You can use Goop hand cleaner to remove any remaining residue from the adhesive.

TruF 

Found the serial number: GK409312. So based on the information at https://www.jaysmarine.com/TH_raleigh_serials.html (Thanks, gbalke!), it was manufactured at the Gazelle production facility in July of 1974.

Road Fan

The Simplex derailleurs can be replaced with NOS or good used ones. When I was collecting parts for my PX-10 build I found it pretty easy to find them.

The cottered cranks can be a pain to replace on Raleighs, since on the GP they didn't always use standard threads. The Super Course is really a better project, since they used English threads. If the original bearing cups are in good shape, you can re-use them (like any other part!). The main point of overhauling is to clean out interior dirt and old hardened grease, and get clean gooey new grease in there, on smooth bearing surfaces.

The GP is not really a heavy frame, but it was near the bottom of Raleigh's lineup back in the day. At the top of their line, the Competition, International, and Professional frames were on a par with most of the competition of the day and are still exemplary compared to modern hand made steel frames.

Road Fan

Probably the closest thing to a parts poster are teh exploded drawings of parts and bikes to be found in the old Tom Cuthbertson's Anybody's Bike Book (contemporary with your new Raleigh, a true classic and $2 to $8 at your local used bookstore or Goodwill), and Lennard Zinn's The Art of Road Bike Maintenance. Both authors spend a lot of time on "what are the parts, what do they look like, and what are they called?" They both use hand-drawings to illustrate. Not as sexy as color photos but in my antiquated opinion more informative and easier to use. Zinn has sections covering bike tech back into the late '50s and early '60s.

There may not be a need to replace the crankset. If you find you love the frame (ride, fit, handling, paint, coolness) but need a lighter bike, fine. But if its looks charm you (as they do me), you just need to overhaul it ultimately. Really it should be done say within a year as a preventive measure, along with the wheel and headset bearings. This annual routine will prevent those nice old bearings from failing prematurely, say within the first 50 years of their life. With good maintenance, they might never die.

A friend here on teh site who is an English Lit scholar, said he wants bikes designed for planned non-obsolescence in mind. While built to a price, I think these old Raleighs are in that category. '50s/60s Schwinns, too!