Originally Posted by
cudak888
Stan - that reminds me, did the P13's revised fork geometry first pop up in 1972 or 1973? The P13 in the '72 catalog shows the earlier geometry (which found its way onto the P15, IIRC).
-Kurt
Good question.
The 1971 Paramount catalog lists the following fork rakes:
P13-9: 2 inches (50.8mm)
P15-9: 2 inches (50.8mm)
P14-0: 1-5/8 inches (41.3mm)
Unfortunately, I haven't been able to obtain a copy of the 1972 Paramount catalog evern though I've been actively looking for about five years. However, the 1973 Paramount catalog includes a specifications supplement page that states there were no significant "equipment" changes from the 1972 specifications for the P13-9, P15-9, and P14-0. It introduces the P10-9 as having "...the same basic specifications as P15 Paramout with the exception that gearing will be ten-speed. Gear range with standard equipment will be 51 to 100.
The 1973 Paramount catalog doesn't list the fork rakes except for the P14-0, which is 1-3/8" (35mm). For the P10 and P15, the frame specifications state "...slightly longer wheelbase and longer fork rake for a more 'shock-absorbing' ride." The P13 frame specifications state "...short wheelbase and shallow fork rake combine to produce quick and responsive handling." These descriptions seem to be written by marketing people who don't understand front end geometry since, for the same head tube angle (in this case both the P13 and P10/P15 have 73° HTAs) less rake = more trail = slower, less responsive handling.
It isn't until the 1976 Paramount catalog that we see the complete geometry picture for all the Paramount models. This geometry page describes the head tube angle and seat tube angle of the P10, P13, and P15 as 73° parallel (just as they had been since 1971), and the P14 as 74° parallel. The P13-9 is shown as having a fork rake of 1-3/4" (44.5mm) and the P10-9 and P15-9 are shown as having a fork rake of 2" (50.8mm). Again, with all of these frames having a 73° HTA, the P13-9 with shorter rake will have longer trail, which makes for slower, less responsive handling compared to the P10 and P15 forks which have more rake and less trail. Frankly, this doesn't make sense. I've sort of given up on trying to figure out whether the fork rake numbers in the catalogs are real or not, or if they are, what the heck was Schwinn thinking? The catalog descriptions and fork rake specs say that "shallow fork rake ... produces quick and responsive handling" while the opposite is true.
This BikeCAD illustration makes the point. The P13-9 fork on the left with a 44.5mm rake has
more trail (56.8mm) than the P10-9/P15-9 fork on the right that has 50.8mm of rake and only 50.2mm of trail. Remember, more trail = slower, less responsive handling.
Originally Posted by
cudak888
P.S.: I still maintain that is the all-time corniest Schwinn Paramount ad ever created (and not because of his trousers either) - though probably the most effective.
Boy riding bicycle sees girl in bikini. Boy stops and talks to girl. Use your imagination to figure out what happens next.