Original gearing??
 

13-14-16-19-22-26 / 52-45 was how the bike was set up at time of purchase. I doubt that it came with this gearing because it duplicates too many gears. Bike is a ’73. When I could afford to get into bikes in the early ‘80’s 13-21 / 52-42 seemed pretty standard on road bikes. Any comments?

What brand, model and approximate year? You never know what catalog someone may have. You can easily find a lot of Fuji and Raleigh catalogs online.

A '73 Raleigh Pro was spec'd in the catalog as 52/44, 13-24 6 speed.

My International was spec'd as a 52/44, 14-24 5 speed. Mine actually came with a 52/43.

My 1974 Paramount had a 52 & 49 half-step crankset with an oddly spaced 14-26 freewheel. Not a good set-up. I changed the freewheel to a 13-24 and made do.

Today I run 3x7 or 3x8 gearing.

http://i289.photobucket.com/albums/l...HHH2010008.jpg

I recall that when I first noticed derailleur bikes in the very early 70's the chainrings on "sport" bikes were often 52-42 or 52-40. I don't know that I ever saw a 52-45. "Racing" bikes would more likely have 52-42, or for a serious half-step crossover 52-49. Also as I recall, the idea of a freewheel with one very large cog on an otherwise corncob-ish sprocket set was an 80's thing. But I might misremember.

52/44, 52/45 were not than uncommon.

14 top was with a five block.

14-24 was pretty common too.
14-21 on some models.

By today's standards most were over geared for the low gear.

Duplicate gears were not uncommon too.

My '74 Internat'l came 52/42 14-24, my MK IV Pro came out the box 52/45 14-24.
Neither left the shop with an OEM drivetrain, bars/stem, wheels, tires or much else.

That's how it was if you knew what you were doing.

http://bikeforums.net/attachment.php...hmentid=414786http://bikeforums.net/attachment.php...hmentid=414787

-Bandera

Seems like the CONI manual used a 52/46 with 14-16-18-20-22 FW setup for one illustration. It doesn't look all that great on paper, either. I'm not sure that the gearing on production bikes was always as meticulously mapped-out and optimized as we do here, so long as it had a decent enough range and gear spacing.

My 1986 Sierra with the original 48-38-28 and a 14-32 freewheel had so many duplicates that it only had 6 different ratios instead of 15. I can ride with the 38 ring and have all but the highest and lowest gears available.

To me there is nothing sacred about original gearing if it's a bike you intend to ride.

'86 Trek 760 has a Shimano SIS 13-26 evenly spaced and with the Campy 53/42 I have a wonderful time.....on the flats.

The reality with this particular model, the Raleigh Professional of the early 70's, is that None that we sold in our high volume old line shop were not modified to meet customer requirements. This was a Racing bike sold almost exclusively to Racers of the era who were correctly concerned with their fit & function.

The most common modifications were for fit, usually by installing the proper Cinelli 1A stem & 64/66 bars for the rider paired with larger/smaller Christophe toeclips & Binda straps. Drivetrain modifications were almost universal as straight blocks for Criterium/TT racing and a wider FW for training and road racing were paired with chainring changes to suit the rider. The OEM wheels were not a thing of beauty or reliability, quite often they were re-built w/ butted spokes and Mavic or Fiamme rims of a proper weight for the rider. The OEM tires were replaced with "race rubber" if the wheels were re-built to competition spec as well.
My point is that the Pro in the catalog was not the Pro that the customer rode from our shop, could have been different elsewhere.


I still have the 144BCD SR Royal course specific chain rings in 54/50/48/45 for my '74 MKIV in my parts box.

-Bandera

There is nothing sacred about original gear ratios, period. As others have observed, custom gearing was common practice. When you have only 9 usable combinations (excluding large-large cross-chaining), you have to pick your cog and chainring sizes very carefully to get good coverage over a decent range.

I remember the Schwinn Paramount half-step: 52-49/14-16-18-23-26, with a gap right where you need some gears. This is something a 6-speed 14-16-18-20-23-26 freewheel, like the one I custom built for my Bianchi, would solve handily. (I use it with a 50-42 1.5-step for general purpose riding, sometimes a 50-47 half-step on flat rides.)

The French were big on 52-45, and my Nishiki came with 54-47. This works OK with something like 14-15-17-19-21, but makes for a stiff bottom gear. I custom-built a 14-15-19-21-28, which gave me 8 fairly nicely spaced gears on top and a granny, but I needed the large-large combination to get something in the low 50s.

The closest thing I have ever found to a decent 10-speed combination is 49-45 / 14-16-19-22-26, but the 10% gaps are a bit larger than I like. I also used to run 50-42/14-16-18-20-23 in my younger days, but I sure like having the 26 added to that now. There is no way I would run the original Capo competition gearing (52-48/14-16-18-20-22) or touring gearing (52-46/14-17-20-23-26) -- too little range in the first, too much redundancy in the second.

I have settled in on custom gear ratios that work for me, which included replacing all of my 5-speed freewheels with 6- or 7-speed units. In the case of the mountain bike with its 8-speed freehub, regearing involved removing the spider pins to liberate the individual cogs for a little mix-and-match, to give me the 12-13-15-17-19-21-24-28 I wanted -- works great with custom 48-40-24 up front.

1973 Raleigh Pro. The freewheel is an Atom.

I do not really know what I am doing, just copying what was. What is "half-step gearing"?

Half-step is where the chainrings are very close in size (roughly one-half of the jumps between gears in back), so that you can use front shifts to fine-tune the overall gear selection. See how there is no duplication in this progression, and that close steps are available from top to bottom:

http://i36.photobucket.com/albums/e2.../half-step.png

Right on the money, nice illustration as well.

"What was" bore little if any resemblance to what was OEM on a Raleigh/Carlton Pro as it came out of the shipping carton.
My '74 MKIV sported 54/45 13-18 for Time trials and went through a Criterium 50/48 14-19 phase before settling into 52/42 13-21 for most of it's racing life.
It never sported OEM gearing and used SR Royal chainrings sometimes. Bars/stem and a lot of other stuff were similarly modified just as my teammates did to suit them.

In addition drivetrains wear and Regina chain/cogs came and went and Sedis & Suntour replaced them and so on for decades of use.

My point: Do as you please and set-up your Pro to suit yourself, that's how we rolled back when and the Period Correct/OEM Police never materialized from the future to chide us. :eek:

-Bandera

This a really cool graph, it just needs a link.

http://www.gear-calculator.com/#

[MENTION=251447]ThermionicScott[/MENTION]: Thanks for that graphic. I've now bookmarked www.gear-calculator.com. :thumb:

It's my go-to tool for playing around with gearing. Enjoy! :thumb:

Who cross-chains on a vintage chain?

Small chainring with the 2 large cogs and middle cog.

Shift to ...

Large chainring with the middle cog and 2 small cogs.

I don't see the rational for that original setup. It's not a real half-step. The incremental ratio of the cluster is 1.15, so the ratio of the chainrings should be 1.075. Then the crankset would have been 52-48.

A half-step for a 52/45 would have been an increment of 1.30. Starting with 14 teeth, 14, 18, 23, 31, 39 would have been the (infeasible) rear end. Starting with 13, 17, 22, 29, 37 is equally unsuitable.

Maybe it's an alpine? What happens when we try an incremental ratio of 1.05? 14, 15, 16,17, 18, 19 - narrow range but build able and the steps are even. It also could be 13, 14, 15, 16, 17, 18.

My guess is most likely the crank was planned for a 5 or 6-speed straight-block, or corncob. But the lowest gear (45/18) is only about 67 inches, so it is pretty much a racing only gearing.

Basically those numbers don't work well together.

13-14-16-19-22-26 freewheel with 52/42 chainrings makes a nice setup. This was the gearing on my '87 Centurion LeMans RS.

I nearly bought a Urago with a 14-31 in the rear (14, 17, 21, 25, 31) and a 47-52 in the front. The gear range would have been 40 inches to 97 inches.

I think that was a really good half-step!