Classic & Vintage - vintage bike gearing..

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View Full Version : vintage bike gearing..


el_chojin
11-07-07, 01:15 AM
Hey all,
I'm a bmx guy, but I've been looking at older road bikes lately. And almost every single one I have looked at is either a 10 or 12 speed. 2 chainwheels usually ~40T and ~52T and a set of 5-6 freewheels in back. I'm planning a long distance ride with a buddy of mine that will include long steep climbs at Big Bear or SF. I don't know if I'll be able to make it with that kind of gearing above. I have a hard enough time on local hills on my bmx which is at 39x16...so I guess my question is, are there vintage road bikes with smaller chainwheels or can I modify a drivetrain by adding a 3rd smaller one? Multiple gears gives me headaches =)


vpiuva
11-07-07, 02:03 AM
Those 5 or 6 speed rears still probably have lower gearing than 39x16. Even my flatlander racing Trek with 42x21 low gear is lower than yours.

There are some older bikes with triples up front, and you can make that conversion yourself, but you'll more than likely need a new [and longer spindle] bottom bracket to match up with the triple crankset, and you'll probably need a new front derailleur. Look for an older bike that already has a triple front.

pastorbobnlnh
11-07-07, 03:54 AM
Since you don't have a bike yet, look for a vintage road bike with a triple that has a small chainring of at least 28-32. Then depending on the existing rear derailleur and freewheel, you can add a freewheel with a biggest cog of 28-32. This (little in the front - big in the back) combination will give you about the best gearing you can find on a road bike for the really steep hills. Some combination in between will give you what you need for a long, but not so steep climb, and you should still have enough gears for flats and decents.

A couple of my road bikes have a 30-42-49 or 50 front and 12 or 13-30 rears. My longest climb around here in NH is about 4 miles long. I also have lots of shorter, but really steep stuff (10-20% and higher), and the my low gearing is really appreciated by my legs at those times.


John E
11-07-07, 06:56 AM
With few exceptions, bikes from the early 1960s came with fairly close-ratio gearing and derailleurs which simply cannot handle a wide range. By the early 1970s we saw various touring derailleurs, including long-cage rears with generous chain takeup capabilities and long-throw fronts which could shift across three chainrings. If you do not mind being non-authentic, you can easily retrofit a SunTour V-GT rear derailleur onto almost any older bike, permitting you to accommodate up to 34 teeth on the rear cogset. If you really need the range, follow the good pastor's advice to look for a bike which already has a triple chainring. If you do not mind gaps in your gear ratio progression (I do), you can match a 50-36 double against a 14-17-21-26-32 freewheel. If you find a bike with a standard-width 6-speed freewheel (126mm overlock rear axle width), you can even retrofit a 7-speed freewheel, such as 14-16-18-21-24-28-32, giving you both wide range and decently close ratios.

cyclotoine
11-07-07, 12:00 PM
if you are talking about loading touring I would even recommend putting an MTB crank of with something like 22,34,44... honestly I was just on a loaded tour and 24 upfront and 30 in the back was the granny gear and I was thankful for it!

el_chojin
11-07-07, 10:04 PM
Thanks for all the suggestions! It looks like finding a bike with a triple chainwheel is the best way to go...but man, I've seen some gorgeous doubles that I just might want to do a conversion to. Do you guys know of any specific models I should look at? I don't think I've seen a triple in my searching through ebay/craigslist, at least not any in my size. I've been particularly fond of Peugeot. and I've seen tons of Schwinn, Nikishi, Raleighs etc.

pastorbobnlnh
11-08-07, 03:27 AM
Where do you live? Another Schwinn (a 1986 road bike) has followed me home and now it needs a new one because it won't fit any of us here. It has a 21"/53 cm frame, a cromolly frame, and mid range components. I could convert it to a triple for you, or you could do the work.

el_chojin
11-09-07, 12:42 AM
Oh, I live about 3000 miles away in southern California. City of Irvine to be exact. Well, I'm not sure what size road bike is the perfect fit for me, but I've been looking at 52-54cm frames as my friend is a tad bit taller than I am and has a 54 cm Allez. I am 5'8" with an average build. But I must warn you, I am fairly picky about appearance. I don't mind doing any of the work as long as there is a tutorial.

This is just drop dead gorgeous http://i22.ebayimg.com/01/i/000/c0/97/2d46_12.JPG

pastorbobnlnh
11-09-07, 03:26 AM
...But I must warn you, I am fairly picky about appearance. I don't mind doing any of the work as long as there is a tutorial.

This is just drop dead gorgeous http://i22.ebayimg.com/01/i/000/c0/97/2d46_12.JPG

Considering the condition of this Peugeot, I don't think you will be interested the Schwinn I mention above. Keep your eyes open on your CL and ebay, and you'll find something you'll like. Best of luck.

tcs
11-09-07, 06:48 AM
Those 5 or 6 speed rears still probably have lower gearing than 39x16. Even my flatlander racing Trek with 42x21 low gear is lower than yours.

Nope.

BMX bike, 20x1.75 tires, 39x16 gears: 45.5 gear inches.
Road racing bike, 700x23mm tires, 42x21 gears: 52.6 gear inches.

TCS

CardiacKid
11-09-07, 07:20 AM
Old triples seem to be very hard to find and usually go for a premium.
A cheaper way to go might be converting to a compact crank. Sugino and FSA both make a compact that fits a square taper. FSA has one in a 50/34. I think Sugino only goes down to 36T. Both are under $100. You should be able to use your existing FD. Coupled with a 13/28t freewheel, you are almost running as low a gear as you would get on a triple, for a lot cheaper. There are some downsides to a compact. The biggest one is the cross chaining problem. In the small ring, you will not be able to use the 2 or 3 smallest rear cogs. You also are going to lose some top end speed.
One thing to remember is that small changes in the rear cogs have a bigger affect than in the front.
For example, going from a 26 tooth large cog to a 28 tooth is a 7.7% increase, which is the same as going from a 39t ring to a 36 tooth ring.

Little Darwin
11-09-07, 07:36 AM
One model with a triple is the Schwinn Voyageur, since I just got one.

Another thing to consider is that some vintage bikes came with standard double gearing (52/39) but came with cranks that had a bcd of 110. These enable you to go with a compact double configuration very inexpensively... just by changing the chainrings. Check out BCD on Sheldon's site:

http://www.sheldonbrown.com/gloss_bo-z.html

Going compact (50/34) with a fairly common 14-28 freewheel gives pretty good gearing for climbing. Although the high end may lack a little... but you're used to that since you're coming over from BMX. :)

norskagent
11-09-07, 07:41 AM
aw come on, I just read that coppi raced the '53 tour w/ 49/53 x 14,15,16,17,18.

edvalds
11-09-07, 08:12 AM
This sounds familiar

Purchased a used Bianchi for $50 my wife that had a double crank (hardly used ~ 15 yrs old not the Italian frame but a nice bike). Switched out the double crank with a new Shimano 105 Triple the LBS had in stock for $75. Needed longer cage deraileur for another $25.

Living in the Seattle area ... there are hills everywhere ... if your a recreational rider you want the triple. There is lots of hype of compacts, but triples provide a better range if your surrounded by moutains.

John E
11-09-07, 09:05 AM
aw come on, I just read that coppi raced the '53 tour w/ 49/53 x 14,15,16,17,18.
I suspect that was strictly for the time trials or the flats, and that he switched to a 14-26 freewheel for the mountains. 53-49 / 14-16-19-22-26 makes a pretty decent half-step.

The only time I ever tried a corncob was on my Sears Free Spirit: 52-39 / 16-17-18-19-20. :)

When I worked at a Peugeot dealership in the early 1970s most PA/PR/PX-10 buyers opted for something lower than the stock 52-45 / 14-15-17-19-21 gearing. The most popular conversion was a 14-26 freewheel, although one could obtain a much better ratio progression with fewer redundancies by changing out one or both chainrings, as well.

el_chojin
11-10-07, 12:50 AM
Considering the condition of this Peugeot, I don't think you will be interested the Schwinn I mention above. Keep your eyes open on your CL and ebay, and you'll find something you'll like. Best of luck.

Thanks :), I plan on rummaging through many flea markets, garage sales and thrift stores! But I wouldn't mind taking a peek at your Schwinn. I'm not looking for something in pristine condition, but it just has to have a nice paint/color scheme. And also a not so boxy frame geometry.

Please correct me if I'm wrong, but what I've gathered so far from this thread to do a triple conversion is: replace a double with a triple like a shimano 105 triple crankset, a bigger/longer rear derailleur, and chain? And possibly the rear cog set? Speed isn't too much of a priority yet...I know it will be once many people start passing me :D but this will be more like a touring bike. Right now I'm just concerned about being able to keep up with my friend on steep and/or long hills.