Miradaman

Still trying to wrap my head around the whole gearing/gear ratios thing. Never was a math guy. Anyway, I recently acquired an old mongrel road bike with a mixed Shimano 105/600 drivetrain. Up front is 52/42, while the rear has 13-25 cogs. What is the advantage of such a narrow gear range, and why would higher end compnents have it?
Thanks

non-fixie 

From an old racer's point of view that would be "Alpine gearing".

Seriously, high end components would have been geared more towards professionals and ambitious amateurs, whom are generally in better shape and can handle higher gears and like close ratios.

Miradaman

So, basically, they're designed for people who simply don't need lower gears? What's the advantage to not having lower gears, even if you dont need them? Weight savings? Reduction in complexity? Seems that gearing designed to tackle mountains would have a much lower ring than 42 up front...

KCT1986

Couple of reasons. With only 6 or 7 cogs, lower total range was used to keep the ratios as close together as possible to avoid gaps and help with shifting. Rear shifting didn't have the quick shift features that the modern cassette/freewheels have.

Crankset in that era had plain flat chainrings. Without the ramps/pins of the newer rings, shifting 14-16 teeth differences between rings wasn't really ideal.

3alarmer 

...you need to look at the history of bikes, from when shifting first became available, to the gradual progress in increasing the range, given the available technology of the era. A lot of the stuff for shifting you see on an older 52/44 14-25 setup on an older bike would simply not shift reliably (or at all), with bigger jumps or larger rear cogs. It was still quite an improvement over a single speed hub, with maybe a flat cog on one side and a mountain cog on the other, which you stopped and flipped by hand.

jdawginsc 

Also, I think that they were so in tune with cadence, that significant changes in one shift to another would result in loss of momentum, and lots of double shifts to keep the small changes small in ratios.

They wouldn’t have just gone down to a low gear...i on the other hand, often had to find the holy bejeebus gear on some climbs...

genejockey 

This has been a fun aspect of diving into vintage bikes for me - trying to make them work with the rather hilly area where I live. IN the last few months I got a 1989 Schwinn Circuit with 52/42x13-24, and a 1982 Lotus Supreme with 52/43x13-23. Both have Uniglide freehubs, 7 and 6 speed respectively, and while you can find 13-18 or 13-21 for cheap, finding 13-26 is a chore AND it costs. I ended up buying individual cogs to make up 13-26 clusters.

Then yesterday I picked up a 1982 Lotus Classique with 52/40x13-32, and just playing with the shifting on the stand, I can see it's WAY trickier to shift. With Uniglide, it seems to work best to overshift and then back off slightly, but with the 13-32, I found shifting to larger cogs it would often overshoot to the next one up. So I can see why racers went with straight blocks, because you can't afford to blow a shift at a crucial moment.

davester

When you're racing, it's important to have your legs spinning the cranks at the most efficient rate (called cadence). With wide gaps between gears the optimum rate may be between two gears and therefore unachievable and uncompetitive. Also, racers typically have 2 to 3 times the power output of regular folksand need to go at maximum speed all the time so don't have any need for low gears.

Doug Fattic 

This is a good explanation. I wasn't a racer but I trained with them a lot and with my modestly good ability I needed to be in the most efficient gear at all times or I would be off the back. My heart rate was almost always at the limit. I needed a straight block and to always be in that perfect for me gear in order to stay on. I particularly liked a 17,18, 19. If my rear cluster was missing the 18, I would be spinning too fast in the 19 and too slow in the 17 and bye, bye group and I'd be riding by myself back to the start.

A lot of racers would stand up so they could stay in the same gear when going up an incline but that didn't work for me because i'd be using up too much of my modest strength to get out of the saddle. At the speeds we went and the cadence we needed to pedal, anything over a 21 was just silly and used for riding with the inexperienced on a casual ride. It wouldn't be possible for me a spinner to spin that fast. There is a big difference in how one rides in a speedy group than out and about by oneself. The constantly changing speeds necessary when coming out of a corner or when someone attacks to try and lose the losers hanging on means (for me anyway) a high cadence. Otherwise I'd be using up too much energy.

nlerner

People were stronger then. Better looking, too.

Ed Wiser

I still have my vintage gearing on my bike. When trying to ride with people on club rides.
it means I get dropped fast as I don’t have the strength and they have the gears.
What I did was get a Swytch kit for the bike. As I didn’t want to go thru the process of updating the components . As it has a Campagnolo C record group on it and want it to stay the way I had it years ago. So now I can keep up with the new gearing and still ride the vintage bike.
meant to build up a carbon frame bike but the current shortage of parts is not helping.

bikingshearer 

@repechage raced a lot in SoCal BITD. He once said here that, in those days, if you couldn't climb in a 42x23, you couldn't hang. (I replied that I couldn't and I didn't. True then, more true now.) That tells you pretty much what you need to know,.

Bad Lag

Even now, as an old fart, I ride with 42/52 chain wheels and a five speed 14-24 freewheel. I stay mostly in 52-18.

When I was living in Albuquerque, I rode the same gearing. It took a few rides to acclimate to the 6,000 foot altitude and to the mountain roads but it did not require a gearing change. After conditioning, I was able to ride some never-ending uphill grades in 42X21 or 42X24.

I also had an Ultra-6 freewheel that is 13-32T and some 42/45T chain wheels. I just didn't need them for the mountains or altitude.

I'm not bragging, just explaining.

Trakhak

Makes sense. Roads are graded intelligently out West. The really steep climbs in the U.S. are found along the East Coast for the most part.

thinktubes 

As I age, going to a 50x39 crank was a revelation. With a 12x23 8-speed, I use the full range of the cassette and still have enough low gear for Southern Wisconsin. The 50T is sweet for riding into a headwind.

Kabuki12

Yea, I am still jealous of that triple crank you had in Paso Robles, 2017 I think? God I miss the Paso ride!!

Kabuki12

For the most part , you are correct.But every now and then..........

unterhausen

If you watch races from a couple of decades ago, they were really bogged down going up even fairly small hills. There was a stage of this year's Giro that featured very steep hills and most of the racers were spinning, so they must have had fairly low gears. But even now, someone will win a race because they have lower gears than anyone else.

I remember thinking 44-24 was granny gears. The granny gear on my tandem is 36-24.

genejockey 

I think that the actual slopes in the West are steeper, so to make them passable you have to use switchbacks, while in the East the slopes are gentler, so the roads just go up them. I discovered this when I had been riding for a couple years out here in CA, and was going Back East to visit family. I shipped one of my bikes so I'd be able to ride while I was there. With all the climbing I'd been doing out here I thought I'd fly up any climbs there. Not so much.

Then there was the humidity. Yeesh.

John E

Streets are steeper on the east coast? Look up the annual Fargo St. climb in Los Angeles.

I am with genejockey -- I use a lot of freewheels with 26T bottom gears, because that is the capacity of a vintage short cage Campag. or SunTour rear derailleur. I deplore that 26T cogs are so rare.

If you have an older crankset with a 144mm BCD, you are stuck with a 42T minimum chainring size, unless you can find either a very rare 41 or a triplizer and a longer spindle. Thus, two of my road bikes have 42/26 bottom gears, which I still find adequate for most of my riding. I like to limit the gap between gear ratios to 6 or 7 percent, and hence need at least a 2x6 setup to get the range I want. I am not a big fan of tall gears on the top end, so I usually settle for something in the mid-90s, which is perfectly adequate for a spinner like me who doesn't care about being able to pedal at or above 30mph.

People have mentioned 1.5-step, or "Alpine," gearing, which I use a lot, as wel.

Road bikes: 50-42/14-16-18-20-23-26; 46-38/13-15-17-19-22-25; half step: 45-42/13-15-17-20-23-26

Mountain bike: 46-38-28 / 12-13-15-17-19-21-24-28, although I do have a 24T chainring I plan to swap in next time I overhaul the BB (requires pulling the crank)

Trakhak

True. I remember a couple coming into a bike shop where I worked who had ridden across the country from somewhere in California. I said that crossing the Rockies must have been tough. They laughed and said that they didn't encounter any difficult climbs until western Maryland.