jlaw

Took my new 39-26 SRAM MTB crankset out for a spin (on a Trek 410 with 11-32 ten speed cassette and indexed DT shifters) with the local bike club the other day and I'm wondering why most road bikes still come with a 50 or 52T large ring. I had all the high gearing I needed to keep up with the 15-16 mph average pace that the guys on the carbon bikes with electronic shifting were setting - and lots of comfortable ratios in the middle of the cassette with the 39T ring. I also had enough crawl-gearing for the steep hills near my house that I actually shifted up 1 or 2 at times from the lowest possible ratio 26-32.

The 39-11 combination yields a speed of about 25 mph on my rim/tire combo at a 90 rpm cadence. This is about the same as a 50-14 combo. With the 39-11 max. combo. on my bike all I'm potentially missing on the high end is the 50-13, 50-12, and 50-11 - each of which adds about 2 mph more up to a max. speed of 32 mph at 50-11.

I just don't spend much time pedaling at speeds above 25 mph. I also don't miss the complexity of the triple cranks that I have on two other of my bikes - 2 chain rings is preferable - nice, clean shifting. I also love the indexed DT shifters - just reach down and click, click, click - don't think I would ever want the extra fuss of friction.

I think I'm sold on this chainring set-up for future projects.

fietsbob

So? when I ride my freewheel hub bike the high gear is a 13:50 .

verktyg 

See my post from 2014: Vintage Cyclocross bikes? Please post yours

In the 80's I ran 46-38 x 13-26 gears on my Bertin road bike for riding in the woods and on dirt roads. Later in 1992 I built a butted Reynolds 531 - 700c frame for off road trekking, rough stuff riding and gravel crunching. I used TA Cyclotouriste cranks on it with 42-26 sprockets and a 13-28 FW. The 42x13 combo was plenty high for casual road use.

These days I run 48 or 49 x 38 or 39 chainrings with 13-28 FW or cassettes on my road bikes. I like a lot of close ratios in the mid range.






verktyg

ascherer 

GrainBrain

I replaced my 53t ring with a 50t, but have had an awful nagging feeling I should've gone with a 48t instead. She'll be on the road in a couple weeks, but this post is really making me wonder

Is there really a market for these "large" (48t+) rings when new groupos go to 11 or 12 on the cassette? Today I was doing 30mph in my top gear of 52x14, maybe at 80 rpm with a good tailwind.

Do other people really live in an area with total feet climbed of greater then 2,000ft in a ride?

Edited to add that this year 105 isn't offered in 46/36 config, which I think would be nice. Tiagra doesn't offer this either. Harrumph

letenn 

I switched to 48/38 on my Shimano Tri color cranks last year. I would have went smaller than 38, but you can't go that low on 130 BCD cranks. If I could find vintage style 110 BCD cranks I'd try more of a compact setup. Probably 34/48. I've looked at the Sugino XD2s. Might switch my rear cassette out instead. I'm currently running a 12/26. I should try a cassette in the 28-32 range. I'm also thinking about switching to 9 speed, but that just adds to the circular decision process that spins faster than my bike wheels.

Aubergine 

jlaw

Where I live in the N.E. U.S. most ride routes will have between 500 and 750 feet of gain for every 10 miles on paved roads. For a 40 mile ride the gain will be 2000 to 3000 feet. Riding un-paved roads can sometimes add to additional climbing.

ascherer 

Here's what I ordered. They've been discussed on BF elsewhere. Source

HTupolev

Because standard cranks have always been "one size fits all", where "all" is professional racers.

At least the small rings have gotten smaller. The ~40" granny gears on a lot of "recreational" vintage road bikes are kind of ridiculous for a lot of people in hilly areas.

The best-shifting fronts in my stable are triples. Modern doubles behave just as clean and consistently, but since the gaps between chainrings tend to be bigger, the shifts take longer to resolve (and can require bigger double-shifts to compensate for the ratio change). A 10-tooth jump with a modern FD on a compatible crank can be almost like a rear shift.

Salamandrine 

Use what works for you. Race bikes have race gearing. If you're a recreational rider, there's no point. A 95 inch gear (39x11) is plenty. In olden days there didn't used to be 11 tooth cogs...

For me a modern compact 50/34 is perfect. I couldn't live without the 50. Usually it stays in the big ring on the flats. I did race as a teen though, and I have some residual fitness or something, despite being a middle aged weekend rider nowadays.

The downside to compact setups is they wear out faster than the old 52/42 x 14-21 (for example) type gearing.

ThermionicScott 

Your 39/11 isn't far off from the 48/13 on my rando bike, and that's plenty of top end for my riding as well.

In a feat of poor planning, I installed bigger tires on one bike just before RAGBRAI years ago and discovered while on the trip that I could no longer shift into the big ring of my triple. So 38/12 was my top gear for that whole week. While it was annoying to discover, I quickly found it liberating.

RobbieTunes

If one can run 80's and 90's cadences, those gears may work. I've got 50/34/26 on my tourer, 50/34 on two bikes, and full 53/39 on the others. I still prefer the 53/39, as I spend time with a group that likes to run in the low 20's, and I simply can't run that for a long time on my compacts.

My cadences are lower, 60's (and 70's when I concsiously work at it), but I'm not there, so the gearing keeps me where I need to be.

At this point in the lifespan of my body, I'm not sure I'll be moving my cadence up much.

crank_addict

Throwing a wrench into the spokes:

Another surprise is when one's been accustomed to longer cranks and then switching to much shorter arms. The leverage and your piston change, also ones mass sits higher.

RobbieTunes

Cranks come in different lengths?

Andy_K 

amedias

Bit late to this thread but...

Optimal gearing invariably works is a mix of box local geography and personal preference.
Some people live in flat areas, some live in hilly areas, some are spinners, some are stompers, some are fit and strong, some are less so.

On some rides I'd be lost without my 26t granny ring, and 39x11 would see me off the back of the mid-week chaingang about 3 mins after the start, the speed fo the ride will play a big part too. I use a very different set of gears on 13-15mph avg. all-day rides than I do on 20-22mph avg. training rides. So you tailor your gearing to your personal requirements for me that works out roughly as follows:

Tourer:
24/36/48 x 13-30

Rando/Audax bikes:
26/36/48 x 12-28
26/38/50 x 13-26

'General' Road bikes:
52/36 x 12-28 or 50/34 x 11-25
44x17 SS
48x18 Fixed

Race bikes:
52/36 x 12-25
52/39 x 12-27

I've tried various alpine double setups like 42/26, 46/30 etc and invariably end up either jumping between rings all the time, or when they do 'work' ok for me I jsut find myself always up one end of the cassette, which is OK but the combination of worse chainline and smaller sprockets leads to noticeably worse transmission life.

hahahahaha! Sorry, but had to laugh, 2,000 ft is a flat ride round here. In this part of the country on average rides come in at about 80-100ft per mile, the only way to get flatter than that is to ride along the roads that follow the bigger rivers up the valleys, and there's only two of them so routes get boring very quickly. I spend very little time spinning along the flat so I'm often at either end of my gear range, you also learn to develop a really good aero-tuck round here as it's the fastest way down most hills!

People who live in very different areas often don't have an appreciation of the real differences. I've been laughed at numerous times when away from home when I rock up on a bike with a triple and a 26t granny ring and they're all on 52/39 racing roubles, but then when you tell them your last ride had over 9000ft of climbing and plenty of 20-25% climbs they start to get it.

Use what works for you in your area, if that's a 54t ring that's fine, likewise if you need a 24t granny and a dinner plate cassette, that's also fine. Requirements are often different to what bikes come shipped with as the manufacturers can't/wont do regional spec variations.

RiddleOfSteel

Over the all too rare miles that are consistently flat here on the Puget Sound side of the Seattle Metro area, I can spin a 50-13 or easily, and top out a 50T with an 11T cog in the back if I sprint to push the speed and hold for a bit. And that's on a big 63.5cm Miyata touring bike (ok ok, light 700C wheels and 32mm tires). I do like my 50+ tooth rings, and at my younger age, I can push it.

To the point of 2,000 ft of gain/ride. I don't know how many miles constitutes a ride but many a modest 12 mile loop (out and back) can rack up a quarter of that value easily. Granted, there are ways to avoid a hilly ride via paths and roads, but you find hills everywhere, and they are often steep. It's just the topography of the area. Nothing is super moderate, or at least for very long.

Therefore, for me (and others), Seattle gearing is a combination of rock crawling ratios for going up hills and mega overdrive for going down them and not spinning out within the first 100 ft. Steep up and steep down. For all around capability + classic looks, 53/39T in front and an 11-28T 10-speed cassette in the back allows me to tackle unpleasant out-of-the-saddle climbs up 10-18% grades (common enough) while being able to get close to topping out (via cadence) on long 8% descents. I have that setup on three of my bikes.

Ultimate NW gearing, for me, is installed on my '74 P15 Paramount. 3x9 indexed down tube shifting, running a 53/39/28T triple up front and an 11-32T cassette out back. I get my capable 53-11T top end (with 26 lbs of Reynold, Nervex, and leather to add momentum) while also possessing a walking-speed 28-32T low range.

I would love to just roll with what I call "prairie gearing" and have a 53/42T double and a 12-19 or 12-23 corn cob on the back. Get up to speed and just fine tune the cadence. For the hills of Seattle, Campagnolo's tight rear gearing (12-23 or 13-26) for 8/9/10 speed groups lacks the extremes that I'd like for our topography, but man, on generally flat terrain, that tight gearing is sublime. On mostly flat, I'd never top out a 53-13 combo, which would be great. And I could pick the perfect gear. But I don't live in the Midwest, though growing up I've roadtripped out with my family to see grandparents and relatives plenty of times, and do like the area.

RobbieTunes

I was on a small group ride, and the Kestrel under a friend suffered an FD failure. I built it, so I gave him the Wraith and volunteered to ride his Kestrel in on the 39....

For some reason, spinning that day came easy, and a youngster and I dropped the group and I am quite sure it was my fastest 5-mile leg ever......

...so a 39T can be badass.

nlerner

My ride today was 31 miles and about 1700 feet of climbing. Most of that was up to Blue Hill Observatory in Milton, MA, just south of the Boston border and at 635 ft above sea level! I'm running a 48/34t double crankset and a rear cassette with a 32t max cog. I was glad to have it.

FlMTNdude

rm -rf

(10 speed and 11 speed threads in Classic & Vintage? Well, Campagnolo is now 12 speed...)

There have been a lot of alternate drivetrain setups posted on BF lately -- good. I think that a lot of riders could use lower overall gearing than the typical 50/34 and 11-28. But that standard set works reasonably well for riders, anyway, and stores don't really want to stock a big set of alternatives. Some new bikes are shipping with 48/32, about a half rear shift easier than a 50/34.

Your 39/26 and 11-32 10-speed is somewhat similar to my alternate 50/34 and 14-34 11-speed.

~~~~~~
39/26 and 11-32 at typical flat road cadences. (Calculator link).

I used Sram cassette tooth counts, sometimes Shimano has different cogs.

It has some extremely low gears, very nice for steep or long climbs. 2.9 mph at 45 rpm, very good.
The big chainring is good from 10 mph on up, so it doesn't need a lot of chainring shifts on flatter rides. There's somewhat bigger cadence jumps over 15 mph, but not too bad.



~~~~~~~

My 50/34 and 14-32 in 11-speed. (Calculator link). This is what I ride most of the time.

It's a combination cassette, part from 11-32 and part from 14-28. More info in this thread post.

This has a similar top speed, and I rarely miss the original 50-13 through 50-11. I do switch the cassette back to 11-32 if I'll be riding lots of long downhills, where I like to at least soft pedal instead of coast down. And the 11-32 is better on flatter, casual rides, where the speeds are often in the range of 13-17 mph -- with this 14-32, I have to shift the front quite often at that 13-17 speed range.

This cassette is designed for fast-for-me group rides, which can be in the low 20 mph range at times. I'm working hard to hang onto the group, so I like lots of close shifts at those 18-24 mph speeds. It's perfect for those rides. And I can still climb pretty steep hills.

This setup can be somewhat annoying at times, near 15 mph, where I'm shifting the chainrings a lot if the speeds go up or down from there. The other downside is having to shift 4 or 5 cogs when I shift the chainring.

rm -rf

I used to think that a 50-11 was just "marketing". Most riders aren't going to need it for sprints. But the 11 cog has a couple of uses:

1. An 11 cog makes the 34-12 usable. So riders can stay in the small chainring past 20 mph, instead of having to keep shifting the front in the 15-20 mph ranges.
2. It's kind of nice to soft pedal in the 50-11 on long, shallow downhills, instead of coasting down.

~~~

Ha, your "2000 feet" comment got a lot of replies. It does depend on ride distance, not just hills. A "quite hilly" 50 feet per mile ride can hit 2000 feet pretty easily -- 40 miles. The standard "hilly" ride is 100 feet per mile, which is going to be almost all climbing and descending, with very few flats.

RobbieTunes

I still find value in the 52/53 rings, but not combined with 11t or 12t. For me, the 14t-23t cog range, combined with the "bigger" rings, is where my legs like to be.

JReade

All this talk of doubles and nobody is talking about a 1x wide range?