much difference on a hill using 26 or 28 cog?

On Friday, October 25, 2019 at 8:54:57 PM UTC-4, jbeattie wrote:
On Friday, October 25, 2019 at 4:53:18 PM UTC-7, Oculus Lights wrote:
On Thursday, October 24, 2019 at 10:14:39 PM UTC-7, Sir Ridesalot wrote:
Okay folks here's something bicycling related.

I have a number of bicycles with freehubs that use UNIGLIDE cassettes.. I have one I want to change because the cogs are pretty rusty looking. I have a nice newish 13 - 26 cassette to use instead of the original 13 - 28 cassette.

Using Sheldon Brown's Gear Calculator and gear inches I see that a 42 x 28 combination is 40.5 gear inches whilst a 42 x 26 combination is 43.6 gear inches. Is that a very noticeable difference if one is riding uphill?

NO! I am not changing freehubs or wheels to Hyperglide. I'm ONLY interested in answers discussing the difference between the 26 and 28 cogs.

Cheers

Only way to see the difference to your own legs and your own riding style is to try it.
To my legs its a big difference. When I was 10 pounds lighter and race-fit, 11-26 (SRAM Red) was my standard cassette for everything.
For the LowKey Hillclimb races, on a hill in the South Bay called Soda Springs, I did my PR with a 50/26 combination, gasping and spent by the finish. Also when I did the Mt. Diablo Challenge in under an hour. In both cases, a 28 would have been much easier and manageable, but slower because I wouldn't have been forced to keep up that higher level of effort all the way up.
Now I think I might blow out a knee or something if I tried it in a 26 again. For the many fewer miles I ride now, switched the road bike to an 11/30 cassette.

It sucks getting old. Anyway, styles have also changed. Back in the day, us manly men were racing on 13-18 corncobs and had 21t freewheels for the big hills. These days, even pros are riding on mid-compacts with 28t cassettes. Spin is in. Its just a smarter way to ride. People also don't have the same macho attachment to tiny cogs, which is a good thing. In fact, I don't think people even care anymore, although some rodie might say something if you showed up with one of those 50t rear Eagle pie plates. https://www.excelsports.com/assets/gallery/110490-1.jpg

It may have been in the midst of the corncob fashion era, when I had a young guy
sneer at my touring bike's freewheel. He asked incredulously, "How big is that
rear cog? I've never even SEEN one that big!"

It has 32 teeth. It's no longer so unusual.

- Frank Krygowski

On Fri, 25 Oct 2019 19:09:30 -0700 (PDT), Frank Krygowski
wrote:

On Friday, October 25, 2019 at 8:54:57 PM UTC-4, jbeattie wrote:
On Friday, October 25, 2019 at 4:53:18 PM UTC-7, Oculus Lights wrote:
On Thursday, October 24, 2019 at 10:14:39 PM UTC-7, Sir Ridesalot wrote:
Okay folks here's something bicycling related.

I have a number of bicycles with freehubs that use UNIGLIDE cassettes. I have one I want to change because the cogs are pretty rusty looking. I have a nice newish 13 - 26 cassette to use instead of the original 13 - 28 cassette.

Using Sheldon Brown's Gear Calculator and gear inches I see that a 42 x 28 combination is 40.5 gear inches whilst a 42 x 26 combination is 43.6 gear inches. Is that a very noticeable difference if one is riding uphill?

NO! I am not changing freehubs or wheels to Hyperglide. I'm ONLY interested in answers discussing the difference between the 26 and 28 cogs.

Cheers

Only way to see the difference to your own legs and your own riding style is to try it.
To my legs its a big difference. When I was 10 pounds lighter and race-fit, 11-26 (SRAM Red) was my standard cassette for everything.
For the LowKey Hillclimb races, on a hill in the South Bay called Soda Springs, I did my PR with a 50/26 combination, gasping and spent by the finish. Also when I did the Mt. Diablo Challenge in under an hour. In both cases, a 28 would have been much easier and manageable, but slower because I wouldn't have been forced to keep up that higher level of effort all the way up.
Now I think I might blow out a knee or something if I tried it in a 26 again. For the many fewer miles I ride now, switched the road bike to an 11/30 cassette.

It sucks getting old. Anyway, styles have also changed. Back in the day, us manly men were racing on 13-18 corncobs and had 21t freewheels for the big hills. These days, even pros are riding on mid-compacts with 28t cassettes. Spin is in. Its just a smarter way to ride. People also don't have the same macho attachment to tiny cogs, which is a good thing. In fact, I don't think people even care anymore, although some rodie might say something if you showed up with one of those 50t rear Eagle pie plates. https://www.excelsports.com/assets/gallery/110490-1.jpg

It may have been in the midst of the corncob fashion era, when I had a young guy
sneer at my touring bike's freewheel. He asked incredulously, "How big is that
rear cog? I've never even SEEN one that big!"

It has 32 teeth. It's no longer so unusual.

- Frank Krygowski

I believe that SRAM builds a set with an 10-42 cassette and a single
32 tooth chain ring :-)
--
cheers,

John B.

On Fri, 25 Oct 2019 17:54:54 -0700 (PDT), jbeattie
wrote:

On Friday, October 25, 2019 at 4:53:18 PM UTC-7, Oculus Lights wrote:
On Thursday, October 24, 2019 at 10:14:39 PM UTC-7, Sir Ridesalot wrote:
Okay folks here's something bicycling related.

I have a number of bicycles with freehubs that use UNIGLIDE cassettes. I have one I want to change because the cogs are pretty rusty looking. I have a nice newish 13 - 26 cassette to use instead of the original 13 - 28 cassette.

Using Sheldon Brown's Gear Calculator and gear inches I see that a 42 x 28 combination is 40.5 gear inches whilst a 42 x 26 combination is 43.6 gear inches. Is that a very noticeable difference if one is riding uphill?

NO! I am not changing freehubs or wheels to Hyperglide. I'm ONLY interested in answers discussing the difference between the 26 and 28 cogs.

Cheers

Only way to see the difference to your own legs and your own riding style is to try it.
To my legs its a big difference. When I was 10 pounds lighter and race-fit, 11-26 (SRAM Red) was my standard cassette for everything.
For the LowKey Hillclimb races, on a hill in the South Bay called Soda Springs, I did my PR with a 50/26 combination, gasping and spent by the finish. Also when I did the Mt. Diablo Challenge in under an hour. In both cases, a 28 would have been much easier and manageable, but slower because I wouldn't have been forced to keep up that higher level of effort all the way up.
Now I think I might blow out a knee or something if I tried it in a 26 again. For the many fewer miles I ride now, switched the road bike to an 11/30 cassette.

It sucks getting old. Anyway, styles have also changed. Back in the day, us manly men were racing on 13-18 corncobs and had 21t freewheels for the big hills. These days, even pros are riding on mid-compacts with 28t cassettes. Spin is in. Its just a smarter way to ride. People also don't have the same macho attachment to tiny cogs, which is a good thing. In fact, I don't think people even care anymore, although some rodie might say something if you showed up with one of those 50t rear Eagle pie plates. https://www.excelsports.com/assets/gallery/110490-1.jpg

-- Jay Beattie.

Yup, when you are young you don't know anything and when you are old
you can't do anything :-)



--
cheers,

John B.

On Friday, October 25, 2019 at 9:09:33 PM UTC-5, Frank Krygowski wrote:

It may have been in the midst of the corncob fashion era, when I had a young guy
sneer at my touring bike's freewheel. He asked incredulously, "How big is that
rear cog? I've never even SEEN one that big!"

It has 32 teeth. It's no longer so unusual.

- Frank Krygowski

Guessing that was in the 1970s. Before mountain bikes and their big cogs were invented. Big cogs were only available on touring bikes. Not racing bikes.

On Friday, October 25, 2019 at 4:49:51 PM UTC-5, Sir Ridesalot wrote:

I see that if I drop the 42 chainring to a 39 and then change the rear cassette from the 28 to the 26 one that I have very nearly the same gearing. I have a 39 chainring here somewhere so I think that's what I'll do.

Cheers

Yes 42x28 and 39x26 are identical gears. Or if you have a 130mm bcd crankset, then you could also go to a 38 inner ring. Little lower.

But the awful, horrible, terrible thing about running a 39 inner ring instead of the wonderful 42, is that you have crap shifting between chainrings. You MUST shift the rear derailleur 4 or 5 cogs every time you switch between chainrings. But with the 42, you only shift 1 or 2 cogs and you are in the correct gear. Perfect shifting with the 42. Bad shifting with the 39. I cannot even imagine how awful shifting with those nutty 50-34 compact cranks is.

On 2019-10-25 21:45, wrote:
On Friday, October 25, 2019 at 4:49:51 PM UTC-5, Sir Ridesalot
wrote:

I see that if I drop the 42 chainring to a 39 and then change the
rear cassette from the 28 to the 26 one that I have very nearly the
same gearing. I have a 39 chainring here somewhere so I think
that's what I'll do.

Cheers

Yes 42x28 and 39x26 are identical gears. Or if you have a 130mm bcd
crankset, then you could also go to a 38 inner ring. Little lower.

But the awful, horrible, terrible thing about running a 39 inner ring
instead of the wonderful 42, is that you have crap shifting between
chainrings. You MUST shift the rear derailleur 4 or 5 cogs every
time you switch between chainrings. But with the 42, you only shift
1 or 2 cogs and you are in the correct gear.


I've got 42T and 52T up front. In the city I always shift back to 42T
when a red light or stop sign comes up. Then back after acceleration. I
never have to shift the rear derailer for that yet the gear change up
front is smooth and fast. Also at surprisingly little movement of the
lever. Old Shimano 600 downtube shifters.


... Perfect shifting with
the 42. Bad shifting with the 39. I cannot even imagine how awful
shifting with those nutty 50-34 compact cranks is.


It probably depends on how cleverly the front derailer cage and
mechanism has been engineered. On my MTB the cage is much more intricate
that the square thing of the Shimano 600 on the road bike.

--
Regards, Joerg

http://www.analogconsultants.com/

On Saturday, October 26, 2019 at 7:17:55 AM UTC-7, Joerg wrote:
On 2019-10-25 21:45, wrote:
On Friday, October 25, 2019 at 4:49:51 PM UTC-5, Sir Ridesalot
wrote:
... Perfect shifting with
the 42. Bad shifting with the 39. I cannot even imagine how awful
shifting with those nutty 50-34 compact cranks is.


It probably depends on how cleverly the front derailer cage and
mechanism has been engineered. On my MTB the cage is much more intricate
that the square thing of the Shimano 600 on the road bike.


I think Russell was referring more to the step in gear ratio between chainrings being too large an increment to be appropriate on its own much of the time, and the hassle of having to trim things back more at the rear with any such 52-39 shift, whereas a 52-42 shift can be useful on its own.

This is more of an issue with a limited range of gears in the back. I've found that with a 42 chainring, my 13-24 cluster works well on level ground, whereas with the 39 chainring I previously had, I'd often find it didn't have quite enough range and I'd shift to the 52 and back off a gear in the back. Adding a 12 sprocket in the rear could have addressed this just as well for me. This trend has continued adding more and more sprockets in back.

What makes the compact crank work is that the rear clusters that go with them have such a wide range that incremental gear changes usually happen without overflowing to a front shift. Incremental shifts largely happen on level ground where the ratios you work are in the overlap between the chainrings' coverage. Larger shifts happen when your run out gears in the transition from level ground to climbs or descents, but these are times where your gearing needs can change suddenly and the large step of the front shift actually works well.

So far as how smooth the front shift itself happens, I think the pins and ramps on modern chainrings make as much of a difference if not more than derailleur cage designs. I'm regularly amazed by how quiet my modern triple crank shifts and still often find myself looking down at my crank to see if an upshift I'm trying to do actually took or not.

-Luns

On Friday, October 25, 2019 at 3:01:10 PM UTC-7, AMuzi wrote:
On 10/25/2019 4:49 PM, Sir Ridesalot wrote:
On Friday, 25 October 2019 15:49:58 UTC-4, duane wrote:
On 25/10/2019 3:30 p.m., jbeattie wrote:
On Friday, October 25, 2019 at 11:33:02 AM UTC-7, Luns Tee wrote:
On Thursday, October 24, 2019 at 10:14:39 PM UTC-7, Sir Ridesalot wrote:
Using Sheldon Brown's Gear Calculator and gear inches I see that a 42 x 28 combination is 40.5 gear inches whilst a 42 x 26 combination is 43.6 gear inches. Is that a very noticeable difference if one is riding uphill?

How about a direct experiment? Assuming your cassettes aren't riveted together (or if they are, assuming you're prepared to grind off rivet heads), leave out one of the smaller sprockets from the 13-26, and assemble the rest, adding your 28, then go for a ride that involves the climbing you're concerned about.

Of course you'll notice the missing sprocket on the flats or descending, but that's not the point of this. Once climbing, limit yourself to the 26 at first and see if find yourself wanting the 28. When you do, see if it really makes a difference for you.

There are of course a bunch of variants of sprocket combinations you could try for this that might not leave as obvious a gap as my initial suggestion - e.g. you could substitute the new 26 for the second largest sprocket (24?) of the 13-28, or some other such.

I think results will vary a lot depending on your fitness relative to the local geography. When I lived in Toronto, I had a 28, and later 30 large sprocket on one bike, but seldom missed it when riding another bike with a 24. Now that I'm older, heavier, and in the SF Bay area where all the good rides of interest involve some amount of climbing, the 24 became a barrier which I addressed by going to a triple crank.


I can say that the spread between a 28t and 30t means about an extra six feet before I stall out on a dirt climb and take the adjacent stairs on one of my commuter trails. Its also where I test tire grip in dirt -- and the speed with which I can exit my SPD pedals before falling into the brambles. Total distance up the hill can be measured by the number of stairs passed, and that has diminished over the years.

-- Jay Beattie.


I did a race with a 53/39 12-25 with ~1800m and I did the same one with
11-28 and I appreciated the 11-28 on a couple of the steeper grades.
I'm thinking of doing the same race this year with my 52/36 and I expect
that if I get an 11-30 on the back I'll be floating up those hills.

I see that if I drop the 42 chainring to a 39 and then change the rear cassette from the 28 to the 26 one that I have very nearly the same gearing.. I have a 39 chainring here somewhere so I think that's what I'll do.

Cheers


Then when you get old there's still that 39 with the 28...

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

I'm climbing the hard stuff in the 34-28. Feeling good I can get down into the 23 which I prefer since you climb so much further with each push on the pedals.

On Friday, October 25, 2019 at 3:44:22 PM UTC-7, Sir Ridesalot wrote:
On Friday, 25 October 2019 18:01:10 UTC-4, AMuzi wrote:
On 10/25/2019 4:49 PM, Sir Ridesalot wrote:
On Friday, 25 October 2019 15:49:58 UTC-4, duane wrote:
On 25/10/2019 3:30 p.m., jbeattie wrote:
On Friday, October 25, 2019 at 11:33:02 AM UTC-7, Luns Tee wrote:
On Thursday, October 24, 2019 at 10:14:39 PM UTC-7, Sir Ridesalot wrote:
Using Sheldon Brown's Gear Calculator and gear inches I see that a 42 x 28 combination is 40.5 gear inches whilst a 42 x 26 combination is 43.6 gear inches. Is that a very noticeable difference if one is riding uphill?

How about a direct experiment? Assuming your cassettes aren't riveted together (or if they are, assuming you're prepared to grind off rivet heads), leave out one of the smaller sprockets from the 13-26, and assemble the rest, adding your 28, then go for a ride that involves the climbing you're concerned about.

Of course you'll notice the missing sprocket on the flats or descending, but that's not the point of this. Once climbing, limit yourself to the 26 at first and see if find yourself wanting the 28. When you do, see if it really makes a difference for you.

There are of course a bunch of variants of sprocket combinations you could try for this that might not leave as obvious a gap as my initial suggestion - e.g. you could substitute the new 26 for the second largest sprocket (24?) of the 13-28, or some other such.

I think results will vary a lot depending on your fitness relative to the local geography. When I lived in Toronto, I had a 28, and later 30 large sprocket on one bike, but seldom missed it when riding another bike with a 24. Now that I'm older, heavier, and in the SF Bay area where all the good rides of interest involve some amount of climbing, the 24 became a barrier which I addressed by going to a triple crank.


I can say that the spread between a 28t and 30t means about an extra six feet before I stall out on a dirt climb and take the adjacent stairs on one of my commuter trails. Its also where I test tire grip in dirt -- and the speed with which I can exit my SPD pedals before falling into the brambles. Total distance up the hill can be measured by the number of stairs passed, and that has diminished over the years.

-- Jay Beattie.


I did a race with a 53/39 12-25 with ~1800m and I did the same one with
11-28 and I appreciated the 11-28 on a couple of the steeper grades.
I'm thinking of doing the same race this year with my 52/36 and I expect
that if I get an 11-30 on the back I'll be floating up those hills.

I see that if I drop the 42 chainring to a 39 and then change the rear cassette from the 28 to the 26 one that I have very nearly the same gearing. I have a 39 chainring here somewhere so I think that's what I'll do.

Cheers


Then when you get old there's still that 39 with the 28...

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

That's what I figured. After all, I'm only 67 years young now. Grandad lived to b well over 100 years of age. In his late 90s he was saving up for his old age.

Cheers

If you've been riding continuously you shouldn't have any problem at all with a 39-26. Because of the concussion I had spent several years off of the bike. I had been climbing with a 39-25 low and I never went into that always keeping it for a bail-out gear. After the concussion I could still climb in the 39-23 but it hurt for several years before I started getting the shape back.

On Saturday, October 26, 2019 at 7:17:55 AM UTC-7, Joerg wrote:
On 2019-10-25 21:45, wrote:
... Perfect shifting with
the 42. Bad shifting with the 39. I cannot even imagine how awful
shifting with those nutty 50-34 compact cranks is.


It probably depends on how cleverly the front derailer cage and
mechanism has been engineered. On my MTB the cage is much more intricate
that the square thing of the Shimano 600 on the road bike.


I think Russell was referring more to the step in gear ratio between chainrings being too large an increment to be appropriate on its own much of the time, and the hassle of having to trim things back more at the rear with any such 52-39 shift, whereas a 52-42 shift can be useful on its own.

This is more of an issue with a limited range of gears in the back. I've found that with a 42 chainring, my 13-24 cluster works well on level ground, whereas with the 39 chainring I previously had, I'd often find it didn't have quite enough range and I'd shift to the 52 and back off a gear in the back. Adding a 12 sprocket in the rear could have addressed this just as well for me. This trend has continued adding more and more sprockets in back.

What makes the compact crank work is that the rear clusters that go with them have such a wide range that incremental gear changes usually happen without overflowing to a front shift. Incremental shifts largely happen on level ground where the ratios you work are in the overlap between the chainrings' coverage. Larger shifts happen when your run out gears in the transition from level ground to climbs or descents, but these are times where your gearing needs can change suddenly and the large step of the front shift actually works well.

So far as how smooth the front shift itself happens, I think the pins and ramps on modern chainrings make as much of a difference if not more than derailleur cage designs. I'm regularly amazed by how quiet my modern triple crank shifts and still often find myself looking down at my crank to see if an upshift I'm trying to do actually took or not.

-Luns