rawly old

Kv501, you'd think so as far as cross-chaining goes, but what I've done with my compact
is used an old triple front derailleur giving me a little extra leeway. this also helps with the
big jump between chainrings. The down side is that if I shift the front too quickly, it throws
the chain off. However, having accustomed myself to this, I'm very careful how I shift.
Dino has a point, The thing that seems to help me with that problem is pausing for a
second as I gently shift without tension on the chain. Again, this takes practice &
learning the feel of your bike.
Also, KV, addressing the issue of 50/17 or 34/11. Yes the ration is the same, but the
34, being smaller offers greater leverage against with pedals. For me it's just a lazy
way to mush the bike at my age.

achoo

If the ratio is the same, the ratio is the same.

The greater leverage you get at the pedal end with a 34-11?

You give it right back with less leverage at the rear cog on the 11.

rawly old

If you say so achoo but 50/17 feel like more resistance to me.

Homebrew01

Nope

Cafe

I do not understand why you would have to go to the 34 on level ground. That makes no sense. I'm always on the big ring on flats, and see my chain somewhere in the middle of the cassette when going 18-20mph.

rawly old

The thing is, I'm old. I've been on bikes since before some of your parents were born. I can ride 50/11,
for some distance, but on a touring stage of 25 miles lactate builds up quickly in my muscles. You will
find that the older you get, the longer it takes for your body to process lactic acid. An easy pace of
12 mph is just fine with me, especially when hauling a loaded tourer over distance.
The 34 is my go to ring; I ride there 90% of the time. If I were 40 years younger and 40 pounds
lighter I'd ride the 50 90% of the time. The way I'm set up, I only use the 50 on descents &
on the flat with an unladen bike. As a kid I rode as much as 140 miles in a day, but that was a long,
long time ago. I'm set up to get all 7 on the 34, & in no hurry. So just let this old turtle drag his
tail in the mud.

Fastfwd01

Ordered a 12/25 and the tools to swap out my 11/32. It should be interesting to see if I realize any improvements where I believed I was hitting a wall before.

Fastfwd01

Went for my first ride with the 12-25 on one of my usual bike paths hitting a lot of popular Strava segments. I've gained several pounds since riding season has slowed down and I was way overdressed for the temperatures (still trying to figure out what works to keep me just warm enough). I still set several personal records and for some reason they were mostly the longer segments (a few about 9 miles and an 18 mile segment). Conditions may have played a role in that - including my winter weather gear and the extra pounds.

The extra gears in the midrange must have helped to keep my average speeds up, but I wasn't hitting that 23/24 mph wall where I believed it would help me over that hump (mostly under that speed). I am enthused to see what happens when I catch some warmer weather.

Bandera

Yep, that's how proper gearing works to the riders advantage, now that you are geared correctly for your terrain it's a matter of seat time to improve fitness.
Keep your 11-32 cassette to change out for very hilly rides, that's what they are for and will have an advantage in that terrain.

-Bandera

BoSoxYacht

yep. That is exactly what I had been saying throughout the thread. Proper gearing for the terrain you ride.

If I lived in an area with lots of climbing and descending, a 52/36 crankset and 12-32 cassette might be better for me. It's mostly very flat in my area, so a 50/34 crank and a 12-25 cassette works great on the flat rides I normally do, and the 34t little ring makes things easy on those rare occasions that I get to do some real climbing.

bbattle

Why won't this thread die already?

BoSoxYacht

Some people keep posting in it.

RollCNY

Any idea who?

BoSoxYacht

Nope

dtrain

Some type of Alien Life Form.

RollCNY

I am equally stumped.

BoSoxYacht

Some people just won't let things die.

rawly old

Actually the ratio is not the same. 50/17 is a bit less than 3 to 1, 34/11 is a
bit more than 3 to 1, and yes it does provide more leverage because the pedal
extends farther beyond the chainring. You have 4500 posts; I have only 118.
Might that be because I spend more time riding and less time talking about it.

stephtu

Um, you apparently have no clue how leverage works. The 50/17 is going to be easier to push than the 34/11, not the other way around. Mechanical advantage is basically a function of how much wheel motion you get per distance of pedal travel. Given that you are not changing crankarm length (which *would* change the leverage), the pedal moves the same distance for one revolution with either the big ring or the small ring. You don't get "more leverage" from the position of the pedal relative to the chainring; the lever arm length is from the pedal to the bottom bracket spindle and is the same. Then you have to take in to consideration the ratio between the front and rear gears, and 50/17, a lower ratio than 34/11, is going to require more movement from the pedal to get the same # of revs of the rear wheel. More motion = less force required to produce the same torque.

Of course the easiest way to see this is to actually go out on the bike and observe for yourself that 50/17 is slightly easier to push. Just make sure you actually have a 17 cog and which position it is in, maybe you were comparing to a 50/16 which is just barely a higher gear than the 34/11.

WhyFi

Um, you apparently have no clue of how leverage works.

stephtu

OK fair enough. I should have more carefully expounded that you get more leverage based on chainring diameter if you are looking directly at the speed of the chain and not the end result of tire movement. But this is essentially cancelled out by driving a smaller sprocket at the hub, and if you look at the entire overall system, it turns out the only things that matter in the end are: chainring teeth vs. sprocket teeth ratio, and crank length vs. tire radius ratio.

Physics2014 - Bicycle Dynamics I: The Drive System

It would be nice if you'd explain things though rather than just declare someone wrong which is basically worthless and unelightening.

Kindaslow

Over 300 opinions in a matter of weeks, you would think this was a motorcycle forum arguing about the best oil....

By the way I like the 34 on my cassette, the UI2D shifts just fine, and I am too lame for cadence to be a big issue for me!

UnfilteredDregs

BLASPHEME!!!

WhyFi

It would be nice if you weren't a jackass to someone else whilst being wrong. Also, despite your linking, you're still not technically correct in your "the only things that matter in the end are: chainring teeth vs. sprocket teeth ratio, and crank length vs. tire radius ratio" declaration. While that may work for an average over an entire revolution, mechanical advantage is going to be affected by the radius of the load position (where the chain meets the chainring) relative to the input (pedal) and fulcrum (spindle), regardless of the tooth count. The tooth count is a nice proxy, but when we're talking about immediate mechanical advantage, we're looking at the load radius, not the circumference/tooth count, per se. See also: Biopace and Rotor Q-Rings

stephtu

You are making things overly complicated by bringing in oval chainrings. The guy's claim was basically something like a 34/17 gear is easier to push than a 50/25 gear despite them being the exact same gear ratio, by virtue of the 34 being smaller. This is simply incorrect and my main point. When you say I am wrong, are you saying he is right? OK I should have worded my initial post a little more carefully, but I still say that 34/17 and 50/25 are identical gears (neglecting minor drivetrain losses with the smaller sprockets) and will require the same effort to drive the bike at the same speed.

The load radius advantage at the crank chainring is canceled once you combine it with the radius disadvantage comparing the smaller rear sprocket to the radius of the tire, if we are using the same gear ratio just with smaller sprockets. OK with oval chainrings your advantage will vary throughout the rotation but on average I am way more right than rawly old about this.