Hill Climbing & Gear Shifting

[dhk2]

alfeng, that Park Tool excerpt that you highlighted in red above makes no sense at all. I'm not surprised that it was retracted, and wouldn't be surprised if the person that wrote it was fired either. Whoever wrote that drivel clearly had no understanding of how shifting works.

Originally Posted by swampy1970

I don't care what Park Tool has to say, all I care about is that when I hear that click and then let go, my gear changes cleanly and near instantaneously.

Maybe one day when I'm riding I'll try and figure out what this dwell is...

Let's define dwell as the time delay between the completion of movement of the lever (the shift request by the rider) and the completion of the shift itself. I've found noticeable "dwell" in my Shimano shifting only when shifting out to the small cogs under heavy load at low cadence, eg, standing on a hill. This dwell of course has nothing to do with the shifter, because once the cable is released, any delay has to be due to the derailleur, chain and cog design.

The RD spring tries to push the guide pulley out a measured increment, but the spring force is resisted by the high tension in the chain. As a result, nothing happens until the chain outer plate brushes up to a ramp on the smaller cog which then pushes it up enough to derail It and allow the shift to complete. If the rear wheel is rotating slowly, say about 1 rev/second (under 5 mph bike speed), seems the delay is about 1/2 rev, or 1/2 a second.

I rarely shift like this, but did it mostly to search for the "phantom delay" that alfeng keeps harping on. We know the delay can't be designed into the shift lever because it's related to the load on the chain and the speed of the rear wheel and occurs after the lever has released the cable. At normal road speeds and loads, shifting is bang quick going up or down.

 

[AyeYo]

Just to play devil's advocate... isn't this "dwell" alfeng is talking about only a rear downshifts? That would make more sense, because he's claiming some non-linear cable pull from the lever. There's no cable pull on a rear upshift, it just releases the derailleur. "Dwell" or hesitation on a downshift would make more sense, allowing the chain time to catch a ramp (which is how I read Park's comment about it) rather than just slamming the chain over the big gear. However, as I said earlier, this seems like a GOOD thing to have and not the horrific, riding experience ruining performance alfeng is claiming.

 

[alfeng]

dhk2, you are kidding, right?

• On BOTH counts ... But, particularly the second where you suggest that the connection, or lack of, between the shifter, the cable, and the rear derailleur .... UNLESS your set up is so sloppy ([color=808080]e.g., poorly maintained cables-and-housing[/color]) that the release of the rear derailleur mechanism is delayed!!! [color=ff0000]You do understand that on a normal ([color=FFA500]non-Rapid Rise[/color]) derailleur that it is the derailleur's SPRING which moves the derailleur cage from the larger Cogs to the smaller Cogs, don't you? [/color]
• FYI. Rapid Rise ([color=FF0000]reverse-pull[/color]) rear derailleurs are in the neutral position when the derailleur is on the largest Cog & the shifter is used to move the derailleur to the smaller Cogs. Shimano doesn't call their reverse-pull rear derailleurs "Rapid Rise" just to humor me AND one can readily infer that the right-to-left ([color=0000FF]when viewed from the rear of the bike[/color]) motion is more rapid ([color=008000]faster!!![/color]) than their STI shifters can typically-and/or-consistently facilitate.

Again, both YOU & swampy1970 are inverting the derailleur's direction described by the term ...

• and, AyeYo is correctly interpreting the term ([color=0800FF]whether or not one wants to believe that "dwell" exists and/or has a negative-or-positive influence on the shifting[/color]).

 

[dhk2]

Alf, I assure you I'm not kidding about this subject. I'm not here to insult you or waste your time, but in an attempt to get you to do some critical thinking before posting nonsense.

Of course there is a connection between the shifter and the RD, but it's just a cable which can only pull, not push. I would like to think you understand that much, but honestly, I'm not sure anymore.

My little paragraph describing the RD action when shifting out to a smaller cog was all about the action of the spring. The sentence starts "The RD spring...." Since the cable can't push the RD out, the action has to rely on the spring. But when the chain tension is high, it takes considerable force to derail it from the cog and push it out to the smaller one. As a result, shifting out under heavy load is more difficult and takes longer than shifting under light load when everything is turning fast. IAW, the action of the RD is DELAYED, which I defined above as the DWELL. It has nothing to do with the shifter, which has already done it's thing. but everything to do with the design of the RD, chain and cogs. Is there something here you don't understand?

After that explanation of what the RD spring does, I find it incredible that you would come back and question if I understood that the SPRING moves the RD out to the smaller cog (after the cable is released by the shift lever). I don't know if you lack the ability to read and comprehend, or just want to fire back so quickly to belittle me that you skip the reading part. I suppose I should put key words in red or large fonts to aid your comprehension, like you do for us village idiots.

I thought you'd be happy that I finally found the DWELL, but instead, just more insults and responses that indicate you either choose not to read what I write, or can't comprehend it.

 

[alfeng]

Quote:Originally Posted by dhk2 .Alf, I assure you I'm not kidding about this subject. I'm not here to insult you or waste your time, but in an attempt to get you to do some critical thinking before posting nonsense.
Of course there is a connection between the shifter and the RD, but it's just a cable which can only pull, not push. I would like to think you understand that much, but honestly, I'm not sure anymore.
My little paragraph describing the RD action when shifting out to a smaller cog was all about the action of the spring. The sentence starts "The RD spring...." Since the cable can't push the RD out, the action has to rely on the spring. But when the chain tension is high, it takes considerable force to derail it from the cog and push it out to the smaller one. As a result, shifting out under heavy load is more difficult and takes longer than shifting under light load when everything is turning fast. IAW, the action of the RD is DELAYED, which I defined above as the DWELL. It has nothing to do with the shifter, which has already done it's thing. but everything to do with the design of the RD, chain and cogs. Is there something here you don't understand?
After that explanation of what the RD spring does, I find it incredible that you would come back and question if I understood that the SPRING moves the RD out to the smaller cog (after the cable is released by the shift lever). I don't know if you lack the ability to read and comprehend, or just want to fire back so quickly to belittle me that you skip the reading part. I suppose I should put key words in red or large fonts to aid your comprehension, like you do for us village idiots.
I thought you'd be happy that I finally found the DWELL, but instead, just more insults and responses that indicate you either choose not to read what I write, or can't comprehend it.


[color=0000FF]WOW! [/color]

• NOT to insult YOU, but while some springs can push, the rear derailleur spring pulls ... so, your remark was not even worth correcting, before ... MAKE THAT, [color=ff0000]your remarks[/color] were not worth correcting ... BECAUSE it sounds as though you have a limited understanding of how the indexed shifting works ... AND, that YOU never actually handled either a "normal pull" or "reverse pull" rear derailleur.

AND SO, not to insult YOU, but the poor maintenance of your cables must be causing the lag in response when moving from a larger Cog to a smaller Cog ... And, the lag you are experiencing is not the consequence described in the fanciful narrative which you have posted. NOT to insult YOU, but maybe YOU should (have someone) do some maintenance on your bike's cables-and-housing ... AND THEN it is [COLOR=FF00AA]YOU[/COLOR] who should do some critical thinking & stop wasting our time by pretending that your experience is universal to the exclusion of the poor downshifting which other riders have experienced with their Shimano STI shifters.

 

[dhk2]

You're of course correct alf, the RD spring pulls in tension to pull the RD out. My grievous error in the post above has been duly noted. The RD could be designed with a compression spring rather than a tension one, but my 7700 is a tension spring. But that doesn't change the fact that the regular Shimano RD relies solely on the spring, not the cable to PULL the arm out for the shift. The shifting works the same either way. Since, you should take pride that you caught me in such a major error, using push instead of pull.

But, afraid you're still wrong about the state of maintenance of my cables causing the delay in shifting under heavy load, low speeds. That's another one of your constructs, based on some thin negative assumptions, which serves your purposes of an easy and self-satisfying explanation. The "dwell" I've experienced and defined has got nothing to do with the cables or the levers, since they are all done once the cable has been released. If the shifting was slow under normal loads and high cadence, maybe it could be the cables, but I get quick shifts always under those conditions.

If you care to view this "dwell" for yourself, just shift out a click on your RD while the rear wheel is stationary. Doesn't matter whether it's Shimano or Campy. You'll see the RD move out a bit, but then stop....you know this I'm sure. Then as you slowly turn the crank, the chain will derail in about 1/2 to 1 rev of the rear wheel and complete the shift. If the rear wheel is moving less than 1 rev/second , say 3 mph like I do on steep hills, the delay or dwell can be perhaps a half second or more....never timed it exactly.

Apparently this is not the "dwell" you've been ranting about for ever but can never explain. So if it's not this, then what? Let's try eliminating what it can't be, then maybe your real "dwell" will be left standing.

Just answer in a couple of short sentences please, without more insulting questions about me. One: When does your "dwell" occur, under what specific conditions? Two: What do you think causes it ? Can those questions really be hard to answer concisely and clearly?

I have to admit in closing that I'm starting to enjoy you testing my limited understanding of mechanical things and their maintenance. And when you admonish me for "wasting our time".....I gotta love that one!

 

[alfeng]

[COLOR=FF00AA]Tsk, tsk ... [/COLOR] Shame-on-me for not realizing before this that you are either a Troll or delusionsal or both! Just re-read my prior explanations of "dwell" if you are really interested OR use your own definition which suits wherever you are in your own little world.

 

[dhk2]

OK, not surprised you end with a personal attack rather than answering any simple questions clearly. I've concluded you've really got nothing to offer, so I won't question you further.

 

[CAMPYBOB]

Can't we all just get along? And we do all agree that Campagnolo is vastly superior to any shimaNO product and has far less dwell time!

 

[AyeYo]

This whole thing is riduclous, but for some reason you guys don't seem to realize that one of you is talking about downshifts and one is talking about upshifts. It's like a boxing match with the guys standing back to back and swinging at the air.

 

[CAMPYBOB]

Fight! Fight!

After suffering my failed Spesh tube (that took out my Michelin tire's bead) I had to spend the next 50+ miles listening to the clunking 'long dwell time' shifts of my bud's Dura-Ass equipped Tarmac. The pain...the pain...

Worse, he dragged me up almost every climb and all I could do was sit there on his wheel and listen to those noisy, unrefined, inaccurate downshifts. Yeah, I had less dwell time, but not the legs to do anything about it! Damnit.

<Jens>"Shut up derailleur!"</Jens>

 

[dhk2]

Actually CB, that is the best cyclist-fight I've ever seen....most just involve a few weak attempts at slapping. And yes, I'll agree that Campy is just superior, because it's Italian.

After all, Campy Record on a rental DeRosa took me on that week of fantastic rides in Italy. And it only failed me once, when the front brake spring broke and tingled to the ground. Not a major problem I thought, we'll just wire the brake open and continue. But the Italian guide determined that I might endanger the group trying to ride back down to the coast with just a rear brake....and called up the support van. Did get to meet a classic mechanic at an LBS who installed a used brake in about five minutes total, speaking to me as if I could understand Italian.. I had studied Italian phrases for a few months before the trip, thinking that the least I could do before my two-week trip was learn the language. Turns out the most useful phrase I had was "Aspetta en cima".

Come to think of it, the guy that nailed my butt on last Wed's sprint was riding his steel cyclocross bike with a 14 speed Rohloff hub. He's been telling me how quickly they shift.......

 

[CAMPYBOB]

Quote by dhk2:
"Come to think of it, the guy that nailed my butt on last Wed's sprint was riding his steel cyclocross bike with a 14 speed Rohloff hub. He's been telling me how quickly they shift......."

Don't you hate when that happens?

At least my bud was on his new 50 MM aero wheels and new Spesh aero helmet on when he rode me off his wheel. Sadly, he can also do it on his new cyclocross bike with the tank-like 32 MM tires.

He's half my age. I guess youthful legs trumps short dwell time shifting every time!

 

[alfeng]

[color=800000]

url="/t/502532/hill-climbing-gear-shifting/60#post_4114129"]OK, not surprised you end with a personal attack rather than answering any simple questions clearly. I've concluded you've really got nothing to offer, so I won't question you further.

[color=800000]NICE! [/color]

• [COLOR=FFA500]Once a Troll (yes, I'm talking about YOU), always a Troll ... Apparently, an Alinskyite, too ...

Okay, [color=800000]Troll, it's probably time for you to slink back under the bridge where you dwell.[/COLOR] Incredibly, YOU now want to pretend that you cannot re-read the explanation which you have bemoaned has been previously posted numerous times ...

• HOW do you think my repeating my prior explanation will now benefit your comprehension?!?

AND SO, you now need to pretend that your query has not been answered. Again, the reply is to [color=0000ff]re-read the prior explanations[/color]. THAT should be simple enough to do ... even for a [color=800000]maroon[/color] like you.

 

[CAMPYBOB]

Quote by Alf:
"Apparently, an Alinskyite, too ..."

Alf! That's going too far! We reserve one that for...Democrats! But, I guess it's OK to use to disparage shimaNO users, too.

I keed! I keed!

 

[dhk2]

alf, you know, after going back and re-reading your posts , believe I finally understand what you're saying. The dwell is on the big lever (outer or brake lever) action. It was designed into Shimano shifters by way of a cam-shaped take-up spool, probably going back to the Biopace days. Shimano could have re-designed and fixed this dwell years ago, but hasn't because they are trying to get the legions of fans to upgrade to the Di2 system.

So, because this dwell is an inherent design flaw, it's got nothing to do with the slow shifting under heavy loads or low road speed that I've noticed and explained above. It's also got nothing to do with the inner lever, and the delayed action of releasing cable which swampy mentioned. Those notions I had were clearly off-track.

Sorry it took me so long to get it and for trolling/badgering you to keep repeating yourself. Although I don't actually live under a bridge, if I did I'd certainly slink back under it now.

 

[alfeng]

Originally Posted by dhk2
alf, you know, after going back and re-reading your posts , believe I finally understand what you're saying. The dwell is on the big lever (outer or brake lever) action. It was designed into Shimano shifters by way of a cam-shaped take-up spool, probably going back to the Biopace days. Shimano could have re-designed and fixed this dwell years ago, but hasn't because they are trying to get the legions of fans to upgrade to the Di2 system.

So, because this dwell is an inherent design flaw, it's got nothing to do with the slow shifting under heavy loads or low road speed that I've noticed and explained above. It's also got nothing to do with the inner lever, and the delayed action of releasing cable which swampy mentioned. Those notions I had were clearly off-track.

Sorry it took me so long to get it and for trolling/badgering you to keep repeating yourself. Although I don't actually live under a bridge, if I did I'd certainly slink back under it now.

"May the wind be at your back ...."

 

[CAMPYBOB]

Great! Now that we're all drinking together again...everyone repeat after me, in Eyetalian, "Something must change in the rear!".

Si!

"cambiá qualcossa de drio!"

And thus, dwell was eliminated from the flip-flop hub and mankind marched ever so steadily towards Super Record EPS shifting...zero dwell thanks to high-speed servo's and Romanian elves.

 

[Volnix]

Originally Posted by CAMPYBOB
zero dwell thanks to high-speed servo's and Romanian elves.

These Romanian Elves are very "Shifty"...

 

[swampy1970]

Originally Posted by CAMPYBOB
Can't we all just get along? And we do all agree that Campagnolo is vastly superior to any shimaNO product and has far less dwell time!

Nabali loves Campagnolo so much that he decided not to use Campag cranks, bottom bracket, hubs, headset, pedals or pretty much most of the Super Record groupset come to think of it.

... guess that leave two brake levers and front and rear mech. Even the bearings in the rear mech pulley's are made in Germany.

Campag wins the Tour de France! Well, according to their webshite.