It's long and rambling, but you'll learn two to four things about derailers or shifting that you didn't know before.
Modern shifting systems, indexing or electronic, are coordinated packages that deliver perfect results no matter what your skill level or experience.
You push till it clicks, you tap and it shifts.
For many riders and most manufacturers it's a godsend-dream-come-true. Not for all.
Big bike makers know that’s how to put people at ease with bicycles and expand the market, and they turn that independent fact into a green and philanthropic cause: to save the world by getting more people onto bikes by making bikes that require minimal to zero thought, learning, finagling.
When you're learning something, you don't want to have to think or finagle, you just want the result. Nothing could be more natural.
The thing is, thinking, learning, and finagling with bicycles is a blast. It turns a plain ride into a multi-dimensional one, as human interacts with machine, each helping the other. Is that too "special"?
Finagling is a hard concept to sell to nervous beginners who just wants to ride down the road and watch the pounds melt off while they detox from the news.
So it comes down to: Is bicycling better simpler and one-dimensional? I think it's FUN to manipulate the mechanisms on your bike.
to push the lever and shift.
to overshift and correct, to trim the derailers, front or rear, to quiet the chain or whatever.
to find yourself in too hard of a gear up too steep of a hill, and have to cut across it to lessen the slop so you can get up enough speed to float the pedals around without pressure and sneak in a shift.
to tighten the wingnuts on a friction shifter now and then as they come loose to no doom.
to grunt up a hill thinking you're in your granny gear while you're not, and then to discover that and shift to the small gear and find great relief. It's not fun to hear an undiagnosed click or squeek, but it's fantastic when you finally figure it out.
Would you really want a bike that prevented that kind of discovery moment?
Here's the guts of our Silver shifter.
It's more complicated than a pure friction shifter needs to be, and you could argue that the ratchet-and-pawl make it NOT a pure friction shifter, and I'd back you on that. But it's better, so much better. It's worth it. The ratchet and pawl still obey "the laws of friction," but they oomph it up a ton and just make life wonderful.
Internal gears have their place, and I seriously wish I understood them as much as some people I know do (A.G. and S.G. and B.H.). I kind of wish we had a three-speed option. But we don't and won't and it's because nobody here knows anything about them, and we can't get into stuff we're not experts at, so we leave them alone...and meanwhile, we have these marvelous bikes with external gears and (when you want 'em) friction shifters and derailers that require some skill but not much, but not none.
Bikes that don't require you to think remove all opportunities for you to fiddle with them. They say it lets you pay attention to the nature you’re riding in, or to get the workout you’re out there for without distractions, and they present it as improved technology.
But the goal is to turn you from player to spectator, driver to passenger, eater to salivator. Removing you and your human fallibility is good when the thing being done is tedious, boring, not fun, and a goofup risks life, limb, or job. When you might blow up the rocket with grampa in it.
But for bicycle riders who aren’t pros, or who aren’t racing, nothing's at stake.
I’m not saying the more challenging something is, the more fun it is, or the better it is. We all apply different degrees of skill to different daily tasks or hobbies. If you love riding bikes and are comfortable with them, you may find it fun to shift gears when shifting requires more than pushing a button, when it requires a coordinated effort between hands, legs, brain, and ears. If you prefer to minimize your input, that's totally cool, too. I'm just suggesting you consider whether—for YOU—there are benefits to hassling with stuff, with rejecting (as you know we like to do) the latest technology that removes you.
Somewhere along those lines there's a connection to bikes of the future, and sometimes the future is now. Electric bikes have wonderful potential to replace car trips, although right now it's hard to fit them into the current infrastructure. I think they'll need their own lanes to live up to their enviro-potential, and also storage capacity and weather protection. They need to be kind of like mini-cars. They will be.
Do they need this?
Electrical bikes are here and anti-lock brakes are coming, and gears will go internal, derailers will go away, chains and chainrings will disappear, and Shimano will compete with Honda in the next ten years. The mechanical bike is going to be ultra-niche-y, and we'll be here for you, or not.
I think there is a line, but I don't know where it is, when change keeps masquerading as progress but stops actually being progress.
When Shimano and SRAM are afraid the other will out-tech them and beat them to the next big thing, and then there are tech companies and automobike companies and even guys like Elon Musk dipping their fingers into the tech-athletic future, and independent entrepreneurs working on pedaling hovercrafts...then things gangly things like derailers become symbols of the dying present. When you can see how something works, when it's not a mystery hidden in a box, that intimidates some people and is harder to sell for more money. People will ALWAYS pay more for things they don't understand, because it makes them feel like smarter people are making them. And the first and easiest way to make something mysterious is to put it into a box. Sometimes it's unavoidable. Hubs, things with pawls and ratchets, and so on. But a lot of times now, things are boxed for no good reason, or they are designed with shapes that are unnessarily fancy and slick, and the shapes alone can serve as a box.
And, it's ironic, because derailers, which are one of the parts I'm thinking of, have never been better than they are now...(unless it was in the early 2000s when Shimano was still making RapidRise derailers). They'd look better simpler.
If Shimano would make them again, we wouldn't have to make the SILVER OM-1, which is basically a copy of Shimano RapidRise derailers, which were influenced by SunTour's 1964 Grand-Prix derailer, which itself was influenced by opposite-moving derailers in the 1950s, so there. Nobody's claiming "invention!"
I don't know when or even if our SILVER derailer will happen. In a month we'll have a better idea. It's a matter of money. Engineering, testing, and trusting too...but right now the hurdle is money. Here's where we are RIGHT NOW:
Every dimension affects things that seem obvious when explained, but aren't obvious until that. Like "largest rear cog" it'll shift to. That depends on the tilt/slant of the parallelogram, the angle of it separate from the tilt, and the size of the top (guide) pulley. The more slanted inward it is, the steeper faster sooner it drops, which is good for bigger cogs.
Here's how that works.
Here's a movie of a NON-SLANT parallelograme derailer showing how the pulleys in their cage move horizontally. In this case (and not shown her), the top pulley moves down with the PPO. But this vid shows only how the vertical (non-slanted) parallelogram guides the inward movement horizontally. In the videos that follow, you'll see the difference a slanted parallelogram makes. Like the illustration (by Jon Grant) above.
xcrane sideways.MOV from Rivendell Bicycle Works on Vimeo.
xconcentric pulley from inside no movement.MOV from Rivendell Bicycle Works on Vimeo.
Now this one here shows a derailer designed to shift to 51t. It doesn't have any PPO, but it has a super-slanted parallelogram, like on the right-side Jon Grant illustration.
x51t movie.MOV from Rivendell Bicycle Works on Vimeo.
Now in this link-video (concentric 51t), you'll see how the top pulley doesn't move downward as the cage rotates forward...BECAUSE this derailer has no PPO (pulley-pivot offset). I'm confused as to why it doesn't, but I'm not second-guessing the designers. They must have had a reason, but who knows?
I'm not sure what this link is. Will was helping me add the vimeo stuff, and this got up here too, and I'm to ashamed to ask him for further help.
from Rivendell Bicycle Works on Vimeo.--------------
Then there's something that I'd like the whole world to refer to as PPO, but that won't happen. It's Pulley-Pivot offset. Here's a picture of it.
The derailer in this example happens to be a 1973 Shimano Crane derailer. Shimano wasn't allowed to use a slant parallelogram at the time (SunTour had the patent), so it accomplished pulley-lowering by offsetting the center of the pulley with the cage pivot--standard practice at the time for all the sad-sack manufacturers who couldn't use the slant-parallelogram until SunTour's patent expired in 1985. Most modern slant-parallelograms have PPO on top of the slant parallelogram. But not all. Like, Shimano's Deore RD-591 derailer has PPO, but it's "updated" Deore RD-592 doesn't. It makes up for it with a steeper slant, but --- who am I to question Shimanos derailer designers, my god, they're the best in the world--but the thing is, the hell of it all IS, that PPO seems, to my funky brain, to allow the top pulley to ride closer to the cogs--an advantage. It allows a shallower slant, and relegates some of the pulley-lowering to the offset.
Are ANY of you still with me on this? I have no idea. Is this too much of a deep-dive? I don't mean that as an insult. I'm sure 80 percent of you are smarter than I am, and the remaining 20 percent are just as smart, but this will test your patience.
I'm going to languish here.
You don't need to know how rear derailers work, but knowing that makes it easier to want to have one on your bike. That's what this is all about—liking rear derailers even while manufacturers are planning to get rid of them.
This is how to shift. It has been here before and is on our site, but seeing it again might help you act on it for the first time:
1. Pedal like normal until your right foot reaches 4:30. SHIFT.
2. Float your right foot to 12:00 and let your left foot move to about 6:00 but with ZERO pressure on it. If you truly "floated" the pedals, by the time your right one reaches 12:00 (sometimes 1:00), the shift will be complete, and you can power on or whatever.
If you tension the chain by pushing EVEN A LITTLE on the pedal during the FLOAT stage, the chain will be too tensioned to move to the next cog. To drive home how important it is to detention the chain, get off your bike, push down on the pedal with maybe ten pounds of force, and then push the upper section of the chain inward. Don't drive the bike forward, just push down on the pedal and push the chain inward, toward the tire.
You'll see the chain doesn't move.
Now unweight the pedal and try it. It wiggles inward easily. This is the state the chain must be in for the shift to take.
Here's a video showing how the lower chain is unaffected by pedal pressure, so even if you shift with your front foot at 2:00 or 3:00 and under high pedal pressure (and high chain tension), the derailer will still initiate ye old shifte on the lower part of the chain....but then if the upper chain is under tension when the chain rolls around to the top, the chain won't move to the cog you think you're shifting to.
This isn't a failure of the shifter or the derailer.
INDEXING doesn't overcome a stiff chain. When you shift in index, the shift still happens the same way--only when the chain is slack.
If the above lesson seems hard, it isn't. Try it. If you don't want to learn to shift, you can still have a great time riding a bike with indexed shifting.
Back on hiatus for a month at least. I hope you got something out of this even if you already knew how to shift perfectly. Every ride I go on, I blow a few shifts. I forget to do stuff, I get distracted, whatever. It's just my bike reminding me that I matter to it. Thanks, bike!
------FLASH. This image just in, should be coming in a month or so. Buy early in case public opinion forces us to soften it! (I was going to buy one for my seven year old, but now I guess I can't....")
out of here. G