That new rear derailer

[Johnny Alien]

Big pulley and rapid rise. Gonna buy a couple of these.

[Pancake]

From the Blahh:

“Yesterday our first sample rear derailer was sent to us from ye olde People's Republic of China, made by the same people who've made the derailers many of you are riding with now, assuming they are not Shimano or Microshift or Campagnolo. They made it according to our design, which borrowed some of its geometry from Shimano's Rapid Rise derailers, which I ordinarily wouldn't do, but justify now because Shimano has discontinued this style of derailer, and it's too good to be extinct. If Shimano decides to make them again, which NO WAY, they'd have to do it before we sink tons of money and have to stop and disappoint the factory and lose all kinds of international face. It's complicated. Nobody in Taiwan is interested. Nobody in America is capable beyond "theoretically." It sure can't happen in Europe. A small CNC machinist is not going to do it, assembly and all, for less than a price to us that would mean a price to you of less than $800. So please don't punch up at your beloved Rivendell or an unbeloved me for "going to China."  China is the only way these are gonna get made before Kingdom Come. Your buddy the machinist is not capable of making one of these in a form and with a price that will work.”

I’ll also be ordering at least one of these. I’ve wasted enough dollars and hours trying to find a RD that will fit a 11-40t cassettes and keep the chain tight with a double crankset (46/30t). This looks like a shinny silver bullet solution for a fair price. 

Does it look like a 11t jockey and 13t pulley?

[Ray Varella]

I’m definitely in for at least one. 

I’m also curious about the V-brakes. The feature of being able to open far enough to clear a fat tire has me sold. 

Ray

[Corwin]

I tried rapid rise last time I was in Walnut Creek. I really liked it. I ditched friction about ten years ago though. Dislike friction for the same reason I like rapid rise: Hills! The San Francisco Bay Area is the home of long hills, steep hills and long, steep hills. I can't count the times I have been grinding up a hill with a derailleur in friction only to have my rear derailleur decide I was in the wrong gear and shift for me.

But rapid rise? It makes it trivial to get to a bigger cog. Just bought a rapid rise derailleur for my new Roadeo. Up till recently, I could not see any point in rapid rise. Now that I have tried it - it makes perfect sense. I wonder how many people that disdain rapid rise have actually tried it?

Namaste,

Corwin

[iamkeith]

Is there a reason this derailleur couldn't be used with index shifters if someone was so inclined?  Grant said they copied the parallelogram geometry from Shimano.  I assumed that meant it had a 1.66:1 cable pull ratio, so any index shifter up through 9 speed, with a corresponding number of detents, should work.  The only issue should be that the gear numbers on the shifter will be backwards.

What I keep wondering - and nobody ever answers - is what happened to the original idea of making these so that the spring could be moved to the opposite corners of the parallelogram, so that it could function in EITHER a high-normal or low-normal mode.  I hope they're doing that.   I don't dis-like rapid rise at all, but I have a lot of bikes and every time I get on my one that has it (Susie), I shift the wrong direction by habit if I'm in a crux move.  It would be nice to have both options.

[Bill Lindsay]

iamkeith asked one question and then implied a second question by stating a wonder.

The question:

"Is there a reason this derailleur couldn't be used with index shifters if someone was so inclined?"

There is no reason somebody could not use this derailer with index shifters if they were so inclined.  Whether or not it actually indexes to that person's liking would be up to them.  I know more than most people about the math and geometry of derailers and it's nasty math.  When Riv says it won't index well, I expect they have no idea whether it will index well, and at some point they'll try it.  I do not expect it to index well, mainly because I expect that the paralellogram will be steeper than most/all Shimano models, so even if the four legs are identical to Shimano, the cable rates needed will be different in relation to the greater tilt of the paralellogram.

The wonder:

"What I keep wondering - and nobody ever answers - is what happened to the original idea of making these so that the spring could be moved to the opposite corners of the parallelogram, so that it could function in EITHER a high-normal or low-normal mode"

If they suggested that they were going to try to do that, my guess is that they had that on a list of "nice to have" features but had not yet begun the actual design task of trying to think about whether such a thing was even feasible.  (#narrator voice -- It's not feasible)  The cable anchor hangs off the rear leg of the paralellogram in RapidRise and hangs off the front leg in "normal rise".  Take a good look at Shimano models side by side and it's clear a derailer can't have both at the same time, so that arm thing would have to be removable and remountable, but the thing is small, so you'd strip bolts or lose pieces.  It would be an immensely complex adder to a project that has already dragged on for several years.  A convertible Rivendell RD would achieve what?  It would allow people who love Rivendell but hate RapidRise to spend extra money on a Rivendell RD, but flip it back to work the same as a cheap Shimano Altus that is already awesome.  I don't see any point in that.  

Bill Lindsay

El Cerrito, CA

[iamkeith]

On Sunday, May 1, 2022 at 2:25:31 PM UTC-6 Bill Lindsay wrote:

iamkeith asked one question and then implied a second question by stating a wonder.

The question:

I don't always do as good of a Job as Bill at making the message-posting sequence as clear as Bill does, but my message - and rhetorical query of my own - was mostly meant as a response to Corwin's question.  My point was that I too suspect indexing might actually work for those who want it - though there's no way I could know for sure yet.   I was just hoping somebody might.   My other point was that I agree with Corwin saying that there's absolutely nothing to "hate" about rapid-rise.   But both options are still nice to have.  Horses for courses.

 A convertible Rivendell RD would achieve what?  It would allow people who love Rivendell but hate RapidRise to spend extra money on a Rivendell RD, but flip it back to work the same as a cheap Shimano Altus that is already awesome.  I don't see any point in that.  

Well, to me, it would offer an option to continue getting what will be presumably HIGH-quality and presumably polished silver,  normal-rise derailleurs - as opposed to perfectly-functional-but-cheap-and-not-attractive Altus derailleurs - which could help me keep my old (and new) bikes running with my preferred 7, 8 and 9 speed drivetrains.  I've long since tired of cruising ebay, looking for obsolete parts, but I like what I like.  It would be wonderful to have a new and in-productcion option available.  And "yes," supporting Riv would just makes it that much better.  Not saying I won't buy one or more anyway - just daydreaming out loud.

I wish I could find the old Blahg or Peeking through the Knothole or Reader article where they were tossing around the idea of the reversible spring.  It seemed so genius and simple to me.   Though I suspect you're right - it probably wasn't simple at all.

[brendonoid]

You can't just flip the spring on a derailleur. You need to change where the cable is pulling from and where it is attached. Non-trivial since it is built into the single molded top part. Where the barrel adjuster is attached on a rapid rise derailleur is actually the biggest flaw in the design and I suspect ACTUALLY the main reason Shimano gave up on it in the end. Evidenced by their shift to the 'shadow' layout, specifically designed to limit a derailleurs exposure beyond the frame, limiting damage from drops and trail debris.

I love the rapid rise derailleur that I've used but a single fall my bike experienced from a gust of wind in a car park smashed the barrel adjuster and bent the derailleur hanger. The rest of the bike received zero damage other than a scuff on bar tape.That is a very simple problem that a large parts manufacturer like Shimano would have got sick of covering warranties on.

[Bill Lindsay]

iamkeith followed up, saying: "I wish I could find the old Blahg or Peeking through the Knothole or Reader article where they were tossing around the idea of the reversible spring.  It seemed so genius and simple to me.   Though I suspect you're right - it probably wasn't simple at all."

I think the idea of a reversible action rear derailer would be super cute.  As a feature it's a strong 'nice to have'.  The problem is that you can't achieve that feature with a normal Cable+return spring mechanism unless the derailer itself is made up of parts that can be disassembled and reassembled.  If we made that feature (reversibility) a "MUST HAVE", then the way to achieve it would be to ditch the traditional mechanism.  We'd design a desmodrmic actuation method.  This means we actively move it in both directions and there is no return spring.  Old french rear derailers, made famous by Bicycle Quarterly had a continuous loop of cable actuating the rear der.  You could take your 1950's Rene Herse and give it a SICK Grant Pedersen flavor by reinstalling the cable in a figure 8: now it's Rapid Rise Rene!  Alternatively, one could fashion a hydraulic actuation method that pushes the RD in each direction.  It's trivial to insert a control valve that flips this flow and makes it Rapid Rise Hydro!  

Either one would be fun projects.  I've got pretty copious design notes on both of the above.  

Bill Lindsay

El Cerrito, CA 

[Corwin]

Not to belabor the point - but...

My question was not "Will the new derailer index?". My question was "How many people that disdain rapid rise have actually tried it?" Based on my experience using drivetrain components not matched [or not quite matched] for each other, I am not likely to try indexing on a derailer not specifically designed to index. I do think rapid rise is unfairly maligned.

Regards,

Corwin

[Jon Dukeman]

Not sure if this is the answer you are looking for.

I removed my 9 spd Altus and replaced it with a 9spd Shimano XT rapid rise derailuer. I'm using Microshift 9 speed indexing thumb shifters that work great with11- 36 cassette Front derailuer is friction. Silver 38×24 cranks

I did not have to do anything to the chain length.

I really like having front & rear shifters move the same way for high and low gears. 

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[brendonoid]

I finally got around to reading the latest blahg and those last few images show that Grant is tantalizingly close to solving the exposed barrel adjuster problem that Shimano never solved. Very interesting.

[R. Alexis]

This rapid rise deraileur sounds and looks intriguing. I have a couple of Shimano RD-C201 Mega-Range Rear Derailleur 8-Speed, Rapid Rise Silver. I have wanted to try it, but don't have anything to do so on in my personal use stable. My put it on some junk bike I have just for fun. Look forward to what the final product will look like once done. 

Reginald Alexis