Rapid rise -- stick or shift?

[Retrorockit]

When I walked into my LBS with one of these NOS Rapid Rise Revoshifters the owner was so impressed that he sold me an XTR Medium Cage Rapid Rise derailer for $30. I guess he knew no one else would ever come in having a use for it.

 

[Retrorockit]

I've seen reports of 40t cogs working OK with XTR Rapid Rise derailers. I have one of the new Shimano 9 speed 11-40t cassettes.
https://www.amazon.com/dp/B0BMQDN2PB?tag=bravesoftwa04-20&linkCode=osi&th=1&psc=1&language=en_US When I Googled this setup the first post I found was a user wanting this because he was sticking with Rapid Rise 9 speed for intense up and down trails. So this is an actual thing.
"I've been waiting for the Absolute Black 9 speed 40T cog, but they have now decided not to make a cog for 9 speed. It doesn't look like anyone else is going to do one either. I ride a lot of really tight up & down trails with big logs - almost trials stuff, so I'm a holdout for low normal rear derailleurs as these work great in this type of terrain.(you can't get low normal der in 10 or 11 speed ) I've contacted several of the 10 speed 40 & 42 cog makers to see if theirs would work on 9 speed and they all said it wouldn't work due to shift ramps and/or spacing."

 

[Retrorockit]

I installed the Shimano 11-40t 8 speed cassette, with the Rapd Rise XTR mid cage derailer. I ran the B screw all the way in and it would shift into low gear but the idler and cassette were amost touch. Installed a longer B screw and a few more turns and everything is looking and working great.
This is on a 1500W mid drive Ebike. While installing the cassette I put a square rubber O ring with silicone grease behind the cassette to cause a friction drive against the hub. This forces the chain to keep moving when you stop pedaling so you can still shift any time the bike is moving. So now the bike shifts like an IGH. The freewheel in the cranks of the mid drive allows this. I had been using small zip ties between the cassette and spokes to test this so when domething happened the zip tie would break and the bike would return to normal. Now that I have more experience with this I went with a friction clutch which is what Shimano did when they offered this in the '70s.

 

[Mod-Master]

This is quite interesting, can you show some pictures of your drivetrain?

More specifically the rubber o ring behind the cassette as I can’t quite wrap that round my head

 

[Retrorockit]

Here's a thread on this mod at electricbike.com.
https://electricbike.com/forum/foru...ussion/156222-mid-drive-cassettte-zip-tie-mod The flat O ring just softly fills the gap between the cassette and hub flange. Not much to see there.
My bike is kind of a worst case for this. Cross chained, No Narrow Wide chain ring., and a vintage Rapid Rise derailer.
It's kind of an Ebike thing because of the front freewheel requirement.
But the retrobike tie in is the Shimano Front Freewheel System, which pointed me towards the need for a breakaway or slip ring solution.

 

[Retrorockit]

40 mile test drive of the latest mods. The B screw mod lets the Rapid Rise XTR mid cage work with the desired 11-40t 8 speed cassette.
The Shimano ICE Tech rotors are working with the vintage Avid BB7s (not SRAM version) and metallic pads 203f/180r.
The friction drive between the hub and cassette is also working as planned. Shimano FFS clone.

 

[Retrorockit]

This is quite interesting, can you show some pictures of your drivetrain?

More specifically the rubber o ring behind the cassette as I can’t quite wrap that round my head

Since there was some interest in this Ebike hack, here is an update. One user who had chain drop offroad (his street bike it worked just fine, both 1500W BBSHD). Added a clutch type derailleur to his MTB. That solved the problem for him by pulling slack out of the chain all the way around. So it's looking like for this to work you need some kind of tightass chain management in place. You can either eliminate the slack, or control it with a chain guide. But if that's there it's just a zip tie to try it, and once it's not dropping the chain a friction drive solution.
Here's that Ebike thread again .
https://electricbike.com/forum/foru...ussion/156222-mid-drive-cassettte-zip-tie-mod

 

[Retrorockit]

I pulled the Rapid Rise off of one of my bikes. I definitely miss it. I did a 1x11 conversion on my 26" 2004 KHS Team Issue Softtail XC bike (with Schwalbe Kojak slicks).
I got a 46t Wide narrow chain ring in the middle position on the vintage XT v1 splined cranks.
I picked up a M7000 GS derailleur. Off label for an 11-51t cassette, but it worked. I wanted the mid cage for 26" wheels.
SRAM NX Gripshifter , also off label but works.
Wippermann 11s8 chain. 118 link (perfect length). Thank you online chain length calculator.
M5100 11-51t cassette. Moron this later.
I'm testing the limits of what will fit on this bike. Some compromise might be needed later, but for now bigger is better.

It all bolted right up. The cable anchor on the derailleur looked like it wanted to hit the giant cassette. But I chained it up , and set the limit screws, and B screw with no shifter installed. Everything cleared. It did require a trimming of the Jagwire Elite Link cable housing. So no going back now.
The single chain ring looks right in character for the stripped down XC racer frame. The derailleur isn't hanging down in the dirt.
But the all steel Deore "Death Star" cassette has got to go. 1lb.6oz. weight on this bike is a deal breaker.
So I found a Prestacycle PRO Gravel 11-42t billet cassette. Similar to some of the high end SRAM Stuff, but more in my budget (70th birthday present to myself) It also brings the M7000 derailleur in spec.
https://prestacycle.com/products/prestacycle-uniblock-pro-gravel-cassette-hg-11-speed This will give a more stealthy look to this mod and weigh about 1/3 as much (265g.). I've seen 0 reviews of this part.
I may have to swallow my aging pride and drop down a size or 2 on the chain ring. But that's in fashion now too.

 

[Retrorockit]

It's looking like this right now. That cassette has got to go. But it was fun to do the update. 24 spoke Mavic Crossrides are the original Romanian ones with eyelets. Not the Chinese ones with raised alloy bumps instead.

 

[Retrorockit]

It turns out the Prestacycle cassette was a road bike 11 speed part. Due to the US Labor Day holiday I got the order canceled before it shipped. So I'm still looking for a cassette solution.