advent x rear and friction shifting...not enough pull
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advent x rear and friction shifting...not enough pull
I thought i would do a 1x system using an advent x rear derailuer which gets great reviews. No friction shifter i have has enough pull to get it up into the granny gears in the rear. Granted all my friction stuff is older suntour ratcheting stuff but those have worked in every other configuration i have ever tried. Ether way im only able to get 7 speeds out of this setup. I have another use for the rear mech on a couple of other bikes so its not a total lose but a fun experiment anyway. I might run it like this for a while. I wont imagine needing those granny gears around here.
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As I recall, the Microshift Advent stuff uses about a 1:1 shift ratio, meaning they need more cable pulled than what a traditional Shimano 7/8/9-speed derailleur would need. A Shimano/SRAM 10-speed cassette has a 3.95mm sprocket pitch and, if I'm doing the maths right, you'd need to pull about 35.55mm of cable (3.95mm * 9 shifts) to hit all 10 sprockets. I'm sure you've checked derailer limit screws and such to be sure those aren't limiting the derailer's travel, but it may be worth mentioning anyway.
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yup...the limit screws are ok. Just not enough pull to suck the cage in to get those last couple cogs. I can push it in fine and get them manually with my hand leaving a bunch of slack in the cable.
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Maybe a JTek Shiftmate will help. Not sure which one, or how well it works, but people have used them for Campy/Shimano compatibility.
John
John
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There is one more possibility, but you’ll have to figure it out if it is possible with an Advent X RD, alternate cable routing.
I’ve done alternative routing with Shimano, but have no clue with your RD. “Maybe” a simple 360* wrap around the arm and then to the attach bolt.
I still think a JTek is better, but alternate routing is pretty simple to understand, especially with friction shifters.
What you are doing is wrapping the cable closer to the RD pivot point so it moves over more for the same amount of cable pull. If your RD is 1:1, then getting it to 1.2 or 1.3:1 might give enough additional movement.
With friction shifting you don’t need to worry about specific cog-to-cog spacing and can use the barrel adjustment to take out any settling of the wrapping.
John
I’ve done alternative routing with Shimano, but have no clue with your RD. “Maybe” a simple 360* wrap around the arm and then to the attach bolt.
I still think a JTek is better, but alternate routing is pretty simple to understand, especially with friction shifters.
What you are doing is wrapping the cable closer to the RD pivot point so it moves over more for the same amount of cable pull. If your RD is 1:1, then getting it to 1.2 or 1.3:1 might give enough additional movement.
With friction shifting you don’t need to worry about specific cog-to-cog spacing and can use the barrel adjustment to take out any settling of the wrapping.
John
Last edited by 70sSanO; 05-17-22 at 04:20 PM.
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There are devices (Travel Agent for brakes) that multiply the cable pull. I don't have a name to Google but I've heard people using them on derailleurs. All reports I've heard is that they work very well.
Edit: The JT Shiftmate mentioned above might well be what I am talking about..
Edit: The JT Shiftmate mentioned above might well be what I am talking about..
Last edited by 79pmooney; 05-18-22 at 11:59 AM. Reason: Saw another post
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Friction shifter pull ratio?
Downtube shifters that pull a lot of cable...
https://www.bikeforums.net/classic-vintage/1123217-friction-shifters-compatible-all-speeds.html
Downtube shifters that pull a lot of cable...
https://www.bikeforums.net/classic-vintage/1123217-friction-shifters-compatible-all-speeds.html
Last edited by dedhed; 05-19-22 at 07:34 AM.
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I did not know that either. Ill check those out.
I bought this rear probably 6 months ago just prior to winter and kind of forgot about it. I wanted to try and run it with my old ratcheting suntour downtube shifters. IM kind of surprised that it wont pull the full range but its the wrong application for this thing all around. A MTB rear mech on a road bike with drop bars. and the shifter, while bomb proof is probably 40 years old
I have had time to stare at it again but will eventually.
I bought this rear probably 6 months ago just prior to winter and kind of forgot about it. I wanted to try and run it with my old ratcheting suntour downtube shifters. IM kind of surprised that it wont pull the full range but its the wrong application for this thing all around. A MTB rear mech on a road bike with drop bars. and the shifter, while bomb proof is probably 40 years old

I have had time to stare at it again but will eventually.
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Finally got around to riding it again today. Definately not enough pull to get into the highest 2 cogs using a suntour ratcheting dt shifter. Also..it seems no matter what gear.....if i get on it hard or dare get out of the saddle it skips like crazy. It could be the rear tiagra free hub slipping but i dont think so. These wheels are new take offfs. No matter how careful i am at trimming/adjusting...its just a pain in the neck and if i cant get out of the saddle and hammer it once and a while....its getting trashed/relegated to another bike.....and thats fine.
Looking for any band clamp downtube 9 speed rear indexed shifting/rear mech that isnt garbage at this point. I know thats a loaded question but just anything that works well is fine by me. I hope you can still get band clamps for downtube shifters.....
Looking for any band clamp downtube 9 speed rear indexed shifting/rear mech that isnt garbage at this point. I know thats a loaded question but just anything that works well is fine by me. I hope you can still get band clamps for downtube shifters.....
#14
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Dia-comp makes an 11-speed downtube shifter. That and a clamp-on shifter boss would probably work.
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I put on an older model Shimano SLX long cage and it works perfect. The microshift makes no sense. I guess thats what i get for putting it on a road bike. I thought friction shifters basically were compatible with everything provided you were smart enough mechanically to know how to shift properly (which i would argue eliminates almost everyone except those mechanically inclined common sense types)........but......apparently not. Time to put this thing in the parts bin ...to later be swapped out to the mtb. THis thing does not have enough pull and then "skips" under load enough not to trust it under hard accelerations. Oh well......at least i have another use for it so i didnt piss away 60 bucks.