Going from 2x9 to 3x9 - FD Selection

[Dennis Wong]

Hello,

I currently have a 2x9 with a 26/38 crank (Silver brand) and a 11/34 cassette on my Rivendell Clem Smith Jr - H.

I want to add a third/outer chainring (maybe a 44 or 46), which can be done by replacing the Silver bashguard with an outer chainring.

I am shopping for a replacement front derailleur (either a Shimano XT M771 or XTR M971) because I don’t think my Claris FD is capable of a 3x.

I am looking at the specs of both FDs.

The “Front Chainwheel Tooth Difference” is 20T/22T for the XTR and 18T for the XT

The “Min. difference between top and intermediate” is 12T for the XTR and 10T for the XT

How closely do I need to meet these two requirements?  If I get a 46T, I don’t meet the Shimano specs.  The Front Chainwheel Difference is 20T and the Min Difference between the top and intermediate is 8T.   Will either FD work?  I wanted to save money by leaving the 26/28 alone.

On a side note, I don’t plan to use the smallest chaining (26T) very often (if ever) as I basically spinout for most of the 9 cogs. 

Thank you.

[aeroperf]

My Sam came as a 2x9 with 26/38 rings on a Suguino XD2 crank, and a Claris FD.
I went to 3x9 with 26/36/46 by replacing the bashguard.  The Claris FD was NOT capable of handling the 3x.
After trying a number of things and learning a lot about FDs and chainlines, I went to a Shimano Sora FD-3030 for the front.
It may be a “road” FD, but it works perfectly.
Good luck.

[Bill Lindsay]

I think it could be really useful to the group, and maybe to you, if you could describe what problem you are looking to solve.  

The implication is that you have decided you need higher gearing, because you ride too fast for the gearing that is on the Clem.  Depending on what tires you are running, the 38x11 highest gear on the bike now should be plenty to pedal well above 30MPH, but is not high enough to pedal up to 40MPH and beyond.  Is that the problem?  You spend too much time >30MPH and can't pedal at all when you are going >40MPH and need the gearing to keep up with your riding?  That's a valid use case, but many would consider that an odd use case for a Clem.  That's more like a Roaduno use case.  

You say that you spin out on most of the cogs when you are in the 26.  Have you decided you don't need the 26?  Have you considered moving from 26/38 up to 32/44?  Then you wouldn't need a front derailleur.  Have you considered going from 26/38 to a 40T 1x?  Then you could sell your front derailleur and you wouldn't need one at all.  

Removing a chain guard and adding a third ring can be complicated because of the shift from the 38 to the big ring.  Most triple front derailleurs are set up for jumps that are closer to equal.  Have a look at the Silver Triple on the rivbike website.  It's 24/34/44, nice 10 tooth jumps at each step.  26/38/44 with that 6-tooth jump could interfere with some front derailleur cage designs.  That's more like an old-school half-step setup.  

The point is that a bicycle has a lot of interdependencies.  You think you are changing one little thing, but it influences other things.  Planning a solution is good, but it should be to address a well-defined problem.  What problem are you trying to solve?

Bill Lindsay

El Cerrito, CA

[John Hawrylak, Woodstown NJ]

I use a Sora FD-R3030b to shift a Sugino AT triple and it works fine.  The Sora is designed for a 45mm front chain line so it should work you Silver crank.  I paid $27.99 for the Sora, so it's not much to pay for trying it.

RBW states the Microshift FDs they sell ("skeleton key'??) works with Siver triples.  You can find it at Universal Cycles cheaper than the $34 RBW wants.

John Hawrylak

Woodstown NJ

[Dennis Wong]

Hi Bill,

After writing that note I started thinking the same thing - what exactly is the problem I am trying to solve.  (Other than becoming obsessed with tinkering and "upgrading.")  In my mind I was thinking that I want to expand the range of the 9 speed.  On the big chainring, I find that the I seldom use the 3 largest cogs because I do spin out.  Maybe going to a 1x would fix that "problem."  You've got me second guessing myself.  LOL.  

Really do appreciate the thoughtful response, 

[Stephen Merelman]

I have a similar range that's handled well by an IRD Alpina, if you can track one down. 

smm

On Monday, July 8, 2024 at 9:06:56 PM UTC-4 wong.d...@gmail.com wrote:

[Drew Saunders]

I have a 26-42-guard New Albion setup, and although the 16 tooth shift is huge, it's pretty manageable if I'm not in a hurry. Maybe you just need a new "middle" ring and chainguard? It's also possible your chainguard is big enough for a 42. Going from 38 to 42 is about the same as changing 1t in the back for the higher gears (i.e.: a 42x11 would be like getting a 10t high gear with your 38), so is pretty noticeable. That would give you a 1x plus bailout, and you'll probably use the 42 for about 90% of your riding. How often do you use the 26x34? If rarely or never, I'm sure there are 11-32 or 11-28 cassettes that will work.