Gus front derailleur reccomendation needed

[Jacob Byard]

Hello good people,

I'm finishing up my Gus build and the front derailleur from my stash doesn't work. I'm using a triple crankset (42/32/22 Ritchey) with a 123mm bottom bracket. 9 speed in the back and a 2.25" rear tire.

I actually bought a Shimano FD-M780 but it was the braze on style (mistake on my part). When I got the clamp in and everything mounted it didn't seem to have enough throw to push into the big ring. I'm pretty confident I had everything installed correctly.

The Skeleton Key FD on Riv says a 118mm BB. 

If I change the BB to something narrower will I run into tire clearance issues? I don't plan on going larger but it would be nice to have the option.

Thanks for any insight!

Cheers,

Jacob

[Justus G]

If you look for a good condition old stock XT M737 or LX M563 you should have a perfect match for your ring sizes, a small/short enough cage to not hit the stays and enough range for the triple.  I am currently using this setup with a 110/74 Ritchey Triple that I run with a Phil ~119mm BB.  But you may not need a new FD anyway.

Is your crankset the Ritchey Logic 94/58 Compact?  If so, that is meant to be run with a 110-113mm BB so if that is the case my concern is you are out of range due to the extra length which will also effect chainline. 

My recommend is to measure and see if a 113mm BB will work (need 5mm vs what you have now to tire) and go to that.  Perfect chainline.  Great Q-factor.  Prefect.  

[Jacob Byard]

I just checked and it’s a 110 BCD on the big ring. I’ve got just under .5” of clearance if I’m in the small/ big combo. So I should be fine swapping in a narrower BB. 

I’ll see about picking up one of the m737 or m563’s 

Thanks for the help! 

Cheers,

Jacob

Sent from my iPhone

On Dec 3, 2022, at 6:46 PM, Justus G <cjus...@gmail.com> wrote:

If you look for a good condition old stock XT M737 or LX M563 you should have a perfect match for your ring sizes, a small/short enough cage to not hit the stays and enough range for the triple.  I am currently using this setup with a 110/74 Ritchey Triple that I run with a Phil ~119mm BB.  But you may not need a new FD anyway.

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[Scott Luly]

A spindle length of 107mm should give a chain line of 47.5mm (which is kind of standard, if I'm not mistaken) and 113mm a 50mm.

I run a 113 because I like to run my rings a scratch more outboard.

I'm not a subject matter expert, but a 123 BB sounds very long for a triple set-up, or even double.

Service Instructions for my Shimano FDs indicates recommended chain line for various Shimano BBs and 123 isn't even on the list. I can double check when I return home and send you the chart I have.

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[Jacob Byard]

In my notes I had 123mm written down. So who knows how I came up with that. I have notes everywhere. Like a crazy person. I’m ordering a 113mm now and will swap it out. Going narrower will probably help my knees too. 

Cheers,

Jacob

Sent from my iPhone

On Dec 3, 2022, at 7:44 PM, 'Scott Luly' via RBW Owners Bunch <rbw-owne...@googlegroups.com> wrote:

A spindle length of 107mm should give a chain line of 47.5mm (which is kind of standard, if I'm not mistaken) and 113mm a 50mm.

To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/1179663755.673016.1670114680232%40mail.yahoo.com.

[Scott Luly]

Probably a typo on your part?

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On Sat, Dec 3, 2022 at 5:57 PM, Jacob Byard

<jacob...@gmail.com> wrote:

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[brendonoid]

My Susie is clearing a 2.8" rear tyre with a triple setup on a 113mm BB atm. Not the same crank but majority of that era triples were pretty much made for 110mm BBs except for some Suntours which needed crazy long ones.

[Garth]

Jacob, by "not having enough throw" is that hooked up with a cable or not ?  If it's with a cable then it's obviously a cable adjustment issue, but really whenever a derailleur capacity is in question it's best to simply do it without a cable and manually see how much it can travel with the adjustment screws open all the way.

The Riv derailleur for a 118mm BB is referring to the Silver crankset only, it's not universally applicable. 

[Jacob Byard]

I did not have the cable installed. I just manually grabbed the cage and I did have the limit screws open. By my eye it didn’t reach the big ring. But if I’m using too wide of a BB then that probably explains it. I’ve ordered a 113mm width. 

I did not realize the 118mm BB referred to Silver cranks only. That’s good to know. 

I’m an ambitious but poor mechanic. Thank goodness for this list and YouTube. 

Thank you for the help! 

Sent from my iPhone

On Dec 4, 2022, at 8:03 AM, Garth <gart...@gmail.com> wrote:

Jacob, by "not having enough throw" is that hooked up with a cable or not ?  If it's with a cable then it's obviously a cable adjustment issue, but really whenever a derailleur capacity is in question it's best to simply do it without a cable and manually see how much it can travel with the adjustment screws open all the way.

The Riv derailleur for a 118mm BB is referring to the Silver crankset only, it's not universally applicable. 

On Saturday, December 3, 2022 at 8:58:28 PM UTC-5 brendonoid wrote:

My Susie is clearing a 2.8" rear tyre with a triple setup on a 113mm BB atm. Not the same crank but majority of that era triples were pretty much made for 110mm BBs except for some Suntours which needed crazy long ones.

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[Jingy]

The stock BB length for a 110/74 Ritchey triple crank is 120mm.

I'm using an old Campy Veloce triple FD with my Ritchey crank and it shifts fine

Jim in Mpls

[Justus G]

Jim:  Correct, however if you see the original post, he is running 42/32/22 which is not compatible with 110/74bcd.  Until I see otherwise or those gear numbers change, we have to assume he is really running the Compact 94/58 Ritchey Logic and 110-113mm is the correct recommend.  His issue seems to support this with the thought being you might not be able to swing a cage out far enough if your spindle is 10mm longer than setup spec.

Jacob:  Feel free to post a pic to clarify, but I think the group has you on the right track.  Good on you for digging in and learning.

[Jingy]

I was going off what Jacob said in a later post- "just checked and it’s a 110 BCD on the big ring."

So Jacob will need to confirm exactly what crank and chainrings he has, and go from there.

Jim

[Justus G]

I know.  Conflicting info.  Hopefully all good teaching moments and good discussion.  

Justus in Mpls ;)

[Jacob Byard]

Well I’m an idiot. The chainring says CSP3 42 and the first thing that popped up on google had 110 but that was an add. Yes, it’s a 94 bcd. 

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On Dec 4, 2022, at 11:36 AM, Jingy <indepthin...@gmail.com> wrote:

I was going off what Jacob said in a later post- "just checked and it’s a 110 BCD on the big ring."

To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/b560400b-e153-4bdd-baca-1e07bf5f0cc4n%40googlegroups.com.

[R. Alexis]

Hey Jacob,

You say:

"I'm using a triple crankset (42/32/22 Ritchey)" and state it is a 110 bcd. From the ring sizes and the bottom bracket, it would seem that this is a 94/58 or 56 BCD crank. Lowest you can probably get the middle on a 110 bcd is 34 usually, possibly heard of a 33 and the smallest on the granny is a 24. 

I have two bikes with the Ritchey 110/74 and most of my fleet is running a 110/74 bcd of some type with the exception of possibly a couple. 

Thanks,

Reginald Alexis

[Justus G]

All good!  You are on the right track.  As Scott stated earlier, you can likely even go lower with the spec of 110-113mm and I am sure I am running a touch shorter on mine just for the reduced Q and good chainlink for gears I use.

BTW great cranks you have and love the finish on them.  I have that same finish my Potts.  I run these as doubles and triples for road, mountain and gravel setups in the standard and compact versions.  One of the all time great cranksets.

[Justus G]

chainline not chainlink

[Jacob Byard]

Oh I love learning all this stuff. It’s funny because I’m way more familiar with hydro, di2/ AXS and that crap but older components are very foreign to me. All part of the process. I’ll get there eventually. Hopefully. 

Sent from my iPhone

On Dec 4, 2022, at 12:21 PM, Justus G <cjus...@gmail.com> wrote:

I know.  Conflicting info.  Hopefully all good teaching moments and good discussion.  

To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/d99c7f9b-6984-46b2-9796-b4a55cb1bd22n%40googlegroups.com.

[R. Alexis]

Looks like your pic was posted at the same time I was typing this reply.

Looks like the 110-113 bb is what is needed. 

Good luck with the build.

Thanks,

Reggie

[Garth]

Jacob has the Logic Compact Triple, 94/58 BCD that took a 110--113mm BB originally. Some people have the Logic Triple(no compacto !) 110/74 which took a 120mm originally.

It must be noted though that back then before cartridges every manufacturer had their own offsets. So when you now go substituting a cartridge for the former ones just going by spindle length may not work as it depends on the offset differences with what's available. Hence, a Logic 110/74 Triple for most stays a 122.5(123mm label) is often the best. So if Jacob used a 123mm BB for his it was just an oversight of the "Compact" part which denotes the shorter BB !  Back in the say I substituted a Shimano UN74 127mm for the original Sugino AT triple 3U spindle that was 124.5mm with a large offset. I don't know the original Ritchey offsets so hopefully the 113mm works. I've found it's helpful to keep various cartridge lengths on hand if for anything , fitting purposes.