46/30 frame issues or FD issues?

Especially for light weight issues concerning cyclocross / touring bikes & parts.

Moderator: Moderator Team

Surfshack
Posts: 10
Joined: Thu Apr 11, 2019 10:38 pm

by Surfshack

Looking at switching a 1x setup to 2x climbing gravel rig and I was curious if anyone is having any issues with frame clearance or front derailleur shifting with the small 30t chainring.
Thanks.

User avatar
ultimobici
in the industry
Posts: 3351
Joined: Sun Nov 21, 2004 2:45 pm
Location: London, UK
Contact:

by ultimobici

What frame are you using?


Sent from my iPad using Tapatalk

by Weenie


Surfshack
Posts: 10
Joined: Thu Apr 11, 2019 10:38 pm

by Surfshack

Ridley x trail.

jemima
Posts: 149
Joined: Fri Apr 22, 2011 12:36 am
Location: Perth

by jemima

What shifter/derailleur/crank/rings are you using?
Curve Grovel ti.

User avatar
Curious George
Posts: 265
Joined: Fri Sep 08, 2006 11:48 am

by Curious George

Running a Trek Checkpoint with 46/30, standard cranks and DI2 front derailleur with no issues.

User avatar
IrrelevantD
Posts: 629
Joined: Sun Nov 29, 2015 5:47 pm
Location: Near DFW Airport

by IrrelevantD

Are you buying a new crank, or are you looking at getting something like the Absolute Black rings for your existing crank?

If you're buying new (IE: Easton EA70), see if you can find chainline specs. I want to say the EA70 has a normal chainline, I was able to swap mine for a SRAM/Quarq BB30 and I don't recall having to make any major derailleur adjustments, but there may have been a differenece in the width of the spacers.

The AB rings push the chainline in toward the frame and may not work on some frames. I don't know about the Ridley specifically.

As for derailleur, you should be able to adjust the innner and outer stops to acomodate any change in the chainline.
* There is a 70% chance that what you have just read has a peppering of cynicism or sarcasm and generally should not be taken seriously.
I'll leave it up to you to figure out the other 30%. If you are in any way offended, that's on you.

gb123bike
Posts: 50
Joined: Mon Dec 16, 2019 1:02 am

by gb123bike

I have a bike with a 24/39 on the front, and the Shimano 105 FD can shift it.

Note that I did not say it shifts it well :D . That it does not do. However, it does manage. The only problem I ever had was once or twice I shifted off inner ring, but a bit of FD range adjustment seems to have solved that and I haven't had that happen in years.

User avatar
Noctiluxx
Posts: 905
Joined: Tue Feb 07, 2017 7:17 pm
Location: Southern California

by Noctiluxx

Revolt running Ultegra with Easton EC90SL, 46-30 and no issues at all.
2018 Bianchi Oltre XR4, (Celeste Matt)
2018 De Rosa SK Pininfarina (Blu)
2019 Trek Madone SLR (Rage Red)
2019 Giant TCR Advanced SL (Chameleon Blue)
2019 Cervelo R5 Disk (Team Sunweb)
2019 Giant Revolt Advanced 0

User avatar
IrrelevantD
Posts: 629
Joined: Sun Nov 29, 2015 5:47 pm
Location: Near DFW Airport

by IrrelevantD

Surfshack wrote:
Fri Dec 27, 2019 11:17 pm
Ridley x trail.
Got to thinking about this again after reading something someone posted in another thread. They mentioned the small ring limtation on their bike being due to a dropped chainstay design. After looking at some pics of different frames, my guess is that some of the bikes with large drops to acomodate massive tires put the chainstay into the chainline if you get too small of a ring. So if you put a 30T on some of those bikes the chain would rub on the bottom of the stay going back to the derailleur.

The x-trail having a fairly traditional drive side stay should probably be fine.

Regarding the FD, Shimano doesn't list a minimum ring size for road FDs, only the difference between the number of teeth which is usually 16t or 17t for GRX (not sure about SRAM). I think the limiting factor is going to be how low can you mount the FD. The Alloy X-Trail being a band clamp mount should be no problem. Carbon being essentialy a braze on, you might be limited but I'd bet you'd be OK going down to 30T.
* There is a 70% chance that what you have just read has a peppering of cynicism or sarcasm and generally should not be taken seriously.
I'll leave it up to you to figure out the other 30%. If you are in any way offended, that's on you.

User avatar
kytyree
Posts: 680
Joined: Thu Oct 09, 2008 4:55 am
Location: US

by kytyree

I think that frame uses a band on front mech so that should remove one limitation. My frame for example can't use a ring smaller than 48 because the front mech would be too tall.

Surfshack
Posts: 10
Joined: Thu Apr 11, 2019 10:38 pm

by Surfshack

My concern is the FD Hanger. It's not a band on so I don't know if the FD will adjust down to accommodate the small inner ring.
I'm looking at the FSA 46/30 adventure crank and using an Ultegra FD.

Surfshack
Posts: 10
Joined: Thu Apr 11, 2019 10:38 pm

by Surfshack

That's for all the reply's btw

User avatar
kytyree
Posts: 680
Joined: Thu Oct 09, 2008 4:55 am
Location: US

by kytyree

I tried to look it up and thought it was adjustable, my bad. But that could be a problem for sure. I can get a new hangar for my frame that works with a 46. Is this one removable?


User avatar
Stendhal
Posts: 250
Joined: Sun Sep 25, 2016 1:43 am
Location: Silicon Valley

by Stendhal

No problems with Easton EC90 SL 46/30 on my Cervelo Aspero.
Cervelo Aspero (7.87)
Retired: S-Works Tarmac SL6, LOW// mki, Pinarello Dogma F10 \ F8, Lapierre Pulsium, TIME Fluidity, Wilier Cento1 SR, Ridley Noah, Cyfac Cadence, Cervelo S2, R3, R5, Felt Z25, Klein Quantum, Cannondale 2.0

by Weenie


Post Reply
  • Similar Topics
    Replies
    Views
    Last post