Go Back  Bike Forums > Bike Forums > Fifty Plus (50+)
Reload this Page >

Anyone using a 46/30T crank on a road bike?

Notices
Fifty Plus (50+) Share the victories, challenges, successes and special concerns of bicyclists 50 and older. Especially useful for those entering or reentering bicycling.

Anyone using a 46/30T crank on a road bike?

Old 08-20-19, 10:18 AM
  #426  
jppe
Let's do a Century
 
jppe's Avatar
 
Join Date: Oct 2004
Location: North Carolina
Posts: 7,456

Bikes: Cervelo R3 Disc, Pinarello Prince/Campy SR; Cervelo R3/Sram Red; Trek 5900/Duraace, Cervelo P2C/Duraace, Cannondle Tandem/Ultegra, Lynskey GR260 Ultegra

Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 358 Post(s)
Liked 85 Times in 50 Posts
I received the Shimano GRX600 46/30. I removed the Shimano 46/34 (46/36 originally) and put in the 46/30. The Original FD works okay but I still need to tweak it a bit. Itís a little rough going from the 30 to the 46 and there is some chain rub on the 46 and harder gears.

I need to get the outer plate on the FD to move out a little more and so far I havenít been able to get the outer limit screw to move it enough. Itís rideable but not quiet enough for my taste just yet.
jppe is offline  
Old 08-20-19, 10:36 AM
  #427  
wsteve464
Senior Member
 
Join Date: Jul 2016
Posts: 296
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 81 Post(s)
Likes: 0
Liked 6 Times in 5 Posts
Originally Posted by jppe View Post
I received the Shimano GRX600 46/30. I removed the Shimano 46/34 (46/36 originally) and put in the 46/30. The Original FD works okay but I still need to tweak it a bit. Itís a little rough going from the 30 to the 46 and there is some chain rub on the 46 and harder gears.

I need to get the outer plate on the FD to move out a little more and so far I havenít been able to get the outer limit screw to move it enough. Itís rideable but not quiet enough for my taste just yet.
If you want to do the install right you need the GRX FD as the chain line is 2.5mm outboard. A spacer of some kind may work but the FD arm needs adjust 2.5mm further from the seat post.
wsteve464 is offline  
Old 08-20-19, 12:56 PM
  #428  
shelbyfv
Senior Member
 
shelbyfv's Avatar
 
Join Date: Jun 2007
Posts: 5,529
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 1201 Post(s)
Liked 201 Times in 133 Posts
Thanks for the report. Looks as if the FD needs to go in the cart with the crank. Now we know!
shelbyfv is offline  
Old 08-20-19, 03:14 PM
  #429  
jppe
Let's do a Century
 
jppe's Avatar
 
Join Date: Oct 2004
Location: North Carolina
Posts: 7,456

Bikes: Cervelo R3 Disc, Pinarello Prince/Campy SR; Cervelo R3/Sram Red; Trek 5900/Duraace, Cervelo P2C/Duraace, Cannondle Tandem/Ultegra, Lynskey GR260 Ultegra

Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 358 Post(s)
Liked 85 Times in 50 Posts
Originally Posted by wsteve464 View Post
If you want to do the install right you need the GRX FD as the chain line is 2.5mm outboard. A spacer of some kind may work but the FD arm needs adjust 2.5mm further from the seat post.
I was aware of the different chain line but I was hoping I could just set the FD outer limit on the big ring out far enough. 2.5 mm is quite a lot though. So far it doesnít look like there is enough play to move it out far enough. I did notice the FD outer plate was pretty high above the big ring so I lowered it probably 2 mm. That really helped the shifting between the rings but there is still too much chain rub on the outer plate. The 30 ring is really quiet through all the gears. The 30/34 combination feels like a ridiculously easy gear.....

If Iím in the 30/11 and coasting the RD canít take up enough of the chain and the chain relaxes on the chain stay. Thereís really no reason to be in that combination so thatís not a big deal.
__________________
Ride your Ride!!
jppe is offline  
Old 08-20-19, 03:35 PM
  #430  
Marcus_Ti 
Frozen Solid.
 
Marcus_Ti's Avatar
 
Join Date: Sep 2014
Location: Lincoln, Nebraska
Posts: 4,795

Bikes: Roadie: Seven Axiom Race Ti w/Chorus 11s. CX/Adventure: Carver Gravel Grinder w/ Di2

Mentioned: 29 Post(s)
Tagged: 0 Thread(s)
Quoted: 2000 Post(s)
Liked 91 Times in 63 Posts
Originally Posted by jppe View Post
I was aware of the different chain line but I was hoping I could just set the FD outer limit on the big ring out far enough. 2.5 mm is quite a lot though. So far it doesnít look like there is enough play to move it out far enough. I did notice the FD outer plate was pretty high above the big ring so I lowered it probably 2 mm. That really helped the shifting between the rings but there is still too much chain rub on the outer plate. The 30 ring is really quiet through all the gears. The 30/34 combination feels like a ridiculously easy gear.....

If Iím in the 30/11 and coasting the RD canít take up enough of the chain and the chain relaxes on the chain stay. Thereís really no reason to be in that combination so thatís not a big deal.
Well it is...until you're on a 15%+ dirt/gravel road ascent where you cannot stand due to losing drive-traction.
Marcus_Ti is offline  
Likes For Marcus_Ti:
Old 08-20-19, 05:46 PM
  #431  
jppe
Let's do a Century
 
jppe's Avatar
 
Join Date: Oct 2004
Location: North Carolina
Posts: 7,456

Bikes: Cervelo R3 Disc, Pinarello Prince/Campy SR; Cervelo R3/Sram Red; Trek 5900/Duraace, Cervelo P2C/Duraace, Cannondle Tandem/Ultegra, Lynskey GR260 Ultegra

Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 358 Post(s)
Liked 85 Times in 50 Posts
Well......I haven’t thoroughly researched it but I’m not seeing a GRX FD that’s not a braze on. My FD is a clamp on.

Rut roh......
__________________
Ride your Ride!!
jppe is offline  
Old 08-20-19, 05:49 PM
  #432  
Marcus_Ti 
Frozen Solid.
 
Marcus_Ti's Avatar
 
Join Date: Sep 2014
Location: Lincoln, Nebraska
Posts: 4,795

Bikes: Roadie: Seven Axiom Race Ti w/Chorus 11s. CX/Adventure: Carver Gravel Grinder w/ Di2

Mentioned: 29 Post(s)
Tagged: 0 Thread(s)
Quoted: 2000 Post(s)
Liked 91 Times in 63 Posts
Originally Posted by jppe View Post
Well......I havenít thoroughly researched it but Iím not seeing a GRX FD thatís not a braze on. My FD is a clamp on.

Rut roh......
Get an adapter clamp. I can't remember the Shimano part number but it is all of $15
Marcus_Ti is offline  
Old 08-21-19, 06:08 AM
  #433  
jppe
Let's do a Century
 
jppe's Avatar
 
Join Date: Oct 2004
Location: North Carolina
Posts: 7,456

Bikes: Cervelo R3 Disc, Pinarello Prince/Campy SR; Cervelo R3/Sram Red; Trek 5900/Duraace, Cervelo P2C/Duraace, Cannondle Tandem/Ultegra, Lynskey GR260 Ultegra

Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 358 Post(s)
Liked 85 Times in 50 Posts
Originally Posted by Marcus_Ti View Post
Get an adapter clamp. I can't remember the Shimano part number but it is all of $15
Yep. Part 9150
jppe is offline  
Old 08-21-19, 10:31 AM
  #434  
jppe
Let's do a Century
 
jppe's Avatar
 
Join Date: Oct 2004
Location: North Carolina
Posts: 7,456

Bikes: Cervelo R3 Disc, Pinarello Prince/Campy SR; Cervelo R3/Sram Red; Trek 5900/Duraace, Cervelo P2C/Duraace, Cannondle Tandem/Ultegra, Lynskey GR260 Ultegra

Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 358 Post(s)
Liked 85 Times in 50 Posts
Okay, I now have the GRX 11 sp FD and Shimano FD Mount adapter headed my way. That way I can mount the braze on FD to my seat tube.

You could ride it with the existing FD but the chain rub on the outer FD plate is quite annoying......not to mention all the watts Iíd be losing pedaling!?!???

At least I tried using the R8000 FD.....
jppe is offline  
Likes For jppe:
Old 08-21-19, 12:10 PM
  #435  
tomtomtom123
Senior Member
 
Join Date: Jan 2017
Posts: 325
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 103 Post(s)
Likes: 0
Liked 3 Times in 3 Posts
You could switch the road BB cups to mtb BB cups. That would make the overall BB width 2mm shorter, and bring your chainline 1mm inward. You'd have to shave the plastic stops on the water sleeve so that they'd fit in between the mtb BB cups while on the narrower BB shell. The left crank arm probably has enough tolerance to eat up the extra 2mm of spindle protrusion, and you get 2mm narrower q-factor.
tomtomtom123 is offline  
Old 08-21-19, 01:36 PM
  #436  
shelbyfv
Senior Member
 
shelbyfv's Avatar
 
Join Date: Jun 2007
Posts: 5,529
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 1201 Post(s)
Liked 201 Times in 133 Posts
Originally Posted by tomtomtom123 View Post
The left crank arm probably has enough tolerance to eat up the extra 2mm of spindle protrusion
elaborate?
shelbyfv is offline  
Old 08-21-19, 03:10 PM
  #437  
jppe
Let's do a Century
 
jppe's Avatar
 
Join Date: Oct 2004
Location: North Carolina
Posts: 7,456

Bikes: Cervelo R3 Disc, Pinarello Prince/Campy SR; Cervelo R3/Sram Red; Trek 5900/Duraace, Cervelo P2C/Duraace, Cannondle Tandem/Ultegra, Lynskey GR260 Ultegra

Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 358 Post(s)
Liked 85 Times in 50 Posts
Originally Posted by tomtomtom123 View Post
You could switch the road BB cups to mtb BB cups. That would make the overall BB width 2mm shorter, and bring your chainline 1mm inward. You'd have to shave the plastic stops on the water sleeve so that they'd fit in between the mtb BB cups while on the narrower BB shell. The left crank arm probably has enough tolerance to eat up the extra 2mm of spindle protrusion, and you get 2mm narrower q-factor.

I could see how that might work. At least the GRX FD and FD adapter arenít a huge expensive so hopefully those will do the trick.

Iím surprised I couldnít adjust the high limit on the R8000 FD out more but I guess thatís why Shimano is making the GRX FD....
__________________
Ride your Ride!!
jppe is offline  
Old 08-21-19, 04:59 PM
  #438  
tomtomtom123
Senior Member
 
Join Date: Jan 2017
Posts: 325
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 103 Post(s)
Likes: 0
Liked 3 Times in 3 Posts
Originally Posted by shelbyfv View Post
elaborate?
There is probably enough of a gap between the ends of the splines between the left arm and the spindle to allow the spindle to protrude some more before bottoming out. Each crank might be different, but I saw a video where a guy took one of the 2.5mm shims out of his MTB BB for his 68mm width shell, and the left mtb crank arm did not bottom out. He then took out the 2nd 2.5mm shim, but had to shave down some of the splines in the left crank arm to prevent bottoming out.
If the same applies to road cranks, then the left arm could probably eat the 2mm extra protruding spindle length, when you switch to the 2mm narrower mtb bb. If it does bottom out, you could add 1 or 2mm of shims to the left cup.
tomtomtom123 is offline  
Old 08-21-19, 05:00 PM
  #439  
tomtomtom123
Senior Member
 
Join Date: Jan 2017
Posts: 325
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 103 Post(s)
Likes: 0
Liked 3 Times in 3 Posts
Originally Posted by jppe View Post
Iím surprised I couldnít adjust the high limit on the R8000 FD out more but I guess thatís why Shimano is making the GRX FD....
Did you completely withdraw the H limit screw on the FD?
tomtomtom123 is offline  
Old 08-21-19, 05:13 PM
  #440  
shelbyfv
Senior Member
 
shelbyfv's Avatar
 
Join Date: Jun 2007
Posts: 5,529
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 1201 Post(s)
Liked 201 Times in 133 Posts
Originally Posted by tomtomtom123 View Post
If the same applies to road cranks, then the left arm could probably eat the 2mm extra protruding spindle length,
These are current Shimano HT II cranks. They eat what they are designed to eat, no more, no less. Seems lots has changed since back when....
shelbyfv is offline  
Old 08-21-19, 06:04 PM
  #441  
tomtomtom123
Senior Member
 
Join Date: Jan 2017
Posts: 325
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 103 Post(s)
Likes: 0
Liked 3 Times in 3 Posts
Originally Posted by shelbyfv View Post
These are current Shimano HT II cranks. They eat what they are designed to eat, no more, no less. Seems lots has changed since back when....
If you're interested, here is where I saw it:

And some info here:
FAQLoad - XT M760/761 cranks - Shrinking the Q-Factor
tomtomtom123 is offline  
Likes For tomtomtom123:
Old 08-21-19, 06:31 PM
  #442  
shelbyfv
Senior Member
 
shelbyfv's Avatar
 
Join Date: Jun 2007
Posts: 5,529
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 1201 Post(s)
Liked 201 Times in 133 Posts
What a kludge I drill out half the spline on my crank arm, I'll be a little nervous standing to climb. Darwin Thanks for posting, though. It's fun to see the weird stuff folks think up.

Last edited by shelbyfv; 08-21-19 at 07:01 PM.
shelbyfv is offline  
Old 08-21-19, 07:10 PM
  #443  
tomtomtom123
Senior Member
 
Join Date: Jan 2017
Posts: 325
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 103 Post(s)
Likes: 0
Liked 3 Times in 3 Posts
Well, he's only done it because he's taken out more than 1 spacer. The other article says that the other guy didn't have to do anything for just 1x 2.5mm spacer, other than trimming off the plastic stops on the water sleeve. I would be ok with taking 2x spacers out and removing 2mm of spline. As the article explains, you aren't reducing the amount of spline engagement with the spindle when removing 2 spacers and only shaving 2mm of spline. You'd actually be adding more engagement. +2.5 + 2.5 -2mm = 3mm extra spline engagement.(well, depending on the crank arm model). One problem i see though is that the 2 clamping bolts won't be centered on the spline.

Last edited by tomtomtom123; 08-21-19 at 07:15 PM.
tomtomtom123 is offline  
Old 08-21-19, 09:20 PM
  #444  
jppe
Let's do a Century
 
jppe's Avatar
 
Join Date: Oct 2004
Location: North Carolina
Posts: 7,456

Bikes: Cervelo R3 Disc, Pinarello Prince/Campy SR; Cervelo R3/Sram Red; Trek 5900/Duraace, Cervelo P2C/Duraace, Cannondle Tandem/Ultegra, Lynskey GR260 Ultegra

Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 358 Post(s)
Liked 85 Times in 50 Posts
Originally Posted by tomtomtom123 View Post
Did you completely withdraw the H limit screw on the FD?
Not completely, just barely still in there though. The outer plate stopped moving outward though. I felt like I had moved it as far as it would go, guessing it needed about another 1.5-2 mm to completely clear the chain. I thought about rotating the FD clockwise a little more to see if that might give it a little more clearance. But it was shifting so well between the chain rings after Iíd dropped the FD down a little I hated to rotate it. It looked like the outer plate was aligned really well. I even thought about putting a coating or smooth plastic sleeve on the inside of the outer plate for noise reduction from the chain rub but ďband aidsĒ only work for so long....
__________________
Ride your Ride!!
jppe is offline  
Old 08-22-19, 02:15 AM
  #445  
tomtomtom123
Senior Member
 
Join Date: Jan 2017
Posts: 325
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 103 Post(s)
Likes: 0
Liked 3 Times in 3 Posts
Originally Posted by jppe View Post
Not completely, just barely still in there though. The outer plate stopped moving outward though. I felt like I had moved it as far as it would go, guessing it needed about another 1.5-2 mm to completely clear the chain. I thought about rotating the FD clockwise a little more to see if that might give it a little more clearance. But it was shifting so well between the chain rings after Iíd dropped the FD down a little I hated to rotate it. It looked like the outer plate was aligned really well. I even thought about putting a coating or smooth plastic sleeve on the inside of the outer plate for noise reduction from the chain rub but ďband aidsĒ only work for so long....
I have sharp chain angles due to short chainstay and a fat seat tube, and the chain would rub at the middle of the inner plate, so I widened my FD at the inner plate with a pair of wrenches by about 1 to 1.5mm. One wrench clamped to a table and holding the front of the inner plate. The other wrench in my hand holding the rear of the inner plate, and bend. In you're going to throw the FD away, you could try bending the outer plate.
Or simply rotate the FD out and loosen the L screw and give it a test
tomtomtom123 is offline  
Old 08-23-19, 02:30 PM
  #446  
jppe
Let's do a Century
 
jppe's Avatar
 
Join Date: Oct 2004
Location: North Carolina
Posts: 7,456

Bikes: Cervelo R3 Disc, Pinarello Prince/Campy SR; Cervelo R3/Sram Red; Trek 5900/Duraace, Cervelo P2C/Duraace, Cannondle Tandem/Ultegra, Lynskey GR260 Ultegra

Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 358 Post(s)
Liked 85 Times in 50 Posts
The GRX FD and adapter mount arrived today. I had a few extra minutes and removed the R8000 FD and installed the new stuff. I followed the installation instructions srep by step and it all works very well. There isnít any chain rub on any sprocket.

If if anyone is thinking of installing the GRX 46/30 Iíd highly recommend spending the extra $50 and using the GRX FD. I just couldnít tweak the road FD enough to eliminate all the chain rub. Now I just need to find some gravel.....


__________________
Ride your Ride!!
jppe is offline  
Likes For jppe:
Old 09-07-19, 04:56 PM
  #447  
PhoenixBiker 
Senior Member
 
Join Date: Jul 2018
Location: Huntington, West Virginia, USA
Posts: 101

Bikes: 2001 Waterford RST-22, 2002 Gunnar Sport, 1999 Trek 520 gravel grinder

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 30 Post(s)
Likes: 0
Liked 3 Times in 2 Posts
Took my first ride with a 46/30 crankset today and loved it! I replaced the 19-year-old, 9-speed Ultegra triple (52-42-26) drivetrain on a Waterford RST-22 with Ultegra 11 speed brifters, a Shimano GRX 46-30 crankset, GRX front and rear derailleurs, and a Shimano 11-42T cassette (enabled by a RoadLink). I'm just as fast on the flats as I've ever been, and I can climb much better. What's not to like?

PhoenixBiker is offline  
Old 09-07-19, 10:17 PM
  #448  
TimothyH
- Soli Deo Gloria -
 
TimothyH's Avatar
 
Join Date: Aug 2015
Location: Northwest Georgia
Posts: 14,779

Bikes: 2018 Rodriguez Custom Fixed Gear, 2017 Niner RLT 9 RDO, 2015 Bianchi Pista, 2002 Fuji Robaix

Mentioned: 232 Post(s)
Tagged: 0 Thread(s)
Quoted: 6814 Post(s)
Liked 634 Times in 403 Posts
Easton EC90 SL "Cinch" 46/30 cranks

CS-M8000 XT 11-42 mountain bike cassette using a 1.85 mm spacer on the freehub.

Ultetra R8000 GS derailleur with the B screw reversed.

19.5 inch low gear.




-Tim-
TimothyH is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
cpsqlrwn
Road Cycling
0
05-03-08 03:26 PM
simplyred
Road Cycling
3
11-16-05 10:51 PM
onelesscar
Bicycle Mechanics
1
10-20-05 05:56 AM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.