Gearing up for the Rockies....
07-29-22, 09:32 AM
#26
Banned.
Thread Starter
Join Date: Jan 2022
Posts: 1,070
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 359 Post(s)
Liked 582 Times
in
336 Posts
The GRX Shimano crank will probably fit without changing your BB. However it's chain line is 47 mm and the current crank on that Domane is probably about 43.5 mm. So even if the crank fit the BB shell width, the shifting will be crappy trying to get to the low ratio cog on the back. If it would even get there.
This has been our experience elsewhere. Anxiety-driven preparation often enabling a fine day when it finally comes.
07-29-22, 09:34 AM
#27
Banned.
Thread Starter
Join Date: Jan 2022
Posts: 1,070
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 359 Post(s)
Liked 582 Times
in
336 Posts
Absolute Black makes sub compact chainrings that will fit a 6800 crank. I'm running their 46/30 rings on my 5800 cranks and I didn't need a new FD. AB's rings are expensive so you'd have to decide if it makes more sense to go GRX or AB rings. If I were doing it now I'd go 48/31 GRX.
Last edited by bamboobike4; 07-29-22 at 10:01 AM.
07-29-22, 09:59 AM
#28
Banned.
Thread Starter
Join Date: Jan 2022
Posts: 1,070
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 359 Post(s)
Liked 582 Times
in
336 Posts
Thanks for all the info....
I've gathered the great advice and devised a set of plans, if not for now, certainly for the future. Tech/Equipment is moving so fast.
Plan A:
GRX crankset 46.30 (already on her gravel bike)
Shares the same BB type.
2mm spacers inboard for each ring (8 total)
Try it and see if it shifts with the Ultegra Di2 FD.
Check chain slap and either remove link(s) to work a bit better, or buy a chain.
Will be a 46/30 front, 11-36 rear, 170mm cranks and she gives up her Stages power meter.
About $15 for the spacers, and another $50 for a chain if needed.
Plan B:
Absolute Black 46/30 rings
Absolute Black special bolts (come with rings)
Absolute Black bolt caps
Try it and see if it shifts with the Ultegra Di2 FD (it should.)
Check chain slap and either remove link(s) to work a bit better, or buy a chain.
Will be a 46/30 (oval) front, 11-36 rear, 170mm cranks and she retains her Stages power meter.
About $190 for the rings/caps, and another $50 for a chain if needed.
Plan C:
GRX crankset 46/30 (already on her gravel bike)
Shares the same BB type.
GRX Di2 FD
Try it and see if it shifts OK (it should). Chain line should be OK, not super.
Check chain slap and either remove link(s) to work a bit better, or buy a chain.
Will be a 46/30 GRX front, 11-36 rear, 170mm cranks and she loses her Stages power meter.
About $250 for the FD, and another $50 for a chain if needed.
This is all pretty much fun to think about, but basically, Iride01 and others are not wrong; she could be fine with the current 50/34 and 11-36.
We hope to climb each pass in the studio before we leave next week. Plenty of acclimation time, staying at 6500' for a few days, then 8500' until the event.
Thanks to everyone who shared their thoughts, opinions, and advice.
Plan A:
GRX crankset 46.30 (already on her gravel bike)
Shares the same BB type.
2mm spacers inboard for each ring (8 total)
Try it and see if it shifts with the Ultegra Di2 FD.
Check chain slap and either remove link(s) to work a bit better, or buy a chain.
Will be a 46/30 front, 11-36 rear, 170mm cranks and she gives up her Stages power meter.
About $15 for the spacers, and another $50 for a chain if needed.
Plan B:
Absolute Black 46/30 rings
Absolute Black special bolts (come with rings)
Absolute Black bolt caps
Try it and see if it shifts with the Ultegra Di2 FD (it should.)
Check chain slap and either remove link(s) to work a bit better, or buy a chain.
Will be a 46/30 (oval) front, 11-36 rear, 170mm cranks and she retains her Stages power meter.
About $190 for the rings/caps, and another $50 for a chain if needed.
Plan C:
GRX crankset 46/30 (already on her gravel bike)
Shares the same BB type.
GRX Di2 FD
Try it and see if it shifts OK (it should). Chain line should be OK, not super.
Check chain slap and either remove link(s) to work a bit better, or buy a chain.
Will be a 46/30 GRX front, 11-36 rear, 170mm cranks and she loses her Stages power meter.
About $250 for the FD, and another $50 for a chain if needed.
This is all pretty much fun to think about, but basically, Iride01 and others are not wrong; she could be fine with the current 50/34 and 11-36.
We hope to climb each pass in the studio before we leave next week. Plenty of acclimation time, staying at 6500' for a few days, then 8500' until the event.
Thanks to everyone who shared their thoughts, opinions, and advice.
07-29-22, 11:46 AM
#29
Senior Member
Join Date: Jul 2006
Location: San Jose (Willow Glen) Ca
Posts: 9,930
Bikes: Kirk Custom JK Special, '84 Team Miyata,(dura ace old school) 80?? SR Semi-Pro 600 Arabesque
Mentioned: 107 Post(s)
Tagged: 0 Thread(s)
Quoted: 2375 Post(s)
Liked 2,904 Times
in
1,583 Posts
shimano says use the grx derailler with the crank, but of course they would https://bike.shimano.com/en-US/infor...ad-compon.html
here is compatibility chart for di2 https://bike.shimano.com/en-EU/e-tub...atibility.html
it seems if you want a slam dunk, minimum fiddle set up go with grx crank and front derailler
here is compatibility chart for di2 https://bike.shimano.com/en-EU/e-tub...atibility.html
it seems if you want a slam dunk, minimum fiddle set up go with grx crank and front derailler
__________________
Life is too short not to ride the best bike you have, as much as you can
(looking for Torpado Super light frame/fork or for Raleigh International frame fork 58cm)
Life is too short not to ride the best bike you have, as much as you can
(looking for Torpado Super light frame/fork or for Raleigh International frame fork 58cm)
07-31-22, 12:31 PM
#30
don't try this at home.
Join Date: Jan 2006
Location: N. KY
Posts: 5,977
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 987 Post(s)
Liked 530 Times
in
365 Posts
Join the club. A mechanic, I ain't.
I only know "little in front, big in back" is better for climbing.
Making it all work, fun.
I finished my climber last night: 50/34 front, 11-34 rear, DA9100 with a Roadlink DM.
Hits all the gears just fine, both big and small rings, but not real happy getting in/out of 11T.
1996 frame, maybe it's just mad about it.
I'll ride it tomorrow night on hill repeats and see what's up. We do 6 climbs, 11 miles, 1900'. Repeat if time permits.
I only know "little in front, big in back" is better for climbing.
Making it all work, fun.
I finished my climber last night: 50/34 front, 11-34 rear, DA9100 with a Roadlink DM.
Hits all the gears just fine, both big and small rings, but not real happy getting in/out of 11T.
1996 frame, maybe it's just mad about it.
I'll ride it tomorrow night on hill repeats and see what's up. We do 6 climbs, 11 miles, 1900'. Repeat if time permits.
Shift the rear derailleur to the smallest
sprocket, and then tighten the top-side
stopper adjustment bolt until it touches
the stopper at the position where the
rear derailleur finally stopped. From this
position, turn the top adjustment bolt
counterclockwise one turn so that an
over-stroke allowance can always be
maintained.
The manuals are here: https://si.shimano.com
07-31-22, 05:22 PM
#31
Senior Member
Appreciate it, and noted. It's about the bike setup I'd like to do.
I know the rider. (see my earlier post).
Low wattage.
Normal rpm (rarely over 90, rarely under 75)
High endurance (has done 228 in one day, 107 centuries)
Lower speed (Averages 15-16, but has a 5:29 century and a 13:29:00 for 228 ina 6-man pace line, a year ago, but that was a special year,
Rides by HR and sticks to it.
But I'll get specific on the route(s):
-Triple Bypass, 106m/10,900' event support though we're hoping for an extra stop or two.
-Cherohala Challenge, about the same, event support
-Six Gap, roughly the same
-Dairyland Dare, shorter and steeper.
-----If successful at the first 4, probably Horrible Hilly Hundred.
Last year was an endurance year, and we trained for it.
Coming off a rough winter/early spring, we're planning Colorado, and then go from there.
I'm asking about the bike setup, specifically, for this ride and 3 others, using what works now on the rear and gaining some improvement on the front.
All the advice is great, though.
I know the rider. (see my earlier post).
Low wattage.
Normal rpm (rarely over 90, rarely under 75)
High endurance (has done 228 in one day, 107 centuries)
Lower speed (Averages 15-16, but has a 5:29 century and a 13:29:00 for 228 ina 6-man pace line, a year ago, but that was a special year,
Rides by HR and sticks to it.
But I'll get specific on the route(s):
-Triple Bypass, 106m/10,900' event support though we're hoping for an extra stop or two.
-Cherohala Challenge, about the same, event support
-Six Gap, roughly the same
-Dairyland Dare, shorter and steeper.
-----If successful at the first 4, probably Horrible Hilly Hundred.
Last year was an endurance year, and we trained for it.
Coming off a rough winter/early spring, we're planning Colorado, and then go from there.
I'm asking about the bike setup, specifically, for this ride and 3 others, using what works now on the rear and gaining some improvement on the front.
All the advice is great, though.
08-01-22, 10:00 AM
#32
Banned.
Thread Starter
Join Date: Jan 2022
Posts: 1,070
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 359 Post(s)
Liked 582 Times
in
336 Posts
We did 8,100' Saturday over 104 miles, and she was OK, feels better about heading west.
Last edited by bamboobike4; 08-01-22 at 10:07 AM.
Likes For bamboobike4:
08-01-22, 10:05 AM
#33
Banned.
Thread Starter
Join Date: Jan 2022
Posts: 1,070
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 359 Post(s)
Liked 582 Times
in
336 Posts
The Di2 Dealer's Manual pdf (recommended--these pages are easy for a non-mechanic to follow) explains that the high limit screw needs to allow for an "overshift" to get into the smallest cog:
Shift the rear derailleur to the smallest
sprocket, and then tighten the top-side
stopper adjustment bolt until it touches
the stopper at the position where the
rear derailleur finally stopped. From this
position, turn the top adjustment bolt
counterclockwise one turn so that an
over-stroke allowance can always be
maintained.
The manuals are here: https://si.shimano.com
Shift the rear derailleur to the smallest
sprocket, and then tighten the top-side
stopper adjustment bolt until it touches
the stopper at the position where the
rear derailleur finally stopped. From this
position, turn the top adjustment bolt
counterclockwise one turn so that an
over-stroke allowance can always be
maintained.
The manuals are here: https://si.shimano.com
My issue was an IRD 11-34 11-speed cassette (very light, not expensive at all) that does not play all that well with my DA 9000 setup.
On a Colnago Master Extra Light with 50/34 DA 9000, it would not shift well under moderate or higher load.
On a Litespeed Classic with 50/34 DA 9000/9100 mix, it would get cranky (pun intended) on the lower small cogs.
On the rack, fine, and on the same cogs, on the big front ring, fine, and I could move straight to the small ring, no issue.
Trying it under load on either, loud complaints from the back end.
My guess is a chain/cassette compatibility issue (SRAM 1071 and KMC X.1), but I swapped in my Shimano 11-34 cassette instead and it works fine on the Colnago. I'll figure out something with those two IRD cassettes, maybe use a different chain or step back, refresh, remove the chains and re-set the RD's. FD's work fine.
Last edited by bamboobike4; 08-01-22 at 10:11 AM.
08-01-22, 10:10 AM
#34
Banned.
Thread Starter
Join Date: Jan 2022
Posts: 1,070
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 359 Post(s)
Liked 582 Times
in
336 Posts
Shimano says use the GRX derailleur with the crank, but of course they would https://bike.shimano.com/en-US/infor...ad-compon.html
here is compatibility chart for di2 https://bike.shimano.com/en-EU/e-tub...atibility.html
it seems if you want a slam dunk, minimum fiddle set up go with GRX crank and front derailleur
here is compatibility chart for di2 https://bike.shimano.com/en-EU/e-tub...atibility.html
it seems if you want a slam dunk, minimum fiddle set up go with GRX crank and front derailleur
We leave in 3 days, and ran a pretty decent training climb Saturday, 8,100' over 104 miles, mostly leg-punchers.
She did fine, and our approach is to take it easy, enjoy an all-day ride.
So, now I'm in disassemble, clean, lube, adjust mode. Everything needs to be sparkly, right?
Likes For bamboobike4:
