Change large ring only on crank?
#1
Senior Member
Thread Starter
Join Date: Apr 2007
Posts: 6,760
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 1109 Post(s)
Liked 1,200 Times
in
760 Posts
Change large ring only on crank?
I have a Shimano LX crank with 44-32-22 rings on my commuter (set up road-bike style). BCD is 104/64. It shifts really well front and rear.
Rear cassette is a 9 speed 12-26.
I'd like to change ONLY the big chain ring to a 48 - or even a 50 (if a 50 is even available in that BCD. I know the 48 is). Can I simply change the large ring to a 48 (or 50) and leave the others as-is? This would be my simplest/cheapest change and is really all I want to do. Or would I need to change the middle ring as well - or all three?
The other two chain rings suit my purposes just fine, so I don't feel a need to change them. Other than expense, it wouldn't bother me to change them as well, but only if it's necessary to make the shifting work with the 48 or 50.
I've thought about a cassette change, but the 44/11 would not be appreciably better and don't want to buy a new cassette.
Please don't advise to learn to pedal faster - I really just want to know if the big ring change is workable.
Thanks for any help you can give.
Rear cassette is a 9 speed 12-26.
I'd like to change ONLY the big chain ring to a 48 - or even a 50 (if a 50 is even available in that BCD. I know the 48 is). Can I simply change the large ring to a 48 (or 50) and leave the others as-is? This would be my simplest/cheapest change and is really all I want to do. Or would I need to change the middle ring as well - or all three?
The other two chain rings suit my purposes just fine, so I don't feel a need to change them. Other than expense, it wouldn't bother me to change them as well, but only if it's necessary to make the shifting work with the 48 or 50.
I've thought about a cassette change, but the 44/11 would not be appreciably better and don't want to buy a new cassette.
Please don't advise to learn to pedal faster - I really just want to know if the big ring change is workable.
Thanks for any help you can give.
#2
Senior Member
26T jump may be more than your FD can handle. I believe triples have around a 22 tooth max. capacity.
#3
Senior Member
Join Date: Oct 2005
Location: Fresno, CA
Posts: 4,454
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 128 Post(s)
Likes: 0
Liked 12 Times
in
10 Posts
FD capacity numbers tend to be conservative, although I have no experience to say if a FD rated with 22t capacity would handle 26t or 28t diff between small and large chainrings.
If you have bar-end shifters (so, non-indexed front shifting) you could put on FD with higher capacity.
But that would already be getting into territory where you'd be spending as much as just buying a cassette with 11t small cog.
I'd say, mount your FD as high as you can (that will still not bump the chain in the small chainring) and see how much space you have above the large chainring teeth. This will give you a sense of whether you could update to 48t or 50t large ring.
If not, just get a new cassette with 11t cog.
If you have bar-end shifters (so, non-indexed front shifting) you could put on FD with higher capacity.
But that would already be getting into territory where you'd be spending as much as just buying a cassette with 11t small cog.
I'd say, mount your FD as high as you can (that will still not bump the chain in the small chainring) and see how much space you have above the large chainring teeth. This will give you a sense of whether you could update to 48t or 50t large ring.
If not, just get a new cassette with 11t cog.
__________________
"c" is not a unit that measures tire width
"c" is not a unit that measures tire width
#4
Senior Member
Join Date: Feb 2005
Location: Oklahoma
Posts: 9,438
Bikes: Trek 5500, Colnago C-50
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 7 Times
in
6 Posts
The difference between your big and middle chainrings is already 12 teeth. I would not increase the size of the big ring only. You could probably increase all three rings by 2 teeth and still have good shifting. Or you could increase the big and middle leaving the smallest at 22, but the shifting might suffer some. I would not do it any other way.
Is it possible? Yes. A good idea? Not in my opinion.
A cassette starting with an 11 would make more sense.
Is it possible? Yes. A good idea? Not in my opinion.
A cassette starting with an 11 would make more sense.
#5
Senior Member
Thread Starter
Join Date: Apr 2007
Posts: 6,760
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 1109 Post(s)
Liked 1,200 Times
in
760 Posts
Thanks for the advice. I looked at the Sheldon Brown gear calculator and a 44X11 would be exactly the same as a 48X12. I might try to dig up a 11t cassette instead.
Last edited by Camilo; 05-20-10 at 07:04 PM.
#6
Senior Member
#8
The Weird Beard
Join Date: May 2005
Location: COS
Posts: 8,554
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 3 Times
in
3 Posts
I am building a rig right now and have a choice of two cranksets I have lying around. Whichever I use will have only the big ring when installed (1x9): A 42t and a 44t. To address your question, the reason these cranksets are lying around is because when I bought the bikes, I immediately replaced the stock MTB cranks with trekking cranks (48-38-28). With a 12-25 cassette, I still spin out on hills, although only barely. If you go from 44t to 48t, the difference will be marginal. To test this theory, I rode my commuter to work tonight on the 42t ring (it is a tall double, 52-42-30 with the 30t removed). Aside from descents, it was awesome.
Unless you are strong enough to spin out on flats on your 44-12, it may not be worth your time. I don't spin out on flats on 42t because of the freaking headwind that follows me around
Unless you are strong enough to spin out on flats on your 44-12, it may not be worth your time. I don't spin out on flats on 42t because of the freaking headwind that follows me around
#9
Mad bike riding scientist
Join Date: Nov 2004
Location: Denver, CO
Posts: 27,334
Bikes: Some silver ones, a red one, a black and orange one, and a few titanium ones
Mentioned: 152 Post(s)
Tagged: 1 Thread(s)
Quoted: 6192 Post(s)
Liked 4,190 Times
in
2,351 Posts
I would caution Camillo to not use a 48 or 50 with a 32 middle however. It will shift fine but the jump between the chainrings would be very large and not that pleasant to ride.
__________________
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
#11
Senior Member
Thread Starter
Join Date: Apr 2007
Posts: 6,760
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 1109 Post(s)
Liked 1,200 Times
in
760 Posts
I found my lightly used 11-23 9 sp cassette that I thought I had given away and will put that on this weekend. I'll gain a little high end from 44-12 to 44-11 (which I need) but lose some low end from 22-26 to 22-23 (which I *think* I can afford to lose; I've been "practicing" using only the 23 as my lowest gear in back for the toughest hills on my commute).
If it's still unsatisfactory, I'll start looking for a good used stock-configured crank with larger rings and ebay this one.
Thanks for the advice.
If it's still unsatisfactory, I'll start looking for a good used stock-configured crank with larger rings and ebay this one.
Thanks for the advice.