Switching chainrings and Cassettes
09-07-07, 12:00 PM
#1
Senior Member
Thread Starter
Join Date: Jul 2006
Location: Columbia, MO
Posts: 126
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Switching chainrings and Cassettes
I'm thinking of purchasing a 'cross bike that comes with a 10 speed 11-25 Shimano 105 rear and a FSA Crank with 36/46 chainrings. I would like to change the rear to a 12-27 and the front to a 34/50. Should this be a simple swap or will I likely need to work on the chain, change the rear derailleur, etc.
The bike will NOT be raced. It will be used on pavement, gravel roads and the Katy Trail.
Thanks for your input. I just want to know what I'm talking about if the LBS tries to feed me a line.
Joe
The bike will NOT be raced. It will be used on pavement, gravel roads and the Katy Trail.
Thanks for your input. I just want to know what I'm talking about if the LBS tries to feed me a line.
Joe
09-07-07, 11:42 PM
#2
Elitist Troglodyte
Join Date: Jun 2006
Location: Dallas
Posts: 6,925
Bikes: 03 Raleigh Professional (steel)
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
You are increasing capacity by 5T so it's likely that you'd need a longer chain. RD should be okay (though I note that you don't say which RD you have...).
Racing (or not) has nothing to do with the physics of the drive train.
I hope you don't expect us to second-guess every interaction with your LBS.
Racing (or not) has nothing to do with the physics of the drive train.
I hope you don't expect us to second-guess every interaction with your LBS.
__________________
Stupidity got us into this mess - why can't it get us out?
- Will Rogers
Stupidity got us into this mess - why can't it get us out?
- Will Rogers
09-08-07, 05:32 AM
#3
Senior Member
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 30,225
Bikes: Catrike 559 I own some others but they don't get ridden very much.
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1572 Post(s)
Liked 643 Times
in
364 Posts
I wouldn't bet on the front derailleur working satisfactory with the 50t big ring.
09-08-07, 02:20 PM
#4
Elitist Troglodyte
Join Date: Jun 2006
Location: Dallas
Posts: 6,925
Bikes: 03 Raleigh Professional (steel)
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Likely a 105 FD (FD-5600). Why wouldn't it work?
Unless you mean that it will need to be moved, and thus re-adjusted. If so, good point.
Unless you mean that it will need to be moved, and thus re-adjusted. If so, good point.
__________________
Stupidity got us into this mess - why can't it get us out?
- Will Rogers
Stupidity got us into this mess - why can't it get us out?
- Will Rogers
09-08-07, 07:40 PM
#6
bike rider
Join Date: Feb 2005
Location: Seattle
Posts: 288
Bikes: 83 Trek 500, 2x 90s Novara Randonee, Zion 737, Specialized Rockhopper, Nishiki Colorado, Univega Specialissima
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked 0 Times
in
0 Posts
If it has road shifters, it will not (should not)have a MTB front derailleur. All of the new cross bikes I've seen are all road groupo stuff.
Unless they're bar-end or downtube friction shifters, which will work OK with a MTB FD, but I'm guessing this is not the case for the OP.
Unless they're bar-end or downtube friction shifters, which will work OK with a MTB FD, but I'm guessing this is not the case for the OP.
09-10-07, 07:17 AM
#7
Senior Member
Thread Starter
Join Date: Jul 2006
Location: Columbia, MO
Posts: 126
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
I apologize for not being more specific. Yes the FD is a 105. I had made the statement about the intended use of the bicycle because for some reason I felt a need to justify my desire to change the gearing.
Thank you for the responses!
Joe
Thank you for the responses!
Joe
09-10-07, 08:08 AM
#8
rebmeM roineS
Join Date: Jan 2006
Location: Metro Indy, IN
Posts: 16,216
Bikes: Bacchetta Giro A20, RANS V-Rex, RANS Screamer
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 653 Post(s)
Liked 347 Times
in
226 Posts
You're going to end up with a bit lower low but not much different high. Is it worth the effort and $$ to do this? Why not just replace the 36 with a 34?
Of course, if you end up with perfect gears, it's worth it.
Of course, if you end up with perfect gears, it's worth it.
Last edited by JanMM; 09-10-07 at 08:17 AM.
