Go Back  Bike Forums > Bike Forums > Cyclocross and Gravelbiking (Recreational)
Reload this Page >

Help me understand compact gearing

Notices
Cyclocross and Gravelbiking (Recreational) This has to be the most physically intense sport ever invented. It's high speed bicycle racing on a short off road course or riding the off pavement rides on gravel like : "Unbound Gravel". We also have a dedicated Racing forum for the Cyclocross Hard Core Racers.

Help me understand compact gearing

Old 05-31-07, 10:50 PM
  #1  
Senior Member
Thread Starter
 
Join Date: Nov 2004
Location: CO
Posts: 505

Bikes: Gunnar Hyper XF, Jamis Dragon Race, Surly LHT

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked 19 Times in 9 Posts
Help me understand compact gearing

I apologize in advance for my ignorance on this topic.

Over the winter I bought a carbon crankset for my Poprad. Looked cool, was carbon, weighed less than my existing crankset, and had similar (so I thought) chainrings -- the original Poprad (Bontrager) rings were 46/38, the FSA rings are 46/36. The FSA crankset I bought and installed is a compact crankset. I had no idea what that meant when I bought it. After one ride on the flats, I realized I was missing gearing on the high end.

My question is, how off am I now, and what might I do to get back to where I was? I have two wheelsets, a cross set with 12-25, and a road set with 12-26. I thought the gearing was perfect then. I climbed well with those setups, rarely dropping to the 38 when climbing, and I live in CO (which makes me wonder if I'll ever use a compact 36) so I'm worried that I screwed up by unknowingly going to a compact crankset.

So do I need new rear cog clusters? Or get bigger rings for the compact crankset?

Thanks,

Last edited by KeatonR; 05-31-07 at 11:04 PM.
KeatonR is offline  
Old 06-01-07, 01:26 AM
  #2  
Just a commuter
 
stockholm's Avatar
 
Join Date: May 2005
Location: Stockholm, Sweden
Posts: 262

Bikes: Scott Metrix 20 for commuting, Specialized Dolce Elite for fun

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
this explained it all to me, at least: https://bikeforums.net/showthread.php?t=241679

HTH
stockholm is offline  
Old 06-01-07, 03:57 AM
  #3  
cs1
Senior Member
 
cs1's Avatar
 
Join Date: Feb 2004
Location: Clev Oh
Posts: 7,093

Bikes: Specialized, Schwinn

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 225 Post(s)
Liked 27 Times in 25 Posts
Originally Posted by KeatonR
I apologize in advance for my ignorance on this topic.

Over the winter I bought a carbon crankset for my Poprad. Looked cool, was carbon, weighed less than my existing crankset, and had similar (so I thought) chainrings -- the original Poprad (Bontrager) rings were 46/38, the FSA rings are 46/36. The FSA crankset I bought and installed is a compact crankset. I had no idea what that meant when I bought it. After one ride on the flats, I realized I was missing gearing on the high end.

My question is, how off am I now, and what might I do to get back to where I was? I have two wheelsets, a cross set with 12-25, and a road set with 12-26. I thought the gearing was perfect then. I climbed well with those setups, rarely dropping to the 38 when climbing, and I live in CO (which makes me wonder if I'll ever use a compact 36) so I'm worried that I screwed up by unknowingly going to a compact crankset.

So do I need new rear cog clusters? Or get bigger rings for the compact crankset?

Thanks,
A lot of riders that switch to compact swap cassettes to an 11 tooth version. See if you can beg/borrow one and try it out. It will return some of the top end you are missing. Good luck

Tim
cs1 is offline  
Old 06-01-07, 06:40 AM
  #4  
Double Secret Member
 
CaptMatt15's Avatar
 
Join Date: Jul 2006
Location: Raleigh, NC
Posts: 298

Bikes: 2004 Gary Fisher Marlin, 2007 Redline Conquest

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I don't understand how you are loosing speed in the flats when you're highest gear (46-12) is the same as with your old cranks. The only difference is going to be if you are in your smaller chain ring (a 36, as opposed to a 38).

Technically, both of your cranks would be considered "Cyclocross Compacts" because the rings are different than a traditional Road compact (a 50/34).
CaptMatt15 is offline  
Old 06-01-07, 06:44 AM
  #5  
Senior Member
Thread Starter
 
Join Date: Nov 2004
Location: CO
Posts: 505

Bikes: Gunnar Hyper XF, Jamis Dragon Race, Surly LHT

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked 19 Times in 9 Posts
I dunno, felt like I had a lot more pedaling that I could have done when I went out.

From what I've now been reading from the link above, it appears I've been overthinking this a bit. One thing I will do is order a new 38 inner ring from FSA and ditch the 36, and then I'll think about going to a cogset with an 11 for the road wheelset, and leave the cross wheelset the same.
KeatonR is offline  
Old 06-01-07, 07:00 AM
  #6  
Senior Member
Thread Starter
 
Join Date: Nov 2004
Location: CO
Posts: 505

Bikes: Gunnar Hyper XF, Jamis Dragon Race, Surly LHT

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked 19 Times in 9 Posts
Have done some more digging and this is looking really useful:

https://sheldonbrown.com/gears/

Especially for someone who is (obviously) not a math guy.
KeatonR is offline  
Old 06-01-07, 12:23 PM
  #7  
So I says to Mable I says
 
somnambulant's Avatar
 
Join Date: Jul 2005
Location: Toronto
Posts: 4,947

Bikes: '05 Urbanite Fixie, '06 Lemond Croix de Fer, '06 Jamis Dragon Pro, '07 IRO Bikeforums Track, '07 Planet-X Uncle John

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
yeah, 46 = 46. Doesn't matter if it's a compact or standard crankset. Did you perhaps change the crank arm length as well?
somnambulant is offline  
Old 06-02-07, 03:48 AM
  #8  
cs1
Senior Member
 
cs1's Avatar
 
Join Date: Feb 2004
Location: Clev Oh
Posts: 7,093

Bikes: Specialized, Schwinn

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 225 Post(s)
Liked 27 Times in 25 Posts
Originally Posted by KeatonR
I dunno, felt like I had a lot more pedaling that I could have done when I went out.

From what I've now been reading from the link above, it appears I've been overthinking this a bit. One thing I will do is order a new 38 inner ring from FSA and ditch the 36, and then I'll think about going to a cogset with an 11 for the road wheelset, and leave the cross wheelset the same.
If your problem is top end gearing, don't waste any money on a new inner chainring. It has ZERO effect. Get the new cassette. Good luck

Tim
cs1 is offline  
Old 06-02-07, 08:26 AM
  #9  
Senior Member
Thread Starter
 
Join Date: Nov 2004
Location: CO
Posts: 505

Bikes: Gunnar Hyper XF, Jamis Dragon Race, Surly LHT

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked 19 Times in 9 Posts
Definitely now understanding that a 46 = 46. Was in a bit of a late-night panic when I first posted, thinking I had screwed up by going to a compact crankset without even knowing what it was.

I think I will try an 11 on my road wheelset and from there think about a 38 inner ring. I never use the third ring on my mountain bike, and I liked the 38 on my previous setup for climbing.
KeatonR is offline  

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

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

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.