Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 08-19-04, 02:00 PM   #1
Glasspacker
Epitome of Mediocrity
Thread Starter
 
Join Date: Aug 2004
Location: Iowa
Bikes: Rans V2
Posts: 65
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Eliminate Front Sprockets to reduce weight

(LWB 'bent technical question from a non-tech person) If I don't need granny gears (I would still have 3-1 and hope I don't meet the "big" one), would there be any benefit to eliminating two of the three front sprockets and just going with the biggest sprocket? The weight would be reduced by two sprockets, front derailler, and shifter. Is running in 3-1 or 3-2 or 3-3 less efficient because the chain isn't running as "true" as it otherwise would if in the 2nd front sprocket?
Glasspacker is offline   Reply With Quote
Old 08-19-04, 02:17 PM   #2
sydney
Senior Member
 
sydney's Avatar
 
Join Date: Jan 2004
Bikes:
Posts: 9,428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Glasspacker
(LWB 'bent technical question from a non-tech person) If I don't need granny gears (I would still have 3-1 and hope I don't meet the "big" one), would there be any benefit to eliminating two of the three front sprockets and just going with the biggest sprocket? The weight would be reduced by two sprockets, front derailler, and shifter. Is running in 3-1 or 3-2 or 3-3 less efficient because the chain isn't running as "true" as it otherwise would if in the 2nd front sprocket?
With a triple crank, mount the single ring in the middle ring position. Optimum chainline for that crank/BB.
sydney is offline   Reply With Quote
Old 08-19-04, 03:31 PM   #3
Glasspacker
Epitome of Mediocrity
Thread Starter
 
Join Date: Aug 2004
Location: Iowa
Bikes: Rans V2
Posts: 65
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks. So it's not a completely silly question then? I'm always fumbling to find those in-between gears anyway and prefer to just move up or down on the same ring. I must be missing something tho. If everyone is so concerned about weight, (I realize lwbs are heavier by nature but it's still an issue, or Rans wouldn't come up with an all alu V2) why doesn't this question get asked more often? Do the speedsters still want those granny gears? I know just enuf to be dangerous.
Glasspacker is offline   Reply With Quote
Old 08-19-04, 03:49 PM   #4
noisebeam
Al
 
noisebeam's Avatar
 
Join Date: Jun 2004
Location: AZ
Bikes: Cannondale SuperSix, Lemond Poprad. Retired: Jamis Sputnik, Centurion LeMans Fixed, Diamond Back ascent ex
Posts: 14,109
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 77 Post(s)
Quote:
Originally Posted by Glasspacker
Thanks. So it's not a completely silly question then? I'm always fumbling to find those in-between gears anyway and prefer to just move up or down on the same ring. I must be missing something tho. If everyone is so concerned about weight, (I realize lwbs are heavier by nature but it's still an issue, or Rans wouldn't come up with an all alu V2) why doesn't this question get asked more often? Do the speedsters still want those granny gears? I know just enuf to be dangerous.
When a third low gear chainring is required, it far out-benefits any weight increase. Low gears are often desired for mountain bikes for steep hills and touring for heavy loads over moderate hills. Not everybody is concerned about weight - for example if you have 80lbs of cross country gear on your bike, adding a few extra hundred grams of gearing is well worth the ability to carry that load over the Rocky Mountains into a strong headwind.

There are many folks who only want or need 2 chainrings. And there are quite a few folks who prefer the simplicity and lower weight of one chainring. And there are still some folks that prefer the minimim weight and complexity of one chainring and one cog. One can generalize (but there are certainly exceptions) that the folks who want simplier and lighter are folks who desire speed over the flexiblity to deal with varied terrain and loads.

Al
noisebeam is offline   Reply With Quote
Old 08-19-04, 03:58 PM   #5
seely 
The Rabbi
 
seely's Avatar
 
Join Date: Apr 2004
Bikes:
Posts: 5,087
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
You would probably want to consider a chainguide for a single ring setup, so any weight savings would be non existant or negligable with a single ring setup.
seely is offline   Reply With Quote
Old 08-19-04, 04:12 PM   #6
sydney
Senior Member
 
sydney's Avatar
 
Join Date: Jan 2004
Bikes:
Posts: 9,428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by seely
You would probably want to consider a chainguide for a single ring setup, so any weight savings would be non existant or negligable with a single ring setup.
I haven't needed one.
sydney is offline   Reply With Quote
Old 08-19-04, 05:15 PM   #7
halfspeed
Senior Member
 
halfspeed's Avatar
 
Join Date: Nov 2003
Location: SE Minnesota
Bikes: are better than yours.
Posts: 12,276
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Glasspacker
Thanks. So it's not a completely silly question then? I'm always fumbling to find those in-between gears anyway and prefer to just move up or down on the same ring. I must be missing something tho. If everyone is so concerned about weight, (I realize lwbs are heavier by nature but it's still an issue, or Rans wouldn't come up with an all alu V2) why doesn't this question get asked more often? Do the speedsters still want those granny gears? I know just enuf to be dangerous.
Granny gears are generally considered more important for 'bent riders because, unlike on upright bikes, the position doesn't lend itself to using body weight as leverage on steep uphills. The solution is to just spin lower gears on climbs. So, while you can go to a single chainring, you would have a harder time climbing with it than you would on a comparably geared road rig. Only you can decide if you can power over everything you would normally ride.
halfspeed is offline   Reply With Quote
Old 08-19-04, 05:26 PM   #8
supcom
You need a new bike
 
supcom's Avatar
 
Join Date: Aug 2002
Bikes:
Posts: 5,433
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
If you remove the rear cluster and replace the cassette hub with a freewheel hub and BMX freewheel, you can remove the rear der and shifter and just run singlespeed. You'll save even more weight.

Better still, out on a track cog and go fixed gear. With all the weight savings, who needs more than one gear? With a fixie you can even remove the rear brake (and the front if you're really brave) and save even more weight.
supcom is offline   Reply With Quote
Old 08-19-04, 05:53 PM   #9
Retro Grouch 
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Bikes: Rans Rockst (Retro rocket) Rans Enduro Sport (Retro racket) Catrike 559, Merin Bear Valley (beater bike).
Posts: 26,614
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 89 Post(s)
I wouldn't worry about chain line on a long wheelbase recumbent.
Retro Grouch is offline   Reply With Quote
Old 08-19-04, 07:10 PM   #10
bmph8ter
crackhead
 
Join Date: Jun 2004
Location: little rock, ar
Bikes: santa cruz blur, felt F50, motobecane super mirage
Posts: 170
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I say keep the gears. I mean do you carry a water bottle? Half of it weighs more than 2 chainrings.
bmph8ter is offline   Reply With Quote
Old 08-19-04, 07:53 PM   #11
halfspeed
Senior Member
 
halfspeed's Avatar
 
Join Date: Nov 2003
Location: SE Minnesota
Bikes: are better than yours.
Posts: 12,276
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by supcom
If you remove the rear cluster and replace the cassette hub with a freewheel hub and BMX freewheel, you can remove the rear der and shifter and just run singlespeed. You'll save even more weight.

Better still, out on a track cog and go fixed gear. With all the weight savings, who needs more than one gear? With a fixie you can even remove the rear brake (and the front if you're really brave) and save even more weight.
A 'bent fixie? Now that would be different.
halfspeed is offline   Reply With Quote
Old 08-20-04, 08:47 AM   #12
Glasspacker
Epitome of Mediocrity
Thread Starter
 
Join Date: Aug 2004
Location: Iowa
Bikes: Rans V2
Posts: 65
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I should just ditch the bike, save the weight, and just run. Maybe I'll take some weight off myself. (supcom you made me laugh).

Thanks to the others for at least thinking about it. Sydney, are you running a single ring up front? Just curious.
Glasspacker is offline   Reply With Quote
Old 08-20-04, 09:05 AM   #13
cerewa
put our Heads Together
 
cerewa's Avatar
 
Join Date: Jun 2003
Location: southeast pennsylvania
Bikes: a mountain bike with a cargo box on the back and aero bars on the front. an old well-worn dahon folding bike
Posts: 3,155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Quote:
Do the speedsters still want those granny gears?
Quote:
I should just ditch the bike, save the weight, and just run.
That's a thought. If you don't go up steep hills, you probably don't need to save weight that badly. If you do go up steep hills, you need small chainrings and the weight that comes with em.
cerewa is offline   Reply With Quote
Old 09-01-04, 09:30 AM   #14
Glasspacker
Epitome of Mediocrity
Thread Starter
 
Join Date: Aug 2004
Location: Iowa
Bikes: Rans V2
Posts: 65
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I noticed the Challenge Hurricane had a "big single" up front. But then I also noticed that lately they've been changing that to a triple- - apparently even the speedsters want gear range.
Glasspacker is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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



All times are GMT -6. The time now is 01:28 AM.