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 05-11-06, 05:55 PM   #1
LSPR_MTU
whzzzzzzzzz-bam!
Thread Starter
 
LSPR_MTU's Avatar
 
Join Date: Sep 2005
Location: Bloomington, IN
Bikes: Trek 1000, Schwinn Frontier
Posts: 137
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
yet another index question

Hey all,
I've searched, but can't seem to come up with a useful answer to this question:

What, exactly, dictates the rear-derailleur's movement along a cassett or freewheel - spacing-wise?

I have a 6-speed freewheel with 5mm spacing (actually measured at 4.9, but I'll call it 5). I've got a Shimano STX rear derailleur (I'm pretty sure it's 7-speed, but could be 8 "RD-MC30").


I'd like to get a pair of 6-speed indexed clamp-on-stem shifters; I've seen some sunrace 6-speed shifters that claim to work with Shimano stuff.


My real question is which component actually translates to the 5mm spacing that I need? For example, if various-speed derailleurs all move the same distance laterally when the cable is pulled X inches, then the spacing is dictated by the shifters alone. That's what I've been led to believe, which means it doesn't matter which derailleur I use, as long as it's shimano and meets the max-teeth and chain capacity requirements.

So for the short answer, is my setup going to work? For the long answer, spill your guts!

Thanks guys/gals.
LSPR_MTU is offline   Reply With Quote
Old 05-11-06, 06:27 PM   #2
HillRider 
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Bikes: '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
Posts: 28,844
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 66 Post(s)
Starting with 7-speed (and not-including Dura Ace 7 or 8-speed) all Shimano rear derailleurs shared the same geometry so the shifter was the sole determinant of how far it moved with each click. What I'm not sure is if this commonality dated back to 6-speed. I believe it did but maybe someone else has experience that can confirm or refute it.
HillRider is offline   Reply With Quote
Old 05-11-06, 06:38 PM   #3
LSPR_MTU
whzzzzzzzzz-bam!
Thread Starter
 
LSPR_MTU's Avatar
 
Join Date: Sep 2005
Location: Bloomington, IN
Bikes: Trek 1000, Schwinn Frontier
Posts: 137
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Also, one more quick question, since I've got your attention (hehe). I seem to have lost the master link to the 6/7-speed chain I just bought from nashbar:
http://www.nashbar.com/profile.cfm?c...eid=&pagename=

I was going to order this one to replace it, just wanted to make sure it's compatible. I'm sure it'll work fine, but I wanted to check to make sure.
http://biketoolsetc.com/index.cgi?id...m_id=KM-710SCS

Thanks again.
LSPR_MTU is offline   Reply With Quote
Old 05-11-06, 06:46 PM   #4
LSPR_MTU
whzzzzzzzzz-bam!
Thread Starter
 
LSPR_MTU's Avatar
 
Join Date: Sep 2005
Location: Bloomington, IN
Bikes: Trek 1000, Schwinn Frontier
Posts: 137
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by HillRider
Starting with 7-speed (and not-including Dura Ace 7 or 8-speed) all Shimano rear derailleurs shared the same geometry so the shifter was the sole determinant of how far it moved with each click. What I'm not sure is if this commonality dated back to 6-speed. I believe it did but maybe someone else has experience that can confirm or refute it.
Correct me if I'm wrong, but 7-speed cog spacing was also 5mm. So, from your response, I should be ok if I get 7-speed shifters, and just limit the rear derailleur to 6-speed, right? I haven't seen any 7-speed indexed stem shifters anywhere, but I've seen resonably-priced downtube versions.
LSPR_MTU is offline   Reply With Quote
Old 05-11-06, 06:58 PM   #5
HillRider 
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Bikes: '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
Posts: 28,844
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 66 Post(s)
Yes, I think 6 and 7-speed cogs were spaced the same, or close enough to work. 7-speed downtube shifters should work well. Stem shifters were usually very cheaply made since they only came on very low line bikes and few survived.

Yep, the master link from Bike Tools Etc will fit your Nashbar chain. Nashbar chains are made by KMC so its the same chain.
HillRider is offline   Reply With Quote
Old 05-11-06, 07:20 PM   #6
LSPR_MTU
whzzzzzzzzz-bam!
Thread Starter
 
LSPR_MTU's Avatar
 
Join Date: Sep 2005
Location: Bloomington, IN
Bikes: Trek 1000, Schwinn Frontier
Posts: 137
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
HillRider, thanks for all the help - you've been awesome. One more question, I promise. Is there some unwritten rule about not putting mtb shifters on a road bike? I could go for the sunrace downtube shifters, but these intrigue me:


Eah, I'm sure that OCP will get the best of me, and I'll decide against it.
LSPR_MTU is offline   Reply With Quote
Old 05-11-06, 08:10 PM   #7
robhunterx
robhunterx
 
robhunterx's Avatar
 
Join Date: Aug 2005
Location: Germantown, TN
Bikes: Litespeed Ultimate/Kestrel 4000/GT Rage/Litespeed Unicoi/Litespeed Obed FS
Posts: 120
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Last time I looked you could get a 7 speed freewheel pretty cheap on Ebay and most frames have sufficient width. I also think those mtb shifters will work well with the 7 speed freewheel and the derailleurs you have. Have fun setting it all up.
robhunterx is offline   Reply With Quote
Old 05-11-06, 08:12 PM   #8
HillRider 
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Bikes: '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
Posts: 28,844
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 66 Post(s)
The handle bar diameters are different so MTB shifters won't fit on road bike bars which are too large. You could, I suppose, file or Dremel the shifter clamps to make them fit but it might weaken the clamps too much.
HillRider 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 03:03 PM.