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 09-16-10, 06:51 PM   #1
RavingManiac
Senior Member
Thread Starter
 
RavingManiac's Avatar
 
Join Date: Jun 2010
Location: Maine
Bikes: 90 Raleigh Chill MTB, 92 Trek 1200, 2004 Trek 2300, 67 Sports, 70 Sports, 71 Philips, Lotus Challenger, 74 Super Course, Univega Gran Tourismo, Nishiki Seral
Posts: 552
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Spacers in rear dropouts?

The spacers that you sometimes find in rear dropouts, what is their purpose? Why wouldn't you want the axle to slide in as far as possible? This is in reference to horizontal dropouts. I have an old Nishiki Seral touring frame I'm doing a build on, it had the spacers, took up about the last 3/8 inch of the dropout. Why?
RavingManiac is offline   Reply With Quote
Old 09-16-10, 11:23 PM   #2
Jeff Wills
Insane Bicycle Mechanic
 
Jeff Wills's Avatar
 
Join Date: Mar 2008
Location: other Vancouver
Bikes:
Posts: 8,071
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 78 Post(s)
Quote:
Originally Posted by RavingManiac View Post
The spacers that you sometimes find in rear dropouts, what is their purpose? Why wouldn't you want the axle to slide in as far as possible? This is in reference to horizontal dropouts. I have an old Nishiki Seral touring frame I'm doing a build on, it had the spacers, took up about the last 3/8 inch of the dropout. Why?
Because!


Horizontal dropouts were what was available (for '70's era bikes) and people couldn't be trusted to put the axle in its proper place above the derailleur pivot.
__________________
Jeff Wills

Comcast nuked my web page. It will return soon..
Jeff Wills is offline   Reply With Quote
Old 09-17-10, 06:19 AM   #3
RavingManiac
Senior Member
Thread Starter
 
RavingManiac's Avatar
 
Join Date: Jun 2010
Location: Maine
Bikes: 90 Raleigh Chill MTB, 92 Trek 1200, 2004 Trek 2300, 67 Sports, 70 Sports, 71 Philips, Lotus Challenger, 74 Super Course, Univega Gran Tourismo, Nishiki Seral
Posts: 552
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Jeff, thanks for the response. Here are a couple of pics of the spacer and the axle in present positioning without the spacer. Does it look to you like I need the spacer? Why don't they just make the dropout so when the axles all the way back it is in the proper location? Do they play any role in centering between the stays? Just trying to understand there function. The Miyata 210 donor bike a lot of these components came from also had them.
Attached Images
File Type: jpg Nishiki Spacer 00&#.jpg (76.2 KB, 85 views)
File Type: jpg Nishiki Spacer 00&#.jpg (85.7 KB, 89 views)
RavingManiac is offline   Reply With Quote
Old 09-17-10, 10:06 AM   #4
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 22,233
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 1155 Post(s)
No, it looks like you need to be mindful of where you place the wheel in the dropout..
when you tighten down the QR..
fietsbob is offline   Reply With Quote
Old 09-17-10, 10:33 AM   #5
BCRider
Senior Member
 
BCRider's Avatar
 
Join Date: Mar 2008
Location: The 'Wack, BC, Canada
Bikes: Norco (2), Miyata, Canondale, Soma, Redline
Posts: 5,456
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
This is a bit of a guess on my part but I suspect that the longer than required slots even on the later dropouts with integral hangers were designed to be compatible with the older derrailleurs that used the old style hangers that fit into the rear section of the slot. Or possibly with the old style freewheels and shifting of the day the adjustable dropout slots were used to adjust the amount of chain wrap. With today's stuff the amount of wrap is set by the design of the derrailleur and adjustment of the B screw. But back then it seems like the standard for placement of the hanger was a trifle more fluid. By using semi horizontal dropouts that used either the fixed spacers or the adjustable screws seen on some higher end frames this could be adjusted to optimum for the parts being used.

As I say these are just guesses on my part since I wasn't riding and wrenching bikes during those times so I'm not sure. But from the parts that I've played with this almost seems like the ideas fit.
BCRider is offline   Reply With Quote
Old 09-17-10, 10:47 AM   #6
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 22,233
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 1155 Post(s)
the Screw adjusters were likely a Race Convenience for team road support wheel changes to be Quick,
and the alignment preset.
fietsbob is offline   Reply With Quote
Old 09-17-10, 11:13 AM   #7
Jeff Wills
Insane Bicycle Mechanic
 
Jeff Wills's Avatar
 
Join Date: Mar 2008
Location: other Vancouver
Bikes:
Posts: 8,071
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 78 Post(s)
Quote:
Originally Posted by fietsbob View Post
No, it looks like you need to be mindful of where you place the wheel in the dropout..
when you tighten down the QR..

+1. The spacers help locate the axle correctly with respect to the derailleur hanger, but aren't an absolute reference for the wheel.
__________________
Jeff Wills

Comcast nuked my web page. It will return soon..
Jeff Wills is offline   Reply With Quote
Old 09-17-10, 11:22 AM   #8
RavingManiac
Senior Member
Thread Starter
 
RavingManiac's Avatar
 
Join Date: Jun 2010
Location: Maine
Bikes: 90 Raleigh Chill MTB, 92 Trek 1200, 2004 Trek 2300, 67 Sports, 70 Sports, 71 Philips, Lotus Challenger, 74 Super Course, Univega Gran Tourismo, Nishiki Seral
Posts: 552
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Well, this being an 80's Nishiki Seral touring frame built with vintage Suntour ARX derailleurs and a Sachs freewheel I,m thinking I should probably go ahead and put the spacers back in. You can see from the scoring on the dropout that the axle was always further forward in this frame. My thiking in removing them was that one of the features of a touring frame was the longer chain stays and thus longer wheel base, so moving the axle forward in the dropout would somewhat negate that. This bike is going to be used as a tourer with front and rear panniers with a lowrider in the front. I was trying to achieve a little more stability by stretching the wheel base to the max. Thanks to all for the responses, any further insights would be welcome.
RavingManiac 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 06:18 PM.