Retrobike Forum Index

It is currently Thu Dec 08, 2016 3:33 pm

* Login   * Register * Search  * FAQ



Post new topic Reply to topic  [ 11 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: 5sp to 6sp on 122mm ok?
PostPosted: Wed Jun 20, 2012 10:03 am 
Retro Guru

Joined: Wed Dec 28, 2011 2:51 pm
Posts: 1081
Location: Brighton. UK.
I have a 5 speed no name freewheel on my gios that has a 28t top cog which is unuseable due the nuovo record rear der not being able to accomodate it. Can I go up to a 6sp freewheel ok on 122mm rear spacing? there's lots more choice if I can !

Thanks!


Top
 Profile  
 
 Post subject:
PostPosted: Wed Jun 20, 2012 10:32 am 
Dirt Disciple

Joined: Mon Nov 14, 2011 2:10 pm
Posts: 70
http://sheldonbrown.com/cribsheet-spacing.html

http://sheldonbrown.com/speeds.html

Looks like you might have to spring your dropouts apart slightly since standard 6 speed is 126mm, but it might be doable. Presumably you'll also need a longer axle and more spacers outside the cones. My reading of this suggests that if you can get hold of an ultra-6 freewheel and use a modern chain with sticky-out rivets, it will require less of a change (ETA - assuming you're not using indexed shifters)

I've not done this (although I'm considering something similar), so I could be completely wrong.


Top
 Profile  
 
 Post subject:
PostPosted: Wed Jun 20, 2012 10:40 am 
Retro Guru

Joined: Wed Dec 28, 2011 2:51 pm
Posts: 1081
Location: Brighton. UK.
Thanks, completely forgot about the Sheldon Brown info. With a little refining of my searching on ebay I have found a 5sp silver nos '77 regina freewheel that will keep the originality :D


Top
 Profile  
 
 Post subject:
PostPosted: Wed Jun 20, 2012 11:20 am 
Concours Judge
Concours Judge
User avatar

Joined: Wed Jul 06, 2005 3:59 pm
Posts: 8171
Location: a proper EU country
My PEKA is ready for 6s

http://www.retrobike.co.uk/forum/viewtopic.php?t=204230

Some washers removed on the non drive side and moved to the drive side. Wheels centered.

The NR mech handles the 28t largest on my bike btw.


Top
 Profile  
 
 Post subject:
PostPosted: Wed Jun 20, 2012 11:51 am 
Retro Guru

Joined: Wed Dec 28, 2011 2:51 pm
Posts: 1081
Location: Brighton. UK.
Elev12k wrote:

The NR mech handles the 28t largest on my bike btw.


Well this got me thinking, the previous owners nos sachs chain looked a little too loose so I removed a couple of links and hey presto the top jockey wheel doesn't rub the underside of the 28t cog. The tighter chain pulls the top jockey wheel furthur down away from the freewheel. Problem (simply) sorted, a nice hill climbing set up :D

Cheers all.


Top
 Profile  
 
 Post subject:
PostPosted: Wed Jun 20, 2012 1:33 pm 
Old School Grand Master
User avatar

Joined: Fri Oct 14, 2011 8:41 pm
Posts: 8245
Location: Cumbria
28 cog was always a bit hit and miss with Campag NR, I always wondered if some droputs had longer mech hangers?

There is always the suntour winner 6 speed system if you really need a 6 speed :)

Shaun


Top
 Profile  
 
 Post subject:
PostPosted: Wed Jun 20, 2012 1:46 pm 
Dirt Disciple

Joined: Mon Nov 14, 2011 2:10 pm
Posts: 70
shawnb wrote:
Elev12k wrote:

The NR mech handles the 28t largest on my bike btw.


Well this got me thinking, the previous owners nos sachs chain looked a little too loose so I removed a couple of links and hey presto the top jockey wheel doesn't rub the underside of the 28t cog. The tighter chain pulls the top jockey wheel furthur down away from the freewheel. Problem (simply) sorted, a nice hill climbing set up :D

Cheers all.


Isn't the b-tension screw (or whatever the equivalent on non-shimano things) meant to take care of this. Wind it in to move the top jockey wheel away from the sprockets.


Top
 Profile  
 
 Post subject:
PostPosted: Wed Jun 20, 2012 1:48 pm 
Retro Guru

Joined: Wed Dec 28, 2011 2:51 pm
Posts: 1081
Location: Brighton. UK.
I'll take a look when I get home but it didn't stand out when I was tinkering, would it have one being a pat 78 era? Whatever the issue has been sorted by shortening the nos chain that the seller had just slapped on. Reckon I could do the south downs way with this gearing!! It's like a MTb set up!!


Top
 Profile  
 
 Post subject:
PostPosted: Wed Jun 20, 2012 3:49 pm 
Retro Guru

Joined: Tue Feb 23, 2010 1:56 pm
Posts: 1032
Location: West Yorkshire
flimflam_machine wrote:
shawnb wrote:
Elev12k wrote:

The NR mech handles the 28t largest on my bike btw.


Well this got me thinking, the previous owners nos sachs chain looked a little too loose so I removed a couple of links and hey presto the top jockey wheel doesn't rub the underside of the 28t cog. The tighter chain pulls the top jockey wheel furthur down away from the freewheel. Problem (simply) sorted, a nice hill climbing set up :D

Cheers all.


Isn't the b-tension screw (or whatever the equivalent on non-shimano things) meant to take care of this. Wind it in to move the top jockey wheel away from the sprockets.


Those old Campag mechs didn't have such a thing.

The mech hanger does play a part in getting the mech to handle 28T. I found that I had to shorten the chain so far on my bike that the rear mech (an SR not NR - makes no difference really) was way too tight on the big ring. In the end I just gave up and made do with a 24T bottom sprocket.

Mark.


Top
 Profile  
 
 Post subject:
PostPosted: Wed Jun 20, 2012 5:05 pm 
Retro Guru

Joined: Tue Jun 03, 2008 4:31 pm
Posts: 741
My Super Record of that vintage dealt with a 30 by shortening the chain.
However I have also bunged a 6 speed block into a 120mm alloy cyclocross frame. It will go. Just


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 11 posts ]  Go to page 1, 2  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: Bollox64, retrotrack, Sparrow and 34 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

About Us

Follow Retrobike

Other cool stuff

All content © 2005-2015 Retrobike unless otherwise stated.
Cookies Policy.
bikedeals - the best bike deals in one place
FatCOGS - Fat Chance Owner's Group

Powered by phpBB® Forum Software © phpBB Group