Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Converting 7 speed to 8 or 9 speed

Search
Notices
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.

Converting 7 speed to 8 or 9 speed

Thread Tools
 
Search this Thread
 
Old 08-12-04, 03:47 PM
  #1  
Senior Member
Thread Starter
 
markm109's Avatar
 
Join Date: Oct 2003
Location: SE Michigan
Posts: 295

Bikes: '03 Litespeed Blue Ridge; '15 Litespeed T5; '17 Jamis Renegade Exploit; '17 Salsa Fargo 27.5+

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Converting 7 speed to 8 or 9 speed

I have a bike with all shimano exage EX300 components and it a 2x7 or 14 speed. The rear wheel needs to be replaced. The rear cog is a cassette. The bike is cro-mo. So as I see it I have several options:

1. Get a new rim and relace the spokes. One nipple is damages and I would have to find a replacement. I have never built a wheel so this option is interesting, even if I screw it up, a lbs can do it. Would it be good to replace the spokes and nipples as well?

2. Buy a built wheel, new or used, put the cassette on it with a spacer and retune the rear derailure.

3. Since a new wheel is 8 or 9 speed and I have a spare 9 speed cassette, replace the rear derailure with a new one (Shimano 105?) and replace the downtube shifters with a 9 speed setup as well. Or will the 7 speed shifters work? I don't think the rear derailure would work, right?

I am thinking about option 2 or 3, but need to learn more to see if option 3 is viable. Does anything else need to be changed? Cables?

The bike is fun to ride, it has a different geometry than my regular bike and the down tube shifters are neat comparted to my other other bike's sti. I ride this bike on days it may rain and on dry days in the winter. I know the bike is barely worth the price of a new wheel, let alone the full option 3, but hey, the wife won't let me buy another bike so all I can do is fix it and upgrade it. Something about already having 3 bikes, why do I need another one? Women can be funny about things sometimes.

Any and all (even if you say I'm crazy) opinions are welcome. Thanks in advance for your help.

Mark
markm109 is offline  
Old 08-12-04, 05:03 PM
  #2  
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 30,225

Bikes: Catrike 559 I own some others but they don't get ridden very much.

Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1572 Post(s)
Liked 643 Times in 364 Posts
The first thing that I would do is to measure the distance between the rear dropouts. If it happens to be 130mm, go buy a lottery ticket because this is your lucky day. If it's 127.5, go ahead and stick in the 9-speed wheel but skip the lottery ticket.

If it's 125mm, you'll probably have to bend the rear triangle a bit to get the 9-speed wheel to work. There's no need to get too worked up about the bending, it's only a couple of mm on each stay. It's easier to do than you probably imagine. If you want to check the alignment when you are done, hold a straight edge between the head tube and dropout and measure the distance to the seat tube on both sides.

7-speed shifters will probably work in friction mode but they certainly won't index. If you decide to upgrade to 9-speed index shifters, you might find that you have to replace the rear derailleur, but, being a retro grouch and a cheapskate, I'd sure try your current derailleur first.
Retro Grouch is offline  
Old 08-12-04, 06:28 PM
  #3  
Senior Member
 
sydney's Avatar
 
Join Date: Jan 2004
Posts: 9,428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Originally Posted by markm109

3. Since a new wheel is 8 or 9 speed and I have a spare 9 speed cassette, replace the rear derailure with a new one (Shimano 105?) and replace the downtube shifters with a 9 speed setup as well. Or will the 7 speed shifters work? I don't think the rear derailure would work, right?



Mark
The RD works. 7 speed shifters ain't gonna index but have a friction mode.If you get 9 speed shifters,they will be DA and will have a sticker saying compatible only wirh DA RD.Ignore it.
sydney is offline  
Old 08-12-04, 06:31 PM
  #4  
Senior Member
 
sydney's Avatar
 
Join Date: Jan 2004
Posts: 9,428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Originally Posted by Retro Grouch
The first thing that I would do is to measure the distance between the rear dropouts. If it happens to be 130mm, go buy a lottery ticket because this is your lucky day. If it's 127.5, go ahead and stick in the 9-speed wheel but skip the lottery ticket.

If it's 125mm, you'll probably have to bend the rear triangle a bit to get the 9-speed wheel to work.
The numbers for dropout spacaing I have always seen are 128 and 126 for most 7 speed road,although a few may have been made with even 130.
sydney 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



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.