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

Thread Tools Search this Thread
Old 02-17-09, 10:56 PM   #1
Senior Member
Thread Starter
Join Date: Sep 2008
Location: Baltimore, MD
Posts: 155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
8, 9, 10 speed mix-and-match

So my current set up is a melting pot of different road components at different levels:

Sora 8 speed Shifters (Triple)
Tiagra Front Derailleur
Ultegra Rear Derailleur
7 speed cassette 12 - 28t with 4.0mm ghost spacer
8 speed chain
Truvativ Rouleur 10 speed Crankset 53/39t 172.5mm


Except there is a little chain rub when the front is on 39t and rear on 11t (no one should get that combination anyway).

Anyway I have spotted a great deal on some 10 speed Ultegra STI. I would like to ask you guys before getting in to any unnecessarily expensive experiment:

Is it possible to make the 10 speed shifters to work on a 7 speed cassette with 3 ghost spaces if I:
1. Pull out all spacers from a 10 speed cassette (3.95mm).
2. substitute my 7 speed spacers (5.0mm) with 3.95mm spacers.
3. Take up the extra spaces with aftermarket single speed spacers (they are cheap!)
4. Adjust the rear derailleur low limit screw.

I know this sound pretty extreme, but I already get a 7 speed cassette to work with a 8 speed shifter with 1 ghost space, why not 3 'ghost' gears? Theoretically the chainline will be straighter than before!

The limiting factors are:
1. Can the derailleur be set to a low limit that is THAT far (toward the HIGH) away from the wheel.
2. Are the thickness of 10 speed cogs the same as 8 speed cogs?

I just wanna know what you guys thing coz I dont wanna throw away my 7 speed cassette since it is still relatively new (less than 2500 miles)
JimJimex is offline   Reply With Quote
Old 02-17-09, 11:56 PM   #2
zzyzx_xyzzy's Avatar
Join Date: Sep 2008
Posts: 804
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)

Problem is the cogs on a 10sp cassette are thinner as well as the spacers, so subbing spacers from a 10sp cassette into a 7sp cassette will not get you 10sp spacing.

Cog spacing on 7sp and 8sp are nearly the same, so that's why that works for you.
zzyzx_xyzzy is offline   Reply With Quote
Old 02-18-09, 02:28 AM   #3
Bill Kapaun
Senior Member
Bill Kapaun's Avatar
Join Date: Feb 2007
Location: Mid Willamette Valley, Orygun
Bikes: 86 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds.
Posts: 10,135
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 413 Post(s)
My 8 speed actually uses 7 speed cogs with thinned spacers.
I had two 7 speed cassettes and picked up an 8/9 speed FH body for too cheap not to, so I thought why not?

Basically, you just have to have the center to center spacing of the cogs correct for the speed of the shifters and a chain narrow enough to fit between them without rubbing.
Bill Kapaun is offline   Reply With Quote
Old 02-18-09, 12:08 PM   #4
Spin Forest! Spin!
WNG's Avatar
Join Date: Sep 2007
Location: Arrid Zone-a
Bikes: I used to have many. And I Will again.
Posts: 5,964
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Everything all went wrong when companies decided to go to 9/10/11 speeds. Thinned cogs, chains, and sometimes chainrings, makes interchangeability with 8 and older problematic. No more simple compatible swaps with other bikes and equipment in your inventory.
IMHO, for the average recreation cyclist, going to 9+ is simply flushing money down the drain.
But we live in a consumerism society where having the latest and greatest boosts one's self-esteem.
WNG is offline   Reply With Quote
Old 02-18-09, 12:42 PM   #5
Senior Member
parcoju's Avatar
Join Date: Apr 2008
Posts: 80
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
As long as you properly choose where you want those "ghost gears," thus adjusting for good chainline, my instinct says that it should work. However, my instinct has proven me wrong before....
parcoju is offline   Reply With Quote
Old 02-18-09, 12:50 PM   #6
mcgreivey's Avatar
Join Date: Jul 2008
Location: North Bergen, NJ
Bikes: '80 Windsor Carrera Sport, '02 Specialized Sirrus A1, '10 Giant Escape 2
Posts: 778
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Yeah, give it a try. Fiddle with it.

Don't throw away the old cassette. Put it back on if the experiment doesn't work out.
mcgreivey is offline   Reply With Quote

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 02:49 AM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.
  • Ask a Question
    get answers from real people!
Click to start entering your question.