[snowdenn]

i tried looking it up, but im pretty sure its an unusual question.

anybody know if its possible to 'downgrade' a 10 speed wheel to take a 7 speed cassette just by adding spacers?

 

[ultimobici]

Provided it's not a Dura Ace 7800/7801 freehub pattern it will work fine.

 

[SilverStar]

If I recall correctly, all it takes is a 4.5mm spacer. Don't forget to also adjust your RD's limit screw to avoid a nasty surprise!

 

[bikerjulio]

check out this chart. if its converting shimano 10 spd then the spacing needs to end up at 5.0mm. if the cogs are 1.6mm thick, then you need spacers of 3.4mm.

http://www.sheldonbrown.com/gloss_sp-ss.html#spacingk7

 

[Dave Hickey]

I use a 4mm spacer with 7 speed cassettes on a 9/10 speed hub...it works fine

As Ultimobici said, just make sure it's not a Dura Ace 7800 hub...This hub has deep splines and will only work with 10 speed cassettes. 7, 8, and 9 speed cassettes won't work with the 7800/7801 hub

 

[bikerjulio]

perhaps i was misunderstanding your question. Are you wanting to convert a modern cassette, or do have the 7-speed cassette and are asking if it will work?? and are we talking campy or shimano?

If shimano as long as it's a hyperglide freehub which have been around since the 7-spd era, then no prob. just a spacer a the back to enable the cassette to tighten up.

 

[frdfandc]

Remove 10 speed cassette. Install 4mm spacer onto freehub body. Install 7 speed cassette. Adjust rear derailleur.

 

[snowdenn]

thanks guys. its a shimano 105 5600 hub (think thats last years). thinking about putting in down tube shifters and like the idea of fewer gears on the cassette. eight is good. seven sounds better. would probably get a shimano hg cassette.

im hearing 4, 4.5, and 5mm spacers. i cant imagine 0.5mm would matter (couldnt the lock ring just screw in a bit tighter?), but maybe a full 1mm would.

@bikerjulio, the sheldon brown chart wasnt clear to me, since i didnt understand what was being measured. like center to center of each sprocket? then whats the spacer thickness mean? do i just total the shimano hg 7 speed cassette (if thats what im looking at) and subtract that total from the shimano 10 speed cassette? what numbers do i total?

 

[bikerjulio]

OK, sprocket thickness plus spacer = c-c spacing of sprockets.

overall width of 7 spd = 6 x 5mm + 1.85mm = 31.85 mm.

overall width of 10 spd = (9 x 3.95mm) + 1.6mm = 37.15mm

difference = 5.3mm = theoretical spacer needed. but if guys say 4mm works i'm sure it does.

this chart helped me on a project by telling me that for campy, spacing remained the same between 7 & 8 speed clusters. thus I used an 8 spd shifter with a 7-spd freehub.

and for a brief moment in time, compatibility between campy & shimano.

 

[SilverStar]

0.5 mm DOES make a difference...you can't just crank the lockring tighter to take up the difference.

I've always followed Sheldon Brown's advice for this, having put a seven-speed cassette on an 8/9/10 body:
Straight from Sheldon's mouth...or at least his website:

" (Add a 4.5 mm spacer before installing a 7-speed cassette on an 8-, 9-, or 10-speed hub.)"

From this page: http://sheldonbrown.com/k7.html

 

[Stogaguy]

8-speed on a 10-speed freehub?

If I understand it correctly an 8-speed HG cassette will install onto a 10-speed HG freehub body without the need for any spacers. Please confirm that I have this right, or set me straight if I do not. My specific case involves fixing a friend's bike with an 8-speed RSX drive train by installing a set of 2010 Mavic Ksyrium Equipe wheels.

My question is a bit of a high-jack but still somewhat on-topic. Sorry, this just seems like a good place to ask. Great thread! Thank you for the information. A posthumous thanks to the late great Sheldon Brown as well.

 

[frdfandc]

Mavic wheels require their 3mm spacer to be behind the cassette.

 

[silkroad]

does anyone have pictures of their 7speed with newer wheelsets? TIA

 

[pedro_xpto]

I has a weelset Frulcrum Racing 7 that has a hub for 10, but work without problems with cassette 8 speed, therefore i think that also work with cassette 7 without problems!

 

[carsareexpensive]

It should work- no problem. If you need a spacer just bring it into a local bike shop and ask them for the proper spacer. They should only charge you for the spacer.

 

[PlatyPius]

I has a weelset Frulcrum Racing 7 that has a hub for 10, but work without problems with cassette 8 speed, therefore i think that also work with cassette 7 without problems!

Modern Shimano freehubs are 8/9/10. For a 7 you need a spacer.

 

[Peanya]

Old thread with a new question? I had a question like this before, but realized an 8sp casette will work without a spacer, you just can't use one of the cogs, but at least you get a choice.