7 spd cassette on 8/9 speed wheel

[BartJ]

I have an older Specialized Sirrus and have begun riding again after a 10 year lay off. I feels great! I'm making some upgrades to my bike and want to do the wheels next. Is it possible to take the 7 speed (Shimano 105) cassette I have and put it on a new 8/9 Shimano compatible wheel? If I continue to ride as I hope a new bike seems like a logical choice in the future, but I would hold on to my old bike. (Too many good memories!)

 

[boudreaux]

Originally posted by BartJ
I have an older Specialized Sirrus and have begun riding again after a 10 year lay off. I feels great! I'm making some upgrades to my bike and want to do the wheels next. Is it possible to take the 7 speed (Shimano 105) cassette I have and put it on a new 8/9 Shimano compatible wheel?

Yes,but you need a 4.5mm spacer on the hub before the casette.The 8/9 wheel might also require wider rear dropout spacing than your frame has.

 

[BartJ]

Thanks. Someone told me my metal frame could be spread for the 8/9. Is that a tough thing to do? Is it a permanent spread, or do you just spread them to get the wheel on? Fixing the the new spread in place seems the way to go for when you have to take the wheel off and on. It seems like I could make a threaded spreader of some sort, but wonder if the spread would be centered when complete. Is this something the shop needs to do?

 

[KingB]

Originally posted by BartJ
Thanks. Someone told me my metal frame could be spread for the 8/9. Is that a tough thing to do? Is it a permanent spread, or do you just spread them to get the wheel on? Fixing the the new spread in place seems the way to go for when you have to take the wheel off and on. It seems like I could make a threaded spreader of some sort, but wonder if the spread would be centered when complete. Is this something the shop needs to do?

Is a 10+ year old Sirrus a steel frame? If so, you should have no problem realigning the stays to accomodate the new wheel size. the re-alignment would be permanent (I suppose you could bend them back later if you were to go back to a narrower wheel). I would also suggest that you get this done by someone competent in frame building/repairing. They will know how to work the frame and get the precise distance.

If it is alum or any other metal, I don't think it is as simple, but may be doable. You may also have to be worried about metal fatigue more with other frame materials.

 

[boudreaux]

Originally posted by KingB
Is a 10+ year old Sirrus a steel frame? If so, you should have no problem realigning the stays to accomodate the new wheel size. the re-alignment would be permanent (I suppose you could bend them back later if you were to go back to a narrower wheel). I would also suggest that you get this done by someone competent in frame building/repairing. They will know how to work the frame and get the precise distance.

If it is alum or any other metal, I don't think it is as simple, but may be doable. You may also have to be worried about metal fatigue more with other frame materials.

It does not even have to be permanent. You can just cram the wider hub in and ride it. Many late 7 speeds had a compromise 128 spacing that does not even need messed with.

 

[Gonzo Bob]

How old is it? Early 7/8-speed cassettes were Uniglide. While the splined Uniglide cogs will fit on a HyperGlide freehub body, the threaded cog may not. If it is Uniglide you will probably have to also buy a 7-speed HyperGlide cassette.

 

[boudreaux]

Originally posted by Gonzo Bob
How old is it? Early 7/8-speed cassettes were Uniglide. While the splined Uniglide cogs will fit on a HyperGlide freehub body, the threaded cog may not. If it is Uniglide you will probably have to also buy a 7-speed HyperGlide cassette.

Alot of relatively recent 8/9 hubs were threaded on the outside end for uniglide, as well as a thread on the inside end for the HG lockring.

 

[Gonzo Bob]

Originally posted by boudreaux
Alot of relatively recent 8/9 hubs were threaded on the outside end for uniglide, as well as a thread on the inside end for the HG lockring.

True, but BartJ was talking about buying new wheels and most (all?) new hubs have "compact" freehub bodies that allow use of an 11T cog and they do not have the Uniglide threading.

 

[boudreaux]

Originally posted by Gonzo Bob
True, but BartJ was talking about buying new wheels and most (all?) new hubs have "compact" freehub bodies that allow use of an 11T cog and they do not have the Uniglide threading.

Probably time for a new casette and chain anyway. If it's early 90s vintage, it's probably HG anyway. Acording to Sheldon, HG was introduced in the late 80s.

 

[dobber]

Originally posted by BartJ
I have an older Specialized Sirrus and have begun riding again after a 10 year lay off. I feels great! I'm making some upgrades to my bike and want to do the wheels next. Is it possible to take the 7 speed (Shimano 105) cassette I have and put it on a new 8/9 Shimano compatible wheel? If I continue to ride as I hope a new bike seems like a logical choice in the future, but I would hold on to my old bike. (Too many good memories!)

Echoing the above

A 7 speed cassette will work fine on a 8/9 speed hub. You'll need a spacer behind the cassette. It should be about 4.5mm. One of my recent conversions needed a slightly thinner spacer as the cassette was pushed to far out. Pick up a couple of spacers from your LBS, or knock apart an old cassette.

If your frame is steel, speading the stays should not be a problem. I simply pulled em apart a little while inserting the wheel, really didn't take anymore effort then dropping a typical wheel into a typical frame.

And after you get that new bike, turn the old one into a single speeder. Then it will become your favorite bike.

 

[daveornee]

Originally posted by BartJ
I have an older Specialized Sirrus and have begun riding again after a 10 year lay off. I feels great! I'm making some upgrades to my bike and want to do the wheels next. Is it possible to take the 7 speed (Shimano 105) cassette I have and put it on a new 8/9 Shimano compatible wheel? If I continue to ride as I hope a new bike seems like a logical choice in the future, but I would hold on to my old bike. (Too many good memories!)

If you are going from 126 to 130 mm check out Sheldon Brown's article at:
http://sheldonbrown.com/frame-spacing.html

 

[recycle]

Originally posted by boudreaux
Yes,but you need a 4.5mm spacer on the hub before the casette.

I did that on one and the chain dropped over the big cog every time ... put the space on after the cassette ... and the derailler didn't need any adjusting. The cogs lined up the same as they had on the previous 7 speed freewheel set up.

Any problem with the spacer on the outside?

 

[BartJ]

Things for me to consider! The bike is late 80's. I am thinking 1989. Yes, it is steel. Not sure about the type of hub and cassette. I am not up on the differences yet. Yes, I am talking about new wheels. So it sounds like maybe a spacer, before or after the casette is the question. Maybe a new cassette too!

 

[boudreaux]

Originally posted by recycle
I did that on one and the chain dropped over the big cog every time ... put the space on after the cassette ... and the derailler didn't need any adjusting. The cogs lined up the same as they had on the previous 7 speed freewheel set up.

Any problem with the spacer on the outside?

The proper way is spacer on the hub before the casette,then adjust the LOW limit screw. Spacer on after wont' work with a uniglide setup and the HG casett small cog is designed to have the lockring tighten against it for security,rather than the spacer.. and would usually require a high limit screw adjustment.

 

[boudreaux]

Originally posted by BartJ
Things for me to consider! The bike is late 80's. I am thinking 1989. Yes, it is steel. Not sure about the type of hub and cassette. I am not up on the differences yet. Yes, I am talking about new wheels. So it sounds like maybe a spacer, before or after the casette is the question. Maybe a new cassette too!

It could even be a freewheel rather than a casette.

 

[BartJ]

I'll take a closer look and also take a picture tonight and do some reading on the different terms I have read here today. I'm not sure what I have but will find out.

 

[BartJ]

Can anyone tell me what type of hub this is? Will it work on a new 8/9 speed hub? I've read where some have said I will need a new cassette and others that said it may fit. I've checked both the Park and Sheldon sites. Good stuff. I would really like to do the switch myslef. I feel I have the mechanical skills, just need a little technical knowledge right now.

 

[boudreaux]

Originally posted by BartJ
Can anyone tell me what type of hub this is? Will it work on a new 8/9 speed hub? I've read where some have said I will need a new cassette and others that said it may fit. I've checked both the Park and Sheldon sites. Good stuff. I would really like to do the switch myslef. I feel I have the mechanical skills, just need a little technical knowledge right now.

Sheldon has the answer. That is a uniglide casette. It will work only on a 8/9 speed shimano hub if the hub body is threaded on the outside end to accept the thread on first cog which acts as a lockring.You also need a 4.5mm spacer on the hub before the casette. I'd just get a 7 speed hyperglide casette and new chain and do it right, and ditch that messs.

 

[BartJ]

Thanks Boudreaux, that sounds like a good plan that will not break the bank and keep me on my old bike a little bit longer! I made the mistake of going by the LBS to buy my daughter a new bike (her's was stolen and it was my fault!) and saw all the new bikes. I always thought it was 98% the motor, but it seems technology has made them faster.

 

[boudreaux]

Originally posted by BartJ
I always thought it was 98% the motor, but it seems technology has made them faster.

Trust me, it's still the motor. There are better riders that beat me no matter what I'm riding,but there are plenty who have spent fortunes looking for speed that still fall victim to my old retro bike with 6 speeds in the rear and friction on the downtube.