Mr.Peloton

On my Team Miyata I have an 8-speed setup with a 7-speed cassette. I am wondering since the rear spacing is 130mm if I can just buy an 8-speed cassette or if I have to buy a new rear hub and then buy the 8-speed cassette. I am already going to buy a new front hub since it is not Campagnolo (it's a shimano 600 hub) so I am wondering if I need to buy a rear one as well (saves shipping cost, and cost in general to buy both at the same time).

Choke 

What rear hub is on the bike?

Tim_Iowa

What do you mean by "an 8-speed setup with a 7-speed casette"?

If you have a 7 speed cassette, then I'd call it a 7 speed setup.

Do you have 8 speed shifters and hub, but only a 7 speed cassette (plus a spacer)?


The 1991 Miyata catalog doesn't list a Team Miyata model, just the Team Titanium (which is 7 speeds).

CliffordK

Verify you are using a cassette and not a freewheel.

If you have a Shimano hub with a Shimano 7 speed freehub, then most of the freehubs can be replaced with an equivalent 8/9/10 speed freehub, and it isn't that expensive.

Campagnolo or Shimano compatible?

On Shimano hubs, it is possible to run 8 sprockets from a 9 speed on a 7 speed freehub. But, for indexed shifting, it would require 9 speed shifters.

Mr.Peloton

My current setup has 8-speed shifters, it is a Sachs 7-speed cassette. The hub itself is Campagnolo since it was an option from the factory to have Campagnolo Chorus (7-speed). I believe the Team Miyata is on their 1990 catalog.

Choke 

Campy did make a 7sp cassette hub - they're uncommon but they do exist. It appears that you might be able to use a Campy 8sp cassette on it - Cassettes and Cogs - Branford Bike - Seattle/Bellevue - Campagnolo Pro Shop

Darth Lefty 

There are 8-speed freewheels again now, too.

Choke 

I just thought of something. Even though you said that your rear spacing is 130mm, the Campy 7sp hub that I once owned was 126mm so you might want to double-check. If it's 126 then you probably can only fit 7 of the 8 cogs on it. VeloBase.com - Component: Campagnolo Athena 7 speed

fietsbob

as Long as You are ready to replace axles in the freewheel hubs . as they bent easier when that long on the right end.

Mr.Peloton

I know for sure that the rear spacing is 130mm (I checked the 1990 Miyata catalog). If I can find out how to post a picture without it going to another website I shall do so. I am hoping it is just as simple as putting an 8-speed cassette on and calling it good, but I don't think that'll be the case...

Falcon3

Likely you'll have a 7 speed freehub, which an 8 speed cassette won't fit on. You can buy a new freehub, but costs range from $15-$$$. You'll also want to confirm your hub will take a new freehub. I made the mistake of buying an 8/9/10 shimano freehub for my 7 speed bike before realizing it was a Joytech hub with a proprietary freehub.

Mr.Peloton

I highly doubt that my current hub will accept an 8-speed freehub. I was just trying to see if there was any way that I didn't have to spend the extra money on an 8-speed hub.

Mr.Peloton

This is the rear hub.

Dave Mayer

Sachs cassettes are very rare on this this side of the Atlantic. I've never seen one. But I've seen (and own) buckets of Sachs 7-speed freewheels.

Ditto for Campagnolo 7-speed cassette hubs. I have only ever seen one, which I own. I doubt more than 100 of these came over to America. There was never such thing as a Chorus 7-speed cassette hub. There was Athena, but not Chorus.

The chance of you having two very rare products (Sachs cassette and Campy 7-speed cassette hub) together is incredible.

Mr.Peloton

I hope I have them, I shall try to get more pictures so I can get a detailed description of what I have.

Mr.Peloton

Mr.Peloton

I hope that helps.

Choke 

You have a freewheel hub....not a cassette.

Mr.Peloton

So I've been told... The bike's older than I am. I am trying my best to be somewhat correct.

Choke 

A freewheel is different than a cassette. You can put any freewheel on there that has the same threads....likely BSC or ISO. It should be marked on the hub; IIRC. on that hub it's located where you can't see it unless the freewheel is removed.

Anyway, if it's 130 and if there's clearance between the end of the hub and the dropout then you can fit an 8sp freewheel. But as has been mentioned, the extra length and resulting torque makes for the possibility of a bent axle.

Mr.Peloton

Should I keep it a 7-speed but make it so that it's no longer 13-21t, or should I make it an 8-speed?

pastorbobnlnh 

Yes, that is very much a 7 speed Sachs freewheel and not a cassette. Sachs did make an 8 speed freewheel and I have a few which I used for their sprockets. But looking at the first picture I'm not certain you have enough space for an additional sprocket. It will be a tight fit.

Choke 

If it was mine I'd put a different 7sp freewheel on it.

Mr.Peloton

That's what I'm pulling for too. It's also a conversation starter when people notice that my bike has a 7-speed, but it has 8-speed ergo shifters!

Mr.Peloton

Here is how it looks on the bike.