Rear Cassette Swap Questions?

[partsguy]

I finally found the right wheels for my Western Flyer hybrid build, but the rear cassette isn't exactly compatible with my frame OR the derailleur I chose. The smallest cog is too close to the frame, the chain grinds against the derailleur nut. The biggest cog is too high up for my derailleur to reach. Also, no room for spacers. I cannot fit anything bigger between my dropouts.

The derailleur is an old school Shimano that came from a used Giant Attraction, the rear rim is a Bontrager with a Shimano HG 8-cog cassette. Model number CS-HG50. I would like to downgrade to either a 6 or 7 cog cassette. Shifters are original, non-indexed, thumb shifters, which are not going anywhere. Any recommendations on how to find a match for a cassette that fits my build?

Thanks!

 

[SILVERKINGPC]

Derailleur and shifters are only 6spd compatible, maybe 7. Might work on 6/7spd spin-on cassette hub, but not on the more modern 8spd cassette you have on the bike. Derailleur does not (might not) have the right range ability (H/L limit screw adjust), or ability to run a narrow 8spd chain either...

 

[partsguy]

Derailleur and shifters are only 6spd compatible, maybe 7. Might work on 6/7spd spin-on cassette hub, but not on the more modern 8spd cassette you have on the bike. Derailleur does not have the right range ability, adjustment either...

Good info. The bike was originally a 12 speed (built in 1989). When did 6-speed cogs become outdated? They have been hard to find on a wheel that fits this bike. That's why I settled for the 8-speed cog on this wheel. Can I swap in a 6-speed cassette? If so, what brands or models might be compatible, or what should I look for?

 

[partsguy]

I found this HG50 7-speed, would this work?

https://www.amazon.com/Shimano-HG50...coding=UTF8&psc=1&refRID=BJ9NCBATQQS039BDDJR2

 

[SILVERKINGPC]

I found this HG50 7-speed, would this work?

https://www.amazon.com/Shimano-HG50...coding=UTF8&psc=1&refRID=BJ9NCBATQQS039BDDJR2

Might not. Depends on the derailleur and if it was designed for a 7spd. cluster. The derailleur is "indexing" (sis) to be originally run with matching shifter. Your shifter is not indexing but friction, so not sure this shifter/derailleur combo will work or not. If the derailleur is 7spd compatible(which it may be), you should be able to adjust it to move over those 7 cogs with the friction shifter. You have to experiment with it a bit with another 7spd wheel..

 

[RustySprockets]

Friction shifters are compatible with most any derailleur, even between brands. There are limits to how far they can move that derailleur inboard, however. Have you maxed out the travel of the shift lever when attempting to reach the lowest gear? If not, then I think there is hope for getting your existing 8-speed cluster to play nicely.

The photos really aren't enough for me to determine--I'd need more info. But, from what I read in your description, I'm pretty confident I could make that set-up work.

 

[Duchess]

The derailleur itself doesn't care how the cable is pulled (the cassette spacing and index pull length of the shifter determine the compatibility), so a friction shifter is fine as long as it can pull enough cable stop-to-stop for full range of derailleur travel required. If it can't, then you have less usable speeds in your cassette and one or more for decoration. Your derailleur may not be able to work with that entire cassette, but before moving on, since you can't use your smallest cog due to interference, you may be ale to readjust the derailleur to reach the largest cog and it appears that the natural limitations of the derailleur will take care of your small cog interference problem. It might be, though, that it's not just a travel limitation issue and that the derailleur just can't handle that large a ring or can't travel that far towards the center of the frame (the former is more likely and in case of the latter, make sure you check that the limit stops aren't set so that they are preventing the full movement). In either of those cases, you'll need a longer cage derailleur or to go to a different cassette or forgo the largest and smallest cogs by setting your limit stops to just cut them out of the equation. The latter is free and just brings you down to either a 6 or 7 speed without having to buy anything new.

If you still want to change out the cassette, it should be fairly easy to find a 6-speed HG cassette (though, you might more often run into the older freewheels as 6 speed is pretty old for free hub). BUT, you don't need a 6-speed as I believe 6, 7, 8 are all the same width. If you want to go to 6-speed for width reasons, you'll also have to change the freehub and that stuff will be harder to find new as it's old.

As far as the dropout width, a steel frame can be spread a little without an issue, if you want to fit in a small spacer.

 

[RustySprockets]

Duchess' assessment is spot-on. I wasn't going to delve into a long explanation unless partsguy decided to pursue the matter further.

Eight-speed hubs are generally 130mm wide vs 126mm for the others--addition of a simple washer is likely all the space that is needed to eliminate the chain rub. My suspicion is that everything else is adequate to gain full functionality with a little tweaking.

 

[partsguy]

Good Morning, my fellow rat rodders!

I appreciate all of the feedback! I had a hectic Sunday, and was unable to respond here. I will get pictures of my entire bicycle tonight.

I am running a 2-cog chain ring, old school style, similar to what this bike used to have. I will have to have it blasted and powder coated though, it has quite a bit of rust. I installed it anyway just to see if it would fit. I have not tightened down my new shifter cable, I moved the derailleur with my hand to make sure it would move so far inward. I did not want to crimp my new cable for a useless drivetrain setup.

I actually had to spread the rear of this Western Flyer a wee bit to get this wheel to fit. I have no room at all for shims. Something MUST go on this hub. Either the chain rubs and grinds into the derailleur fitting, or it cannot reach into the highest gear without tearing into the spoke protector. I removed the dust cap on the non-drive side, and saw a series of spacers. I am not sure if I should just start removing spacers though. Yes, this hub is a free-wheel cassette.

I would concur that my derailleur and shifter combo is good, but this cassette is a little too sophisticated. I just do not know what cassette to go with, I never swapped cassettes before.

 

[Chad T]

One other thing. The key with indexed shifting is that the pull ratio of the derailleur matches the type of shifter. (How much the cable moves per indexed shift at the shifter)...but doesn't matter with friction shift.

Not real familiar with 8-speed cassetes and what the difference is in width between that and a screw-on 7-speed freehub. I know modern 9-10 and 11 speed cassette hubs are all the same width.

 

[RustySprockets]

No, removing spacers won't fix the problem. You still need to add 4mm (about 1/8 inch) to the drive side to gain space and eliminate the rub. Manipulating spacers on the non-drive side will only make the O.L.D. narrower and move the wheel off the centerline of the bike. One option might be to move 4mm from the non-drive side to the drive side and then re-dish. But, only you know what kind of spacers you have to work with.

In the interest of clarity, a "freewheel" and a "cassette" are not the same thing. Using the terms interchangeably can cause a great deal of confusion. Cassettes are a separate, removable stack of gears that are keyed and only compatible with a freehub body from the same manufacturer--they don't work with older spin-on style freewheels at all.

Now confirming that you possess a freewheel hub body--not a cassette--I can say with authority that switching to a 7-speed item is easily done. But, I still say that the 8-speed is possible, if you desire it, with the materials you already have.

 

[partsguy]

No, removing spacers won't fix the problem. You still need to add 4mm (about 1/8 inch) to the drive side to gain space and eliminate the rub. Manipulating spacers on the non-drive side will only make the O.L.D. narrower and move the wheel off the centerline of the bike. One option might be to move 4mm from the non-drive side to the drive side and then re-dish. But, only you know what kind of spacers you have to work with.

In the interest of clarity, a "freewheel" and a "cassette" are not the same thing. Using the terms interchangeably can cause a great deal of confusion. Cassettes are a separate, removable stack of gears that are keyed and only compatible with a freehub body from the same manufacturer--they don't work with older spin-on style freewheels at all.

Now confirming that you possess a freewheel hub body--not a cassette--I can say with authority that switching to a 7-speed item is easily done. But, I still say that the 8-speed is possible, if you desire it, with the materials you already have.

Following this video, I am confident that I have a cassette on here.

A Google search of Shimano CS-HG50 also reveals it is a cassette.

After discussing on the CABE as well, I am wondering if would be best if I just built a set of wheels to match my requirements. Maybe, reuse these rims, and install new hubs and spokes?

 

[RustySprockets]

Ah...then you do have a cassette and don't have a freewheel. Freewheels are the "spin-on" style--cassettes (aka freehubs) are the "slide-on" style.

Will a Shimano 7-speed cluster fit on that hub? Yup. Will changing to a 7-speed cluster change the overall width of the hub? Nope. Only the spacers do that.

I must be missing something very obvious here, because I don't see many obstacles to getting your existing items to work harmoniously. What I see in the photos looks reasonable.

 

[SILVERKINGPC]

This is a good example as to why you should try to match shifters with derailleurs with hubs/frames. Like the previous posts here, you may be able to get it to work. 6/7/8 speed "cogs" are spaced the same. 9/10/11 is spaced more narrowly, and require narrow chains. Since you had to spread the frame, then the hub is clearly not designed for your dropout design, and is causing rubbing in the high(small) cog in back. Friction shifters probly should not be used with 7speed SIS derailleur OR rear cog setup, as the length of cable pull is questionable to begin with, depending on brand of old friction shifter.
I cannot imagine why you are so settled on the old friction shifter? If you must have it, go with an old 6spd, threaded, spin on cluster on a non-cassette hub, and friction shift away!. It would also solve your rubbing problem as the 6th (high gear) cog is spaced much further away from the dropout.. Good luck!

 

[RustySprockets]

Meh...at the bike co-op, we swap out broken indexed shifters with friction "thumbies" all the time. They work perfectly and we find the set up very straightforward. Mixing and matching components, especially across brands, is usually asking for trouble. Friction shifters are kinda universal.

 

[Duchess]

I figured it was a cassette because I don't think there were Hyperglide freewheels (though I could certainly be wrong) and that you're having more trouble with the hub OLD being too wide than you should be. Redistributing the spacers and redishing the hub may be your best bet (or you might be able to just grind down the smallest cog to where it doesn't bother anything). What I would do is measure your dropout width and your hub OLD. A problem with freehubs on old frames is that the hub OLD is usually a lot wider than the old dropouts. You might have better luck with an old freewheel hub with a 6-speed. I actually have one to spare, if you want it. My next project bike is to use a 6 speed freewheel in a 1961 Columbia Firebolt and I had the hub from a 1983 Fuji Grand Prix when I changed to 700c wheels. But I want to convert it to rear disc brake, which was a whole fun thing trying to find a freewheel hub I could use blah, blah, blah, anyway I no longer need that Fuji hub if you want it, but you'll have to find a freewheel cassette (which shouldn't be hard). I don't know if the possible hub flange differences will require you to get new spokes, though.

I've done all kinds of custom friction shifters and never had compatibility problems—all it's doing is pulling the cable, moving the derailleur in turn and when it goes into gear and stops making noise, you're good. While I love the nice click of index shifters properly indexing, I prefer friction for its ease of setup, versatility (especially with the weird things I do), and ability to more rapidly jump through gears in one move.

 

[SILVERKINGPC]

Looks like the friction shifter crowd here is still going strong! I may have to dig out my old friction shifters and see how many are out there willing to pay for em! Gots some indexing 7-spd xt thumbies as well I oughta dump. Perfect for this project!!! May even have to find my old spin-on 6-7spd dura-ace freewheel clusters that are sitting in a box that I used to run on Bullseye hubs before "cassette carrier" hubs came out. Still have the bullseys..(and a lot of other bike junk stuffed in boxes)

 

[RustySprockets]

Here's a clip I found that explains some of the hardships you can expect when you switch to a 7-speed cluster on a hub designed for eight.

 

[Duchess]

I may have to dig out my old friction shifters and see how many are out there willing to pay for em!

Don't charge too much—the other thing I like about friction shifters is that they're cheap!

 

[RustySprockets]

...and durable.