Five to seven speed freewheel conversion...

[CFM]

Looking at upgrading my ancient (1984) Univega Land Rover Sport from 15 to 21 speeds with a Shimano Megarange freewheel, as the origional 14 X 34 five speed freewheel cluster is well-worn from many years and miles of use...I just replaced the chain, and the crankset is fairly new, so now I'm down to the cluster. With the extra two gears, it looks like I will also need a longer axle and skewer to go with it, and possibly redish the wheel for the additional offset. I need to go measure the axle, but I take it that longer axles are available? Any advice or experience with this kind of project?

[C.P.]

Whoa, now there's some history for ya. Having done this for a few bikes many years ago, the only thing that became a bit of an issue, was that the axles were more suseptable to bending, since the right side cone is so far in. Here's the how to, Taken from Sheldon Brown's (http://www.sheldonbrown.com/harris/freewheels.html)site:

"Hubs originally intended for 5-speed freewheels can be converted to use 6- or 7-speed freewheels. You will generally need to add a few spacer washers to the right side of the axle, building it up far enought that the cone locknut can reach the frame dropout through the wider freewheel body. You will need to re-center the axle but probably won't need to replace it with a longer one. You'll also need to re-dish your wheel (http://sheldonbrown.com/gloss_da-o.html#dish) , and probably re-space your frame (http://sheldonbrown.com/frame-spacing.html). If you're fairly handy, this is not an unreasonable thing to do."

[bikdav]

Try to see what you can get away with before going through all that trouble. Longer axles are available, but might not be necessary. Let me explain some situations that I ran into. On some old bikes that I had some years ago, going from a five speed to a normal spaced six speed (normal at the time) only involved me putting an additional thin spacer washer on the freewheel side. That was all there was to it; no wheel redishing, longer axles or anything of that nature. BTW, all my freewheels were Suntour brand. Later, I tried installing a seven speed freewheel in place of a normal spaced six speed freewheel. I was expecting a problem with this. But, no problem cropped up, except for needing a seven speed chain at the time. It turns out that the seven speed freewheel body was the same width as the previous six speed. In other words, the the narrow sevens were the same width as the normal sixes of that era. I am assuming that you are going to use Shimano freewheels (or one of the shimano copies). If that's the case, you may not have to do a lot of rework, because Shimano's spacing was almost exactly like Suntour's.

[AA]

I am assuming that you are going to use Shimano freewheels (or one of the shimano copies). If that's the case, you may not have to do a lot of rework, because Shimano's spacing was almost exactly like Suntour's.

The spacing is not an issue because the original 5 speed shifter is not indexed. Friction shifters don’t care what the spacing is between the cogs.

For those that weren’t alive when bikes came with friction shifters (from Sheldon Brown)

Friction shifting
Shifting operated by a lever that moves smoothly through its range. With friction shifting, the rider must learn exactly how far to move the lever to get from one gear to another. If the rider moves the lever too far, or not far enough, the chain will not line up properly with the sprocket, causing noise and roughness.

[bikdav]

The spacing is not an issue because the original 5 speed shifter is not indexed. Friction shifters don’t care what the spacing is between the cogs.

For those that weren’t alive when bikes came with friction shifters (from Sheldon Brown)

Friction shifting
Shifting operated by a lever that moves smoothly through its range. With friction shifting, the rider must learn exactly how far to move the lever to get from one gear to another. If the rider moves the lever too far, or not far enough, the chain will not line up properly with the sprocket, causing noise and roughness.

Opppsss! You're right about that. I forgot about that since I caught the tail end of the friction shifting era.

[CFM]

Thanks for the great feedback! I was aware of the axle bending issues when they tried 8-speed freewheels, guess 7-speed is the outer limit for the axle. I'll know more when I get the freewheel...it's always fun figuring out how to upgrade this bike.

BTW, I still use the friction shifts that the bike came with...I'm so used to them that I can trigger them without a second thought up and down the range. Kind of old-school, but they work well. I did upgrade the rear derailler to a Shimano Deore XT so that the downshift was springloaded instead of the upshift like the origional Shimano derailler (that I plumb wore out), adjusted for the five-speed range, so it shouldn't be a big deal going to seven.

[kilozebra]

Thanks for the great feedback! I was aware of the axle bending issues when they tried 8-speed freewheels, guess 7-speed is the outer limit for the axle. I'll know more when I get the freewheel...it's always fun figuring out how to upgrade this bike.


FWIW, my bike came with a 7-speed freewheel ('09 Specialized Hardrock), and I found myself bending axles on every ride until I replaced it with a freehub.

I'm a "super" clydesdale (~290 lb), so that may well have had a good bit to do with it.

The bends were consistently at the nose of the drive-side hub cone, bent in drive direction (ie, axle midsection pulled toward the front of the bike). Tried standard and "upgrade" (CrMo) axles to no avail. The 7, 8, and 9 speed freewheels are not that much different in width (less than 5mm covers the range), so I would expect that any problem you'd see on an 8-speed freewheel would also affect a 7-speed.

/Andrew

[CFM]

Well, I only weigh about 125lbs, so I may be able to get away with it. I did kick around the idea of going to a freehub and gaining a really impressive range of gears, something that I keep thinking about. In the end, it might not be a bad idea considering all the years and miles on the bike...

[bikdav]

Well, I only weigh about 125lbs, so I may be able to get away with it. I did kick around the idea of going to a freehub and gaining a really impressive range of gears, something that I keep thinking about. In the end, it might not be a bad idea considering all the years and miles on the bike...


That's a good point also. Regular replacement rear wheels with the freehub system are not expensive anymore.

[kilozebra]

That's a good point also. Regular replacement rear wheels with the freehub system are not expensive anymore.

Yup, and the gear ranges available are pretty nice. Sourcing freewheels is getting tougher and tougher every day.

I went from the 7-speed MegaRange freewheel (14-34) to a 7-speed HG50 cassette (14-32) when I upgraded to a freehub... I don't really miss the extra two teeth. :)

/Andrew

[CFM]

One of my coworkers gave me a 6-speed Shimano 14-28 freewheel today, bought it years ago and only used it a few times before going to a cassette. I was really impressed with the difference in gearing from my old 5-speed 14-34, completely different bike...having gotten along with the 5-speed freewheel for so many years, I can really appreciate the improved gearing!

I measured the axle length with my dial verniers while I had the freewheel off, it measured 5.265" long. I only needed a couple extra washers for the 6-speed freewheel to clear, although it did just graze the derailler hanger nut inside the dropout. I have about 1/4" on either side of the axle with the nuts and washers, so I would need a slightly longer axle to use the 7-speed freewheel, maybe around 1/2" longer would be sufficient...probably have to get a corresponding skewer to go with it.

[CFM]

I picked up a longer axle and skewer the other day and installed it; had to spread the frame a bit per Sheldon Brown's article and make some minor adjustments with the brakes and derailer, but it was no big deal. I never did install the Megarange, though; quite a jump from 24 to 34 teeth, too much of a gap in the gearing...I really like the gear spread on the 6-speed freewheel with the 28-tooth low gear better.

[bikdav]

There are some 14 to 28 six (and seven) speed freewheels still on the market. The question is; does anyone locally have such a freewheel? Or, are you going to have to mail order someone that has one?

[CFM]

Well, when I go to replace the freewheel again, I'll just convert to a freehub/cassette setup. As you (and others) have pointed out, the freewheels are harder to find these days. For now, though, I'm happy with what I have...I tend to wear things out, so this should last me awhile.