Sixty Fiver

Chombi - Maillard freewheels are nice but not as common on this side of the pond... Suntour really dominated the entry to mid level market and Regina freewheels were fitted to many high end racing bikes until Shimano UG and HG freewheels took over due to their low price and rather excellent shifting properties.

I have a nice little collection of Maillard freewheels (metric) and even have one Suntour body with a metric thread and am just looking for some old French hubs to mate them to. They do not shift as well as some but I like the fact they sound like a swarm of angry bees when they are freewheeling... can also tell the difference between a Suntour and a Shimano by the sound and lack of it.

bax76

Hi,
I have a couple of Shimano 600 freewheel 6spd from 80s, that look quite good, no significant visible teeth damage, but when I put new chains they all jump and slip during load.
Because of aesthetic quality of old components, is there any way to refresh them and use them in light conditions for weekend rides?

Regards.

pastorbobnlnh 

Most of the wear on freewheel and cassette sprockets is actually on the inside and is not easily seen until the sprockets are removed from the body or carrier. If your "jumping/slipping" is on every sprocket it could be another issue related to the RD. If it is on specific sprockets, those could be the ones with the most significant wear and could be replaced (if available). Can you post some pictures of your 600s? Hope this is helpful.

noobinsf 

Do you have access to a derailleur hanger alignment gauge? I recently fixed a bout of ghost shifting on my Motobecane by straightening an ever-so-slightly out of plumb derailleur hanger. I actually just used a level to check it vertically.

Salamandrine 

Chain skip is the classic symptom of a worn out freewheel. Generally speaking, the wear on freewheel teeth isn't visible. BITD, you knew it was worn out when the chain started to skip. This typically took about 7 or 8 thousand miles, maybe a little more, depending on lots of factors. If you were a cheapskate and worked in a shop like me, freewheel life could be extended by replacing the offending/skipping cogs only. Typically it was the smaller ones that got used a lot during base training: a 15t and 17t for example.

This is why buying used freewheels is a coin toss.

Early Shimano freewheels, IMHO and IME, were not long lasting compared to competitors at the time. (They got much better later) I'd say there's a good chance those ones are toast. However, you could play around with your chain length and wheel position in the dropouts and the B screw if you have one. If you can get a bit more wrap you might be able to correct the skipping for a time.

For sure check your hanger. ^^^ A bent hanger will cause the same symptoms.

CliffordK

Refreshing?

If your freewheel is a pre-hyperglide freewheel, it theoretically might be possible to disassemble the freewheel and reverse many of the cogs.

As the teeth on the freewheel wear, the spacing remains at 1/2", but the pulling side of the teeth gets angled so that the chain tends to ride high (and thus goes around a circle with greater spacing.

I've thought that it should be possible to mill the pulling side of the teeth back to the original profile. It would lengthen the slots between teeth, but that shouldn't affect performance.

Vintage freewheels tend to have blocky teeth, and should have plenty of material to mill down without significantly compromising the sprockets.

You'd need precision, and probably an indexing head, so hand filing probably wouldn't be adequate.

SamSpade1941 

bax76

I cant post photos because I am new user. I am postive that my hooks are ok, because I reapir all these bikes with new freewheels. I Preserved some of them, that are skiping due the worn teeth. I was hoping that some easy fileing of teeth can do the job or something else....

mpetry912 

+1 on the recommendations above for the current issue 6 and 7 speed Shimano FWs. I have several and have had zero problems with them. At $25 bucks they are hard to beat.

I'm fortunate enough to have bought a large box of loose cogs, parts and bodies for the best FW ever, the Dura Ace MF-7400. These FWs are very well made, have the hyperglide tooth profile, and very smooth running. I made up a new FW and swapped it in for one of the current Shimano units. Shifting performance is identical ! the only difference is the sound of the pawls. The DA freewheel has a "whirr" like a swiss watch.

https://www.petry.org/pics/DAFW%20Aug18.jpg

https://www.petry.org/pics/DACcogs3.jpg

Mark Petry
Bainbridge Island, WA USA

pastorbobnlnh 

Now that you have 10 posts, you can add pictures. Hooray for reaching this level!

@CliffordK most Shimano 600 6 speed freewheels I have worked on all had a specific orientation for the sprockets and they will only fit with the lettering facing out. I could be wrong, but only the 5 speed 600 models used the three nub sprockets which can be flipped.

CliffordK

Ahhh... thanks for the clarification.

Are a couple of the nubs redundant? So, perhaps one could file/grind off a nub, and flip? Squish everything together, and it should hold pretty well.

I've tried the flip trick with the middle/inner chainring on the past, and it seems to work. If only the outer chainring was tapped for moving the drop stop peg. And, of course, potential issues on middle rings with bolt heads.

pastorbobnlnh 

No, they are a continuous jagged pattern. The current Shimano HG freewheel sprockets use the same pattern with an added rectangular notch to make certain every one lines up in the perfect shifting profile. Below are some DuraAce 6 speed sprockets and you can see the pattern well enough. The smallest sprocket is threaded and the remaining ones have the pattern.

bax76

bax76

CliffordK

Those don't look too bad at all. Perhaps my freewheel-foo is off.

You've got two 5-speeds and one 6-speed. I assume you're using some kind of friction or retrofriction shifting (not indexed).

You should be able to pull the freewheels apart using two chain whips, or a chain whip + freewheel vise. You could try flipping the sprockets on the 5-speed freewheels. However, see below.

You're sure you're using a standard multi-speed 3/32 chain, and and not a single-speed 1/8" chain, or a 10/11 speed chain (9 may be ok) (11/128ths?)

One other thing to do is to check for a stiff link, or the chain catching somewhere. Put your bike up on the stand or upside-down on carpet, and slowly roll the crank backwards (or forwards). Look for the rear derailleur hopping.

In general, I like the freewheel marked Shimano UG with the silver/gold middle. I see some wear on the middle sprocket, but almost no wear on the highest and lowest sprockets.

bax76

I have one more Shimano 600 in similar condition, but in different location. These are from different bikes. Their visual condition is reason why I keep them in Box. So the most realistic option is to fleep these cogs on 5spd devices. I use standard 6 speed KMC chains, or old ones if they are in OK measures.

Bad Lag

I use a 5 speed Shimano Dura-Ace freewheel from about somewhere around the 1972-1974 timeframe. It is smooth as glass and goes on and comes off easily using the QR skewer trick.

I have the chain tools and a selection of cogs which allows me to install whatever gearing I want on the freewheel body. It is currently set up as 14-16-18-21-24 and goes with my 42-52 tooth chain wheels. This serves me well from the flat ocean-front bike path to high altitude, modest slope mountain climbs (5, 6, 7% grade for a few miles).

For serious climbing in the mountains, I use a completely different, wide range gearing set up, including a different rear derailleur and different chain wheel rings.

pastorbobnlnh 

On the "UG" 5 speed the top two smallest sprockets are threaded and only go on in the orientation pictured.

On the "Singapore" 5 speed, the top smallest sprocket is threaded and the remaining have the zig-zag pattern and only go on in the orientation pictured.

So, there really won't be a great deal of flipping that you can actually attempt.

Consider purchasing an 8 or 9 speed KMC or SRAM chain and try it along with making certain your derailleur hangers are aligned.

sonali31

This discussion helped me getting the best freewheels.

bax76

Thank You very much for this information, at least I wont waist too much time.
So basically I will continue buying cheap new ugly black cog Shimano Tourney freewheels as solution.

jcb3