Tag Archives: Suntour freewheel

Overhauling a Freewheel, Part II

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2016-02-20 024

When I left off from my last post, I was midway in the process of overhauling an early 80’s Shimano freewheel.  I was having trouble getting the freewheel cogs seated over the freewheel body, after cleaning and reinstalling the lower set of bearings at the base of the freewheel body.  The process of mounting the cog body over the freewheel body involves turning the cogs counter clockwise, while somehow not dislodging the lower bearings, but every time I tried it I failed because I couldn’t see the bearings, as I was using the “top down” method.

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Maillard freewheel body with rubber band holding the pawls in place.

So, I took a break and did some reading and experimenting with other freewheels.  Older freewheels have pawls held in place only by gravity, which is fine if the freewheel body when disassembled is right side up.  But, what I read was that the best way to get the cogs back on is to turn the freewheel body upside down first, then turn the cog body counter clockwise over the base of the freewheel.  However, the only way to keep the pawls from falling out is to secure them with a rubber band, attached with a string. This was the method described by Sheldon Brown.  When you flip the freewheel body upside down after installing it loosely on a wheel, you hope that you can get the string, rubber band, pawls and bearings to all end up in their rightful positions while maneuvering the cog body into the bearings.  I tried this as a “dry run” – sans bearings – a few times on the Maillard freewheel that I had disassembled, and was never able to get the string to pull the rubber band out, and this was without having any bearings to worry about.

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Shimano freewheel with top set of bearings installed, after applying a bead of grease.

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Spacers going back in over the top bearings.

But, the Shimano’s pawls were held in place with a clip, and I realized that I could just turn the body upside down, position the cogs, and slowly turn them counter clockwise as I gently seated them over the bearings.  Having the freewheel body upside down for this step allowed me to be sure that all the bearings stayed in place during the process.  I did this while the body was attached to the wheel.  After that it was easy to apply a bead of grease to the upper cup of the freewheel body, install the bearings, place the spacers, and then re-thread the cover plate BACKWARDS (because it is reverse threaded).  Then, by taking a chain whip to the cogs, you can tighten the cover plate back down with your pin spanner.  Some experts suggest applying thread locker to the cover plate, but I instead used a bit of grease.

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Cover plate back on.

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Pin spanner and chain whip, to tighten the cover plate.

I removed the freewheel from the wheel, spun it, and was satisfied with the result. Voila – mission accomplished.

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Suntour Perfect 5 speed freewheel

Meanwhile, I recently purchased a used Suntour Perfect freewheel on eBay that I wanted to have on hand because of its useful wide gear range.  Unfortunately, this freewheel was shipped in a small box surrounded by “popcorn” – that horrible stuff which clings to everything – and in this case imbedded its tiny carcinogenic particles into every possible opening of the freewheel during the shipping process.  While described as being in “great condition” by the seller, I found that this Suntour freewheel was totally dry and did not spin freely.  So, it became another candidate for an overhaul.  As you can see from the above photo, the cover plate is easily accessible, with normal sized holes which my Park pin spanner fit perfectly.

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Suntour spacers

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Suntour pawls – held in place with a clip

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Suntour freewheel body, beautifully machined

As I was removing the cover plate, once the body was off the wheel, I had a small mishap when I accidentally bumped the body, and the bearings went flying around my shop. Fortunately, with my magnet in hand, I believe I recovered all of them.  It’s important to have all of the bearings if only for the purpose of counting them, top and bottom, even if you aren’t going to re-use them.  And, this venture definitely gives new meaning to the phrase “losing one’s bearings.”

I noticed right away, as I observed the Suntour’s freewheel body and cogs, how nicely engineered these are compared to the Shimano freewheel.  The Suntour’s freewheel body has a wider base and a larger cup, which makes installing the bearings much easier.  It has one pawl per side, held in place with clips.  The top spacer has lock rings, another nice feature. However, you can see from the photo above that there is some wear on the pawls, which I think was caused by the complete lack of lubrication over the life of this freewheel.  The pawls seemed robust enough to be re-used, so I proceeded to the next step.

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Lower bearings installed in a bead of grease, a small bit of grease added to each pawl.

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Top bearings installed, ready for spacers and cover plate.

I was able to easily install the cog body over the freewheel body by using the “upside down method”, and from there it took no time at all to apply a bead of grease to the top cup, install the bearings and spacers, and secure the cover plate.  This overhauled Suntour Perfect freewheel now spins beautifully, with that pleasing tick-tick sound that Suntour freewheels emit.

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Cyclo 4 speed freewheel

So, I kept going. I wanted to overhaul this Cyclo freewheel which, even after lubrication, was fairly unresponsive.  I believe it dates to the 60’s or 70’s.  It is French threaded, but accepts a Suntour two prong removal tool.  While it was fairly easy to get the cover plate loose, the tedious process to unscrew it all the way made me think that the cover plate had been cross threaded, and I worried about getting it back on again.

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Cyclo freewheel pawls part of cog body

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Notches in freewheel body, instead of cog body

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Pawls which fell out on disassembly

When I took the Cyclo freewheel apart, I was intrigued to see that its pawls are part of the cog body, and not the freewheel body, which instead houses the notches which allow for the freewheel to lock under forward motion.  And, the pawls fell out of the body immediately, as they are not held in place by any kind of clip.  So, this Cyclo will require a different method for getting the pawls to stay in place while mounting them over the freewheel body. And now I am getting another headache.

One thing I learned from this process is that nicely engineered freewheels are easy to overhaul as long as the pawls are clipped into the body (but probably almost never need to be overhauled).  In fact, the only procedure you may ever need to do, aside from routine lubrication, is to remove the cover plate to add or remove a spacer.  If the freewheel is too tightly adjusted, you add a spacer, and if it’s too loose you remove a spacer.  Poorly engineered (and badly adjusted) newer freewheels are time consuming to overhaul, if you are even able to do it, as the cover plates on some freewheels are difficult or impossible to remove.  Meanwhile, my 7 speed Suntour Winner freewheel, which was the impetus for this undertaking, is now working better.  I tightened the cover plate, lubricated it with a bit heavier oil, and now it is working fine, without the need for an overhaul.

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Suntour Winner 7 speed freewheel

Overhauling a Freewheel, Part I

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1941 French 3 Speed Freewheel

Vintage bicycles generally use freewheels, and not freehubs, as part of their drive trains, although it is interesting to note that the first freehub was actually invented by the British company Bayliss-Wiley back in 1938, and used thread-on cogs. Later, BSA created a splined freehub in 1948, which was set up for 4 cogs. And, Stronglight, Maxi-Car, and a few other manufacturers developed and marketed cassette freehubs in the late 1940’s through the 1950’s.  Shimano came out with its first freehub in 1978, and the rest is history.  Freehubs with splined cassettes are now the standard equipment on all modern bicycles.

Shimano, Sunrace, Ventura, DNP and IRD still manufacture freewheels, but the style, number of speeds, and spacing of the cogs, as well as the overall width of the freewheel often makes them inappropriate choices for a vintage bicycle restoration project.  Plus, weight and reliability can be an issue with any new non-Shimano freewheel (see below).

It is still possible to find NOS or good quality used vintage freewheels, such as Suntour, Regina, and Cyclo, on eBay or even Craigslist, but sometimes the cost is just too high to justify the expense in dollars.

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1940’s Cyclo Freewheel

I can attest to the reliability of virtually all vintage freewheels, having had no failures even after riding and restoring hundreds of bicycles. With a bit of lubrication, by dripping automotive oil into the space where the freewheel turns on its body, most freewheels can be brought back to their original functionality.  Sometimes, with a very dirty freewheel, I will first lubricate the body with a light oil, to clean the debris out, then follow that up with heavier automotive oil (the same 30 weight that I use for lubricating internal hubs).  The 1940’s freewheel pictured above came back to life easily after this simple process.

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1929 Peugeot Freewheel and Fixed Cog

Some freewheels don’t even need that much attention.  This 1929 Peugeot single speed freewheel with its helpful hinged lubrication port (part of the 1929 Griffon that I am restoring) didn’t require much lubrication – it was still working perfectly after 87 years of service!

Freewheels require a precise bearing adjustment, accomplished by the use of spacers and the torque on the cover plate.  While pawls can wear out over time, the stress on the bearings themselves is quite low, compared to bearings found elsewhere on a bicycle, and that is one reason why so many older freewheels work perfectly with simple cleaning and lubrication.  Hence, some mechanics have never found the need to perform a freewheel overhaul, myself included.  There are a number of resources on the web which provide detailed freewheel overhaul instructions.  There is even a business called the “FreeWheelSpa” which has dedicated itself to this zen-like work. Not wanting to deprive myself of the joy of tearing apart a mechanical device on a grey, rainy Portland winter day, I decided to tackle the job myself.

My Suntour New Winner 7 speed freewheel, installed on my winter bike, had begun making clunking sounds while under load, and grinding sounds while freewheeling.  I replaced it with a different vintage freewheel from my dwindling stock so I could keep riding the bke, but before attempting to overhaul the Suntour freewheel, I decided to take apart a number of other vintage freewheels on hand, to make sure I understood the process.  Possibly, this was a bad idea.

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From left to right: French freewheels, including Cyclo, Atom, Maillard and Milremo, Suntour freewheels including Perfect, New Winner, and Pro-Comp, and various Shimano and Shimano copies, both vintage and new.

I have a small collection of vintage French and English threaded vintage freewheels, plus a number of newer freewheels from Shimano, IRD, and DNP.

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This is an IRD freewheel that had previously failed after only a few hundred miles.  I marked it with a zip tie so that I would never use it again.  This seemed like the first obvious choice for an overhaul in my quest to master the freewheel overhaul process.  Unfortunately, the cover plate on this freewheel could not be removed, even after much pounding on the cover plate with a punch and hammer.  After that failed experiment I tried removing the cover plates on all the newer Shimano and Shimano copy freewheels on hand.  In each case, the cover plate could not be removed, partly caused by the tinier holes present on the newer freewheels – which would not accept my Park pin spanner.  Clearly these freewheels were meant to be tossed when they failed, part of the now de rigueur built-in obsolence doctrine in the cycling industry.

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So I grabbed an early 80’s made-in-Singapore Shimano freewheel, and had no trouble at all getting the cover plate off.  You need to mount the freewheel to a wheel first, before attempting to loosen the cover plate, so that the freewheel body is held in place.  I used an old rear wheel with English threads that I didn’t mind abusing for this process.  Once the cover plate is loose, you want to remove the freewheel off the wheel, and the take the cover plate off.  The cover plate is REVERSE THREADED, so you turn it clockwise to loosen it.

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When the cover plate was off, I was able to see the first set of 1/8″ bearings resting quietly in the top cup of the freewheel body.  There is another set of bearings at the bottom of the freewheel body.  I used my magnet to remove the bearings, and placed each set of bearings in a separate container.  I did not intend to replace the bearings, so I cleaned them with a little alcohol and let them dry out, planning to re-use them.

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Then I applied a bead of grease to the lower cup first, and began the mindful process of placing each bearing back in its rightful spot.

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Shimano freewheel pawls

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Maillard pawls on the left.

But, before doing so I noticed that this Shimano freewheel’s pawls differ substantially from this earlier Maillard freewheel that I had previously disassembled.  The Maillard’s pawls are held in place only by gravity, and there is one pawl on each side of the freewheel body, but the Shimano has double pawls on each side, held in place with a clip.

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After the lower bearings are installed, you need to screw the freewheel body back onto the wheel, then very, very carefully put the freewheel cogs over the top, and seat the pawls.  That’s where I ran into trouble, and decided to take a break before proceeding further.  It can be quite tricky to get the pawls back into the ratcheting mechanism.  Sheldon Brown used a technique involving a rubber band and some thread.  Reading about it gave me a headache.

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Meanwhile, my failed IRD freewheel is taking up its rightful position as a doorstop.

It’s Not Me, It’s the Bike

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1990

These are the words I say to myself when I am riding especially fast.  Or especially slowly, as of late.

This winter I have been using my Panasonic MC 7500 winter bike as my primary commuter, which is a change from past winters, partly driven by this winter’s wet and colder conditions which heralded the onset of a typically Portland rainy season last November.  Very recent winters have been gloriously warm and dry, so my choice of commuting vehicles was vastly expanded and even included scooter rides in the dead of December.  But, not this winter.  Portland is back to typical seasonal weather which can include anything from 35 degrees and raining hard, to light sprinkles in the lower 50’s (like today), and the occasional freezing rain and snow.  The short days also come with twilight seeming to descend in apocalyptic fashion in the middle of the afternoon.

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This bike was actually quite the machine in its day – the top of the line Mountain Bike in Panasonic’s line up in 1987.  It is built with Tange Prestige Cro-Mo double butted tubes, with forged drop outs and chromed chain stays.  The geometry on the smaller frame that I am riding features a slack 70 degree head tube combined with minimal fork rake, which would normally make it less than ideal for commuting, but its long wheelbase (107 cm) makes up for the higher than ideal wheel flop.  Consequently, I can usually avoid putting my foot down as I approach red lights and four way stops.

I bought this Panasonic as a frame and fork, then built it into a city commuter.  It went through various iterations, and now is set up for maximum comfort and utility.

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I was using a Shimano grip shifter and a 6 speed cassette, but after a black ice crash in 2012, the shifter broke apart (because it is made of plastic), so I splurged on a $7 no name friction shifter, made of good old steel.  That meant that I could install a 7 speed freewheel, and increase the bike’s gear range a bit.

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I had been using these UNO city bars, pictured above, but the shape and width did not agree with my anatomy, so I swapped them out for a vintage steel Northroad bar.  This bar is a great improvement in comfort, being narrower and putting my hands and shoulders in a much more neutral position, and increases the bike’s un-coolness factor by a few thousand degrees.

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Steel Northroad bars

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Further agitating bike snobs in Pdx, the Panasonic is sporting a duct tape rear fender repair job, and a ghastly kickstand.

The kickstand is a convenient accessory, and this design is useful for any bike where mounting in back of the bottom bracket is not an option (in this case due to the U-brakes residing there).  The stand is adjustable to any wheel size, and keeps the bike secure, even when I have my bags loaded up with groceries.

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I like using these Jandd Hurricane bags, which are aptly named and can handle just about any kind of weather.  Their vibrant colors augment my winter bike’s 1980’s color scheme, and add a lot to its visibility.  If you haven’t used Jandd bags, you are missing out on the ultimate in practicality and quality.  I have a set of Jandd panniers that are 30 years old, and still look new.

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The Panasonic MC 7500 is a bike that enthusiasts have embraced, but the frame does have its downsides – one of them being that on some builds, holes drilled in the seat stays (necessary to allow heat to escape while brazing), were actually drilled very close to the seat stay attachment.  Fortunately, on my frame, the holes have been drilled near the dropouts.  Unfortunately, the seat stay holes have caused a stress riser to appear on this cyclist’s bike.

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Paul’s chain keeper for my 1×7 drive train, with vintage Peugeot branded crankset.

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Specialized Nimbus Tires. Never a flat in six years, and the exact opposite of supple side walls.

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Possible stress crack

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After sanding to remove the paint, no stress crack visible.

On my own frame, I had concerns about the paint cracks which had developed near to the U-Brake braze-ons on the chain stays.  Whenever you heat the tubes to braze, there is a danger of overheating and weakening them. Since the frame was already cosmetically challenged, I had no qualms about taking my emery cloth and sandpaper to this area to see what lay beneath the cracked paint.  Fortunately, nothing at all.  But now I can monitor this area.  I will paint it with Testor’s clear paint so that I can watch for any future changes.

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SunRims on the wheelset I built for this bike – holding up okay but the sidewalls have been scored by my too hard brake pads.

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Offending hard pad on the U Brake – showing no wear which is a bad sign. Meaning that my rims have suffered instead.

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Repair job on the broken fender attachment.

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Repaired fender bracket.

While I had the bike in the shop stand, I decided to do a full tune-up.  I washed the wheels (a new wheelset which I built last year, and which are working well), picked rim material out of the brake pads, sanded the rear ones, replaced the too hard original Tektro pads which had messed up my new rims, and cleaned and lubricated the SunTour freewheel (more on that, below).  I repaired the broken fender attachment by rummaging through the parts bin to find a reasonable facsimile with which to repair the broken bracket.  I drilled a new hole through the center of the fender, and installed the new bracket.  Hopefully, it will survive and thrive.

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New front Kool Stop pads – replacing the original Tektros which badly scored my new rims.

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But now, to my chagrin, my newly cleaned and lubricated 7 speed Suntour freewheel is making very odd grinding and clunking sounds.  I have always loved Suntour freewheels, and have never had one fail on me.  After doing some research, Sheldon Brown (RIP) came to the rescue.  He described a situation similar to mine, where my newly lubricated freewheel began sounding clunky under load, and noisy while freewheeling.  I believe the problem may be a loose cover plate.  Meanwhile, I have a fun old Atom 5 speed freewheel from the 1970’s with English threads which I am going to install while I troubleshoot the beloved Suntour. The higher geared old Atom freewheel should make me ride even more slowly.  But, as I said before, it’s not me, it’s the bike.

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28 lb machine ready to hit the road.