|
|
Post by brianbutler on May 22, 2020 0:41:03 GMT
I just placed a Buy It Now order for three used 13-34 skip tooth freewheels ( www.ebay.com/itm/283873880276.) Two look to be in good shape. The third has a broken tooth on the smallest cog but "otherwise" OK. I plan to disassemble, clean, and refurbish them. I probably have the replacement cog in my bushel of old freewheels. I've been practicing disassembly on some others in anticipation of this task. If I get them back together I plan to fit them on my Viscounts where they will look outstanding, based on photos of Triitout's skip tooth. Wish me luck.
Brian
|
|
|
|
Post by franco on May 22, 2020 8:39:27 GMT
Interested to hear how you get on with this Brian. Overhauling a freewheel looks a tricky job and one I haven’t tried yet, in the past I’ve opted for RJ’s method of flushing them out with penetrating fluid and then trickling oil into the joint spinning the cogs to work it in.
Mixed results with this, tried it on two Maillard freewheels, one turned out nice but the other was really noisy.
|
|
|
|
Post by brianbutler on May 22, 2020 12:04:08 GMT
I have generally used the flushing method as well. I made a little jig with a threaded rod and washers that I put in a hand drill chuck. I can immerse the freewheel in a gallon can of solvent and spin it. By holding the cogs still, it flushes the bearings, otherwise it cleans the cogs themselves. Then I lubricate with oil as you mentioned. I recently took apart a Maillard freewheel that I had treated this way and the results were mixed. It was quite clean. There was a bit of residual grease. I was surprised how little oil remained on the bearings after lubricating from outside. That's why I am thinking about opening these skip tooth freewheels and lubing with grease. There are not many parts inside and it is an easier job than overhauling a three-speed hub. It is also easier than overhauling the Campy freehub I just did, where it was very tricky to get the pawls and springs back into the freehub body because they are not supported by clips and you have to rig up a thread to hold them in place during insertion.
|
|
|
|
Post by franco on May 22, 2020 19:05:04 GMT
Ive seen people use cotton or an elastic band to hold the pawl springs in place.
I wonder if the grease in a spray can would work better than oil, might give this a go.
Nothing better than a proper overhaul though. I need to have a crack at a Sturmey Archer at some point too, maybe a few winter projects.
|
|
|
|
Post by brianbutler on May 23, 2020 1:04:28 GMT
Now that you mention it, I did use a rubber band covering half the width of the pawls, just enough to get them inside the body. It still took multiple tries.
If you decide to overhaul an SA hub, download this document:
It gives good instructions and diagrams on disassembling and reassembling the hub. The only thing I don't like is step 2 in the disassembly where you are supposed to pound the ball ring with a drift punch. This is where you need that nifty tool I mentioned, which I do not have. Using the punch always mars the notch on the ball ring. Even a brass drift damages the part. Trust me, I know.
For that matter, I don't like any of Sheldon Brown's advice that involves whacking, banging, punching, or otherwise hammering bike parts. There is almost always a better way.
|
|
|
|
Post by triitout on May 23, 2020 1:54:23 GMT
I give you full credit for attempting that kind of rebuild. I picked up a 14-32 NOS in the original Shimano box on e-bay a few years back. I believe the one you were referred to on my Sport is original. I haven't weighed the NOS freewheel but it is amazing how heavy it is. Long Island is fairly flat and I've yet to use the 32 tooth cog, but I find the gaps between cogs leave me wanting when searching for the right gear. I look at 14-32 as insurance for my riding if I'm still going in my 70's, 80's and up. For now, 14-28, 6 speed freewheel is my go to freewheel. If I could find a 38 or even 40 tooth inside chainring for the porthole crankset, I'd be all set.
|
|
|
|
Post by franco on May 23, 2020 7:58:41 GMT
Now that you mention it, I did use a rubber band covering half the width of the pawls, just enough to get them inside the body. It still took multiple tries.
If you decide to overhaul an SA hub, download this document:
It gives good instructions and diagrams on disassembling and reassembling the hub. The only thing I don't like is step 2 in the disassembly where you are supposed to pound the ball ring with a drift punch. This is where you need that nifty tool I mentioned, which I do not have. Using the punch always mars the notch on the ball ring. Even a brass drift damages the part. Trust me, I know.
For that matter, I don't like any of Sheldon Brown's advice that involves whacking, banging, punching, or otherwise hammering bike parts. There is almost always a better way.
Thanks for the advice. what concerns me is the later AW hubs didn’t have an oil porthole and the grease or whatever lubricant that was used during assembly is not going to last forever. That’s how the one is on my 1997 Raleigh Courier. Considered swapping the wheel eventually, the chrome isn’t great on it either. I notice on the SA website they advise against any lubrication on the newer hubs and say to get the hub serviced at a SA dealer. |
|
|
|
Post by brianbutler on May 23, 2020 10:53:11 GMT
You can add oil periodically through the axle chain indicator hole. It opens into the hub body that contains all of the mechanisms. Perhaps Wheelson can confirm this or has another method. I believe he is an SA expert.
|
|
|
|
Post by brianbutler on May 23, 2020 11:06:36 GMT
I misspoke about the brass drift punch damaging the ball ring. Instead, the ball ring damages the brass punch. I think what is needed is to shape the end of the steel or brass punch so it seats into the inside corner of the notch at the angle you plan to strike it. Otherwise either the outside corner of the notch or the edge of the punch is damaged, depending on the punch material and diameter. I might try to make a special punch out of some small square steel or brass stock, but I will have to wait until our town's recycling center reopens so I can look for material.
|
|
|
|
Post by wheelson on May 23, 2020 19:48:59 GMT
Using a punch is the only way I ever took the ball ring from a Sturmey Archer hub. Actually, I was shown how to do this way back in 1966 as a rookie bike mechanic. The method was to use a steel punch called a nail set, the carpenters on the forum will know what I'm talking about. It works great and doesn't damage the ring. Now with the Shimano 3 speed hubs, the ball ring removal tool is an absolute must. In my opinion, the Shimano parts were not hardened correctly and were quite brittle. Cracked parts were common.
A couple of posts above, in the discussion of rebuilding freewheels, it was mentioned to use rubber bands to hold the pawls in place for reassembly. I was shown a trick using dental floss to do this. A gentleman by the name of Harvey Sachs used to put on a freewheel rebuilding seminar at the Classic Rendezvous bike gettogether every year. What patience is required for freewheel work! Also I suggest to be wary of grease used in freewheel lubrication. Aging of the grease or cold weather can inhibit the pawl operation and make them slip. Of course, the new light Teflon based grease is more stable. I also like the Teflon based oils such as the newer formula PB Blaster. Triflow is great as well.
Best,
John "wheelson" Wilson
|
|
|
|
Post by franco on May 23, 2020 21:06:25 GMT
Using a punch is the only way I ever took the ball ring from a Sturmey Archer hub. Actually, I was shown how to do this way back in 1966 as a rookie bike mechanic. The method was to use a steel punch called a nail set, the carpenters on the forum will know what I'm talking about. It works great and doesn't damage the ring. Now with the Shimano 3 speed hubs, the ball ring removal tool is an absolute must. In my opinion, the Shimano parts were not hardened correctly and were quite brittle. Cracked parts were common. A couple of posts above, in the discussion of rebuilding freewheels, it was mentioned to use rubber bands to hold the pawls in place for reassembly. I was shown a trick using dental floss to do this. A gentleman by the name of Harvey Sachs used to put on a freewheel rebuilding seminar at the Classic Rendezvous bike gettogether every year. What patience is required for freewheel work! Also I suggest to be wary of grease used in freewheel lubrication. Aging of the grease or cold weather can inhibit the pawl operation and make them slip. Of course, the new light Teflon based grease is more stable. I also like the Teflon based oils such as the newer formula PB Blaster. Triflow is great as well. Best, John "wheelson" Wilson Thanks for the information. How would you go about lubricating the later Sturmey Archer hubs without the oil porthole? Brian mentioned running oil in down the indicator rod, which is the only possible way without taking the hub apart, as far as I can see. It’s an odd one, the hub is made in England 1992 (I typed the wrong date in previously), I thought the hubs were the same until they moved operations to the Far East. |
|
|
|
Post by brianbutler on May 24, 2020 2:11:14 GMT
Actually you should unscrew the indicator rod and pull it out, then put oil down the hole. Screw it back in when you are done.
|
|
|
|
Post by brianbutler on May 24, 2020 2:32:11 GMT
Using a punch is the only way I ever took the ball ring from a Sturmey Archer hub. Actually, I was shown how to do this way back in 1966 as a rookie bike mechanic. The method was to use a steel punch called a nail set, the carpenters on the forum will know what I'm talking about. It works great and doesn't damage the ring. Now with the Shimano 3 speed hubs, the ball ring removal tool is an absolute must. In my opinion, the Shimano parts were not hardened correctly and were quite brittle. Cracked parts were common. A couple of posts above, in the discussion of rebuilding freewheels, it was mentioned to use rubber bands to hold the pawls in place for reassembly. I was shown a trick using dental floss to do this. A gentleman by the name of Harvey Sachs used to put on a freewheel rebuilding seminar at the Classic Rendezvous bike gettogether every year. What patience is required for freewheel work! Also I suggest to be wary of grease used in freewheel lubrication. Aging of the grease or cold weather can inhibit the pawl operation and make them slip. Of course, the new light Teflon based grease is more stable. I also like the Teflon based oils such as the newer formula PB Blaster. Triflow is great as well. Best, John "wheelson" Wilson I definitely agree about [too much] grease in the freewheel bearings. The races are quite close to the pawls. But a little bit of grease makes the task of inserting all those tiny balls manageable. Also on that topic, make yourself a ball applicator out of a small creased paper (ahem, a rolling paper would work perfectly). Load it up and let one ball at a time slide onto the greased race as you rotate the part. Much easier than tweezers or bead pliers. |
|
|
|
Post by franco on May 24, 2020 19:49:33 GMT
Actually you should unscrew the indicator rod and pull it out, then put oil down the hole. Screw it back in when you are done. Looks like I’ll be going further with it, bear in mind I only picked this bike up on Friday... Had a grinding feeling coming through the pedals this morning, so I checked the back wheel and it didn’t have any lock washers on the axle so it was tightening the bearing cups up whilst riding. Adjusted the cups, added lock washers, all good, took it back out and still grinding. So I overhauled the bottom bracket thinking it may be dried out or need new bearings. Took it back out again and it’s still grinding, so I’m assuming the bearings have had it in the rear hub, it only does it when I pedal forward and It does feel rough unless it’s loosened off to the point the whole thing rattles. Just ordered two races, hope that solves the problem. I had a few wheels spare so one of them has been fitted for now. |
|
|
|
Post by franco on May 30, 2020 23:12:33 GMT
Any updates on the freewheel overhaul Brian?
|
|
|
|
Post by brianbutler on May 31, 2020 1:08:58 GMT
I received the three freewheels a few days ago. One of them has a broken tooth on the small cog so I thought I would work on that one first to see exactly what is inside, and also to disassemble the cogs from the body to possibly replace the broken cog. The lock ring, spacers, bearings, pawls and pawl retaining spring came apart easily and are sitting in a cup of solvent. I went to work on the cogs using two chain whips and broke/repaired the older chain whip two or three times before ordering a better one. Unfortunately I still cannot budge the cogs. I have applied some WD-40 in hopes it will loosen the threads. I really need a freewheel vise and a tool more rigid than the chain whip. I'll eventually figure out something.
In the mean time, I will disassemble, clean, and reassemble the innards of the other two. The cogs on those are perfect. In fact the freewheel mechanism works also smoothly as is, but I bought them to take apart, so apart they will be taken. I'll take some photos as I go.
|
|
|
|
Post by franco on May 31, 2020 20:44:20 GMT
Look forward to the updates Brian.
I watched a few videos a while back, looks very tricky, but worthwhile. It’s evident that the quality of steel used in the past is far superior to what the likes of Sunrace use now.
|
|
robt
Viscount
Posts: 558 
|
Post by robt on Jun 1, 2020 9:02:52 GMT
Brian,
While you’re inside the gubbins of the skiptooth freewheels, would you be able to count how many ball bearings are in each end/side? I stripped and re-built mine a few years ago, but wasn’t holding the necessary large bowl beneath it as I loosened the bearing cup. I think that I retrieved all the balls that fell out, but I’ve always had a nagging doubt about it, as it now makes a dry-sounding noise when it’s freewheeling, suggesting that one pair of bearing faces might be touching each other. I have a memory of about 36 ball bearings per side, but I’m reluctant to strip it again for fear of losing them.
I lubed it with an SAE90 marine gear lube, but any tips you may have on the right oil or grease to use would also be welcome.
Good luck!
|
|
|
|
Post by brianbutler on Jun 1, 2020 11:06:58 GMT
Brian, While you’re inside the gubbins of the skiptooth freewheels, would you be able to count how many ball bearings are in each end/side? I stripped and re-built mine a few years ago, but wasn’t holding the necessary large bowl beneath it as I loosened the bearing cup. I think that I retrieved all the balls that fell out, but I’ve always had a nagging doubt about it, as it now makes a dry-sounding noise when it’s freewheeling, suggesting that one pair of bearing faces might be touching each other. I have a memory of about 36 ball bearings per side, but I’m reluctant to strip it again for fear of losing them. I lubed it with an SAE90 marine gear lube, but any tips you may have on the right oil or grease to use would also be welcome. Good luck! I will try to count them. If the bearings are dry, the balls usually fall out (into a tray underneath ideally) before I can count them. If I support the left side I can probably get the lock ring off and count the right-hand balls, then let the whole thing fall apart and count the total.
I usually don't pay attention to the exact number of balls though, just adding balls until the race is "almost" full. I could be wrong and would appreciate advice if anyone knows more about this topic.
My guess on the noise you hear is dirt in the bearing or corrosion of the race or balls. Sometimes old races and balls just aren't perfectly smooth.
I have a modern Trek with ceramic wheel bearings. Once one of the balls disintegrated during a ride - talk about noise!
Brian
|
|
rodh
Viscount
Posts: 118
|
Post by rodh on Jun 1, 2020 18:45:47 GMT
RoT for an un-caged race is to fill it and then remove one. Seems to work OK for the parts found on a bike.
Last time I serviced my Shimano MF-Z015, I found 70 balls, 1/8" diameter (31 top, 39 btm).
Although they were the same size when new, I still keep the two sets separate if they're being re-used.
Make sure any shims you use are stacked with the thin ones between thicker ones so they don't wear through.
My preference is lithium grease on the BB, oil on the pawls, copper grease on threads; no trouble so far ...
HTH,
Rod
|
|
|
|
Post by brianbutler on Jun 2, 2020 17:43:18 GMT
Finished refurbishing one of the Shimano skip tooth freewheels. Here is a link to a photo album of the process:
Here are the steps I did to disassemble, clean, and rebuilt thjs freewheel. I recommend doing this over a tray to avoid losing ball bearings and small parts. Each step corresponds to a picture in the album:
1. Freewheel and tools - nail set, hammer. freewheel removal tool. 2. Freewheel removal tool mounted in vise. 3. Freewheel mounted on tool. 4. Loosen the left threaded lockring/bearing cone. Spin it out making sure bottom of freewheel body is supported to avoid losing bottom balls. 5. Remove cone, spacer(s), and balls. (32 balls on the top.) 6. Support bottom and turn freewheel over, pull out ratchet body, balls will probably fall out (47 balls on bottom coming out, 46 going in, one fell through a crack in the floor.)
7. Pawl retaining spring fits through groove in both pawls and into a groove in the body. Nice design. 8. Gently pull out spring and pawls. Note notch for correct placement of spring ends. 9. Soak parts in mineral spirits, brush and rinse. Clean and ready to reassemble. 10. Replace pawls and pawl retaining spring. Place a drop of 0W-20 synthetic oil on the pawl piviots. 11. Put a thin bead of grease on the bottom race. Pour balls into race with creased paper. They will stick to the race if there is enough grease (but don't use too much.) Finesse the pawl body past the bearings and into the freewheel body. Make sure no balls are dislodged. This took a couple of tries. This semi-tricky step is not shown in detail because I needed both hands for the parts.
12. Place a medium bead of grease on the upper race and pour in the balls. You can just pour them in then adjust their placement to fill out the race. Insert the spacer. 13. Apply another bead of grease to the lockring/cone. This area is somewhat sealed from the ratchet so more grease is probably OK. 14. Screw in the lockring (counterclockwise) and tighten with a pin spanner. I also gave it a tap with the nail set. Check for free spinning and quiet operation. 15. Note the oil port for the bottom race. Out of the three seemingly identical freewheels I received, only this one had this feature.
Have fun.
Brian
|
|
robt
Viscount
Posts: 558
|
Post by robt on Jun 2, 2020 18:10:57 GMT
Last time I serviced my Shimano MF-Z015, I found 70 balls, 1/8" diameter (31 top, 39 btm). Although they were the same size when new, I still keep the two sets separate if they're being re-used. Rod Ah. That might explain my dry scraping noise. When I did it, I think I ended up putting all the ball bearings into one bowl as I dismantled the freewheel, then putting half back into each side (35 each side from your numbers). This would leave the bearing faces supported unequally, never mind any differential wear effects from mixing the ball sets. Looks like I need to go shopping for a big bag of new 1/8” ball bearings. Thanks, Rod (and Brian). |
|
rodh
Viscount
Posts: 118
|
Post by rodh on Jun 2, 2020 23:57:51 GMT
tbh, I think the difference in ball wear will be minor unless you've suffered corrosion, or loss of case hardening on one side only. The noise is more likely to be some grit or rust, or just running dry.
If you have the same model MF as I have, you won't get more than 32 in the upper (outer) race, so you've probably not gone too far wrong.
Interesting point on the "oil hole", Brian. Unless that's fairly closely covered by the wheel hub, I think I'd cover that somehow (big washer made from stainless shim material?). That looks more like an opportunity for dirt to get in than a simplified way of doing maintenance ... but it's your call!
HTH,
Rod
|
|
