Twist-tooth? Any help gratefully received!
#26
Junior Member
Thread Starter
Hi Moe Zhoost, good point about rolling on a piece of glass! I only notice the clicking once-per-revolution of the wheels, more noticeable in H-H, quieter as I change down on the RD. Present under pedaling, absent when not. Never on a bike stand. I observed the click rate under way by looking at the valve stem on the front wheel, which is black, fairly easy to get the rhythm of the click that way when pedaling at the same speed - although wifey reminded me how dangerous it was not to pay attention.
Of course, you made me look up the rhyming mnemonic in your signature. If you've never read Patrick O'Brian, you have a treat in store. I have one for you if you ever want to work out speed using the Doppler equation: "V less observer, over V less source, gives the ratio of frequencies, new to old of course."
Of course, you made me look up the rhyming mnemonic in your signature. If you've never read Patrick O'Brian, you have a treat in store. I have one for you if you ever want to work out speed using the Doppler equation: "V less observer, over V less source, gives the ratio of frequencies, new to old of course."
#27
Junior Member
Thread Starter
Hi CroMo Mike, I am impressed that a PO managed to replicate a tooth profile like that! I really hope I can get the freewheel to quieten down, new 1/8" balls are on order as part of a strip-down.
#28
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I'd post a picture but the freewheel is on a bike and pretty dirty right now, so the pic wouldn't show well. The teeth look exactly like those on the next to the smallest on the Shimano you posted. The amazing thing is that to do it correctly, he had to grind both sides of every tooth on every cog except he didn't modify the smallest cog. He must have had a lot of patience and skill.
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#29
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Of course, you made me look up the rhyming mnemonic in your signature. If you've never read Patrick O'Brian, you have a treat in store. I have one for you if you ever want to work out speed using the Doppler equation: "V less observer, over V less source, gives the ratio of frequencies, new to old of course."
Last edited by Moe Zhoost; 03-24-21 at 05:54 PM.
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#30
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Shimano Twist Tooth Uniglide Sprockets
The Original Subject was in reference to "Twist Tooth" freewheels. They were a Shimano design not Suntour.
Shimano introduce their Twist Tooth profile sprockets for freewheels and cassettes in the late 70's. They were marketed as their Uniglide style and were produced into the late 80's.
I'm still running Twist Tooth Uniglide freewheels and cassettes on a number of bikes and they shift very well. One advantage is when a sprocket wears out, it can be removed and reversed with like new teeth.
In 1985 Shimano brought out their Hyperglide (HG) sprocket design which was a game changer. They had ramps stamped into the sprockets which picked up the chain much faster when shifting to a larger size. These coincided with their SIS Indexing System.
Uniglide vs. Hyperglide teeth profile:
Getting back to the OP's ticking problem, I've had that happen to me on a number of bikes and it drove me crazy finding the cause.
One instance was with a NOS 13-28T Suntour New Winner FW. I checked everything, the hub, spokes, chain, cranks, BB and so on. There was some excess wobble in the free wheel so I removed several of the very thin shims under the outside lock ring and BINGO!
The way I found the problem was to switch freewheels and that's my FIRST suggestion. If the ticking goes away then you have your answer.
Most freewheels being produced today have sprockets with ramps in them for smoother shifting.
Sunrace freewheels seem to have a good reputation these days but they don't make a 6 speed with 13-28T sprockets, only 14-28T.
7 speed 13-28T Sunrace with Shimano Hyperglide style sprockets.
Also, some of the newer FWs are wider that the classic ones. Take some measurements before you chunk out any cash.
Good luck...
verktyg
Shimano introduce their Twist Tooth profile sprockets for freewheels and cassettes in the late 70's. They were marketed as their Uniglide style and were produced into the late 80's.
I'm still running Twist Tooth Uniglide freewheels and cassettes on a number of bikes and they shift very well. One advantage is when a sprocket wears out, it can be removed and reversed with like new teeth.
In 1985 Shimano brought out their Hyperglide (HG) sprocket design which was a game changer. They had ramps stamped into the sprockets which picked up the chain much faster when shifting to a larger size. These coincided with their SIS Indexing System.
Uniglide vs. Hyperglide teeth profile:
Getting back to the OP's ticking problem, I've had that happen to me on a number of bikes and it drove me crazy finding the cause.
One instance was with a NOS 13-28T Suntour New Winner FW. I checked everything, the hub, spokes, chain, cranks, BB and so on. There was some excess wobble in the free wheel so I removed several of the very thin shims under the outside lock ring and BINGO!
The way I found the problem was to switch freewheels and that's my FIRST suggestion. If the ticking goes away then you have your answer.
Most freewheels being produced today have sprockets with ramps in them for smoother shifting.
Sunrace freewheels seem to have a good reputation these days but they don't make a 6 speed with 13-28T sprockets, only 14-28T.
7 speed 13-28T Sunrace with Shimano Hyperglide style sprockets.
Also, some of the newer FWs are wider that the classic ones. Take some measurements before you chunk out any cash.
Good luck...
verktyg
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Don't believe everything you think! History is written by those who weren't there....
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Don't believe everything you think! History is written by those who weren't there....
Chas. ;-)
#31
Junior Member
Thread Starter
Hi Vertkyg, thank you so much for adding to what I am learning here. The more I know, the more I am reminded how little I know! Removing the shims under the lockring sounds an excellent idea, and I will try that if there are any to remove. It's a pity they weren't made adjustable like a BB.
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#32
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...Getting back to the OP's ticking problem, I've had that happen to me on a number of bikes and it drove me crazy finding the cause.
One instance was with a NOS 13-28T Suntour New Winner FW. I checked everything, the hub, spokes, chain, cranks, BB and so on. There was some excess wobble in the free wheel so I removed several of the very thin shims under the outside lock ring and BINGO!
...Good luck...
verktyg
One instance was with a NOS 13-28T Suntour New Winner FW. I checked everything, the hub, spokes, chain, cranks, BB and so on. There was some excess wobble in the free wheel so I removed several of the very thin shims under the outside lock ring and BINGO!
...Good luck...
verktyg
Time to head to your PCP for a cognitive assessment. Your memory is slipping! Which we on C&V need you to maintain as long as possible!
Just to clarify--- Suntour New Winner freewheel does not utilize thin shims as spacers. It has an adjustable outer bearing race with a threaded locking system (which IMO is a real PIA). Suntour Winner and Winner Pro and basically every other brand and model of freewheel uses spacer shims for bearing adjustment.
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Bob
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Bob
Enjoying the GA coast all year long!
Thanks for visiting my website: www.freewheelspa.com