Hello,

No matter how many old bikes I refurbish, getting their rear derailluers to shift smoothly going to larger cogs/easier gears is a crap shoot. Some are as smooth as butter and some are a fight on every shift and sound like metal to metal. I am aligning the hanger, lubing all the pivots on the RD and have a cleaned and lubed the chain and cleaned the freewheel. The b limit screw does not seem to solve the problem. And then they drop to the smaller cogs so easily and smoothly!

What might I be missing? Starting this post here and then moving over to Bicycle Mechanics if needed.

Thanks,
Gary

What derailleurs (brand and model) are you using? I've used virtually only SunTours since 1973 and haven't seen that issue if cables, housing were in good order and the pivots in good shape. Granted, I have tended to smaller FWs and have yet to go bigger than 28 teeth. Had a housemate with a SunTour RD'd bike and the Shimano FW with the huge jump to the enormous cog and it did the shift with little effort.

What shifters are you using? There's a relationship between the amount of cable a shifter can pull, the RD, and the max cog size.

Are you disassembling the RDs and cleaning them, or just adding oil to the joints? I have a few old RDs that need the pulleys to be torn apart and cleaned periodically to shift correctly every time.

Good video on working on the upper pivot:

Yes, I have the problem with the SunTour VGT, VGT lux etc derailleurs. Always new cables and housings. And it is not just getting to the last cog, it is noisy going up to any larger cog.

Sorry I wasn't clearer, these generally are straight rebuilds so the shifters and derailleurs are original and speced to go with the freewheel, and the problem is not just getting to the last cog, but generally noisy the whole way up the cog.

Yes, full disassemble, clean and lube on the pulleys and and the main spring pivot of the pulley cages if needed.

Are you concerned just about noise or are the derailleurs making complaining noises in lieu of shifting to the larger cog? No analog shift by hand is going to be as quick and accurate as an indexed shift with detents if you are comparing to that.

To describe the problem further, it often seems like you have to over shift considerable to get the chain to the next cog and then trim back to center the chain over the cog.

The noise is disconcerting but they do shift. Though they often require a big tug on the shifter and an over shift to get the chain up and then need to be trimmed back. And then smooth on the way down. And then other RD's buttery both up and down.

I'm going to suggest you include the freewheel and chain in your investigation. The tooth shape on the freewheel and formation of the side plates of the chain links can make a noticeable difference in how well the sprocket picks up the shift.

TBH, this could be exactly how it was intended to shift.
If you are used to modern chains and cassettes, you would expect it to be fairly easy to coax the chain onto a larger sprocket.

With a 1970's freewheel and bushed chain, things make some noise when shifting, and the chain doesn't just move effortlessly to the bigger cog. The noise is a feature, in the sense that it lets you know when the chain is in the right position.

I keep one bike equipped with a bushed chain, used with a Campy NR rear derailleur and a SunTour 13-24 five speed freewheel. It keeps me familiar with the characteristics of shifting with that technology.

On another bike, I use a SunTour Cyclone GT with a Shimano 7 speed hyperglide cassette with a SRAM 8 speed chain, and it shifts quite easily... too easily, in some cases, since it doesn't make any noise when the chain isn't centered on the cog. Sometimes it will shift by itself when I left the chain a bit too far to the left or right.

Maybe I need to make a short video of the shifting with the bushed chain?

Steve in Peoria

Good idea!

If the chain is not stretched, I usually will not replace. That said these are older chains and freewheels lacking ramps, pins and all that newer tech. A good test will be to swap out to new chain and test and then swap out to newer freewheel and test. Thanks.

What is a "bushed chain"?

While I expect a friction shifting bike to make some noise in the rear when the chain is not aligned on a cog, the noise I hear is much louder than just the chain misaligned. Sounds more like chain smacking the cage or similar.

If I make a movie, can it be uploaded?

This is my experience. I always rode mid-range, friction-shifting freewheel bikes until recently. When I ride a bike with a smoother system it's hard for me to remember not to overshift and then pull the lever back each time I shift to a bigger cog.

Definitely more than just a over shift. A loudish rackety rackety. In the sense that I would not buy the bike new if it was making that noise!

that is classic friction shifting strategy

I made a quick video of my International with the original Reynolds bushed chain, with Campy NR rear derailleur and SunTour 5 speed New Winner freewheel (if memory serves). This is linked to a file in my google folder.

For the sake of comparison, I also made a quick video of my Raleigh Team with a SRAM PC-48 eight speed bushingless chain (with Campy SR rear derailleur and SunTour New Winner 6 speed freewheel). As before, this is a link to a file in a google folder.

If these links don't do the job, I could upload to my youtube channel.. but let's see how this goes first.

I think it is clear that the shifting with the bushed chain is slower and noisier, but I'm certainly not an unbiased person.

Steve in Peoria

Sheldon Brown has a page that tries to explain the difference between a bushed and unbushed chain (i.e. bushingless).

The bushed chain has a sleeve that the roller rides on, while the bushingless chain has a small flange on the interior of each side plate that supports the roller. I think that the point of this is that this allows the chain to flex laterally more. Sheldon has a page that shows the small flanges on the side plates.

As far as noise... it might indeed be the chain smacking the cage..
Maybe the derailleur hangar is misaligned, or some other problem with the set-up?

Steve in Peoria

This, and everything else too. We really need to know not just the derailer and shifter, but what freewheel and chain you're running with the combos so far. Some of the 5-speed chains from back in the day combined with unrefined Atom freewheels (or Schwinn-licensed Shimano copies of Atoms) could be quite the noisy mess to shift.

Pictures would help too, for if there happens to be a recurring setup issue, it may be visible.

Question for the OP: Generally, in your experience, what combinations have you had that you've been pleased with? It'd help to give us a point of reference.

-Kurt

Thanks for the videos. I will post two tomorrow to try to illustrate what I am seeing and hearing.

all good points and questions. I am going to share two videos tomorrow or two bikes I am working on that show good and bad in my opinion. A basic mixtie with a very early Shimano 600 rd shifting smooth and quiet, and a Viscount with a Suntour VGT Lux clunking along.

In terms of good experiences, it seems once I get into early to mid eighties and forward they seem pretty good and smooth. Prior to that I have always found Simplex to shift nice, some Huerets have been surprisingly smooth. Perhaps Suntours have been a more problematic brand.

Doing my best to rid the clunk…

Found this on ****** and it seems relevant to the conversation, especially the last paragraph:

”With friction shifters, the less dead space in between gears, the better. With a bad derailleur that gives a large pulley gap, along with straight-cut cogs and flat-plated chains, there will be very slow, sloppy gear changes that involve lots of noise and over-shooting. It's actually very difficult to change gears in these situations.

By contrast, say you took those exact same friction shifters and hooked up a modern derailleur (even Claris, but up to Dura-Ace) matched with a modern chain and cogs - even 5 or 6 speeds. Every touch of the lever would result in an instant, exact change from cog to cog. It's astonishingly improved.

At the shop I worked at this summer, I always told people the most cost-effective upgrade they can do on a vintage bike is swap the freewheel and chain to modern equivalents. The shifting difference is remarkable.”

Being able to adjust the "chain gap", the distance from the upper (guide) pulley and the freewheel teeth is re4ally important when the freewheel isn't almost too big for the particular derailer.
The idea here is that you want the smallest gap possible without the pulley and cog teeth ever touching, so that the cage movement isn't so much used up by the chain simply angling over. Hence, modern (i.e. relatively super-flexible) chain can be very problematic with certain older derailers that don't closely follow the freewheel's outer profile.
The old Shimano rear derailers, as well as Simplex and some Huret derailers had springs at both the cage pivot and at the mounting bolt pivot, so the derailer body could swing forward and back to better track the outer profile of the freewheel.
Suntour rear derailers on the other hand often had a "B-tension screw" at the mounting bolt pivot which allowed manual adjustment of the derailer body angle (and of the chain gap), but which had an insufficient range of adjustment to closely follow the outer profile of smaller freewheels. I've often removed the B-tension screw entirely and even filed some metal from the "B"-screw's threaded lug in order to allow the derailer to swing forward further (and which swung the upper pulley closer to the cogs.

Older "bushed" chains were quite stiff laterally and didn't require the top pulley to be very close to the freewheel, but different brands of freewheels performed very differently while shifting due to the shape of their teeth.

So in addition to maxing out Suntour derailer's forward swing by removing the B-tension screw and filing metal off of the screw's lug, Shimano and other "dual sprung" derailers can typically be disassembled and with additional holes drilled for the end of one of the pivot springs in order to effect some adjustment of the derailer body angle.
Note that Simplex derailers often featured a locknut where the cage pivot shaft met the outer cage plate, allowing spring tension adjustment at the cage pivot in order to accommodate a wider range of freewheel sizes (size of the largest cog).
Shown below, this Simplex derailer has had it's cage pivot spring tension increased using said locknut with an Allen key to turn and hold the cage pivot shaft during adjustment while the locknut is slackened slightly and then re-secured. This allowed me to retain super-crisp shifting using the smaller 13-24T freewheel that I wanted to use.
You can see the super-close proximity of the top pulley to the freewheel teeth, giving super-responsive shifting even using a flexible, modern, 9s chain.




Lastly, clunky or recalcitrant shifting behavior can also be somewhat the result of things like metal-to-metal contact between the cable and any guide features or cable housings, and even can be due to a poorly- or non-lubricated shift lever pivot (I always disassemble and oil up friction lever's pivoting internals with plain motor oil, which lasts for quite a while as in years). I also affix plastic "spaghetti" tubing/liner material in any metal cable guide groove or tube, securing the liner using compression-fit or with a spot of adhesive (depending on the configuration of the cable guide and also depending on the diameter of plastic tubing I'm using). A fully plastic-lined cable path hugely improves shifting even on friction-shifted bikes!