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quick tech question - RD switch out

jdd

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"any item you have has a finite life span" Ordinarily, that'd be a hook for me to start talking about vintage guitars, but I'll stifle that. (And many people would be surprised how old some airframes can be.)
 

kiwisimon

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Yes, and if you replace everything but a frame, you will likely spend more money than replacing it with a completely new bike. It isn’t impossible, but if you spend similar money for equipping your frame with new components as getting a new bike, why not go for the new bike and sell the old one? Plus, I would only consider stripping the bike to the frame and building it up from scratch if I would do it myself. If you ask a LBS to do it, that’d probably be another added expense.
I have never had to replace everything on a bike yet. I have replaced bikes in the past but my racing days are done and I gain nothing upgrading from perfectly usable parts.
And the chances that everything needs replacing at once is so small it isn't even a consideration.
the only reason I can see to upgrade to a newer model is go faster, the old one doesn't fit or your riding terrain has changed. Otherwise replacing parts as they wear out works pretty well. YMMV
 

microcord

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Apropos of replacing parts as they wear out (or for any other reason or for no reason at all), for those of us in/near Tokyo, there's a "flea-market" coming up on Saturday. Experience tells me that there'll be quite a lot of fairly new parts, as well as the photogenic old stuff.
 

OreoCookie

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@OreoCookie , I'm always puzzled by how common it is for people to make points about bikes by analogy with cars. […] I see little similarity between a 30-year-old bike and a 30-year-old (four-wheeled) BMW. The former is likely to have parts that are interchangeable with those of a great many other bikes of the same age.
The analogy is quite clear: you choose to ride an older (vintage) bike the same way you choose to drive an older car: it isn’t because it is cheaper, it is because you enjoy the feeling that it gives you. Perhaps you love to tinker. Perhaps you like to restore old things and you appreciate the beauty of cars/bikes of a certain era. You like to strip down a bike to the frame replace all bearings, replace some parts and put the bike back together.
But if you get the rear of your 30-year-old steel road frame "cold set" from 126 mm (if that's what it is) to 130 mm, you've got a frame that's pretty similar to a non-negligible minority of today's new frames, and one that will take a wide range of wheels, cranksets, seatposts and stems that are easily obtained new or old. And as for "downstream" (?) compatibility, my oldie has new "Grand Bois" rims laced to its half-century-old Zeus hubs, new Koolstop pads for its decades-old Mafac brakes, etc.
I’d make a distinction between two strategies: either you opt to put period-correct parts onto the bike, which means you are in the vintage category. Or you put modern parts on it and make a semi-retro build, in which case, your options narrow as standards change over time. My mountain bike was obsoleted by standards, and the same is happening for road bikes, albeit more slowly.

In either case, I’m just saying that going down this route is usually not the cheapest option and requires you to tinker with the bike yourself. Since cycling is a hobby, that’s totally cool 😎 But if you are short on money and/or don’t enjoy wrenching, getting a new or newer bike might be a better option.
 

OreoCookie

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And the chances that everything needs replacing at once is so small it isn't even a consideration.
I guess that depends on how often you use your bike. In my experience it does happen that all drivetrain wear items need replacing. That’s because worn chains like worn chainrings and worn cassettes — they all fit together nicely, precisely because they are worn. And then you replace e. g. the chain and nothing works properly anymore, because the new chain has a smaller pitch between the chain links, too small for the worn cogs.

Pricewise, when e. g. shifters and/or rear derailleurs are worn, things add up. E. g. my previous mountain bike had a 3x10 XT drivetrain. It needed a new RD, one new trigger shifter (for the RD), a new cassette, three new chainrings a new chain, two new disc rotors and a new saddle. (That’s ignoring the suspension.) Shimano doesn’t make 10-speed XT cassettes any longer, just SLX, fine. So I guess I would have been lucky that I had an SLX crank. If you do the math, the cost adds up rather quickly. It was not too far off from some drive train upgrade kits (= cassette, chain, rear derailleur, trigger, but no crank) you can buy online.

On the road side, Shimano doesn’t make things very easy either: you could think that the current 10-speed Tiagra components are perfect replacements, but Shimano is using the 11-speed pull ratios on the Tiagra components, which is incompatible with older 10-speed components.
 

OreoCookie

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"any item you have has a finite life span" Ordinarily, that'd be a hook for me to start talking about vintage guitars, but I'll stifle that. (And many people would be surprised how old some airframes can be.)
Airframes can be old, because they are subject to a meticulous maintenance regimen. Even then there are many cases where in most circumstances it makes no financial sense to keep them around, because the cost of necessary maintenance exceeds the value of the plane. (There are special circumstances like the US military keeping the B-52 around, because they have no new aircraft that can take its place. AFAIK even programs aimed at replacing the ancient engines by more modern ones were canned.)

I suppose things like vintage guitars are easier to keep in good shape. I don’t know much about instruments, but even those need to be cared for. (My wife’s violin needs to be serviced every few years. I am not sure what is being done to it, though.)
 

microcord

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That’s because worn chains like worn chainrings and worn cassettes — they all fit together nicely, precisely because they are worn. And then you replace e. g. the chain and nothing works properly anymore, because the new chain has a smaller pitch between the chain links, too small for the worn cogs.
I believe that this used to be true. But is it still true? Or perhaps I should ask: To the extent that this is still true, is it still an issue? Some time before the Covid pestilence interrupted supplies, I thought that it might be time to change the chain of my not-at-all-antique bike, and so asked about this at my LBS. Yes, good idea, he said. So, um, does that mean that I should also change chainwheels and cassette? I asked. No, these are fine, said he. (Even though he would have profited somewhat from selling me replacements.)

As for the old parts on my newly assembled bike, they're all more or less anachronistic (as they're all at least ten years younger than the frame). I bought the freewheel "new", though for all I know it could have slept in some warehouse for decades after manufacture. Judging by their ramps 'n' pins, the chainwheels really are new. And the chain is new as well.

On the road side, Shimano doesn’t make things very easy either: you could think that the current 10-speed Tiagra components are perfect replacements, but Shimano is using the 11-speed pull ratios on the Tiagra components, which is incompatible with older 10-speed components.
Yes. This doesn't make me happy.

Also, I learned (or misheard) the other day that there are two versions ("generations"?) of Di-2 and that if you want to change some component that's part of an earlier set, you have to pay an exorbitant price for it.
 

Cactaur

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Chains wear faster than chainrings and cassettes. I think it’s 5-7 chain changes before you need to think of replacing the others.

The whole system has sort of worn together, so when it’s finally time to change the chainring and cassette you should do all 3 otherwise won’t run as smooth as it should.
 

OreoCookie

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believe that this used to be true. But is it still true?
Yes, happened to me when I got a new-to-me mountain bike: I noticed the chain was worn, but forgot to check the chain ring. So I couldn’t ride after I had put on a new chain. This is 11-speed mountain bike stuff (XTR groupset, save for the XT cassette).

As Cactaur said, if you replace chains on schedule, chain rings and cassettes tend to last quite a while. However, they don’t last forever, and when they go in the end, they tend to go together. E. g. if your chain rings are worn, in my experience new chains tend to skip if you apply quite a bit of force to it. In the rear it is more of a sensation that “shifting never works right, no matter how long I play with the barrel adjusters”.
Also, I learned (or misheard) the other day that there are two versions ("generations"?) of Di-2 and that if you want to change some component that's part of an earlier set, you have to pay an exorbitant price for it.
Yes, with tiny exceptions: I think the 11-speed Di2 TT shifters might be compatible with 12-speed equipment, because it made no financial sense for Shimano to redesign them. In principle, with electronic shifting there is no reason why you can’t continue to use the same shifters for any number of speeds. Perhaps you’d need a firmware upgrade. But that’s not the game Shimano (and SRAM) are playing.
 

jdd

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Chains wear faster than chainrings and cassettes. I think it’s 5-7 chain changes before you need to think of replacing the others.
Philosophically (ethically, etc), I'd be real disappointed if I had to accept that everything on a bike wore out at once, and that disposing of it and buying a new one was somehow the next step to take.

Oh, and for my problem here, the solution on the ticket is a new cassette and chain. The master at the shop, Mori-san, had a look and he wasn't concerned at all about the RD (the now 16yr old RD). Also, cassette will be a 12-30 instead of 12-28, so I get a fractionally better bottom gear as a part of the deal. New wires/cables, and any attention the levers might need, too.
 

jdd

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What? You want closure...?!? ;)

New chain, cassette, DR pulley wheels, cables/casings. He said the rear shifter cable was funky inside the brifter, and so while it could have been only that, no need to wring hands over it.

It shifts fine now, the rear. The front is as it has always(?) been--mid and big rings get pretty much full range on the rear, but when on the small (teensy-tiny, its-bitsy) ring there's some noise/rubbing of the chain on the FD cage if trying to use the higher gears. By the time I go there I'm going for the lowest gears anyway.

Took a different bike today, some rain on the radar tho it was only some sprinkles now and then.


On my regular route to the bike path:
peaked dahlia.jpeg
 

kiwisimon

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that should be good for another decade.
DR pulleys, makes sense.
Sorry about your Ti cogset.
When I was at BS one of the guys got a Ti cluster sent from the states (27,000 yen) sure it was going to help him win some races. Maybe it did but he had to throw it away after less than one season. He was crying.
 

jdd

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I didn't think to ask for the cassette back, maybe after a cleanup I could've cast it in resin for a paperweight? Passed it on to my grandkids?

I can't remember what it cost, water under the bridge, as they say.
 

joewein

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On the road side, Shimano doesn’t make things very easy either: you could think that the current 10-speed Tiagra components are perfect replacements, but Shimano is using the 11-speed pull ratios on the Tiagra components, which is incompatible with older 10-speed components.
Correct, Tiagra 4700 rear derailleurs are compatible with 11-speed 105 5800, 105 R7000, Ultegra 6800 and R8000 but not with any other 10-speed group sets.

105 5700 rear derailleurs are compatible with any Shimano 10-speed road rear derailleur other than Tiagra 4700 as well as with any 9-speed rear derailleur (road or MTB, Shimano or SRAM).
 
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