Chain Length....
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Chain Length....
OK, I used the big chainring-largest cog +1", bypassing the DR to determine chain length. But this doesn't seem to look right- it's on the largest cog and 42T chainring (I'm running 45, 42, 30...). Should the DR be extending this far forward, or do I need to add a link or 2? (It is shifting fine, BTW...). Thx
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Will the bottom pulley swing forward another inch? If so, I'd say you dialed this in perfectly. Looks isn't the issue. You want the chain long enough to allow for a hiccup on the freewheel/cassette and not tear up the derailleur. (That torn up derailleur leads to all sorts of other bad consequences.) But a chain longer than that leads to sloppier shifting on the smaller cogs. Now, if this derailleur is at its limit for swing forward, add links!
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OK, I used the big chainring-largest cog +1", bypassing the DR to determine chain length. But this doesn't seem to look right- it's on the largest cog and 42T chainring (I'm running 45, 42, 30...). Should the DR be extending this far forward, or do I need to add a link or 2? (It is shifting fine, BTW...). Thx
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Will the bottom pulley swing forward another inch? If so, I'd say you dialed this in perfectly. Looks isn't the issue. You want the chain long enough to allow for a hiccup on the freewheel/cassette and not tear up the derailleur. (That torn up derailleur leads to all sorts of other bad consequences.) But a chain longer than that leads to sloppier shifting on the smaller cogs. Now, if this derailleur is at its limit for swing forward, add links!
If to your eyes, this doesn't look right, well good. A reminder this is a gear you do not want to be in.
If to your eyes, this doesn't look right, well good. A reminder this is a gear you do not want to be in.
You know what you've set up, just be cautious.
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We're it me I would make sure it was long enough for big-big but I am a forgetful old man who may choose the wrong gear. If you don't have that issue pedal on!
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+1 to that ^^^.
I ride often at night with steep hills all over Seattle. It’s easy to forget which ring I’m on when i can’t see it clearly, so I always adjust the chain for safe big-big shifts. There’s no penalty beyond a bit of noise for a slightly too long chain, but as @79pmooney said, there are BIG consequences for a chain that’s too short.
I ride often at night with steep hills all over Seattle. It’s easy to forget which ring I’m on when i can’t see it clearly, so I always adjust the chain for safe big-big shifts. There’s no penalty beyond a bit of noise for a slightly too long chain, but as @79pmooney said, there are BIG consequences for a chain that’s too short.
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Yeah, in the photo the front is on the 42t, and I do know that big-big is a no-no, though that doesn't mean at some point if I'm not paying attention it might not happen... But the RD does have an additional 1" of forward pivot from where it is in the photo. But I may just add another link to play it safe....
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Yeah, in the photo the front is on the 42t, and I do know that big-big is a no-no, though that doesn't mean at some point if I'm not paying attention it might not happen... But the RD does have an additional 1" of forward pivot from where it is in the photo. But I may just add another link to play it safe....
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FWIW
Ability to do big/big is hard requirement....learned that, but got lucky was going slow and was able to fall gently and not hurt me or drive train
I have grown to really like the small/small chain sizing method.... use it for vintage gear when i am pushing limits and for modern gear
Ability to do big/big is hard requirement....learned that, but got lucky was going slow and was able to fall gently and not hurt me or drive train
I have grown to really like the small/small chain sizing method.... use it for vintage gear when i am pushing limits and for modern gear
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I am with the others -- large-large cross-chaining should not lock anything up or bend chain, chainrings, or derailleur. I ran a 48-45-34 / 13-15-17-19-21-24 half-step-plus granny on the PKN-10, with a short cage SunTour Cyclone II rear derailleur, and I accepted a small amount of chain slack in small-small to protect myself in large-large.
Aside: I love half-step-plus-granny gearing, and your 3-tooth drop up front is great with the 2-tooth progression among your smaller cogs.
You are lucky your chain doesn't catch between the chainrings. I did lots of half-steps, 1/3-steps (50-47-44), and half-step-plus-grannies on older cranks, but as Sheldon Brown presciently cautioned me, I could not make a 53-50-39 work with a modern Campag. spider. I settled for a 50-42-39 half-step-plus-overdrive / 1.5-step-half-step, which actually worked out pretty decently.
Aside: I love half-step-plus-granny gearing, and your 3-tooth drop up front is great with the 2-tooth progression among your smaller cogs.
You are lucky your chain doesn't catch between the chainrings. I did lots of half-steps, 1/3-steps (50-47-44), and half-step-plus-grannies on older cranks, but as Sheldon Brown presciently cautioned me, I could not make a 53-50-39 work with a modern Campag. spider. I settled for a 50-42-39 half-step-plus-overdrive / 1.5-step-half-step, which actually worked out pretty decently.
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Yeah, the big-big problem with a too short chain is just too dangerous of a beast to mess with. I did it once...once! You're riding along, going up a hill, feeling like you need a lower gear, shift to a bigger cog without realizing you're in the big chainring, and WHAMMY! Your drive train just exploded -- chain into the spokes, probably cutting a few of them, bent hanger, and your derailleur has twisted itself into a pretzel. It doesn't even necessarily feel like you're forcing the shift -- it didn't for me -- the forces at work are just much more powerful than you'd imagine.
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Aside: I love half-step-plus-granny gearing, and your 3-tooth drop up front is great with the 2-tooth progression among your smaller cogs.
You are lucky your chain doesn't catch between the chainrings. I did lots of half-steps, 1/3-steps (50-47-44), and half-step-plus-grannies on older cranks, but as Sheldon Brown presciently cautioned me, I could not make a 53-50-39 work with a modern Campag. spider. I settled for a 50-42-39 half-step-plus-overdrive / 1.5-step-half-step, which actually worked out pretty decently.
You are lucky your chain doesn't catch between the chainrings. I did lots of half-steps, 1/3-steps (50-47-44), and half-step-plus-grannies on older cranks, but as Sheldon Brown presciently cautioned me, I could not make a 53-50-39 work with a modern Campag. spider. I settled for a 50-42-39 half-step-plus-overdrive / 1.5-step-half-step, which actually worked out pretty decently.
The FD shifting is taking a little getting used to. Going from the small ring to the middle I often end up over-shifting to the big ring, and a couple times I've had the chain come off shifting from the middle to the big. Seems like the limit screw has to be set just right so I've got enough trimming to stop rubbing when in big ring/smallest cog, but tight enough to keep it from coming off when making a fast shift from the middle to the big ring. Seems like it's only happened when I've shifted without a lot of load on the pedals.. The 45t ring was originally the inner ring, so it's lacking the little tab to prevent the chain from falling between the arm & the ring- thinking about drilling & tapping so I can put it on. And I just need to get better at finessing my shifting. The Criterium shifters need to be pretty well tightened down to keep from slipping and aren't exactly the lightest shifting. Looking forward to (eventual) Retrofriction levers....
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I always cut my chains to accommodate big-big. Failure to do this could lead to absolute destruction of the rear derailleur if someone, say a friend that I loaned my bike to, does not understand the ring to cog relationship.
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I have grown to really like the small/small chain sizing method.... use it for vintage gear when i am pushing limits and for modern gear
https://www.youtube.com/watch?v=QuhHn7HaZcQ
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OP's picture looks fine to me. Yes, it's unusual to see the tension pulley pointing forward, but if you are able to push the cage up further with your finger while it is in the big-big combination before it hits any stops or pulls tight, then you are good.
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What's the derailleur look like on small/small? if you can add another link and still have it under tension, I would do so.
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Suntour VX-S
I am with the others -- large-large cross-chaining should not lock anything up or bend chain, chainrings, or derailleur. I ran a 48-45-34 / 13-15-17-19-21-24 half-step-plus granny on the PKN-10, with a short cage SunTour Cyclone II rear derailleur, and I accepted a small amount of chain slack in small-small to protect myself in large-large.
Aside: I love half-step-plus-granny gearing, and your 3-tooth drop up front is great with the 2-tooth progression among your smaller cogs.
You are lucky your chain doesn't catch between the chainrings. I did lots of half-steps, 1/3-steps (50-47-44), and half-step-plus-grannies on older cranks, but as Sheldon Brown presciently cautioned me, I could not make a 53-50-39 work with a modern Campag. spider. I settled for a 50-42-39 half-step-plus-overdrive / 1.5-step-half-step, which actually worked out pretty decently.
Aside: I love half-step-plus-granny gearing, and your 3-tooth drop up front is great with the 2-tooth progression among your smaller cogs.
You are lucky your chain doesn't catch between the chainrings. I did lots of half-steps, 1/3-steps (50-47-44), and half-step-plus-grannies on older cranks, but as Sheldon Brown presciently cautioned me, I could not make a 53-50-39 work with a modern Campag. spider. I settled for a 50-42-39 half-step-plus-overdrive / 1.5-step-half-step, which actually worked out pretty decently.
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1" or 2 half-links is the rule I've always heard/used. It's enough.
OP's picture looks fine to me. Yes, it's unusual to see the tension pulley pointing forward, but if you are able to push the cage up further with your finger while it is in the big-big combination before it hits any stops or pulls tight, then you are good.
OP's picture looks fine to me. Yes, it's unusual to see the tension pulley pointing forward, but if you are able to push the cage up further with your finger while it is in the big-big combination before it hits any stops or pulls tight, then you are good.
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