Optimal Chainlength - It's A New Day

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kytyree
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by kytyree

DaveS wrote:
Tue Apr 27, 2021 1:53 pm
With SRAM, the B screw is adjusted in the little ring and largest sprocket. Don't know about shimano.
https://si.shimano.com/api/publish/stor ... 01-ENG.pdf page 100/174

That's what Shimano show's here, I don't know if it's listed differently elsewhere for them but I don't know how you could set it without being in the largest sprocket to check clearance.

If you look at that same manual, a few pages prior I believe, it uses the verbage of 4 or 6 links added, but in other places Shimano does use the verbage 1 to 3 links, I assume that it's an issue with translation, and in any case I think their manuals are a tough read when it comes to chain length. The first link is the GRX Di2 Manual and the second Ultegra.

https://si.shimano.com/api/publish/stor ... 04-ENG.pdf page 134/169

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RDY
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by RDY

So is this method now gospel for Shimano 11 speed 105 / DA / Ultegra derailleurs?

Anything further to bear in mind if I'm doing it with an XTR 12s chain and Rotor Q Rings?

Karvalo
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by Karvalo

RDY wrote:
Thu Jun 17, 2021 9:02 pm
So is this method now gospel for Shimano 11 speed 105 / DA / Ultegra derailleurs?
Current 11 speed. R9100/8000/7000

Roadbiker10
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by Roadbiker10

Can I have a chain sized for a 10-30 cassette and use it for 10-28 as well? I mean it will be mostly used with 10-28 but the 10-30 will be on a second wheelpair. And will there be any disadvantages in efficiency when used with the smaller cassette? This is for Sram AXS.
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TobinHatesYou
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by TobinHatesYou

Roadbiker10 wrote:
Sun Jan 23, 2022 9:42 am
Can I have a chain sized for a 10-30 cassette and use it for 10-28 as well? I mean it will be mostly used with 10-28 but the 10-30 will be on a second wheelpair. And will there be any disadvantages in efficiency when used with the smaller cassette? This is for Sram AXS.

It will be fine.

Roadbiker10
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by Roadbiker10

TobinHatesYou wrote:
Sun Jan 23, 2022 10:14 am
Roadbiker10 wrote:
Sun Jan 23, 2022 9:42 am
Can I have a chain sized for a 10-30 cassette and use it for 10-28 as well? I mean it will be mostly used with 10-28 but the 10-30 will be on a second wheelpair. And will there be any disadvantages in efficiency when used with the smaller cassette? This is for Sram AXS.

It will be fine.
Ok great, thanks.
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Roadbiker10
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by Roadbiker10

I decided to try and size the chain myself. I just got a Pro 12s breaker. So it says to wrap around big chainring and big on the cassette. Then to add one inner and one outer link. If I am doing the sizing with a 10-28. How many more links do I need for it to work with a 10-30? I don't have the 10-30 cassette right now so I can't size it with that.
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MagicShite
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by MagicShite

Roadbiker10 wrote:
Wed Jan 26, 2022 3:47 pm
I decided to try and size the chain myself. I just got a Pro 12s breaker. So it says to wrap around big chainring and big on the cassette. Then to add one inner and one outer link. If I am doing the sizing with a 10-28. How many more links do I need for it to work with a 10-30? I don't have the 10-30 cassette right now so I can't size it with that.
Which manual is this?

The manual states +1 or +2/+3 depending on where the chain overlaps. This of course applies for R7000/8000/9100 series 11 speed.

Roadbiker10
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by Roadbiker10

MagicShite wrote:
Wed Jan 26, 2022 4:16 pm
Roadbiker10 wrote:
Wed Jan 26, 2022 3:47 pm
I decided to try and size the chain myself. I just got a Pro 12s breaker. So it says to wrap around big chainring and big on the cassette. Then to add one inner and one outer link. If I am doing the sizing with a 10-28. How many more links do I need for it to work with a 10-30? I don't have the 10-30 cassette right now so I can't size it with that.
Which manual is this?

The manual states +1 or +2/+3 depending on where the chain overlaps. This of course applies for R7000/8000/9100 series 11 speed.
Sorry, I might have not mentioned that it's Sram Axs I'm talking about.
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OlieSimpson
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Joined: Sat May 01, 2021 7:20 pm

by OlieSimpson

Might be a silly question however I just bought a new Shimano Ultegra (HG701-11) chain and I was wondering if there is a specific way it should be mounted as the document isn't clear. Should the side of the chain with the writing face the inside, closest to the frame, or face outwards?

tjvirden
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by tjvirden

Writing outside. If you're using the Shimano quicklink, then make sure the arrows point in the direction of movement of the chain.

OlieSimpson
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by OlieSimpson

tjvirden wrote:
Wed Jan 26, 2022 5:56 pm
Writing outside. If you're using the Shimano quicklink, then make sure the arrows point in the direction of movement of the chain.
Perfect, thanks!

Roadbiker10
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by Roadbiker10

I ended up taking out 1 inner and 1 outer from original 10-33.

So you're suppose to leave 1 inner and 1 outer longer where the chain meets. I ended up with 2 inners and 1,5 outers, as shown on the picture. The links ended up in the middle where they overlaped, so as I understand, that was the shortest I could leave. But I'm not sure if it will be long enough for 10-30z
A72B859B-DE4B-4E12-BF14-2E67419518AC.jpeg
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TheDoctor
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by TheDoctor

Comparing your photo to the SRAM manual shows that you now have 2 links above the ideal extra lenth:
Image

One tooth on the cassette is 1 link. So if you size it now on a 28t sprocket you would need 2 links extra to account for a 30 which I believe you are aiming for? Conversely, going from correctly sized chain on a 33t sprocket to a 30t, you'd need to take out 2 (3 is not possible as you'll always change links with even numbers - inner plus outer). Which is what you did. In other words, I don't see why this would be too short?

My advice by the way would be to determine the link where the chain ends meet, and determine the extra links, on the outer ring. Keep the end of the chain that goes up over the ring at ~4 or 5 o'clock and make sure that the other end coming from the cassette rests in the outer ring teeth. When trying to pinpoint this length between the outer ring and the cassette you'll be off unless you can keep the chain in a perfectly straight line.
Park Tool's blog shows what I mean:
https://www.parktool.com/blog/repair-he ... gth-sizing

Roadbiker10
Posts: 495
Joined: Fri Apr 30, 2021 8:22 am

by Roadbiker10

TheDoctor wrote:
Wed Jan 26, 2022 9:45 pm
Comparing your photo to the SRAM manual shows that you now have 2 links above the ideal extra lenth:
Image

One tooth on the cassette is 1 link. So if you size it now on a 28t sprocket you would need 2 links extra to account for a 30 which I believe you are aiming for? Conversely, going from correctly sized chain on a 33t sprocket to a 30t, you'd need to take out 2 (3 is not possible as you'll always change links with even numbers - inner plus outer). Which is what you did. In other words, I don't see why this would be too short?

My advice by the way would be to determine the link where the chain ends meet, and determine the extra links, on the outer ring. Keep the end of the chain that goes up over the ring at ~4 or 5 o'clock and make sure that the other end coming from the cassette rests in the outer ring teeth. When trying to pinpoint this length between the outer ring and the cassette you'll be off unless you can keep the chain in a perfectly straight line.
Park Tool's blog shows what I mean:
https://www.parktool.com/blog/repair-he ... gth-sizing
So I accidentally managed to do it right then, excellent.
For once I didn't screw something up, which I was trying to fix.🙂

Alright, I understand what you mean after watching that video. Now I know for next time. I did it as shown in the Sram picture, but it was hard to get them straight, with no slack. I did only remove 1 inner and 1 outer as you point out, and the chain had have been sized right from the factory for 10-33, which the bike came with.

Does having a chain which is two links longer for the cassette have any impact on efficency at all? I am not sure when or even if I'll be using another set of wheels with a 10-30. And if I do, it will be used much less then the 10-28. But I just wanted to leave that option available.
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