Changing 1x 40 to 44
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Changing 1x 40 to 44
I'm thinking of changing my SRAM Force 1x 40T to 44T. Will I need to change the chain to a longer length? I can't find anything that references the diameter of the different chainrings. If the chain needs to be longer and idea of how many extra links?
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Think of chainring circumference in links, not chainring diameter. The chain engages only half your chainring, so the new chainring will want only two more links, the smallest unit you can normally add or remove.
Will you need to add links? Maybe not. Try pinching a couple of links together with the bike in bottom gear, to see if there is two links worth of slack available without stressing the derailler. As for the advisability of just adding a link pair, that will depend on the wear state of the current chain. Also, two "quick link" master links just a link apart may not be a good idea - others will advise I am sure, I have no data/experience on that.
Will you need to add links? Maybe not. Try pinching a couple of links together with the bike in bottom gear, to see if there is two links worth of slack available without stressing the derailler. As for the advisability of just adding a link pair, that will depend on the wear state of the current chain. Also, two "quick link" master links just a link apart may not be a good idea - others will advise I am sure, I have no data/experience on that.
#3
Depends how it was set up - if it's already as short as it will go then you'll need to add an inch i.e. one inner and one outer link, to compensate for the approximate two teeth more that the chain wraps around the chainring. To check, split the quick link and wrap the chain around the largest sprocket and the 40t chainring, not through the derailleur, so the ends overlap on the chainring - if it only overlaps 4 or 5 links you'll need to add a couple more. Rear suspension and you may need another couple more - it's important that the chain can easily shift to the largest sprocket without binding up, even in the tightest position of the swing arm.
#4
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Put it on the largest cog and see if you have an EXTRA inch of slack.
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Thank you for your thorough response. It's a gravel bike so I don't need to worry about rear suspension.
Even if I don't change the chainring, your explanation will come in handy anytime I replace a chain. It's a nice check rather than just match the old chain.
Thanks again. Mark
Even if I don't change the chainring, your explanation will come in handy anytime I replace a chain. It's a nice check rather than just match the old chain.
Thanks again. Mark
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I really like your description of "Think of chainring circumference in links, not chainring diameter."
I got around to looking at the bike and chain and I now think there isn't space to add a bigger chainring. The bike is an Cervelo Aspero and the chain stay bows out leaving very little of any space. (I can't post a picture due to not having made 10+ post)
Oh well.. But I did learn a lot from everyone's advice and comments.
I got around to looking at the bike and chain and I now think there isn't space to add a bigger chainring. The bike is an Cervelo Aspero and the chain stay bows out leaving very little of any space. (I can't post a picture due to not having made 10+ post)
Oh well.. But I did learn a lot from everyone's advice and comments.
#8
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I really like your description of "Think of chainring circumference in links, not chainring diameter."
I got around to looking at the bike and chain and I now think there isn't space to add a bigger chainring. The bike is an Cervelo Aspero and the chain stay bows out leaving very little of any space. (I can't post a picture due to not having made 10+ post)
Oh well.. But I did learn a lot from everyone's advice and comments.
I got around to looking at the bike and chain and I now think there isn't space to add a bigger chainring. The bike is an Cervelo Aspero and the chain stay bows out leaving very little of any space. (I can't post a picture due to not having made 10+ post)
Oh well.. But I did learn a lot from everyone's advice and comments.
Divide by PI and you have the diameter increase. Divide that by 2 and you have the radius increase.
Assuming you have an 11T smallest cog, can you actually spin a 40T ring?
#9
I really like your description of "Think of chainring circumference in links, not chainring diameter."
I got around to looking at the bike and chain and I now think there isn't space to add a bigger chainring. The bike is an Cervelo Aspero and the chain stay bows out leaving very little of any space. (I can't post a picture due to not having made 10+ post)
Oh well.. But I did learn a lot from everyone's advice and comments.
I got around to looking at the bike and chain and I now think there isn't space to add a bigger chainring. The bike is an Cervelo Aspero and the chain stay bows out leaving very little of any space. (I can't post a picture due to not having made 10+ post)
Oh well.. But I did learn a lot from everyone's advice and comments.
Also note that the above is not "maximum cog size", that is a different value and a function of how low the rear derailleur jockey pulley hangs below the cassette, and/or the "slope" of the derailleur pantograph linkage and how well that matches the slope of the cassette.
#10
Really Old Senior Member
Yes, thinking of only about 180 degrees of chain wrap around the chainring is completely accurate. Just realize that, in terms of the rear derailleur "maximum capacity", to make matters easier for mechanics, that rating is based on "whole" chainrings and cogs, not halves. So for example, my 50/34 crank (16 tooth difference) plus 11-30 cassette (19 tooth difference), total is 35 tooth difference, and requires a rear derailleur with a minimum of that capacity, if I use all gear combinations.
Also note that the above is not "maximum cog size", that is a different value and a function of how low the rear derailleur jockey pulley hangs below the cassette, and/or the "slope" of the derailleur pantograph linkage and how well that matches the slope of the cassette.
Also note that the above is not "maximum cog size", that is a different value and a function of how low the rear derailleur jockey pulley hangs below the cassette, and/or the "slope" of the derailleur pantograph linkage and how well that matches the slope of the cassette.
It would only be "completely accurate" if both sprockets are IDENTICAL in size.
The main question is where does your post show any connection to what the OP said?
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Well, that wasn't the OP's question, but that isn't really that big of a gear (smaller than the 52x13 back in the day). I can easily spin out a 42x11, and I'm not a spring chicken.
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#12
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"The bike is an Cervelo Aspero and the chain stay bows out leaving very little of any space."
I was showing how to tell how much larger the ring would be.
I don't give a rats if you can spin that big of a gear. I was asking the OP.
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I was referring to the OP's statement-
"The bike is an Cervelo Aspero and the chain stay bows out leaving very little of any space."
I was showing how to tell how much larger the ring would be.
I don't give a rats if you can spin that big of a gear. I was asking the OP.
"The bike is an Cervelo Aspero and the chain stay bows out leaving very little of any space."
I was showing how to tell how much larger the ring would be.
I don't give a rats if you can spin that big of a gear. I was asking the OP.
Wrong, but it's certainly close enough. Think of a bike with extremely short chain stays, very large ring & tiny cog. The large ring will have more than 180 and the tiny cog will have less.
It would only be "completely accurate" if both sprockets are IDENTICAL in size.
The main question is where does your post show any connection to what the OP said?
It would only be "completely accurate" if both sprockets are IDENTICAL in size.
The main question is where does your post show any connection to what the OP said?
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Cheers, Mike
-Stupid hurts....ride safe
Cheers, Mike
-Stupid hurts....ride safe
#14
Wrong, but it's certainly close enough. Think of a bike with extremely short chain stays, very large ring & tiny cog. The large ring will have more than 180 and the tiny cog will have less.
It would only be "completely accurate" if both sprockets are IDENTICAL in size.
The main question is where does your post show any connection to what the OP said?
It would only be "completely accurate" if both sprockets are IDENTICAL in size.
The main question is where does your post show any connection to what the OP said?
Last edited by Duragrouch; 05-13-24 at 03:58 AM.