Need help on how I can make this drivetrain acceptable
12-09-20, 03:40 PM
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Need help on how I can make this drivetrain acceptable
Brief story- I was walking my dog and ran across a “mountain bike” a neighbor had out for bulk trash pick up. Being in pandemic times and itching for a project I decide to take the bike home. Turns out, unfortunately, that Dynacraft is the maker of the frame (Walmart bike). The frame seems to be sturdy and decent quality (guessing this), the rest not so much. So I decide to build me a cool mountain bike with it by upgrading/changing components. I have never done this before but I’m a sharp guy so what’s the big deal?
So I decide that I don’t want the stock 3x6 18-speed setup but one of those cool looking 1x11 configurations I’ve been seeing and reading about (obviously not enough reading on my part).
I bought a drivetrain set that includes:
-SunRace 11 speed cassette 11-50T
-Box Two 11speed derailleur x-wide cage
-Box Two 11 speed twin shifter
-Box Two 11 speed chain
-the crank cog bought separate has 35 teeth
So I fiddled with the derailleur adjustments and hop on for a test ride. I knew to expect some chain grinding due to the width of the cassette being driven by one crank cog. I also heard from a bike shop guy recently, as I was finishing this build, that the 1x11 setup was not really intended for a 26” bike. The chain stay is too short. Yep, it’s a 26” bike.
So when attempting to be in one of the first four gears the chain immediately derails. Mid range gears are fine. And cannot get to that highest 50T gear (will try to further adjust the derailleur). What I now have is a six speed bike that is really slow.
I have questions. Can this even be made to work correctly? A longer crank axle? Some kind of chain that has more flex? So I’m a guy that didn’t research the mechanics involved in making this change but I’m kinda enjoying the learning aspect of getting in there and doing it.
Any suggestions will be very helpful. I’m hoping to not replace too much of what I’ve added if at all possible. (I posted a pic of the bike in the Gallery yesterday but wasn’t able to add it to this post due to being new to the site).
So I decide that I don’t want the stock 3x6 18-speed setup but one of those cool looking 1x11 configurations I’ve been seeing and reading about (obviously not enough reading on my part).
I bought a drivetrain set that includes:
-SunRace 11 speed cassette 11-50T
-Box Two 11speed derailleur x-wide cage
-Box Two 11 speed twin shifter
-Box Two 11 speed chain
-the crank cog bought separate has 35 teeth
So I fiddled with the derailleur adjustments and hop on for a test ride. I knew to expect some chain grinding due to the width of the cassette being driven by one crank cog. I also heard from a bike shop guy recently, as I was finishing this build, that the 1x11 setup was not really intended for a 26” bike. The chain stay is too short. Yep, it’s a 26” bike.
So when attempting to be in one of the first four gears the chain immediately derails. Mid range gears are fine. And cannot get to that highest 50T gear (will try to further adjust the derailleur). What I now have is a six speed bike that is really slow.
I have questions. Can this even be made to work correctly? A longer crank axle? Some kind of chain that has more flex? So I’m a guy that didn’t research the mechanics involved in making this change but I’m kinda enjoying the learning aspect of getting in there and doing it.
Any suggestions will be very helpful. I’m hoping to not replace too much of what I’ve added if at all possible. (I posted a pic of the bike in the Gallery yesterday but wasn’t able to add it to this post due to being new to the site).
Last edited by Yibbage; 12-09-20 at 03:52 PM.
12-09-20, 04:00 PM
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The chain will become more flexible as it breaks in, but it still might not work due to the short chainstays. Is the chain too short for the big cogs?
A smaller cassette (11-42) might work.
A smaller cassette (11-42) might work.
12-09-20, 05:13 PM
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Originally Posted by tyrion
The chain will become more flexible as it breaks in, but it still might not work due to the short chainstays. Is the chain too short for the big cogs?
A smaller cassette (11-42) might work.
A smaller cassette (11-42) might work.
12-09-20, 11:17 PM
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Box has good instructions how to set up their RD and size the chain. If you follow them it should work. In high gear with the suspension topped out it should have just a little tension and set the indexing, in low gear you adjust clearance from the cassette to the jockey with the b-screw. If you choose to size the chain in the big bottom gear like old style, you also need to have the suspension compressed.
The front ring is a question mark. 35 is an oddball. Narrow wide rings have even number of teeth. If it’s a single speed ring it needs to be for 3/32 chain. If I t’s part of a double or triple you need to get rid of it, they are made for shifting and chains don’t stay on without a derailleur or chain guide
The front ring is a question mark. 35 is an oddball. Narrow wide rings have even number of teeth. If it’s a single speed ring it needs to be for 3/32 chain. If I t’s part of a double or triple you need to get rid of it, they are made for shifting and chains don’t stay on without a derailleur or chain guide
Last edited by Darth Lefty; 12-09-20 at 11:22 PM.
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12-10-20, 08:06 AM
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Originally Posted by Darth Lefty
Box has good instructions how to set up their RD and size the chain. If you follow them it should work. In high gear with the suspension topped out it should have just a little tension and set the indexing, in low gear you adjust clearance from the cassette to the jockey with the b-screw. If you choose to size the chain in the big bottom gear like old style, you also need to have the suspension compressed.
The front ring is a question mark. 35 is an oddball. Narrow wide rings have even number of teeth. If it’s a single speed ring it needs to be for 3/32 chain. If I t’s part of a double or triple you need to get rid of it, they are made for shifting and chains don’t stay on without a derailleur or chain guide
The front ring is a question mark. 35 is an oddball. Narrow wide rings have even number of teeth. If it’s a single speed ring it needs to be for 3/32 chain. If I t’s part of a double or triple you need to get rid of it, they are made for shifting and chains don’t stay on without a derailleur or chain guide
One thing I do know the OP can probably ditch that bash guard its not gonna do much.
12-10-20, 09:30 AM
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Originally Posted by sloppy12
I am asking this because I don't know, but why would the suspension movement matter on this bike? it looks like the crank is on rear suspension triangle so wouldn't it stay the same during movement?
One thing I do know the OP can probably ditch that bash guard its not gonna do much.
One thing I do know the OP can probably ditch that bash guard its not gonna do much.
Another thing to consider is the chain line. If that crankset is from a single speed as appears, it may have a chain line further inboard than ideal for the cassette. Can be solved with a bottom bracket spindle the correct length.
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12-10-20, 05:28 PM
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Originally Posted by Darth Lefty
Box has good instructions how to set up their RD and size the chain. If you follow them it should work. In high gear with the suspension topped out it should have just a little tension and set the indexing, in low gear you adjust clearance from the cassette to the jockey with the b-screw. If you choose to size the chain in the big bottom gear like old style, you also need to have the suspension compressed.
The front ring is a question mark. 35 is an oddball. Narrow wide rings have even number of teeth. If it’s a single speed ring it needs to be for 3/32 chain. If I t’s part of a double or triple you need to get rid of it, they are made for shifting and chains don’t stay on without a derailleur or chain guide
The front ring is a question mark. 35 is an oddball. Narrow wide rings have even number of teeth. If it’s a single speed ring it needs to be for 3/32 chain. If I t’s part of a double or triple you need to get rid of it, they are made for shifting and chains don’t stay on without a derailleur or chain guide
Originally Posted by Darth Lefty
You are right, I did not look at the frame too closely.
Another thing to consider is the chain line. If that crankset is from a single speed as appears, it may have a chain line further inboard than ideal for the cassette. Can be solved with a bottom bracket spindle the correct length.
Another thing to consider is the chain line. If that crankset is from a single speed as appears, it may have a chain line further inboard than ideal for the cassette. Can be solved with a bottom bracket spindle the correct length.
12-14-20, 02:00 PM
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Originally Posted by DMC707
Wow! Just wow
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