Restrictions on using a single Chainring
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Restrictions on using a single Chainring
I am looking at building up a new bike. I commute, and would like a second bike, setup similarly to my current commuter, so that when I have a repair or maintenence issue, it is not a late night emergency. I have even toyed with the thought of making some components, like wheels, identical so that I can steal from one for the other.
The current bike is built on a touring frame - I like the long (44cm) chainstays since I haul a lot of stuff to/from work and appreciate the heel clearance, a bit longer still would be nice.
My current bike has a 9 speed Shimano hub, with a 12-26 cassette, and a triple (Campy) up front - 30, 40, 50. I use all nine of my rear sprockets, but never move from the middle ring up front. For the next bike I was thinking of using a 9 speed rear cluster, and a single ring up front. Another possibility is to go with an internally geared rear hub, but I am not yet 100% sold on that.
Looking at frames with long chainstays, I came across the Rivendell Atlantis, but they warn about how the frame must be built up with a mountain triple crank - that there isn't clearance for a double, which opened a whole new realm of worry for me.
therefore three questions:
1) When shopping for a frame and Crank - what do I look for to make sure that they are compatible?
2) Are the desires for fatish tires (I like Schwalbe Marathon Plus's), Fenders, long chainstays, and a single crank mutually exclusive, short of going to a full custom frame?
3) I assume that for the shifting to work right with a single ring up front, and 9 speeds in the back, I need to have the chainring properly positioned laterally (probably near the middle of the cluster) - how do I make this adjustment?
The current bike is built on a touring frame - I like the long (44cm) chainstays since I haul a lot of stuff to/from work and appreciate the heel clearance, a bit longer still would be nice.
My current bike has a 9 speed Shimano hub, with a 12-26 cassette, and a triple (Campy) up front - 30, 40, 50. I use all nine of my rear sprockets, but never move from the middle ring up front. For the next bike I was thinking of using a 9 speed rear cluster, and a single ring up front. Another possibility is to go with an internally geared rear hub, but I am not yet 100% sold on that.
Looking at frames with long chainstays, I came across the Rivendell Atlantis, but they warn about how the frame must be built up with a mountain triple crank - that there isn't clearance for a double, which opened a whole new realm of worry for me.
therefore three questions:
1) When shopping for a frame and Crank - what do I look for to make sure that they are compatible?
2) Are the desires for fatish tires (I like Schwalbe Marathon Plus's), Fenders, long chainstays, and a single crank mutually exclusive, short of going to a full custom frame?
3) I assume that for the shifting to work right with a single ring up front, and 9 speeds in the back, I need to have the chainring properly positioned laterally (probably near the middle of the cluster) - how do I make this adjustment?
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On my road bike, it had a triple, but as I remembered never using my front derailleur on my mountain bike, I took it off and two rings with it. Some things to consider is that the probability of your chain coming off is greater if you don't have a front derailleur for obvious reasons. So make sure you have the right length chain (1" longer than your big-big combination), and consider getting a single speed chainring, like a Salsa, or a BMX because they don't have ramps or pins (which aid in shifting) making it more secure. As for mounting it for straightness, if you get a crankset with a triple spider you get plenty of options, usually it works best if you mount it where the middle chainring was.
Maybe this helps?
Maybe this helps?
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Originally Posted by Boss Moniker
On my road bike, it had a triple, .....
. As for mounting it for straightness, if you get a crankset with a triple spider you get plenty of options, usually it works best if you mount it where the middle chainring was.
Maybe this helps?
. As for mounting it for straightness, if you get a crankset with a triple spider you get plenty of options, usually it works best if you mount it where the middle chainring was.
Maybe this helps?
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Single front chain ring with no chance of chain sling = Wetzikon rings! I love mine!
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Originally Posted by sauerwald
Thanks Boss- using a triple crank and only using the middle ring would be an option, although without an Fder, I would worry about losing the chain more easily than with a crank designed as a single.
also, if you are looking at MTB frames keep in mind that some of the newer frames are built with a 34-tooth middle ring in mind.
at least that's the case with my pisgah so i use a 36 that's been spaced out 2mm.
my bike shifts great all the way across the cassette.
this is my only bike and i love it.
ed rader
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Originally Posted by FarHorizon
Single front chain ring with no chance of chain sling = Wetzikon rings! I love mine!
thanks
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Originally Posted by squirtdad
Ok...I'll bite......what are wetzikon rings.........??? thanks
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I just build up a geared rear wheel to put on my single speed Crosscheck so I could have a couple gears. I did it with really cheap stuff from Nashbar, as well as some stuff I had in the junk box. At first I was using the same 48 tooth FSA road chainring as on the SS drivetrain, but I had some chain drop issues when shifting to the highest gear. This hadn't been a problem when single speeding, but then the chain wasn't being yanked from side to side then. I think it was a combination of hitting the ramped sections of the chainring at the wrong time, as well as not having any kind of guide or chainring guard outboard. So here's what I ended up doing.
I mounted a 42 tooth Salsa single speed chainring on the inside of my road crank and a Spot chainring guard on the outside. Had those in the parts box.
I bought a rear wheel built on a Deore hub from REI for $55.
I put an 8 speed cassette ($20 from Nashbar) on the 135mm wide MTB hub in the rear, because 8 speed chains ($13, also Nashbar) do better on single speed specific chainrings. I don't even know if a narrower 9 speed chain would work. I do have an old REI bike with a 1x9 drive train, so it's possible, but I digress.
At first I fitted an ancient friction thumbshifter on the bar. But it would only pull enough cable to shift 7 gears, so I broke down and bought a Sram 3.0 8 speed twist shifter (the cheapest they offer, $16 at an LBS). Once I actually went indexted, I had to run the derailleur cable in the stops on the frame, as opposed to running the whole way in a looong cable housing so I could just ziptie it to the frame for quick mounting.
And finally, I seem to have gotten lucky with the bottom bracket that was on the bike. It's an FSA ISIS with a 108mm length spindle. I was thinking that I might have to fit a wider one, say, 113mm wide, because of the MTB hub in back - especially running the chainring in the inboard position on the crank. But the chain line looks good and I've had no problems with it coming off. It is a bit crunchy in the lowest and highest gears, but the chain is running a quite an angle in either of those. But neither do I spend a whole lotta time in those. Gears 2 thru 7 are very smooth baby!
Finally, I've gone the internally geared hub route. And frankly, I like this better. At first I could feel the extra weight in the rear - compared to the single speed - but not as much as a Sram 7 speed hub I tried before.
I guess I better go. Good luck. DanO
I mounted a 42 tooth Salsa single speed chainring on the inside of my road crank and a Spot chainring guard on the outside. Had those in the parts box.
I bought a rear wheel built on a Deore hub from REI for $55.
I put an 8 speed cassette ($20 from Nashbar) on the 135mm wide MTB hub in the rear, because 8 speed chains ($13, also Nashbar) do better on single speed specific chainrings. I don't even know if a narrower 9 speed chain would work. I do have an old REI bike with a 1x9 drive train, so it's possible, but I digress.
At first I fitted an ancient friction thumbshifter on the bar. But it would only pull enough cable to shift 7 gears, so I broke down and bought a Sram 3.0 8 speed twist shifter (the cheapest they offer, $16 at an LBS). Once I actually went indexted, I had to run the derailleur cable in the stops on the frame, as opposed to running the whole way in a looong cable housing so I could just ziptie it to the frame for quick mounting.
And finally, I seem to have gotten lucky with the bottom bracket that was on the bike. It's an FSA ISIS with a 108mm length spindle. I was thinking that I might have to fit a wider one, say, 113mm wide, because of the MTB hub in back - especially running the chainring in the inboard position on the crank. But the chain line looks good and I've had no problems with it coming off. It is a bit crunchy in the lowest and highest gears, but the chain is running a quite an angle in either of those. But neither do I spend a whole lotta time in those. Gears 2 thru 7 are very smooth baby!
Finally, I've gone the internally geared hub route. And frankly, I like this better. At first I could feel the extra weight in the rear - compared to the single speed - but not as much as a Sram 7 speed hub I tried before.
I guess I better go. Good luck. DanO
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I would think that the only thing that would arise from using a double on a frame designed for a triple, like the riv, would be a less than optimum chainline. But since your ring would essentially be in the position of a middle ring anyway, I wouldn't see a problem. If all else fails, you could try to find a small ring and smaller freewheel to get the clearance. That was what I had to do on a single speed I built. I couldn't fit the 46t ring I wanted, so I went with a 42 and got a smaller rear cog to get the same ratio.
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