Single (double) speed gearing

[gdillon]

I've been using 32 X 22 gearing for a while now.  Works really well for a 26 inch wheel; a little harder for a 29er.  Just seems like I need more, especially with a packed bike, so I'm thinking of switching systems from freewheel to freehub.  Action tec makes titanium cogs that fit onto freehub bodies, so I'm looking at a 25 and 21 tooth, paired with a 32 and 36 tooth chainring.  They say it will work well as long as I use a steel freehub body like one King offers or an XT.

Just wanted to know if there was anyone who has tried this method of titanium (or other metal) cogs on a steel freehub body for a singlespeed (no derailleur) option. My main concern is chewing up the splines after miles and miles of hard pedaling.

[Area54]

It will be fine with a steel or ti freehub body, I've never seen marks on one of these when used with a single, a dingle (double single) or loose sprocket cassette.

[gdillon]

Thanks.  A 22 X 17 gives the same gearing as a 32 X 25.  I'm going to try that out on a few rides before I drop the $$$.

[pro_out]

  I have been thinking of staying with a single cog on the back and running a Truvativ Hammerschmidt crank up front. The Hammer would give a wide range 22/36 or a 24/38 equivalent up front. It's heavy, pricey and could make rear cog selection even more difficult. Since my wife's bike is the only geared bike in the stable think I might (if she will let me) temporarily  replace her 32 with a 36 and see how the wide range jump works out. The climbing doesn't bother me, it's the spinning out that wears on me.

[chrisx]

Thanks.  A 22 X 17 gives the same gearing as a 32 X 25.  I'm going to try that out on a few rides before I drop the $$$.

I can not find a 22 tooth single chain ring for sale.  where do they come from?  I would like to have a 22 in the front, and a 9 speed in the back.  Problem is I cant figure out how to buy a 22 single crank set for a 1 by 9.

[gdillon]

Not a SS crankset.  I use a triple, where the standard 22 tooth just sits there in case something happens to the other chainring(s).  I have also used a fixed-position rear derailleur and treated my Karate Monkey as a 3 speed:  22 X 22, 32 X 22, and 44 X 22 (manually moving the chain, no shifters [commuting]); never used this configuration for mtbing, though. 

chrisx:

You could probably use a triple crankset in a 1 X 9 setup with a short enough chain.  However, I would worry about those lower gears-- lots of torque on very few teeth.  Might as well have 2 chainrings.  Check out action tec, they make a 39 tooth cog!  Not sure how difficult it would be to use, but a 32 X 39 is pretty close to a 22 X 32.

pro-out:

It's fun trying to take the simplicity out of singlespeed!  Spinning out is just one of those things... you can optimize a gear combo for the terrain you like to ride, but sometimes you have to ride some road, too.  For me, I'm just too dumb to shift, hence one gear at a time...  Hammerschmidt might be a good solution, though I don't know much about it.

[JReeves]

Just wanted to know if there was anyone who has tried this method of titanium (or other metal) cogs on a steel freehub body for a singlespeed (no derailleur) option. My main concern is chewing up the splines after miles and miles of hard pedaling.

A lot of single speed specific hubs are made with a similar style to freehub cassette hubs.  Meaning, that instead of a thread on cog or freewheel, they have a cog that has the standard shimano/sram 9 spline that slides onto the cassette, and utilizes spacers to get the chainline correct.  Both of my single speed wheelsets are like this.  I've never had a problem with the splines getting chewed up, but the cogs I use(Surly mostly) have pretty wide bases to avoid exactly that. 

[joeydurango]

Keep the difference in the number of teeth at 2 or 3, rather than 4 (i.e., 32/34 or 32/35, not 32/36).  When you run a four-tooth jump, there is a significant difference in chain tension between the two combos.  Even with the 36/21 set overly tight, the 32/25 will be looser than you'd like.

Same number of teeth per combo, yes, but the chain has to travel a slightly longer distance to get from a large ring to small cog than it does to get from a smaller ring to a larger cog.  Draw it out in diagram form and see what I mean - the increased angle from large ring to small cog as opposed to smaller ring/larger cog makes it so that the chain has to travel a very slightly longer distance.  Seems like it wouldn't matter but it truly does.  Two- or even three-tooth gaps are considerably better than four-tooth gaps in this regard.  Trust me, I've tried this.

Good luck!

[gdillon]

Joey-- thanks for the advice.  It will definitely influence how I set my bike up.  The 4 tooth jump is fine for a bolt on wheel and track ends with rim brakes, since you retension the chain every time and the placement of the brake pads on the rim can be a little variable; this is probably why I've never noticed the difference.  Now that you've mentioned this, it seems like a singlespeed with disk brakes should be just that:  one combination.

On another note, I've now done 3 rides using a 22 X 19 combo.  They've all been on mountainous terrain with few flat spots, some paved, some dirt roads, mostly singletrack, totaling around 50 miles.  With a frame bag containing 3 liters of water and layers, it has been a real treat.  Impractical for flat sections, for sure, and I walked the steepest pitches, but it felt great to spin up most grades.  The search goes on.

[joeydurango]

Whoops, guess I assumed that you were running Paragon dropouts or EBB.  Yep, no problem with track ends.

My favorite part about double single setups is that, if you're running Paragon or EBB systems, it's a 15-second gear change.  Release the QR, move the chain over, put the wheel back in, done.  Sweet!

[gdillon]

I think that I want Paragon sliders, because a disk brake doesn't sit well with me when using track ends. 

[bmike-vt]

Paragon or the Salsa Alternator... If I was to buy my Fargo again it would be an El Mar frame with Fargo or Enabler fork. Gears, IGH, SS, fixed.

[cousinmosquito]

When I was setting up for the  Single Speed worlds here in NZ last year this system worked very well (for training or commuting)
Two sprockets on the front: 34/32 and on the back, I cant recall, one was small, a 15 and the other an 18 or 19 I think. The difference at the rear wasn't an issue. I would ride to the race in the 34-15, slacken the rear "singluator" and swap the chain over to the 32 - 18 and re-tighten it. There was enough horizontal play in the rear roller to handle it with no jumping at all. All I needed was a good sized allen key. No enos or ebbs, just a standard (retro)  bike. I used standard sprockets, but dont know how the free-hub body would stand up with touring loads. Probably better than my knees : )

[cjellmoney]

Keep the difference in the number of teeth at 2 or 3, rather than 4 (i.e., 32/34 or 32/35, not 32/36).  When you run a four-tooth jump, there is a significant difference in chain tension between the two combos.  Even with the 36/21 set overly tight, the 32/25 will be looser than you'd like.

This can also marginally be addressed through cog selection. On your taller gear try and find a cog with deeper cut teeth...helps a tad with the tension variance.