Raise your hand if you love the simplicity and joy of riding a singlespeed mountain bike?! There’s nothing like the look of a stripped down bicycle with all of the extra cogs and derailleurs and cables removed. And there’s quite a few of us that love the added challenge that a mountain bike with only one gear can present.
We’ve got a lot of singlespeed fans and owners here at the shop, and our service department always gets a little excited when a customer rolls a singlespeed conversion project up to the counter. Almost any mountain bike can be made into a singlespeed, and one of the most popular starting points at Pine Mountain Sports is the Santa Cruz Chameleon. The Chameleon is super-versatile with the option of 29er or 27-plus wheels. The frame features swinging dropouts that give you the ability to fine tune chain stay length, and while that feature is mainly for geared use, there’s 15mm of adjustment there. It’s these adjustable rear dropouts that encourage Chameleon owners to easily convert from geared trail charger to singlespeed play bike and back. Santa Cruz does not offer a complete Chameleon with only one gear, but any new Chameleon can be ridden at the next Single Speed World Championships with a few easy steps…
Our Santa Cruz Chameleon converted to a single speed. In this photo it’s currently at 34T/20T.
The Santa Cruz Chameleon frame and complete bikes are offered in either aluminum or carbon, and both options feature singlepeed-friendly dropouts. In these photos we started with Henry’s Chameleon Carbon C with the SE build kit and 29-inch wheels. We removed the stock cassette, rear derailleur, shifter and shift cable. We’ll use the original narrow-wide front chainring and since this bike will become a dedicated SS, we went ahead and shortened the 12-speed chain.
The only new part you’ll need to buy is a singlespeed conversion kit for the SRAM XD-driver equipped rear wheel on the Chameleon. Our favorite is the Problem Solvers Zinger (Your shop can order it via QBP# HU0952). This $79 kit includes both an 18T and 20T cog, which works for most of us. Need another size? Problem Solvers also offers Zinger cogs in sizes 16, 17, 18, 19, 20, 21, 22T. These are proprietary so, for example, your Surly cogs won’t work with this bolt-on-style kit.
We opted to use the stock rear dropouts in order to keep this conversion easy and inexpensive…
Santa Cruz offers a Singlespeed Dropout Kit for the Chameleon, one for 27.5+ and one for 29er wheels. The difference between the Singlespeed Dropouts and the stock geared dropouts is that the rear hub spacing is changed from 148/Boost rear spacing to 142mm rear spacing. The switch to 142mm spacing with the SS dropouts would let you use some singlespeed-specific rear hubs. But that also requires a whole new singlespeed-specific rear wheel, which is not inexpensive. Fortunately, with the Problem Solvers Zinger kit, we can use our stock rear wheel and our existing dropouts!
The one other difference with the Santa Cruz Singlespeed Dropout Kit is that the drive-side dropout looks cleaner because it doesn’t have a derailleur hanger on it. We fixed that with a hacksaw and a file. More on that in a moment…
Our rear hub with the Problem Solvers Zinger kit installed. You can see where we’ve cut off the rear derailleur hanger and Sharpied it.
Step One: Remove the stock cassette, rear derailleur, shifter and shift cable. We’re done with those forever! Or until you decide that you miss having gears. If you think that you’ll likely return to having gears on this bike then we recommend saving your 12-speed chain for later and not shortening it for this singlespeed setup. The Chameleon makes it easy to go from SS to geared if you keep the existing chain (with a quick link), cassette, derailleur, and shifter (with cable and housing still attached) all together in a little bin. Label it with “SSWC” to make it easy to dig out once a year.
Step Two: Install the Zinger kit on your rear hub per the instructions. You’ll need to do a bit of eyeballing to arrange the spacers and rear cog for a near-perfect chainline. The Zinger kit includes two 1mm, two 2.5mm and two 5mm spacers. In our case we wound up with 7.5mm of spacers on the inside, and 9.5mm on the outside of the cog. Your results may vary.
Step Three: Get familiar with how to adjust your Chameleon rear dropouts. If your bike came with gears, you’ve probably never had to mess with the dropouts until now. Santa Cruz has a great Tech Video here that will show you everything you need to know. Make sure to watch it! Again, we opted to use our stock dropouts to save the expense of buying new ones and having to replace our rear wheel.
Step Four: You’ll need a chain. We didn’t plan on saving our stock 12-speed chain, so we shortened it. It’s been working fine with the front chainring and Zinger cog. You could also use any chain that’s made for 3/32″ cogs. If you decide to cut your original chain you’ll do that next…
Step Five: You’ve got everything you need to go ahead and adjust your chainline, your chain length, and your chain tension. Take your time, and pay careful attention to chain tension.
Step Six: These next steps are simply cosmetic items… One you have a fully functioning singlespeed, and have ridden it enough that you are ready to commit, you may want to cut off the rear derailleur hanger. Do you have to? Nope. But if you’re looking to make your single speed conversion clean (and permanent) it’s easy to trim off the derailleur hanger. Look closely and there’s a natural curve/line on the dropout which is a good cutting path to follow. We used a hacksaw to take off the most of it, and then used a file to smooth it out. A bit of touch-up black paint is totally pro, although we simply used a Sharpie (see pic). These dropouts are available individually, so you can always change your mind. Note that each of the Chameleon dropout options are specific to either 29er or 27.5+.
Step Seven: After removing the rear derailleur cable housing from the frame, we replaced the original cable stop with a blank port. On the left side of the top tube, near the head tube, you’ll see that the Santa Cruz Chameleon cable stops can be swapped out to cover the hole. If you’re lucky, you got one with your new Chameleon and didn’t throw it away. If you need another you can get one from Santa Cruz. Though it doesn’t look like it in the pic, this kit includes one blank port..
Step Eight: One of the many joys of riding a singlespeed is that chain slap is not a thing (after using the larger 34T ring). With that in mind we removed the rubber chainstay protector from our Chameleon frame. These are not glued on and are easily removed (and snapped back in place if you change your mind).
That’s it! An upside of going single is that we shaved some weight off of our Chameleon. Not a lot, according to the scale, but the end result is so much cleaner looking! And we’ve come away with a Chameleon trail bike that we think is even more unique and fun to ride. We’ve had lots of interest from Chameleon customers about removing the derailleurs from the bikes, and wanted to show that with the Zinger kit, it’s actually much simpler and less expensive than you might think. Happy singlespeeding!
Got questions about this blog post? Email Henry@PineMountainSports.com
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