This article will not discuss whats the fuss about 1X11 (or 1X10) or what’s the justification why one should shift to this gearing. There are already a lot of articles about that in the internet. Shimano just released their new XTR with a 1 X 11 option this 2015 and it is expected that the rest of the models will follow suit in the coming years. What I will focus on is how to go about converting your existing 3X10 or 2X10 to a 1X10 set-up (yes 10 speed cassette is the minimum requirement but of course you can convert even a 9 or 8 speed but that would defeat the purpose of still having the useful gear combos) in the Philippine setting (local store recommendations).
The key point in the conversion is having the smallest cog- 11-tooth and changing the biggest cog from 36-tooth to 40-41-tooth. This is to cover the granny gear combo that you will be removing with the introduction of only 1 bigger chain wheel. But while your “uphill gears” can be covered by a 30 chain wheel and 41 cassette cog gear combo, the “flats gear” (30-11) will be an issue which is the reason why the natural 1X11 has a 10-tooth cog as the smallest.
As mentioned- this is about conversion of an existing 10 speed set-up; if you are to buy new components, then I recommend that you just out-rightly purchase the 1X11 group-set- that’s pretty obvious. The difference between the actual 1 x 11 to a converted 1×10 is not only the extra gear (11th speed) but having the smallest cog with 10 tooth as previously mentioned. A converted system would start with the 11 tooth cog and while you will find out later that you have an option to change any cog (i.e. the 15 to a 16 tooth cog), this is not feasible to do with the 11 tooth to a 10 tooth cog as it would require the next gear/s to be upgraded as well (the first two gears in a cassette should be one gear step-up only to ensure smooth shifting) thus there is no manufacturer who ventured into this path as conversion will not be economically feasible anymore. But note that there are already options to buy a complete 10 speed cassette designed for 1×10 set-up by third party manufacturers as they found there is a market for such product. Its advantage would be a better gear spacing that starts with a 10 teeth cog. We just hope Shimano itself would sell such cassette for existing system who don’t have the money yet to go to the 11 speed set-up.
So here is how to go about the process:
Step 1- Crank set from a 3 or 2 chain rings to 1. In a 3 chain ring crank set, the recommendation is to use the mid chain so that the chain is centered from the rear derailleur. Of course using the other two options would also work but it will introduce cross-chain. For a two speed crank set, you can use either of the two but in most cases, the lower one is used especially if you will be installing a bash guard on the outer chain ring. Now what is the ideal chain ring size? Based on computation- it should be between 28-32, with 30 the safest. Of course it will also depends on the usual terrain you are riding- 32 or even higher if you usually ride on flats and 28-30 for trails with mountain climbs. One option is to have both and interchange depending on where you are riding- yes it defeats the purpose (in fact in such cases- on frequent changes on extreme ends of types of riding I think a 2X10 or 2X11 would still be the best) but if those changes doesn’t happen that often, then the benefits of having 1 chain ring and changing it once in a while is still worth the conversion. Before you buy the chain ring, you need to note the BCD measurement of your chain ring. Most big local buy shops sells chain rings but better to call first so as not to waste time. If you have a Truvativ or SRAM product- Lifecycle is a good start. Grantrail is the local distributor of Wolf tooth- a popular chain ring manufacturer. If you will replace the entire crank set with a true 1X type; currently you can only buy SRAM or Truvativ as Shimano only released their 1X model this 2015 and is not yet available in the local market as of writing. But don’t worry, the SRAM and Truvativ crank sets works with the Shimano rear components. Can you use the existing chain wheel? Yes but it has lower tooth profile which may cause chains to drop. The chain wheel recommended for conversion are really designed for single setups with high tooth profile.
STEP 2- Acquire the 40 or 42 tooth rear cog. This is the critical component of a 1X system. You increased the number of teeth of your 1 remaining chain wheel from a smaller mid or lower chain ring (usually 26-28) to ensure you can catch up on flats but you need a bigger rear cog to ensure that this increase will not be a problem in climbing steep slopes. This is the hard part on the conversion as this 40-42 rear cog usually cost a lot- 100$ or 4,000 Php up. Currently, you can only buy this from Paulinas (Torqq) and Gran Trail (Wolf Tooth). You can buy it cheaper from Ebay but only if you can get one lower than 50$, Anything higher plus its shipping cost would not be practical- just buy it locally if available.
Then you will need to remove the 17 tooth cog to accommodate the new 42 tooth cog.
Step 3- Replace the 15 tooth cog with 16 tooth. The process of converting by installing the 40-42 tooth cog requires removal of the 17 tooth cog to accommodate the addition of the big cog. But this creates a big jump from 15 to 19 (sequence 13-15-19 with odd numbers in between). So replacing the 15 with a 16 would even out the spacing (13-16-19). You actually don’t need to change this as it will still work but I tell you the feeling is weird with the big jump and sometimes it affects the smoothness of the shifting. A mechanic told me that some people removes the 11 tooth instead of 17 so as not to require the replacement but the consequence of this is the needed small gear when riding on flats. This may be OK if this will be used purely on trails. Buying the 16 tooth is a bit of a challenge. In the US, some conversion manufacturers already includes this cog in the conversion kit. Locally, Gran Trail has the 16 tooth cog (Wolf tooth at 750 Php)- so you now get the idea that the best store to go for conversion is Gran Trail. After having these parts, install the cog.
Step 4 -Replace the derailleur B tensioner screw with a longer one. Most instructions from manufacturers says that in most cases, you don’t need to replace this screw. In my case, I need to. So I guess its the other way around as my bike is pretty much standard. Why is this required? The normal derailleur are made for 36 tooth cog as the maximum so the replacement of a 40-42 would need to push the derailleur to shift from this big cog. This can be done by buying a normal M4 screw with 20-25 mm length (derailleur usually comes with 10 mm length). But that is easier said than done in the Philippines, as I went to a lot of store to buy this type of screw and was not successful. Guess what- Gran Trail has one.
Step 5- Remove the front derailleur and the corresponding shifter. You are now one step to a clutter free bike.
These are the recommended changes to convert. But one manufacturer (One-up) adds the replacement of the rear derailleur roller cage to something that is “optimally” designed for this purpose (I think it mimics the cage design of the Shimano Saint which according to them is the best for this kind of gearing- so some actually uses the Saint RD itself). I say this may be correct as the challenge I had initially encountered was that the existing cage is the one that prevent shifting from 42 tooth down to the next lower cog. I was able to fix this issue with the longer B tension screw but I think it would be great to have both changes working hand in hand. But again this is already a”luxury” and is not necessary to make this thing work. Here is a link to the One-up product – http://www.oneupcomponents.com/products/radr-cage
Of course you need to tune and adjust the shifting and do some test run before we call it a successful conversion.
In my case- so far so good. been riding it a couple of months now and didn’t missed any gears that I have removed.
Here is a youtube instructional from MBAction on how to uprgrade: