OC’s Guide to Cable Management (products out there to manage your cable)
Category Archives: Technical Stuff
There are voluminous discussions on what is the best wheel size- a 26’er, a 29’ner or an in-between 27.5. This is not another article on that subject matter but this is about how to convert an existing MTB with a different wheel size. Most of the assumptions when one chooses a new wheel size is that a new entire bike will be bought. But one question is- what if I would just like to change the wheel size of my bike assuming that the frame can accommodate the change?
In general this is not advised by manufacturers with the claim that the design or geometry of the bike will be severely affected. This pretty much says that you should not convert at all and just buy a new bike if you need a new wheel size. Fair enough, but what if its possible? What are its implications? What are the do’s and don’ts? What if due to financial restrictions, sentimental reasons, etc., you want to keep most of your bike and only replace the wheels to gain the supposed benefits of the new wheel size? Or maybe you can only afford a gradual upgrade of the entire bike as limited budget permits. Would this be possible?
In reality, the bike frame from a bigger wheel sized bike can obviously accommodate a smaller wheel size i.e. a 29ner frame can be fitted with a 27.5 or 26 inches wheel diameter. But according to most articles I have read- this is not the best conversion since the bigger frame’s geometry will have the biggest impact if it will be fitted with a smaller wheel size. In particular- the bottom bracket base will be lower that pedals might hit the ground. So I guess defacto rules will be:
- frames with smaller wheel size can be converted to bigger wheel size only and not the other way around- frames with bigger wheel size to change with smaller wheel size.
- convert to the next increment only and don’t jump two sizes ahead- i.e. if its a 26er- then convert to a 27.5 and not a 29. If its a 27.5 then you can do a 29.
- Check if your feet on the pedals will not touch the front wheel when turning if you convert to a bigger wheel size.
I would think this conversion scenario is only feasible for the current people who owns a 26er bike which is a majority of us. I don’t see any reason why one with a 27.5 would convert to a 29ner. And of course I don’t think somebody will go from bigger to smaller. So given the points above, we can further simplify that this is only applicable for 26er converting to a 27.5. Or that is the only valid reason. Period.
Besides the foot hitting the wheel rule, another thing of course which is obvious is to see if the frame can accommodate the bigger wheel. If the frame cant, then its not possible. If the frame can and the fork cannot, then there is still hope of buying a 27.5 specific fork which is cheaper than replacing the frame. Note that there should be ample space between the frame and the tire. Sometimes this clearance can be further improved by choosing a tire with a smaller casing like a 1.95 than a 2.10 tire size. In the end- even if all the criteria is possible, you still need to try the bike and see its effect to your handling, comfort and safety before you certify that the conversion is a success. As mentioned earlier, this is not advised by manufacturers and these are my opinion based on other articles so in the end, I also advise that you also do your own research before going this path.
As requested by members of our Outdoor Group- I held my first bike clinic this May. Here are pictures of the said event:
We started the day with a short ride that has some technical portions to assess each one’s skill.
The first exercise was how to change a flat tire.
A lecture on parts of the bike.
More technical stuff.
Bike tuning/ tune up.
Advance mechanical work.
Added bonus: Bike weigh-in.
We did another ride the next day as the second day focused more on bike handling skills.
Here are the participants of the bike clinic:
I recently assembled a new bike (yes I do my own bike), there are glaring new technologies that are now part of the check list for consideration that were not on the list a few years back. Its amazing that bike technologies continues to evolve even if we think we have exhausted every angle there is to improve on. But of course there were golden eras where technologies jumped sky high but even on the lean years, there were still pockets of improvements. We can argue that some of these improvement were driven more of marketing- a need to sell new stuff but in the end, its still us consumers that will benefit and we will still have the last say if a given technology would succeed or will just be another part of bike’s evolutionary history.
Maybe some of these technologies were already existing years before it got mainstream but it is more evident for consideration in building bikes lately as those technologies matured (i.e. gravity seat posts)- here are some of those items:
- Tapered Head Tubes and Tapered Fork Steerer (for both the bike frame (head
tubes) and the fork (steerer)). The normal head tube/steerer measures at 1 1/8 or 44 mm diameter all throughout. A tapered system has 44 mm top and 56 mm bottom diameter. This is designed to Improve rigidity in this critical area which translates to less wheel deflection and more control. Also in most frame designs, larger head tubes gives room to fit a massive down tube that joins the bottom bracket to become the burly heart of the bike. The tapered head tube offers a noticeable advantage and the frame is still compatible with traditional 1-1/8” steerer tube forks with the purchase of a crown race adapter, but a tapered steerer fork serves up a significant increase in rough terrain tracking and stability. Using a non tapered fork on a tapered frame is like getting only half of the advantage of the tapered system in the first place.
- Wide handle bars. When it comes to mountain bike handlebars, wider (to a certain extent) is better (i.e. 750 mm). They offer you more control, easier breathing and better positioning for balance. This makes you more stable and slower to fatigue. But of course in Manila, if you often do urban rides, consider the downside of wide handle bars- getting entangled in the busy streets of Manila.
- 15 mm or 20 mm Through Axle (for both wheel set and fork).
The advantage of a QR 15/20 through axle system is the stiffening of the fork and also of the front wheel. The latter won’t flex so much, especially on turn. The clamping becomes extra safe because for QR 9 axles, a minimum risk of breaking open still exists but with QR 15/20 you can simply forget about it. It is because the axle is mechanically clamped to the fork lowers, so the chances of breaking open is basically zero. Also the QR 15/20 axle construction is more rigid. QR 9 can bend in heavy operating conditions, practically tearing itself apart in the middle. Due to the fact that QR 15 is hollow, it is stiffer and more resistant, regardless of riding conditions. This system is already prevalent on forks/ front wheel set but on some bikes, the rear wheel set are already using the same set-up especially for all-mountain to downhill bikes. For QR 15/20 wheel sets, adapters are available to use it with other platforms (i.e. QR 9).
- 35 mm Diameter Handle Bar (for both stem and handle bar). In the early days- 27 mm is the standard. Then comes the 31.8 mm and it quickly replaced the standard. That was already considered as oversize handle bar. Nowadays there are 35 mm handle bars that of course, would need 35 mm stems. According to Easton- Because of the bulked up center section they managed to decrease the weight while making the bar wider and stronger.
- 1 x 11 Drive train. The concept of this is based on the fact that there are redundant gearings on the other systems especially in a 3 X 9 set-up. The only important thing is that you have the basic gears especially the lowest and the highest covered. This follows the notion of less is simple, less is beautiful. Coverting to a 1X11 would be costly as you need to replace a lot of stuff so the in-between solution is converting the 2X10 or 3X10 to a 1×10. There is a separate article in this blog that explain how to do the conversion.
- Gravity seat post. This has been in existence for a long time but only became mainstream when new technologies made this design more practicable (i.e. light weight, suspension technology and remote lock-out). Nowadays high end “all mountain” bikes has this seat post as part of the standard set-up. Not all are still convince this is needed (like myself) but there are still people out there that considers this as part of an all mountain set-up.
- Fork Offset. Nowadays forks for 29” wheel platform offers two kinds of offset – 46 mm and 51 mm. Although in actual, these offset would mean a minimal (in mm or cm) increase in wheel base, this is critical in 29’ner systems as the big wheels in this set-up usually causes narrow distance between the two wheels which may cause the foot to touch the front wheel when the wheels are turned. As mentioned, the added millimeters would be of big help to clear the wheels when turning.
- The choice between 27.5 and 29 wheel size. Is 26 passe ? Is in-between better? You be the judge.
But there are more coming up- like the Di2 technology which are now available in the mountain bike platform after the release of the XTR 2015. And this is not as simple as the drive train only- there are now bike frames that are specifically designed to accommodate this Di2 set-up (i.e. internal battery compartment and internal wiring). And talking about frame designs, also worth to note is that recent frame designs already have internal cable routing guides brought about by the flexibility of using carbon technology. This routing also made a cross over to traditional aluminum frames as some already have internal routings. The tubular (not tubeless) technology is also being introduced in the MTB segment and lets see how it progresses.
The quests for the lightest disc rotor is quite debatable. The lightest that would come out includes a carbon version and/or an aluminum version (i.e. Scrubs) but I tend not to consider them as they are more of a technical show piece than a real life application. They have disadvantages that the little grams that you save may not be worth the cost and those disadvantages. So the quest is about the normal stainless steel rotors. For the longest time it was the Alligator Cirrus Model. But recently this Ashima Ai2 model came out and it is now the lightest product out there. Note that I have seen a different brand with the exact same look so I guess the Ashima manufacturer (or subcontractor) might be doing OEMs for other companies out there or vice-versa.
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:
Not sure how feasible this will last. Its a bike park- actually more of a BMX jump park. Its located near Baytown- the road that connects Taytay to Angono from floodway.
Its probably one of the best bike shop outside of Manila and a welcome fact that it is located in my hometown. Imagine a local bike shop with several Fox forks, Specialized bikes, Shimano XTRs and other high end brands on display. And at the same time, its like a bike shop in Quiapo- which also has its low end and low priced products. Like a Manila high end bike shop and a Quiapo bike shop merged into one. Its Villamayor Shop located in Binangonan (not Angono- okay I consider Taytay, Angono and Binangonan as one and the same- my home town). So those who are riding Rizal may it be Bugarin for road riders or Antennae for MTBs- better drop by and see an alternative for yourself.
Heard the owner is related to the owners of Joven, the pioneer high end bikeshop- whose husband is the part owner of Lifecycle in greenhills. A small world indeed.