Failed Engineer: Decathlon Btwin mybike - Review

Thursday, 21 January 2021

Decathlon Btwin mybike - Review

At the time of writing this post, I am thirty four years old and the bicycle is slightly over two years old. I am telling you this, just to establish that I have ridden quite a few bicycles in my lifetime and also that I have owned Btwin mybike long enough to provide you a comprehensive and reliable review of the product. 

Btwin - mybike
Also, this is the fifth cycle that I have bought and all my previous bicycle purchases in the past have been quite inexpensive ones. Btwin mybike is also the one that I have ridden the most and perhaps most agressively too. It's also the first hybrid bicycle that I have bought; all my previous bicycles were MTBs. This is just to let you know of my experience or lack thereof, a sort of self-disclosure if you will. 
Btwin mybike - Gap between down tube and top tube in case of size 'L'
Btwin mybike comes in two sizes - M and L. I bought an L size. You can differentiate between the two sizes by simply looking the gap where the down tube and top tube meet the head tube. In case of an L size there is a considerable gap (about one finger wide), while in case of M, there is almost none. 
Btwin mybike - Handlebar and Quill stem
The bicycle does not come with quick-release nut for the seat post, however you can still raise the seat post around 130mm by loosening the seat post bracket. The handle of the bicycle is a classic wedge-shaped quill type with welded stem and non removable face, and it can be raised about 40mm with the use of quill nut. You should be able to get into a comfortable riding position by adjusting the handle and seat as per your preference. I could see from the manufacturer's website that they have tested/designed the bicycle for a 100kg rider, however, in my opinion, even if you are about 6 feet tall and about 120kgs, it would serve you well, and I am a case in point. 
Btwin mybike - Seat post
The frame of the bicycle is made of steel and is sturdy. Decathlon does not offer a lifetime warranty on the frame any longer and it has now been reduced to 2 years (still good in my opinion). The tube (seen below) to which the forks are welded, appears to be the thickest of all, this is also the portion that threads into the headtube since this not a threadless fork. Other tubes however, may not be as thick. I personally prefer bicycles on the heavier side and therefore I feel, seat stays and chain stays could be fatter and more chunky. 
Btwin mybike - Really thick head tube (see hole)
Also, the dropouts (seen below) are laser cut and welded to the chain stay and seat stay tubes, these could have been better designed with a slightly thicker gauge steel, but what you get is expected, considering mybike is one of the most affordable bicycle from Decathlon. 
Btwin mybike - Dropouts
The paint chips off after repeated use of tightening / loosening of the axle nut, and the paint in general is nothing to write home about. The rims are made of aluminium alloys and are as light as they can be, which make the cycle quite light overall. You need to keep in mind that doing stoppie or wheelie is perhaps not the best idea in case of this bike since these rims are not as strong as steel wheels and any major runout may not be fixable with spoke nipple adjustment. 
Btwin mybike - V brakes with aluminium alloy noodle, noodle holder, pinch bolt, mounting bolts etc. Mild steel arms and spring tension centring screws
The Btwin mybike employs what in common parlance are known as V brakes, and advertised as two-finger brake system. The brake geometry is such that it allows for very small tolerance for shoes and rim adjustment. So, the brake setup may be compromised due to any runout since the brake lever travel is limited and you cannot get away with a larger gap between brake shoes and rim (which would make the brakes ineffective). 
Btwin mybike - Plastic brake lever clasp and shroud, aluminium-alloy bolts, levers, barrel and adjusting nut
I should also take a moment to acknowledge that one of the best braking system that I have come across (excluding disc brakes - which I have never used on bicycles) on a budget cycle was the direct-pull brakes also known as the cantilever brakes. I suspect these are no longer available on budget bicycles, at least I haven't seen any bicycle of recent origin fitted with these. 

Cantilever brakes a.k.a direct-pull brakes
These brakes generally have a sharp bite, and I have found them to be more aggressive and rudimentary. However, at the same time, I have found them to be more adjustable and more forgiving in nature, allowing for the inexperienced mechanic in ourselves to indulge and tweak. Sadly, V brakes are a different breed and require some knowhow and aren't as sturdy. Combined with limited travel of the highly curves brake levers, there's almost no room for error if you like fixing the brakes yourself. Any error may result in scraping brake shoe against the rim. This is something that can be fixed with better brake levers that offer larger travel. You may find a contradicting opinion of what I just mentioned, and there may be some versions of cantilever brakes that are indeed worse than V brakes, but this has more to do with specific designs and parts and not brake geometry in my opinion.

Btwin mybike
In my two years' usage I have never had any problems with lateral or axial runout of rim even though I have ridden it carelessly and have bumped into deep potholes on high speeds on several occasions. I never did any stoppies or wheelies, so can't say if these will take that sort of abuse without any effect showing up. The place for bottle holder is provided on the downtube and two stout aluminium bolts are provided to secure it in place, though the bottle holder is not a part of standard equipment. 
Btwin mybike - Bottle holder bolts
Majority of the components are made of aluminium or plastic making them rust-proof and whether resistant. For example, the brake levers, adjusting barrel, adjusting nut, adjusting screws, brake noodles, pinch bolt etc. are all made of aluminium alloy or some sort of rust-proof steel, making them corrosion free. Even with over two years of usage I cannot spot a spec of rust on these parts. The bicycle was only serviced once at Decathlon and during the process, the bottom bracket was lubricated, grease was changed for both axles, chain, brake wire etc. was lubricated. 
Btwin mybike - Plastic brake lever clasp and shroud, aluminium-alloy bolts, levers, adjusting barrel and nut
During the fag end of the second year, I changed the grease for axles myself and have not opened the bottom bracket though I occasionally hear minor creaking noise. This time, I would prefer to get the bearing replaced since unlike other bicycles it's made of fibre and not steel and I suspect its at the end of its life. Upon enquiring, about the part, Decathlon provided me the part info and quoted the price of Rs 450. So, together with service and cost of replacement, it would be around Rs 1000. It's a bit on the higher side if you look at other budget bicycles. 
Btwin mybike - Square taper crank design and fibre bottom bracket
As you can see from above, the pedals are cotter-less and even after years of operation, there's no play between crank and centre shaft. In conclusion, the bicycle is a perfect city companion to run errands and should be on your list to consider if you intend to or are in the market looking for a bicycle. I have planned minor upgrades for this bicycle and would be posting them on my blog. So I would suggest you to follow my blog (using button from top right area) if you would like to get informed about them. If you have any further questions or comments, please feel free to post them in the comment section below.