With all the components (new and also stock) of the Bestrider Pump Pro 20 kids bike in place, proper assembly can now take place! As discussed in the earlier posts, some of the stock components are of good quality and will be reused. Examples include the wheelset, crankset and brake system. On the other hand, other components which are not good enough will be upgraded. These include the handlebar, seat post and saddle, as well as the full drivetrain. The stock Kenda Small Block Eight tires are more suited for light off-road riding, which is not needed here as the kids bike will be used ..read more

On a kids bike, the choice of crankset is very important. The crank arm length, saddle height, and bottom bracket height are all related to each other. If the dimensions are not specified properly, the pedaling ergonomics will be completely wrong, making it uncomfortable for cycling. If you look at the different kids bikes, there are many different crank arm lengths. From the 90 mm found on the Early Rider Seeker 14 bike, to the 102 mm found on the Bestrider Pump Pro 16, it varies quite a lot across kids bikes. Generally, the crank arm length gets longer for larger kids bikes, until it stabil ..read more

When I was deciding on the drivetrain to use on the Bestrider Pump Pro 20, there are many considerations, since this is a kids bike. The stock drivetrain has a 8 speed semi-Shimano drivetrain, which is actually pretty good for kids bikes. However, I wanted something nicer than the 8 speed drivetrain. On the previous Bestrider Pump Pro 16 kids bike, I took extra effort to make sure that the 3 speed drivetrain is easy to use even for kids. It was a unique, one-of-a-kind 3 speed drivetrain for 16 inch kids bikes. Now, on this new 20 inch kids bike, the shifters will be changed from the Revoshift ..read more

One of the stock components from the Bestrider Pump Pro 20 that I considered changing was the 20 inch 406 wheelset. However, I did not order a new wheelset yet, as I wanted to see what the stock wheelset looks like. If it is good enough, I will not need to get a new wheelset. After disassembling the bike earlier, I also removed the stock Kenda tires from the wheelset, to find out the weight of the stock wheelset. Stock front wheel is 527 grams Stock rear wheelset is 802 grams The stock wheelset weight is thus 1329 grams, inclusive of rim tape. Not very lightweight, but can't complain giv ..read more

It's time to disassemble the Bestrider Pump Pro 20, before starting the modifications! As there are some  stock components that are pretty good, I will be reusing them. As for the other parts which do not meet my requirements, I will swap them out for something better. Bike frameset with most of the components removed! Only the aluminium frame left! Frame weight is 1370 grams, with one headset bearing. It was stuck and I could not remove both to weigh. Using sealed headset bearings, which is much nicer than loose ball bearings. Aluminium front fork, with the super tall crown and ..read more

With the Bestrider Pump Pro 20 kids bike in hand, I am now able to study the stock components and also the original bike geometry and dimensions. I did the same geometry study for the Bestrider Pump Pro 16, although it was not as detailed as this one. Wheelbase is about 841 mm, which is longer than 700 mm on the 16 inch version. Rear chain stay length is 330 mm, longer than 273 mm on the 16 inch version. Standover height is about 520 mm, compared to 450 mm on the 16 inch version. Make sure your kid's inseam is longer than this number. Handlebar width is 610 mm, which is even wider tha ..read more

It's new bike day! Today, let's check out a new kids bike. As mentioned in the blog page, the Bestrider Pump Pro 20 is a 20 inch kids bike, which will replace the smaller Bestrider Pump Pro 16. As what I did previously for the Pump Pro 16, I ordered the full bike, as it is not available in just the frameset. In any case, it is always good to see how everything was assembled on the full bike, before disassembling it for modifications. Ordered from Taobao, shipped from China to Singapore. Lots of colours to choose from! Fresh out of the box! Well packed with protection at all the right spot ..read more

Continuing from the previous post, where I showed the shifters and brake calipers of the LTWOO eRX groupset, here are the rest of the components. Front derailleur is 140 grams, quite a bit more than 111 grams of the Ultegra Di2 front derailleur. Similar linkage design as Shimano Di2 front derailleurs Inner view, looks the same as Shimano Di2 front derailleurs. I find that the corners of the motor housing look quite sharp, perhaps they can be rounded off a bit more. LTWOO eRX 12 speed rear derailleur. Looks pretty good! Also uses a similar link design as Shimano Shadow rear deraille ..read more

Nowadays, most mid and high end road bikes are equipped with hydraulic brakes as well as electronic shifting. The most common component brands are Shimano with Di2, and SRAM with AXS. Campagnolo has EPS, but it is rarely found because it is so expensive. There are a few brands which are trying to carve out a slice of the market share for themselves, and one of them is LTWOO. They have been making flat handlebar mechanical shifters for a few years, and now they have decided to release a groupset with electronic shifting and hydraulic braking. This is quite impressive as there are many technica ..read more

Quick comparison of 3 different top tier Shimano disc brake rotors! Dura-Ace RT900 - 1st Gen road specific rotor Large cooling fins help to reduce temperature, and prevent a finger from sticking inside, during a time where people were still wary of the danger of a rotating disc rotor. XTR MT900 - MTB style rotor, with multiple generations of the Ice Tech design Latest off-road style rotor, with small cooling fins. Can be used for road bikes too. Dura-Ace CL900 - 2nd Gen road specific rotor Cooling fins reduced in size to save weight. Design has been refined to be cleaner, while the spider a ..read more