Levena gear and seat post replacement

My child's 18-inch Bridgestone Revena bike has gotten too small, so I replaced the gears and seat post.

[What we prepared]

• Replacement crank 36T 127mm (Rin-ei W-guard gear crank set)
• Seatpost 27.2mm 300mm (TIOGA AL2000)
• Cotterless puller
• Chain cutter
• Replacement chain
• Regular tools (hexagonal wrench, adjustable wrench)

[About exchanges]

The gear ratio of the Revena is too light, so as the child grows a little, you will want to make it heavier. However, even if you want to change the gears, there is not much information on the Internet, so I will upload it for reference. Since the gears on the rear wheel cannot be changed, it is easier to replace the entire gear crank with the pedals attached. The crank used is 127mm 36T, and if it is any larger it may interfere with the frame. This product is black in color, so it fits perfectly. On the other side, the genuine crank is made of aluminum and is light, so it is better to leave it as it is.

Comparison of the size of the old and new cranks. It is much larger.

[Points to note]

Remove the pedals, replace the crank on the chain side, and replace the chain. Also replace the seat post before and after. You can find out more about each step by searching online. There's nothing special about it, it's all the same as for regular bikes. If you're used to it, it's no big deal. However, since I've never tinkered with bikes before, it took me quite a while. What took me a while was removing the pedals (they were too tight) and replacing the chain. The chain in particular was the wrong length, and it would slacken no matter what. I struggled with it, but I realized it could be adjusted later by pulling the chain. (That's obvious.) Basically, it's easy as long as you have the tools, and I think you can do it all by yourself.

[After replacement]

The Revena is very light (7.9kg) and a very well-made children's bike. If you change it to a 22-inch bike, it will suddenly weigh around 11-13kg. Since there are no alternative options, I think many people would like to ride it for a little longer. With this change, I think it can be used as is until it is possible to ride a 26-inch (or 24-inch) bike. Moreover, the plastic chain cover that was typical of children's bikes has been replaced with a gear crank with a guard, giving it a cleaner look and making it look more like a sports bike. You can change the gears and ride faster, so it's a Revena sports version.

To be honest, it would be perfect if I could move the stem or handlebars a little further away and replace the rear brake with a servo brake, but I already bought a 24-inch bike, so I'll leave it at that. It looks like it'll be useful for riding around the neighborhood for a while.