If you go out on a solo touring trip, you can immediately judge whether the bike is in good shape or not.
However, the sense of speed tends to be a sensory thing. Since there is no companion to compare and contrast, there is no way to know if the speed is really fast or not. On the other hand, if you go touring with your motorcycle friends, you will be able to know the level of your bike's condition, speed, and riding technique by starting at a traffic light or riding in a long straight line. The gear connection is good at outgoing acceleration, and my friend has overwhelming acceleration power even though we have the same displacement. When I asked my friend why it was so different, he told me that he had built a cross mission. What in the world is a cross mission?
The shortcut to more power is to increase the bore
The engine displacement is 88 cc with a 52 x 41.4 mm bore (piston diameter) x stroke, incorporating a commercially available bore-up kit. It is commonly known as the Hachi Hachi. This time, a combination of forged Φ52mm pistons and aluminum plated cylinders were used, manufactured by Shift Up. From race use to street use, these parts are reliable.
Bolt-on bore-up kits are available from various manufacturers.
Crank replacement to obtain overwhelming torque increase
I wanted to tune the engine with the S-crank specification commonly known as the 6V battery era (the bike is a 6V era Daksport), so I incorporated an old crankshaft made by Special Parts Takegawa that I had on hand discontinued parts).
It was released for Dax, Monkey, and Gorilla with S crankshafts and has a stroke of 50mm. Various crankshafts are available from various companies, and with the R crank, commonly known as the 12V engine, it is possible to select crankshafts with various strokes and displacement settings. In any case, since a used crankshaft is used, we asked a professional store of internal combustion engines to replace the bearings.
Different parts for different models and years. Make no mistake.
The crankcase has been thoroughly cleaned after a complete disassembly. The transmission bearing bearings were also replaced with new parts. When replacing the bearings, use a special tool to avoid damaging the crankcase and new bearings. Even with the same horizontal engine, the transmission bearings are different between the Cub series and the Monkey/Dax series, and the transmission parts are also special parts for each, so even with similar engines, they are not easily interchangeable. A crankcase with an oil stain removed is beautiful.
Cross-ratio 5-speed specification is selected.
When this work was done, a new Special Parts Takegawa street 5-speed cross mission was installed.
Compared to the standard transmission, the gear ratio is longer. Numerically, the low gear ratio was the same as that of the Taikabu 100, and the other ratios were the same as the famous Benry Super Sport SS50 series of yesteryear.
The construction was very beautiful, and it was designed to accept not only a stock Honda clutch but also a high-performance aftermarket secondary clutch kit. When purchasing the clutch, one must refer to the model and engine number to find compatible parts. For example, if a Super Cub engine is installed in a Monkey and a Monkey cross transmission kit is purchased, it will not be able to be installed. Be careful!
POINT
Point 1 - Cross transmission can convert engine power into driving force efficiently without waste.
Point 2 - Cross transmission is directly related to lap time in track riding
Point 3 - Complete disassembly of the engine = crankcase must be disassembled to replace parts, so let's make a plan including other parts.
After going on a touring trip with my motorcycle friends, I realized that even with the 6V specification 50cc stock head and 88cc engine, it was still underpowered and lacked power. A few days after the touring, I was stuck in traffic on my commute to work, and after much agonizing, I came to the conclusion that the only way was to increase the power even more.
We immediately started looking for a spare engine. Naturally, we were looking for a used engine, but we wanted to find one that was in as good condition as possible, not one that had been run over until it was rattled. That was our main intention. However, if we build a tuned complete engine based on the spare engine, we can simply replace it after completion. And this time, we wanted to build a cross 5-speed transmission instead of the standard 3- or 4-speed transmission.
Officially, it is a closed-ratio 5-speed transmission, but it is commonly referred to as a cross 5-speed. The word "closed" comes from the narrower gear ratio, but tuning parts are so plentiful for the Honda transverse engine that a 6-speed cross gear, which is one more than the 5-speed, is now available.
Even if the engine power is the same, the 4th gear is better than the 3rd gear, 5th gear is better than the 4th gear.
It is true that the 5th gear is better than the 3rd gear, and it definitely changes the driving experience.
As you can understand if you experience sports driving or circuit driving, even with the same engine power, if the transmission that converts the power into driving force is finely divided = by a closed ratio, you will be able to drive more comfortably and lively. Using a normal transmission as an example, a car in low gear (first gear) often blows out of first gear immediately, and the transmission must be shifted to second gear immediately. The normal engine has less power and the gear ratio setting is designed to cover the user's maximum common ratio. In the case of sports driving, it is possible to narrow down the usage so that the engine performance can be fully demonstrated.
However, if the gear ratio is too fine, there is a need to change gears without getting too busy. However, Honda's horizontal tuning parts transmission kits have gear ratio settings for the high street, sport touring, racing, etc., to suit the rider's driving style, so it is possible to set gears according to the individual preferences of each rider, which makes it a very in-depth process. When planning engine tuning, it is important to choose a transmission kit that matches the rider's driving style. This will surely make the engine even more enjoyable.
