Dear Members:
Have you considered the possibility of using a brand J. Costa variator?. At first step you an article which describes its properties.
Transverse Drive Vs Conventional
April 3, 2009 by RCscooter
Filed under Technical Articles
6 Comments
Thanks to Cesar, J. Costa Competition we bring you a comparison between traditional drives and drives cross.
Drive roller
Currently the drive roller is the system used by all major brands, and therefore the most widespread.
The drive pulley mounted a campaign for the outside of the outer chainring.
The dish and bell housings define ramp-shaped slide that called cylindrical roller weights.
Driven by centrifugal force these rollers move out exerting a force on the ramps between which lie outside forcing the plate to move, squeezing the neck of the pulley and increasing the working diameter of the belt.
This will cause a change in gear ratio to a more long.
When the motor turns the rollers lower stop pushing the outer plate of the pulley, the driven pulley spring recovery and return to a more short.
The dishes of the pulleys are usually aluminum, steel hood and rolls of plastic with a metallic core.
All solidarity spin the engine, connected through the clutch. It is therefore evident that the weight of the rollers is very important and is closely related to the behavior of the engine light rollers need a higher speed so that centrifugal force (proportional to mass) allows close the pulley.
Using lightweight rollers get a drive pulley closes higher returns, an exchange rate generally shorter and more motor nerve. In contrast, heavy rollers, the drive will open earlier, close to a pulley system and the ratio will be lower generally longer and feel of the motor will be quieter.
A similar significance has the form of ramps where the rollers are, and clearly also influences the behavior of the drive and the way it distributes the engine's thrust at different engine speeds.
Transverse Drive J. Costa
Transverse Drive is a drive J.costa conceptually not located too far from the drive roller, but with a number of features that simplify not only what but also improve performance.
Starting from a structure like that of a conventional automatic transmission, drive Transverse change the outer plate drive pulley, the bell and the rollers (which, as we shall see, they die rolls).
Cross on the drive there are no ramps or rollers: the mobile plate of the pulley has a series of inclined holes from the inside out, distributed radially, in which are housed sliding masses, finger-shaped and, instead of turning , out pushed out by centrifugal force.
On exit, push the bell of strength and force to the plate that contains them to move laterally and close the pulley by varying the diameter of the belt.
This bell drive force element happens very simple but vitally important when defining the behavior of the drive, because depending on the profile and as the "attack" the masses sliding, the drive will close in one way or another the pulley.
Advantages and peculiarities of cross-drive
Transverse Drive Benefits go beyond the simple construction. Obviously, the assembly does not increase the performance of the engine itself, but improves the performance of the bike, since the design of the hood profile of strength and how the masses sliding bearing allow increased range of gear ratios.
Cross Drive allows to obtain, on a drive as standard, a shorter ratio at low rpm (better acceleration) and a longer relationship when the drive is fully opened (closed block), allowing the motor to run more relaxed when runs on the flat, and improving the end if we drive downhill.
While the engine as we have said never give you more power, which allows the drive to increase the values ​​Transversal power to the wheel at any speed but especially in the range of low to medium speed, improved (often dramatically) the accelerations.
Why is this?
Simply because through the whole design hood / engine turns sliding masses always cheerful and close to the maximum torque speed with the drive as standard, and this simply means having more power to the wheel and ultimately increase overall performance.
Another advantage inherent to the design of this element is the smoothness of operation, especially in the models for 4-stroke engines.
As is known, in the 4-stroke cycle engine only one of every 4 laps driving piston, ie that for every two full turns the crankshaft makes, on average pulled back and the other rotates by inertia, ie that the shift is slightly irregular, and this is especially noticeable at idle where the drive roller with a ringing metallic sound typical, while the transverse drive is fine (like silk) because of the simplicity of construction.
The lack of internal friction gives the transverse drive a better feel and a higher response speed drive roller respect, to have no contact outside bell and pulley rather than the sliding mass, the gas cut pulley closes almost instantaneously, while a drive classic bell and pulley are guided by some intermediate elements that hinder the relative movement of the two pieces and delay the closing and opening of the pulley.
Besides all the virtues described, drive Transverse has the degree of maturity to ensure longevity and maintenance comparable (if not better) than conventional rollers, and quality of materials and machined which has worked for element of this invention a safe, reliable and contrasting features.S
