Rear Drive Train Variator Modification
Published December 31st, 2006 in TFR Project. Tags: belt, buy, centrifugal, clutch, diy, engine, kinetic, luna, maintenance, moped, motor, parts, performance, repair, service, tfr, weights.The Kinetic TFR is basically the retarded cousin of a vespa bravo - only without a variator. They share a common design and most of the parts from the bravo will work on the TFR.
Like the Vespa Ciao, the Kinetic TFR uses a centrifugal clutch system to move the rear wheel. The crankshaft spins and causes the clutch to spin. Within a few seconds, the engine and clutch are rotating at the same speed and moving a belt on a fixed pulley. Buying and installing larger or smaller pulleys on the rear wheel is the only way to vary the gear ratio.
The unfortunate reality of the TFR (and the Vespa cousins) is that the engine doesn’t put out a lot of horsepower on the low end, so acceleration is very slow. The biggest complaint that I hear and read from other TFR owners is that it is incredibly slow on takeoff. In order to help the acceleration, the vespa bravo, grande, and Si all have variators in the drive train to change the gearing in real time through the acceleration.
The vespa Ciao does not have a variator. The ciao is a very light and minimalistic moped and would suit a small lightweight rider. So it isn’t so much crippled at the lack of a variator - not like the TFR. The Kinetic TFR is a much heavier, beefier moped that can hold larger riders and it makes the acceleration on it pretty miserable. Kinetic used to make a model called the “Kinetic Magnum” that was essentially a TFR with a longer seat (for two riders) and a variator transmission. They no longer make the Magnum and they are pretty hard to come by.
You can, however, transplant the drive train from a Bravo, or Grande onto a TFR, but you will also need the rear transmission (located in the rear wheel) as well. I believe you can also use the magnum variator, too. So I am planning on making this modification to my tfr soon.
I have a variator for a Grande, a clutch and rear wheel from a bravo and a mag wheel from a grande. I just need a belt. I hear that they are standard belts available at auto parts stores (Dayco 4L410), which should be easy to get. I will be documenting that shortly.
I was wondering if there is anyway to install a variator without the vepsa rear wheel assembly. Would a Kinetic Magnum variator bolt on without having to change much else. also would I want to inatall a variator if I was going to upgrade to a 70 cc kit anyway? would to extra power be ebough to effect the take off or do I need to give the gearing boost too?
I’m pretty sure that a Vespa geared hub will fit right into a TFR rear wheel. I’m doing this for a buddy’s girlfriend later this spring so I will let you know for sure.
T
I am new to scooters. I am planning on buying a scooter within the next year. I was just wondering with Vespa’s can they be purchased used and if so. Are the parts very expensive? Another question I have is do you have to purchase Vespa parts overseas or can you get them in the USA? I have not decided if I want to purchase something new or old yet. I figure after I complete my research i will know by the end of the year. Just want to let you know that you have great information. I am sure a lot of women know about scooter parts but I am not one of them . Thanks for having the information in a way that I can understand it.