KTM 2WD hybrid dirt bike
This article was on the Gizmag blog this morning. KTM has applied for patents on a hybrid dirt bike that has conventional drive to the rear wheel as its other bikes, but adds in-wheel electric motors to both front and rear wheels for, in effect, a hybrid, all wheel drive motorcycle. KTM announced a hydraulic AWD motorcycle earlier, but I like this idea better. After all, wire is lighter than hoses with hydraulic fluid, and with the small, powerful hub mounted motors now being used in electric bikes, an electric motor is probably substantially lighter than a hydraulic motor. However, I am still concerned about the effect of the substantial increase in unsprung weight and its effect on handling. In addition, I would think tires, rims, wheels and bearings would have to be heftier to handle the increased inertia of the motor assembly, further increasing the unsprung to sprung weight ratio with its attendant adverse effect on handling. We’ll wait and see.
Source: http://www.gizmag.com/ktm-2wd-hybrid-dirt-bike/10348/
(Be sure to check out the 4 images of the patent application drawings)
KTM 2WD hybrid dirt bike
November 12, 2008 Patents lodged by Austrian Competition Motorcycle Manufacturer KTM indicate that a hybrid 2WD dirt bike is not far away. Common sense dictates that a motorcycle with both wheels driven (2WD) will go around corners faster and with greater surety than one equipped only with the motorcycle’s traditional rear-wheel drive, much the same as 4WD cars offer superior traction to their rear or front wheel drive brethren. A lot of interesting development work has been done over the last decade with YamahaOhlins 2WD system
on selected enduro bikes in Europe, Christini developing mechanical AWD (aka 2WD) kits for Honda and KTM dirt bikes and KTM talking publicly about its hydraulic 2WD development. Now it appears KTM is to employ a small electric motor on each wheel to supply additional torque when it’s needed. A recently filed set of patent applications heralds some exciting prospects. offering
Back in 2004, we wrote about KTM’s prototype hydraulic 2WD system which project leader Wolfgang Felber described as having a pre-set torque distribution between the front and rear wheel. He also commented, that although the system was already fairly well developed, it could “definitely be improved upon.”
Having both wheels driven on road, trail or competition two-wheeled machinery offers many advantages. On almost any surface, 2WD offers better traction and stability, but it offers a greater advantage for slippery, wet or loose surfaces, on larger machines and is particularly useful for inexperienced and non-expert riders.
Interestingly, Kurt Nicol of KTM described the 2wd advantages extremely well here, and there’s an excellent account of testing the Yamaha 2wd system on MCNews.com.au – our take is that existing 2WD systems don’t quite offer enough advantage for the expert rider to be worth their additional weight – yet!
The additional weight of a hydraulic system makes it only a marginal advantage for an expert rider, and it’s only a matter of time before a suitable light weight electric motor is available that will offer far more sophisticated, (most likely computer-controlled) power delivery from the front wheel.
The bike pictured in the patent images has the shape of a desert racer - KTM has dominated desert racing for a decade - a desert racer will also be one of the most obvious beneficiaries of the design as 2WD offers much greater stability and better steering in deep sand.
Perhaps most significantly, this is the first time that a motorcycle manufacturer with genuine race credibility has moved into the electric/petrol engine hybrid area and if KTM does bring the 2WD hybrid to market, it will be entirely to gain a competitive advantage. KTM’s ethos is to deliver “ready to race” motorcycles, which guarantees that if it don’t work, it won’t be on its motorcycles.
Almost certainly we’ll see a lot more 2WD motorcycles in the next few years as electric motors develop and proliferate to accommodate the growing electric bike industry. One likely technology contributor to the field of 2WD via electrically powered front wheels will be the motor suppliers to the burgeoning electric bicycle industry which demands very lightweight in-wheel motors. Given that the front wheel of a motorcycle with 2WD needs roughly 15 % of total power, the power output needs for the front wheel electric motor are not that great.
Even more intriguing is the use of an electric motor in the rear wheel and the advantages this offers in delivering predicatable, linear torque at low speeds (perfect for KTM’s strength, it’s core dirt bike clientele) as well as the brutal horsepower of KTM’s entire dirt bike range.
Source: http://www.gizmag.com/ktm-2wd-hybrid-dirt-bike/10348/
Tags: Alternative Fuel Vehicles, Electric Vehicle, electric-bike, electric-motorcycle