This project started up because Stellan Egeland wanted to build a modern bike. Hes two latest bikes had been custom bikes more to the style that is in fashion based on Harley style engines. The bikes had of course been very well executed and had earned him many show awards including a world championship title. Stellan had bought a BMW R1200S and came to us to see if we could do something together. The idea to start with was to build a bike that was functional on the road using modern components and getting rid of some of the excessive parts that are so common on bikes of today. For example adding weight and complexity without achieving riding fun of the bike. Sort of back to basics.
Then the idea of a hubcentersteering came up. The timing cover of the BMW engine was considered strongly enough bolted to the crankcase to hold a front swingarm and the crankcase already adopted to take the loads of the standard suspension. At this point the back to basics idea got lost somehow and with the well developed ability of selfdeception that all bike builders seems to suffer from this project got over board as usual. We have a saying at ISR that goes "What the hell,it ain`t that many parts on a....." (in this case a hubcenter-steering). In most cases there are a lot of parts of course, but the red blooded enthusiasts that we are simplifies difficulties at the start of a project to discover the true volume of work as we go along, and this was certainly such a project.
The basic design of this steering was simple enough,just half an hour at my back in the Sunday morning sofa with the scetch-pad. We opted for a double sided swingarm that would go very well with the boxer engine and there was no need for fast wheelchanges. Stellan also considered that girls would find this more tempting, especially with a tubular space-frame design. Stellan also suggested hydraulic actuation between handlebar and front wheel,but the experience I have of that is that it is very difficult to make hydraulics stiction-free. I instead wanted to try cable operation, that among other things would eliminate the risk of bump-steering. My prime concern when designing the steering mechanism was to make the cable pull and support points whit proper bearings to guarantee a slack-free operation, in order to give the rider the best possible feed-back from the steering. It did take a while to understand the physics of a dual push-pull cable operation, but once established final design quickly fell into place. The work progressed during the fall/winter of 2008 and the bike was revieled to the press and public at the SWEDISH MOTORCYCLE SHOW by the end of January 2009. At this stage we at ISR had spent about 850 hours at this project. The reaction to the bike was really overwhelming, within minutes after the show opened there were pictures on the net spreading like bushfire around the world. Reactions ranging from �engineering art� to �blasphemy�,nobody seemed to be indifferent. I think that we had reached our first goal: to build a spectacular motorcycle. But the real test would come when the bike was tested on a track. We just had to wait for the snow to melt. Spring came and Stellan could not wait to get on the bike and started to make short test rides reporting excellent stability especially under braking. We had kept the ABS system of the BMW and adopted it to the ISR brake components used. It was amazing to see the bike under full braking, it stopped,as it seemed with no effort,with no nosedive. Totally different to a telescopic forked bike that looks to be under a lot of stress under heavy braking,losing its suspension and steering ability. But to test suspension settings and to ride the bike to its full potential we had to take it to a track. I talked to my old friend Anders Andersson who is now a test rider for �hlins. I had worked a lot with Anders during hes racing days, helping him with chassis and braking parts and I know no one better suited to evaluate a bike. The opportunity came in the beginning of June when �hlins had a couple of track days at Karlskoga and we could come to test the settings of the bike. Anders had hes first outing on the bike and came in to report that he would like the bike to steer quicker and also saying that he felt a little bit uneasy because all the normal things like tripleclamps,lamps or fairings was missing. We shortened the trail from 100mm to 75mm and Anders had hes second outing. This time he staid out lap after lap obviously enjoying the ride. After the ride I asked him about the feel from the front wheel,compared to a telescopic front fork, he answered: Its the same,the trick is to look ahead and focus on the track and forget that you are on a hubsteered bike, the stability is the big difference especially on the brakes, even at top speed the bike is steady as a rock. This was of course just what I wanted to hear, stability was expected, but the ability of the cables to transmit the feel of the front wheel was the unknown factor in this design. When first Stellan in road conditions and then Anders on the track have the same opinion about this it convinced me that the steering is a sound design. The fact that none of them even mentioned a steering damper is proof of that. Given the result of the tests an the interest this bike have created I have decided to ad the hubcenter steering to the product line up of ISR.
Acke Rising