Saturday, September 12, 2009

ABS

When I bought my ST1300 two years ago, my local Honda dealer tried to persuade me that ABS didn't really work on bikes, and that the vibration caused by ABS when it activated was destabilizing. He didn't have the ABS version in stock, and I ended up buying my previous-year 2006 ST1300A from a competitor of his. I put my money where my mouth was to the tune of a little over a grand, which is what Honda was charging for the ABS option. The dealer's story about ABS vibration during activation turned out not to be true, by the way, you barely notice when it kicks in, except that you stop very quickly.

In fact, there is no real proof that ABS is effective on bikes, although at the time I believed that it was. But there is a lot of persuasive evidence.

Maids
, for example, flubbed the chance to make a definitive finding on ABS. They discovered that bikes with ABS seemed to be under-represented in the crash numbers, but they discarded these data because they made a mistake in their control group recruitment. (This might be a good opportunity for a masters student to make a thesis, as the control group issue affected only the German part of the study, the rest of the data might be salvaged, and Maids is willing to share their database).

Promocycle of Montreal did some nice studies on braking, finding that ABS, under ideal conditions, added about one-tenth of a negative G to the average deceleration force of about three-quarters of a negative G. That's about a 15% bonus in stopping power, and ABS's real advantage is when the surface is wet or slippery, where you'd expect the benefit to be much greater. My calculations suggest that the average rider can emergency-stop from 60 MPH in 3.77 seconds (4.15 without ABS) or 193 feet versus 210 without ABS - that's a ten percent benefit that might save your life. Again, that's in perfect conditions, in the real world you'd expect much better.

The Netherlands police force dropped their ST1300s this year because of negative reports from the UK police, who found a high-speed wobble in their ST1300s over 90 MPH. I think this was actually due to user error in loading the saddlebags. They went to Honda Transalps this year, but plan to dump them in favor of the Yamaha FJR1300 police version, because the Transalp doesn't have ABS, and the Yamaha does. Yamaha appears to be cleaning up worldwide with its police bike, because it is the ABS bike that's not an ST1300 with its alleged wobble or a Beemer with its heavy dry clutch and high maintenance costs.

Stateside, Harley Davidson seems to be selling to more police departments, despite its weak acceleration, partly because of it's recent decision to put ABS on all its models. They are taking advantage of disarray among the competition and Yamaha's poor police market penetration. This has to be a smart move from Harley.

No-one questions the efficacy of ABS on cars, despite initial negative feedback from some police departments which was based on misunderstanding of the mechanism.

I spent the last weekend as a guest of cyclesafety.net, a Memphis based motorcycle safety school that uses the MSF Basic Rider Course curriculum. I observed the emphasis placed on the quick stop techniques, which is an essential safety skill. Many bikers perform poorly in crash situations because they don't practice this skill enough. It's not something that you do every day, and like all such skills, it goes away if you don't practice it. The problem with emergency braking practice is that it is itself dangerous. Maximum braking is achieved by applying both brakes to within an iota of the wheel lock points, for each wheel. Just a little additional pressure over the maximum on either of the brake controls will cause the corresponding wheel to lock. This situation is correctable, with skill and luck, but is itself dangerous, and even if it doesn't cause a crash, it will make your emergency stop non-optimal. To complicate the matter further, your bike's brake lock points vary with the coefficient of friction of the road surface, which changes in the wet and on poor surfaces. The physics of the situation is lethal, and almost all non-professional riders are guaranteed to perform less than optimally in an emergency stop without ABS.

If you have ABS, emergency stopping becomes simple. You start straightening up the bike, and you jam on both brakes to the max, making sure your handlebars and the bike are straight by the time you stop. Problem solved. The bike and the ABS takes care of the rest. Who wouldn't want that in an emergency situation?

I don't think that any reasonable person can now deny the accumulation of evidence that ABS does work on bikes, and that it saves lives.

It is time for the other bike manufacturers to follow Harley Davidson's lead and make ABS standard on all bikes.

The benefit and necessity of ABS is no longer really in question. Product liability should do the rest, it is time for the other bike makers to jump on the bandwagon before it rolls over them. They have a maximum of about four years to make the change, because the new Federal accident causation study is unlikely to ignore ABS and my bet is that there will soon be enough ABS bikes in the population, because of the Harley initiative, to yield solid statistics on its efficacy. I am willing to bet that ABS will be proven to be effective in that study, after which it will be open season for product liability lawyers representing the 5000+ dead bikers each year.

Putting ABS as standard on all bikes is the cheap option for bike manufacturers. They are endangering their shareholders funds by holding out.

I'd love to get my hands on some of the research that police buyers seem to be doing on ABS.

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2 Comments:

Anonymous TheBikeNut said...

I agree with you on the ABS, it took my a little while to get used to the ABS on my BMW K1200GT but now I can almost say I wouldn't want to give it up.

On a slightly different note have you ever noticed a high speed weave on your Pan.

Over here in the UK all the coppers got rid of their PAN bike as they "weave" at speed.

I test rode one a couple of months ago and didn't experience any weave.

Ride safe mate,
TheBikeNut

September 25, 2009 8:46 AM  
Blogger ET said...

Yes, I heard about your fuzz getting rid of their ST1300s. I wrote about the Dutch police doing the same. I did notice a little wobble around 100 MPH one time, and since then I have been obsessive about weighing my bags before a trip, which seems to have sorted the problem. Stateside, the opportunity to ride the ton doesn't arise a lot, unfortunately :) I still love my ST. Weave and wobble is easily fixed anyway. I'll never buy another bike without ABS.

September 25, 2009 9:48 PM  

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