Aug 16, 2013

Why I Don't Ride Cruisers (or When Seat Height Is All That Matters)

Originally, this was an article requested by my old MMM editor, Sev Pearman. His idea was for me to identify motorcycles with low seat heights (the apparent prime technical specification for the over-50 crowd) that were still competent motorcycles. Going into to this, I thought it was a hopeless task but I was slightly surprised that there are a few options. Maybe this isn’t apparent, but the fact is that a low seat height is an engineering sacrifice on several levels. The only race bikes that even make an attempt to keep the seat low are dragsters and they are the ultimate in single-purpose vehicles. To be sure I wasn’t missing something obvious, I ran the article past Kevin Cameron and he said, in his usual efficient manner, “Everything you’ve said is true.” So, with my apparent appeal to a higher authority in hand, I went with what I had.
 
Apparently, there is no interest in this kind of article in the new MMM editorial regime and it appears to be an unsellable idea to the rest of moto-journalism, so I will “publish” it here for my favorite readers.

All Rights Reserved © 2012 Thomas W. Day

As an MSF instructor, I hear this every week, "I bought a Harley/V-Star/Polaris/etc. because I could touch the ground flat-footed." A lot of the rest of that discussion goes over my head. I don't own a bike I can flat-foot and haven't since the late-1980's, so that selection criteria has rarely connected with me. However, with a 29" inseam (and that measure usually means my pants' cuffs are ragged) and arthritis in every joint, getting a leg over a tall seat is not an insignificant consideration. The problem is physics and physical.

Last summer, a Geezer blog reader, John Kettlewell, sent me a note (titled "Cruisers!") that contained an article from New York state's "The Saratogian" about one more old Harley rider failing to negotiate a curve and meeting a tractor-trailer head-on. John summed up his analysis of this fatal crash with, "[This] is why cruisers are a problem--no matter how much you plan on just puttering down the road to the next rally or bar, there comes a time on a motorcycle when you need to maneuver and/or brake fast in order to avoid some problem. They just aren't safe." Forwarding that note to a few friends started an email conversation that resulted in Sev Pearman challenging me to write a "non-ranty" article that would prove that "If you value low seat height you don't have to settle for all the limitations inherent to a compromised cruiser form." 

John's reasoning is why I avoid the cruiser style of motorcycles. They aren't safe. Now, I have to figure out if there is a way to get a low seat height and still have a competent motorcycle. First, I am going to try to define "low seat height."

While there are motorcycles that go overboard in the pursuit of stumpy seat heights, like the 24" seats from the late-odd Ridley Motorcycle's vehicles, it appears that anything under 30" is an engineering decision to go low as a primary design feature. Engineering anything involves design compromises and the design concessions made to keep motorcycle seat heights low result in long wheel bases, low ground clearance, poor cornering capability, suspension travel limits, and the resulting handling constraints. There are few performance-enhancing options for an engineer who is told "keep the seat under 30 inches." BMW's boxer engine is one way to lower the height of the engine, although that option creates a wide profile that has other issues. For good reasons, BMW doesn't abuse the vertical space saved by their engine design to dramatically lower seat heights. BMW's lowest seat height (using the "comfort seat" and suspension lowering options ) is found on the R1200R and K1600 GTL models at 29.5 inches; 33-35" is more in-line with their design specifications. BMW does offer custom seats on six models with the explanation, "Let's face it - not every one is six feet tall with long inseams. And besides, some folks just want a more easy-handling riding position." Still, what BMW calls "low" compared to Harley Davidson's typical 26" seat heights is a world apart for many riders.

Once a designer has opted to drop the seat height to an arbitrary value very near the height of the rear tire, several things have to give way to make room for the seat base. The obvious, and often used, solution is to stretch the frame to create the necessary real estate. When you couple this requirement with the style-related requirement of a large, padded tractor seat, the frame can get quite long. By necessity, a longer wheelbase means more "stability," which is marketing-speak for "ponderous steering."

Going for a sub-30" seat height, including 3-4" of padding and seat frame, the next thing effected is ground clearance. With 22-24" from the bottom of the seat base to the ground, typical cruiser ground clearance specifications are in the 4-5" territory. That limited clearance not only effects the motorcycle's ability to get over common obstacles, like speed bumps and driveway gutters, but low clearance dramatically reduces the motorcycle's maximum lean angle. If the designer chooses to find some of the necessary real estate for the engine and transmission by increasing engine/transmission width, even more lean angle is lost. Maximum lean is directly related to a motorcycle's ability to turn quickly and perform basic maneuvers.

Ground clearance means more than just the space between the frame and the ground. Ground clearance sets a maximum limit to suspension travel. If the ground clearance is 4", the absolute maximum suspension travel is also 4" and the practical limit is more like 2 1/2" to 3". The first time I rode a modern Harley was in 1993, in Colorado. I was on a Sportster of some sort and as I swung the bike from the dealer's driveway to the street, I ground the pipe when the front tire dropped into the gutter. It was a normal maneuver, I wasn't turning sharply or going fast. When I brought the bike back, I watched other riders leave the dealership and discovered that they all turned right from the drive into the far edge of the four-lane street's center lane, to increase the radius of their turn and reduce the lean angle. Not only is that an illegal maneuver, it's unsafe and a terrible demonstration of one more way cruisers are unsafe vehicles. It did, however, prevent the pipe-grinding problem I experienced when I turned into the near lane. The lack of lean capability is a big part of the "I had to lay 'er down" mythology. Those riders did "have to" lay the bike down, since attempting to do any serious steering maneuver would lever the bike up on to metal parts and throw the vehicle into an uncontrolled slide.

It's important to keep in mind that a low seat height might mean an unacceptably wide seat, too. To cover the hot engine components that have been made wide to avoid making them tall, manufacturers put tractor seats on many motorcycles and shift the footpegs far forward to accommodate broad transmission and engine cases. In many cases, the advantage of the low seat is lost as the feet-forward riding position gives up steering leverage, the rider's ability to stand when the vehicle crosses obstacles, and a well-balanced position of strength when the motorcycle is stopped.

Many women complain that motorcycle manufacturers don't consider their physiology in bike designs. The complaint should more accurately be that physics and nature have conspired against motorcyclists with short legs and limited strength: sex is inconsequential (you don't see that statement often). So far, even electric motorcycles haven't overcome this requirement, since batteries take that same territory in the center of the motorcycle. Allowing for reasonable room for a power plant and transmission necessarily raises the seat height, center of gravity (COG), and usually creates a motorcycle that requires more strength to handle at low speeds and when the bike is stopped. Once the motorcycle is in motion, the advantage moves to the shorter wheelbase, higher ground clearance, quicker steering designs. The scooter and cruiser solution of moving the motor and/or rider over the rear wheel produces compromises in weight distribution and handling.

Going for the lowest seat height possible has produced some odd results; one example would be those 24" seat heights and other non-rider accommodations (auto-transmission, parking brake, etc.) that were found on the late Ridley Motorcycle's vehicles. The company's 2009 (last year of production) 750cc Auto-Glide cost $14,500, has a 24.5" seat height, 5.25" of ground clearance, 3.5" of suspension travel, weighed 482 pounds (wet), and a 77.5" wheelbase. The CV transmission eliminated a lot of real estate demands, which gave Ridley a couple of extra inches to work with between the ground and the seat height. Ridley aggressively aimed their products at Boomer Generation women, a marketing plan that may have backfired as loudly as their barely-muffled motorcycles.
Looking for more traditional and better performing motorcycles in the major manufacturer lines didn't do much to counteract the argument that the low seat height target coexists with performance motorcycles:

Yamaha's "new for 2012" XT250 Dual Purpose all-around commuter/play-bike has a stock 31.9" seat height and a really narrow profile, which makes it a lot more friendly than the specs read to riders like me. Still, 32" is a fair obstacle for many overweight and un-athletic Americans and for those with altitude-challenged inseams. The rest of Yamaha's lineup presents exactly the rider complaint that forces them to the company's V-Star products. Don't get me wrong, I'm not saying you shouldn't consider the Super Ténéré (33.26" or 34.25" with an optional "low seat" that takes another 35mm ( 1.38") away from the stock seat's measurements) or the FZ1/FZ8 (32.1"), FZ6 (30.9") or the FJR1300A (31.69" or 32.48"). We both know those kinds of numbers are exactly what put you in the V-Star Roadliner's 27.8" seat, aren't they?

Honda has always known who the Goldwing market is and that bike's stock 29.1" seat height reflects that awareness. The new NTV700V seems to be less well-positioned with a 31.7" seat and the Adventure Touring NC700X's 32.7" riding height puts that bike in the "questionable" category for those afraid of heights or with limited mobility. The CBR250R is well-designed for its target market, new riders and urban commuters, with a 30.5" seat. The rest of Honda's sportbike line seat heights run very near 32" for the whole product line and their cruisers are predictably around 26".

Kawasaki has, probably, the most commonly modified motorcycle in the history of motorized two-wheel vehicles in the KLR650 (No, loud pipes and cheap chrome don't qualify as "modifications." At best, those bits are no more personal or creative than the Xmas decorations you bought at Wal-Mart.) The KLR's 35" seat height is a prime reason this go-everywhere motorcycle attracts aftermarket vendors. Kawasaki's "little" dual purpose bike, the KLX250S also sports a 35" seat. The Kawai sport bikes are in the 31.7-33.3" territory, except for the 250R and the 2009 500R at 30.5". That company's sporty tourer, the Concours, sits at 32.1", ignoring the lesson Honda demonstrates with the Goldwing. The Vulcan Vaquero, Voyager, and Nomad cruiser-tourers offer a 28.7" platform. Kawasaki drops that to 27" on the Vulcan cruisers.

Suzuki's sportbikes all sit about 32" high and the cruisers drop that to about 27.5". One of the best urban commuting bikes imported to the US, the TU250X standard, has a 30.3" seat. The 650 and liter V-Stroms start at 33". As expected, Suzuki's dual sport bikes aren't playing the low seat game. Only the DRZ125 has a reachable 30.5" seat, while their "serious" dirt bike, the RM-Z450 sits at 37.6".

rahierMost popular motorcycles will attract aftermarket products for lowering the suspension or seat. Lowering the seat doesn't involved a lot of risk, other than a possible sore butt. Dropping the suspension can introduce engineering flaws that can be hazardous. For example, if you lower the suspension 2" on a KLR, you have a math problem. The stock KLR650 has 8.3" of ground clearance and 7.3" rear and 7.9" front suspension travel. Two inches off of the rear suspension means the bike's frame will hit ground while the suspension continues to collapse. There is a solid reason Kawasaki put some margin between ground clearance and suspension travel. Lowering the suspension at one or both ends changes the frame and steering geometry, too. That can have serious handling and stability consequences. Just because some shade tree "mechanic" offers a lowering kit does not mean installing that kit is a good idea.

Where does that leave those of us who walk less-than-tall? The choices are obvious. We can either suffer performance-compromised cruisers that "just aren't safe" or we can learn to ride real motorcycles.

Gaston Rahier Paris DakarThe posterboy for the second choice was Gaston Rahier, the Belgian Suzuki-rider's three-time FIM 125cc Motocross World Champion (he still holds the record with 29 Grand Prix victories), four-time Motocross de Nations winning team member, and three-time Paris-Dakar winner on the highly-modified 1000cc BMW Rally GS motorcycle that he made famous. "The little man with the giant reputation" was 5'4" tall and you can see how tall the BMW in comparison. The GS weighed 507 pounds and with 60 liters of fuel being a substantial portion of that mass. If being able to touch the ground wasn't a big deal when Rahier was crossing the Sahara Desert, not being able to put both feet flat on the ground can't been a critical criteria for selecting your bike.
There are tactics for riding a tall bike that relieve some of the problems associated with that long reach:
  • Assuming you're not sitting on a wide saddle, shift your body to the left side when stopping and plan ahead to stop with only your left foot on the ground. Using this approach, I can often flat-foot my 34" WR250X's at stoplights; it's just one foot, though.
  • Watch for crowned roads and sloped parking spaces. Even if you're shifted off to the side, going for the longer distance could be enough to throw you off balance.
  • Although you'll lose style points, it's often worth getting off of the bike where the ground is flat and the sidestand can help hold the bike up. When you are off of the bike, back it into the parking space and wrestle with positioning the motorcycle without the added problem of dismounting.
  • Mount the bike like you're riding a horse. I can, currently, swing a leg over the WR but I don't usually bother. The sidestand and bracket are pretty stout on that bike and I take advantage of that fact by getting on the bike using the left footpeg as a stepladder. In open terrain, I often mount up "Pony Express-style"; I put my left foot on the peg, slip the clutch to get the bike rolling, and swing up on to the bike as it gets moving. On muddy ground, this can be the only way I can get back on two wheels.
  • Ride wearing real motorcycle boots. Decent motorcycle boots add at least an inch to your leg length and their grip they provide will keep your feet from sliding out from under you when the road surfaces are imperfect.
  • Learn to balance your motorcycle. Regardless of law enforcement mythology, no state law requires a motorcyclist to put a foot down at a stop light or sign. If you can balance the bike, you are more ready to move away from stopped in an emergency and you'll be more likely to have your eyes up and looking for hazards than if you're comfortably relaxing waiting for a light change. Bicyclists do it all the time and it's much harder to balance a bicycle. 
Wrapping this up, I see that I failed to accomplish Sev's assignment. Outside of the Goldwing, I did not find a single competent, new motorcycle with a seat lower than 30". There are, however, several choices for reasonably modern used (especially pre-1990) motorcycles. Even with 30" as an acceptable measure, the choices are all under-500cc motorcycles.  That's not a bad thing because a competent two-fifty is more vehicle than 90% of the height-challenged motorcycling public can ride to the limits of that machine's capabilities. If you're set on that two-liter hippomobile and "value low seat height" above other riding and engineering concerns, you will "have to settle for all the limitations inherent to a compromised cruiser form." Currently, there is no magic bullet that solves the handling problems created by a sub-30" seat height. Outside of scooters and cruisers, there aren't many options out there for riders who insist on looking for a motorcycle that accommodates their physical inabilities. Getting into shape, limbering up, becoming stronger and more flexible is probably out of the question. Right?

eddie-lawson-alligator POSTSCRIPT: Thanks for a few readers, I have been officially turned on to the Gurney Alligator; an attempt to remedy the problems of low seat height and handling. To my eyes, most of the objections still stand with this vehicle. I can see how it might have some improved characteristics on nearly perfect roads/racetracks, but I think I’d rather have a convertible than something this restrictive, uncomfortable, and limited.





















3 comments:

Nikos said...

Good article but too riddled with fact to be published in a commercial publication reliant on advertising income? I have the opposite problem with a 36" inseam!

John J. Kettlewell said...

Since I sent you that article I have noticed many more with a similar accident reconstruction theme: the rider failed to negotiate a corner and had a violent encounter with a vehicle coming the other way or a fixed object. A parallel problem is the extreme width of many feet-forward set ups. I can't imagine those aid cornering ability.

Thomas Day said...

A couple of readers have pointed out that Dan Gurney made a pretty interesting stab at a low-slung motorcycle with handles (http://allamericanracers.com/alligator-motorcycle-dan-gurney-post/). Of course, this is a vehicle designed for smooth, well-maintained race tracks; not rough and irregular public roads. The usual low seat height characteristics continue: no ground clearance, minimal suspension, more weight than necessary, no visibility, painful long-range riding position, and it's not available except to the 1% and only 36 of them. It's an interesting experiment, though.