Honda Hydrostatic Drive vs. Smart Drive

Hi J-D-H, and welcome to MLMF. Your question of the comparison between the two types of transmissions is a good one. I am no expert on either of the transmissions, but my local Honda dealer has one of the Smart Drive transmissions on display in his store, and you are correct, there is a cone that is, for lack of better term, forced into another, and that is what drives the mower forward. This is an over simplification, but picture putting a Solo cup inside another Solo cup, and twisting it. The twisting motion of one will be transferred to the other.

I have heard, just as you have, that Honda's Hydro transmission is the more reliable of the two. I have used one of their mowers with the Hydro, and I liked it. I should say though, that the engagement of it was like the geared transmissions I'm used to, but I did like that I could vary my mowing speed by simply moving the transmission lever on way or the other.

Either way, Honda makes a quality mower that should give you years of good service.

Hi-

Thanks, excellent reply!

It sounds like the Smart Drive scheme might be fine depending on what material they choose for the "cones". If the cone-to-cone interface depends on friction and there are no gear teeth, etc., then the cones are a wear point. Another factor is the belt and whether it's a problem area. I've asked at repair shops about all this but so far all the mower mechanics seemed to have nothing to report.

Everyone universally recommends hydrostatic. No one has said that Smart Drive is bad, just that hydrostatic usage in lawn tractors has proven the worth of the latter approach.

Assuming the hydrostatic trans is well designed, the only thing that might not be very user friendly is having to move the bar to adjust ground speed. My concern is how much bar motion is needed to cover the whole speed range. If they made the bar's range of motion large, like 3-4", this would require the user to entirely move one hand from the main bar to the speed bar. One hand on each bar sounds uncomfortable. However maybe they made the bar motion range small, like 1" or so. If so this might let the user keep both hands on the main bar and adjust the ground speed bar with a thumb hooked over it, etc. This sounds good, but maybe a short range like this would be touchy to adjust? Can anyone fill in some blanks here?

Never having actually mowed a lawn with either mower, I would sure hate to spend $700+ on one of these Hondas and then find I hate it!

John

Have you asked your Honda desler for a test drive? I was at mine the other day and watched from across the sales room as the local dealer explained and demonstrated the Smart Drive to a customer. Much of its convenience seemed to stem from its adjustability at the handle, that allows the user to position the paddles at a point that allows the user to set them at a place that gives them the speed range that is most comfortable to them. Afterwards, the customer took it for quite an extended spin to try it out.

Again, I'm not an expert on either of these transmissions, but so far as the cones are concerned, there is a lubricating oil that forms a barrier between the inner, drive cone, that I believe is made of brass, and the outter driven cone. From what I've been told, the parts do begin to wear from the first time the mower is started, but the same could be said of anything mechanical.

The hydro I've used could easily be adjusted with the left hand along side the handle. Mostly I found it a good way to just set the speed that suited the grass, or me, and go.

Having used both, and having been working for Honda for 20+ years, here's my thoughts:

Hydrostatic (fluid) drive is 25+ years old; the design of the transmission and controls (levers, etc.) has been unchanged. While not flawless, it is a proven design, and is ultra-smooth, reliable and considered by most to be the "best" drive system for mowers available. The drive belt is under constant tension, and the speed in controlled by internal movement of a swash plate / pistons to control pressure from a pump to turn a motor. Sounds complex, but really quite simple and reliable. One control lever (orange) sets the maximum speed, while the other (black) varies the speed from 0-maximum setting. The black control lever moves in the same direction as the blade control lever. This is important to some users. Hydrostatic drive systems are more complex, more expensive, more costly to repair, and parts are more expensive.

SmartDRIVE (until K8 models) was a internal, cone-clutch design. The cones moved to engage and vary the speed as the SmartDRIVE control was moved. The SmartDRIVE control was developed by Honda R&D in cooperation with an ergonomic expert, and the first generation was a fixed position. It was soon updated with 5-position adjuster. Some customers still complained about having to hold the SmartDRIVE control in one direction, and the blade control lever in the other. Starting with the K8 models (HRR), the SmartDRIVE moved from a cone-clutch to a slip-belt design. Now the speed would change by changing the tension on the drive belt. Testing showed this to be as smooth and durable as a transmission-based speed adjustment. However, it has only been out for a short while, and the market will ultimately decide. SmartDRIVE systems are simple, less parts, less costly to produce, made is larger quantities (parts are cheaper).

Warranty for hydrostatic and SmartDRIVE are the same.

As others have said, this is a sizable investment either way, and test drive of each is well worth the time and effort required. You should expect to get years and years of service out of any mower you buy, especially at these price points, and you'd better be happy with your choice. Test each and decide for yourself what you like best.

J-D-H said:

Hi Robert-

Excellent explanation. I now understand far better about the differences.

One remaining question about hydrostatic.... This will be answered if we can get a test drive of, say, a model HRX217HXA mower, but in the meantime, is the movement of the ground speed bar more or less linear when controlling speed? In other words, that bar seems to have a total range of motion of maybe 3-4", so as you move it toward the main bar to begin moving the mower, does the mower take off immediately just as the bar is pushed slightly, or is there a lot of dead motion in the bar before any result is seen? Sorry about the bad phrasing, but does my meaning make sense? The reason for the question is that my wife has small hands and has asked me whether she'll be able to easily vary the ground speed......

Click to expand...

The HRX runs about 4 mph flat-out. You want to set the orange lever to the the maximum speed you want the unit to move on flat open turf. For me, I put it right at mid-point. This is about 2 mph, so when I move the black lever from rest and press it toward the handlebar, the mower starts to move from 0-2 mph. The faster I push the black lever, the quicker the rear wheels spin.

I use my left hand to hold the blade control lever and handlebar together. When mowing flat-out, the black drive clutch lever is fully pressed and held against the handlebar with my right hand. When I need to slow, I'll release the black drive clutch lever slightly, sometimes with just my thumb holding it, others my whole hand, depending on how much speed I need to drop. To coast, I just let it snap back to rest position and continue gripping the handlebar.

With her small hands, using both to operate both the blade control and drive clutch levers might be too much. Hard to say. If she's going to be the primary user of the mower, try and bring her along for any test drives.