CX Speed clocked at 13 MPH

[Mulch Gator]

I clocked my new (5 hrs) CX on an accurate GPS yesterday and after several tests the best I could get was 13 mph. I think the advertised 15 mph is slow enough but I was disappointed to not even get that. It just really seems to be limited by gear ratio and rpm. I don't think any additional break-in will help and the tires are at the factory pressure. I am thinking about contacting JD first to see if the governor or something is out of adjustment. Anyone have any ideas? I would at least like to try to get it to the factory advertised before I think about any modifications.

[Mulch Gator]

I spoke to John Deere today and they suggested I give the clutch more time to break in to see the full potential. The clutch is rated at 15.4 mph.

[Dane]

I can change the top end speed of my 550 by a couple mph just by changing the air pressure in the tires. Also, even though my aggressive Ancla bar tread tires and turf Carlisles are spec'd as the same dimension the Ancla's are a bit taller and give me a few mph over the turf tires.

[Mulch Gator]

I can change the top end speed of my 550 by a couple mph just by changing the air pressure in the tires. Also, even though my aggressive Ancla bar tread tires and turf Carlisles are spec'd as the same dimension the Ancla's are a bit taller and give me a few mph over the turf tires.

Thanks, I will play with the pressure and see what difference it makes. I know they make the same tire in a 22.5 versus the stock 20 so that should help also. My calculations also say that the engine is running about 500 rpm shy of what the engine is rated for so I ordered a tach to take a look at that. My goal is to get it to 20 mph without doing any major mods.

[Mulch Gator]

I installed the 22.5" Cayman tires on the rear. I inflated them to 8 lbs versus the 7 in the stock tires and I inflated the fronts to 11 lbs. Ground clearance was improved by a full inch at the pan and top speed increased by 2 mph. It was surprising how what would seem to be a pretty negligible difference in tire made a pretty big difference in the attitude of the machine and actually helped with acceleration and climbing. The next thing I did was install a digital tachometer and found the top end was only running up to about 3600 rpm. I adjusted it and it now runs 17 mph at 3900 rpm. If the clutch breaks in more as John Deere suggests then I should be getting pretty close to 19 mph. It may not seem like a lot but the 4 mph was a pretty noticeable difference and the the acceleration and handling is better on the trails. The other thing that is nice is that the tires look factory.