How to know MPH travel speed with B7800 hydro?

[sixdogs]

An accurate gps is definitely the best way to go, especially with a foot controlled hydro.

Just an fyi, the speed ranges in the sales flyers are usually only listed for ag tires which I believe are taller on the b7800 so it won't be accurate for turf or r4.

If I can get rolling circumference, I can math out what ought to be correct for different tires. I have done this before. It only has to be sort-of close anyway. I'm pretty sure it was in the original sales flier and I know I have that flier so it's just a case of finding it.

 

[TMGT]

Yup, just a little math, they sometimes specify different speed with different tires but not always, however the defult is almost always for ag with a few exceptions.

 

[CobyRupert]

Use a watch

5 mph = 7.333 ft/sec

Paint stripe across tread of tire.

Determine distance traveled by driving 1 revolution under real world conditions (example soft soil, pulling a load, etc.. .) Note I didn't say determine tire circumference because there are real world slippage factors). Example: One revolution of a 10 foot circumference tire may only travel 9 feet in soft soil pulling a load.

You now know 1 revolution of the tire = x feet traveled.

Use a watch to determine time of 1 revolution = y seconds

Divide 'x' feet by 'y' seconds = this is your speed in "ft/sec". If less than 7.333 ft/sec go faster, if more, slow down.

 

[sixdogs]

I found my original sales brochure last night and under statistics it listed tire sizes and speed of R1 (only) at rated RPM. Here's what I learned:

12.4-16 R1 37.6" diameter-- speed 0- 3.1mph @ rated rpm (540 pto, 2600 rpm) in L, 0-5.5mph in M and 0-12.2mph in H
12.4-16 R4 36.9" dia
13.6-16 turf 38.0" Dia

Since I have R4 tires, I figure the tractor will be going about 2% slower than the 5.5mph in M gear, I can get close enough for my purposes. The fertilizer is flinging out in a 30 to 40 ft pattern, depending on how I set it, so it will have good coverage and my human error exceeds the variables anyway. I'm going to check this with a handheld GPS if I can borrow one or I bet a cell phone will have the same accuracy.

Sound OK?

 

[bdhsfz6]

I found my original sales brochure last night and under statistics it listed tire sizes and speed of R1 (only) at rated RPM. Here's what I learned:

12.4-16 R1 37.6" diameter-- speed 0- 3.1mph @ rated rpm (540 pto, 2600 rpm) in L, 0-5.5mph in M and 0-12.2mph in H
12.4-16 R4 36.9" dia
13.6-16 turf 38.0" Dia

Since I have R4 tires, I figure the tractor will be going about 2% slower than the 5.5mph in M gear, I can get close enough for my purposes. The fertilizer is flinging out in a 30 to 40 ft pattern, depending on how I set it, so it will have good coverage and my human error exceeds the variables anyway. I'm going to check this with a handheld GPS if I can borrow one or I bet a cell phone will have the same accuracy.

Sound OK?

You can try a smartphone using a navigation app but the accuracy issue will be the same as an automotive GPS. It would be better to use a hiking / biking app on a smartphone that is WAAS and GLONAS capable. Many smartphones don't have true GPS functionality. They use cell tower triangulation to determine location and are ok for basic automobile navigation but lack the accuracy you are looking for.