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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Tikvah on February 11, 2016, 02:28:10 PM

Title: Hubometer
Post by: Tikvah on February 11, 2016, 02:28:10 PM
I need a new one.  MCI was too cheap to install a odometer, but the Hubometer seems fine with me.  But, mine is so cloudy I can't see the numbers anymore.
So, time for new.

They are sold by Revolutions Per Mile.
I have the standard 315-80R-22.5 tires
Anybody know how many RPM I need to order?
Title: Re: Hubometer
Post by: TedCalvert on February 11, 2016, 02:41:53 PM
Look it up  on the tire maker's website.  Or measure the OD of the tire and do the math for a rough number.  Looking it up would be much easier and more accurate.

Have fun!
Title: Re: Hubometer
Post by: Tikvah on February 12, 2016, 02:34:06 AM
Second thought, does anybody have a speedometer with odometer laying around?
Title: Re: Hubometer
Post by: rgrauto on February 12, 2016, 02:48:30 AM
If the hubometer has the plastic lens you  can use lacquer thinner and a cloth to clear-clean the lens. Use small amount of thinner as it will melt plastic,you just need to buff off the hazy outside.
Title: Re: Hubometer
Post by: brmax on February 12, 2016, 03:24:51 AM
If you change your mind, I would use the 3m kit for headlamps as this is awesome product.
If its fogged inside from something, dunno. I have ask stemco on replacement lens for one with no luck, mine was broke. Their contact page is useless today
Floyd
http://www.stemco.com/product/standard-hubodometer/ (http://www.stemco.com/product/standard-hubodometer/)
Title: Re: Hubometer
Post by: bevans6 on February 12, 2016, 03:38:19 AM
calculator suggests 476 revs per mile, but doesn't take tread wear or tire deflection under load into account.

Brian
Title: Re: Hubometer
Post by: Lee Bradley on February 12, 2016, 07:20:36 AM
My speedometer doesn't work (speed/miles) so I bought a Good Sam GPS. The  GPS has a dashboard that has a large speedometer and odometer. The odometer matches my hubometer mile for mile and you can enter the starting mileage on the odometer.  I am running the same size tires and my hubometer is a Stemco 650-0595.
Title: Re: Hubometer
Post by: Runcutter on February 13, 2016, 09:58:38 AM
Dave, Brian brought up a good point.  In transit costing and statistical reporting, route mileage is an important number.  I've been on some transit systems that will send a bus out to run a route, reading the hubodometer for mileage.  It is always inaccurate, because of tire wear.  If they chose a different bus, they'd get a different figure.  When I find that, it always has to be redone (I use a smartphone app and ride each route, gives me hundredths while all I need is tenths.)

But, the hubodometer mileage is good enough for things like maintenance needs (PM every 3000/6000 etc. miles, you'll be in the ballpark).  So, a hub designed for your revs/mile won't be anal-retentive accurate, but will be close enough.

Arthur

 
Title: Re: Hubometer
Post by: belfert on February 14, 2016, 06:26:11 AM
Isn't a regular odometer also going to affected by tire wear too?  It seems to me that ultimately any odometer that depends on how many times the tires go around would be affected by tire wear.  It seems like a GPS would be one of the most accurate ways to measure distance driven.
Title: Re: Hubometer
Post by: Runcutter on February 14, 2016, 08:52:24 AM
I agree, tire diameter/circumference will make a big difference in actual miles.  Not long ago, I was on a transit property that had used 2 buses to run a route and get mileage -- wide difference in the report.  In transit, though, it's accurate enough for maintenance needs.  You also have the mechanical margin of error.  My Lincoln speedometer reads a little high on speeds, and the variation between new/old tires is small enough to be unnoticeable.  With larger bus tires, bigger circumference will make a bigger difference.  When you look at transit tire shops, and see the range of heights (diameters) as they're matching duals.  Not unusual to see 1/2-3/4 inch difference, so if they put new duals on one bus, old duals on another, there would be a big difference in actual revs per mile.  Something about Pi R Squared if anyone wants to do the math.  I will admit that I've wondered if Engler configures the gearing for new, old, or average tires. 

I am about to sign a contract with a local transit system, and one of their issues is that their contractor reports route mileage that doesn't seem right.  One of my first tasks will be to ride each route, using a cellphone app that substitutes for a GPS, to get accurate numbers.  Mileage is one of the things reported to the Feds, that goes into apportioning funding -- so it's important to be accurate.  However, maintenance and historical miles on buses and components don't need that level of accuracy, so hubodometer mileage (to me), is close enough.

When I started in the industry as a fueler/cleaner, we recorded mileage every time we fueled a bus.  MPG could have been calculated, but the difference between a smooth and a rough operator would probably make more difference in MPG than would tires.

Arthur