4104 tires and rims

[pennuja]

I need to buy new tires for my bus, the ones on there are not dry rotted or cracking but I know that they are too old.

Right now I have 11.00-20 tires on there and I have steel rims. I have not driven on the highway with these but I think that my top speed is in the mid 60's, but it might even be in the lower 60's.  Is there a better size to go with that increases my chances of getting good used take offs for the rears and helps with the price, I plan on buying brand new tires for the fronts anyway. I do not mind if I need to buy new rims at some point I would like to go with aluminum ones anyway.

Should I check my rear end ratio before deciding? I plan on going on the highway to go get some fuel later in the week so I am going to check my top speed just to see what it is. Just to clarify I do not plan on driving too fast we are fine with 65 but if I can get better milage and not have to be against the governor all the time it would probably be better.

I am curios what others with 4104's are running, maybe I am putting too much thought into it.

[chessie4905]

    I posted before but with 12:00r22.5or 11:00x20- 69mph@2200 for 4:11 and 79mph@2200 for 3:55. About 71 or72mph@2200 for RARE 3:875. If you go with 3:55, starting out on a hill or backing up will require clutch slippage to get started. 11:00R22.5 or10:00 20's would work pretty good with the 3.55, but with 4:11 you are going to lose about 3 more mph. With 4:11's, I'd go with 11:00r24.5 since you will need to buy rims anyway if you go to tubeless. They'll be cheaper than 12:00r22.5"s, easier to obtain replacements out on the road, and maintain the above max speeds. Since you will want to run about 1700 to 1850 rpm for max economy and effiency, subtract about 6 to 8 mph for your cruising speeds. Most truck stops and some trucking companies will sell used tires and possibly rims. Even tires with half tread will last you many miles unless you are full timing.

[Oonrahnjay]

I need to buy new tires for my bus, the ones on there are not dry rotted or cracking but I know that they are too old.

     You should check "date codes" on your tires.  There will be a 4-digit code that tells the date made.  It may look like 0610 - that would be the second week of March, 2006.   Most people think that you should be *very* careful with tires over 8 years old - many people will not drive over 35 MPH on a tire like that, and not for long distances, then.
     And considering tire sizes, rear axle ratios, speed/fuel consumption is not over-thinking it; these are important factors for how well your bus performs, how much it costs you, and how much you like it.

Bruce H,   NC   USA

[TomC]

If you're going to buy a complete set of rims and tires, the direct replacement for the 11-20 is the 11R-22.5 which is a very popular tire. If you want the largest and slowest turning tire (meaning the fastest speed) you want the 11R-24.5. While the 24.5 is only used in N.America, it will be around for a while since many new trucks are still being spec'd with this tire. Good Luck, TomC

[pennuja]

Thanks for the answers guys, I think I am going to try to jack up the passenger side to try to figure out my gearing hopefully I can do that one day this week.

[uncle ned]

I put 11r24.5 on both of my 04s. the tallest tire i could get.
One is a stock6/71 with the 4 speed and the high speed rear end.
the other is HUGGY A 6V92 V730 converted 04.

was the best move i made to either of them, the only trouble is the 6/71 has some trouble starting on hills.
but it sure cruises good down the inter-state,better than huggy but i prefer the auto.

uncle ned

[akroyaleagle]

You could dare to be different!



http://sd.craigslist.org/hvo/4643156361.html

[TomC]

The 445/50R-22.5 super single is the same size as the 295/75-22.5 or 275/80R-22.5. The 455/55R-22.5 super single is the same as the 11R-22.5. No super single is made to duplicate the 11R-24.5, although the 425/65R-22.5 construction super single comes close-but has a 65mph speed restriction. Good Luck, TomC

[chessie4905]

11:00x20 is the same as the 12:00r22.5. 10:00x20 is same as 11:00x22.5. His tires now are tube type with multi-piece rims, unless he listed the size incorrectly.

[Beesme]

So what is dot code 4hbe

[pennuja]

I put 11r24.5 on both of my 04s. the tallest tire i could get.
One is a stock6/71 with the 4 speed and the high speed rear end.
the other is HUGGY A 6V92 V730 converted 04.

was the best move i made to either of them, the only trouble is the 6/71 has some trouble starting on hills.
but it sure cruises good down the inter-state,better than huggy but i prefer the auto.

uncle ned

When you went to a taller tire did you have to adjust your suspension to add clearance or was there enough without changing anything, I know it isn't that much taller just curious?

I found a hand written note from the person who originally converted that has the speeds for each gear written on it. 1st 15mph, 2nd 25mph, 3rd 42mph, & 4th 66mph which leads me to believe that my gearing is pretty low and he also states that it will easily pull a 10% grade in second gear. I definitely need to figure out the ratio because 66mph is fine but I would like to be able to go over 70 so the RPMs are down more.

[HB of CJ]

Would you be happy cruising along the interstates at around 55 mph?  If so, then you might consider just going with a modern replacement tire/wheel combo that duplicates the OEM tire rolling revs per mile...whatever that eventual choice may be.

The 4104 is not a rocket ship or a Crown Supercoach.  It was designed for hauling passengers for a profit just cruising down the highway.  Nothing wrong with that as long as you enjoy the lifestyle and ride.  Start ability may be a non issue with your use.

Have you considered visiting your local or regional heavy duty truck wrecking yards?  Sometimes you can find excellent young tires on good wheels very cheap from trucks or trailers that do not need them anymore.  Might be worth a look.  HB of CJ (old coot)

[pennuja]

Would you be happy cruising along the interstates at around 55 mph?  If so, then you might consider just going with a modern replacement tire/wheel combo that duplicates the OEM tire rolling revs per mile...whatever that eventual choice may be.

The 4104 is not a rocket ship or a Crown Supercoach.  It was designed for hauling passengers for a profit just cruising down the highway.  Nothing wrong with that as long as you enjoy the lifestyle and ride.  Start ability may be a non issue with your use.

Have you considered visiting your local or regional heavy duty truck wrecking yards?  Sometimes you can find excellent young tires on good wheels very cheap from trucks or trailers that do not need them anymore.  Might be worth a look.  HB of CJ (old coot)

Definitely something I will do, I know for a fact that we will not put more than a few thousand miles on a year and probably much less used is fine with me. I am fine going slow too we are not usually in a rush, I just want to do what works out easiest/best/cheapest if that is possible.

Thanks

[RJ]

Jim -

I've posted this info dozens of times over the years on various bus bulletin boards (should make it a sticky!), so take it for what it's worth:

The stock rear axle ratio for your 4104 is 4.125:1.  There were two other ratios available (3.85:1 and 3.55:1), but they're rare.  Based on the handwritten note you mentioned, IMHO that means you've got the stock 4.125:1 rear axle.

GM designed the powertrain around tires that turn 495 revs per mile, regardless of the optional rear axle ratios.  THAT's the number you want to keep in mind when buying wheels & tires.  Got that?  495 revs per mile is the magic number!

Based on the magic number, tires that turn MORE than 495 will lower your top speed and increase your fuel consumption, while at the same time giving you slightly better starting ability on a grade w/o frying the clutch.

OTOH, tires that turn LESS than 495 will have the opposite effect - higher top speed, better fuel mileage at the same speed, but a slight more clutch work needed to get started on a grade.  That's not a problem if you really know how to do it w/o burning up the clutch, but it takes practice.  (Hint: Service brakes.)

So much for theory, now to reality.  22.5s are the most popular rim size around the world nowadays, with a corresponding availability of sizes to fit.  But beware - it's pretty hard to find 22.5 tire sizes that meet the magic number of 495.  Most are in the 500 range, with a few exceptions.

24.5s are not at popular, yet still available, especially here in N America.  It's also easier to find 24.5 sizes that meet the magic number of 495, and even better if you're looking for less than 495.  (Example: Bridgestone makes an 11R24.5 drive tire that turns 470 r/mi.)

Now, to further confuse the issue, the HD tire industry is shifting to metric sizing, similar to what our autos have been using for the last 15 years or so.  295/75R22.5 for example, compared to 11R22.5.  No big deal, just pay attention to the revs per mile of the tire when shopping. 

Load range is another factor when selecting HD tires, but it's not as critical with your relatively light 4104 compared to a 45' Prevost.  However, it is a factor when setting your tire pressures to the correct amount for the weight of your coach.  Thus it's recommended that you run the bus over a set of truck scales in "ready-to-roll" condition to get accurate weights on both axles, and then adjust your tire pressures according to the tire manufacturer's chart for the weight being carried.  Makes a huge difference in the ride & handling when they're set properly!

One last thought:  If you're thinking of getting Alcoa or Accuride aluminum rims, remember that you'll also need longer wheel studs front & rear for the thicker wheels.

Happy shopping, but remember the magic number: 495!

FWIW & HTH. . .

[eagle19952]

so..echoing what RJ said, you really should stay within the parameters that GM designed.

unless you have a desin and engineering firm in your back pocket..