Im looking to put new tires on the duals and currently have 12R 22.5 on the back and 11R 22.5 steers. As Im looking for good take-offs what other sizes can I use. I have been offered 295/75r22.5. Will these be OK. What is the equivalent to 11R or 12Rs in the metric terminlogy.
Thanks
Fred
I use Delo 100!.... :o
Hi;
I had 315 80x22.5 on the front of my mci. It made the speedo fast
by about 3mph. I took them off because of age. I am now looking
for new ones. Again I will use that same size because big trucks are
using them and they are over kill for bus use, also they are more avaliable
than 12rx 22.5. Best price I have found is $365 ea with 20 ply. (china)
Usually run good used tires on the drive, but they are getting hard to
find in either size.
What part of the country are you in?
Good luck. Merle.
Well, I live in Canada(near Vancouver) but am looking at some from Wash. Looking for ones with recent mfg. as my tires age out as opposed to wear out.
What is the vehicle? GMC's with automatics usually can't spare the loss of top mph with smalle drive tires. Also 315's are a little smaller in dia than 12.00's
Its a GM PD 4106 with manual trans.
Thx
Fred
I am not sure here. Did the 12Rx22.5 require or desire a slightly wider rim width? If memory serves, (always suspect) the wheels on my old 1974 Crown VIN 37317 had one half inch wider steel rims? Some help please here. Also, if true, does that imply or beg the question that a 11Rx22.5 may or may not need a slightly different rim width from that of the 12R? Does it matter any? Again, I do not know. HB of CJ (Old Coot)
Quote from: Fred Mc on June 16, 2015, 07:16:16 PM
Its a GM PD 4106 with manual trans.
Thx
Fred
Is there a reason you're getting tire across the border? Son Tire in Burnaby has offered me decent prices on take offs in the past (I believe $160 for Michelin steers with half tread, I would age them out before wear).
I believe 11R22.5s should offer plenty weight capacity, but your revs will be higher on the highway. I got 11R24.5s for my drive axle (35' Prevost, 4.10 rear) to keep my revs reasonable.
On the front I'm running 315/80, but it's way overkill for my weight (3700 kgs). With my narrow rim (8.25") the tread is slightly bowed out, which I don't like. Next time I'm getting 11R22.5s.
Quote from: Fred Mc on June 16, 2015, 07:16:16 PM
Its a GM PD 4106 with manual trans.
Fred -GM designed the powertrain, from engine to transmission to rear axle, around tires that turn 495 revs per mile.
So if you're looking at performance of your coach equal to how the factory designed it, then look for tires that come as close as possible to OEM revs/mile.
More revs/mile translates to lower top speed and greater fuel consumption. Lower revs/mile vs OEM will give greater top speed and slightly better fuel economy.
You choose!
FWIW & HTH. . .
;)
If you go from 1200's to 295's you'll lose about 3 to 4mph top speed and 75 to 100 higher rpm's at your cruising speed.
The determining factor is the weight of the bus. Weigh your bus by axle. My guess is that you could use the 11R-22.5 (a very popular size) rather than the 12R-22.5 (a hard size to readily find). 315/80R-22.5 is a very heavy-duty tire that is WAY overkill for rear axle and expensive. 295/75R-22.5 or 275/80R-22.5 are the most popular tire size on trucks now. You have to decide if you can take the rpm difference between the tires that will make the engine run faster at cruise speed. In general-
11R-22.5 is 495-500rpm, 12R-22.5 and 315/80R-22.5 about the same at 485rpm, 295/75R-22.5 and 275/80R-22.5 are in the 509-517rpm range. Personally, 11R-22.5 14ply would be my choice with highway drive tire. Good Luck, TomC
This is something I have been pondering as well. I have a 4107 that the PO installed a 77 engine and auto tranny in. I drove it home and was able to pull 70mph for just a bit until the engine got hot. I didn't have a tach so I have no idea how fast the engine was running. The bus does have the 12 22.5's on it now but as everyone else is saying they are expensive and not as easy to find. I have a chance to get 6 24.5 aluminum wheels lug centering for next to nothing. What size tire of the 24.5's runs that magic 496 rpm's?
Fred,
We just started to strip down a MCI 9 in Oliver BC.
We have good 22.5 tyres on it.
All other parts as well. [less motor]
Good seats, glass, etc.
Can arrange delivery to Langley or come here for a holiday.
Contact me. Info in profile or:
Bob Hutton 250-498-3269 taibob@persona.ca
These are 11R24.5 43.5" Diameter 32/32 deep tread http://www.ebay.com/itm/4-Tires-11R24-5-New-GL266D-32-32-Rear-Deep-Drive-Truck-Tire-16-PR-11245-/191122773647 (http://www.ebay.com/itm/4-Tires-11R24-5-New-GL266D-32-32-Rear-Deep-Drive-Truck-Tire-16-PR-11245-/191122773647)
43.5 * 3.1415 = 136.65525
63360" in a mile
63360" / 136.65525 = 463.6 rev/mile
My GM is converted to Automatic trans - V730 so im looking for less rev per mile
Fronts > http://www.ebay.com/itm/2-Tires-11R24-5-GL116S-16-PR-Front-Steer-truck-tire-11X24-5-Radial-11245-/141486099943 (http://www.ebay.com/itm/2-Tires-11R24-5-GL116S-16-PR-Front-Steer-truck-tire-11X24-5-Radial-11245-/141486099943)
Atleast they aren't Chinese... ;D
Quote from: Darkspeed on June 17, 2015, 07:16:21 PM
These are 11R24.5 43.5" Diameter 32/32 deep tread http://www.ebay.com/itm/4-Tires-11R24-5-New-GL266D-32-32-Rear-Deep-Drive-Truck-Tire-16-PR-11245-/191122773647 (http://www.ebay.com/itm/4-Tires-11R24-5-New-GL266D-32-32-Rear-Deep-Drive-Truck-Tire-16-PR-11245-/191122773647)
43.5 * 3.1415 = 136.65525
63360" in a mile
63360" / 136.65525 = 463.6 rev/mile
My GM is converted to Automatic trans - V730 so im looking for less rev per mile
Fronts > http://www.ebay.com/itm/2-Tires-11R24-5-GL116S-16-PR-Front-Steer-truck-tire-11X24-5-Radial-11245-/141486099943 (http://www.ebay.com/itm/2-Tires-11R24-5-GL116S-16-PR-Front-Steer-truck-tire-11X24-5-Radial-11245-/141486099943)
They are Chinese but they seem to be getting good reviews.
I believe they are Samson Tires, made in Israel.
But this website says Japan...still not Chinese :) Different size but same designation ??? Gl116s
Good Luck :)
"Quick Details
Place of Origin:
Japan
Brand Name:
(2-tires) 295/75r22.5 Gl116s 16 Pr Front Steer Truck Tire 29575225
Model Number:
(2-tires) 295/75r22.5 Gl116s 16 Pr Front Steer Truck Tire 29575225
Tire Design:
Radial
Type:
Solid Tire
Diameter:
11-15inch
Width:
175-195mm
Car Make:
ALL
Quote from: eagle19952 on June 17, 2015, 08:40:17 PM
I believe they are Samson Tires, made in Israel.
Maybe so, I thought they were Chinese. I have six in storage if i can remember to check next time im out there.
see above..one web site says japan...
Quote from: daddyoften on June 17, 2015, 02:26:04 PM
This is something I have been pondering as well. I have a 4107 that the PO installed a 77 engine and auto tranny in. I drove it home and was able to pull 70mph for just a bit until the engine got hot. I didn't have a tach so I have no idea how fast the engine was running. The bus does have the 12 22.5's on it now but as everyone else is saying they are expensive and not as easy to find. I have a chance to get 6 24.5 aluminum wheels lug centering for next to nothing. What size tire of the 24.5's runs that magic 496 rpm's?
With the powertrain that you have, ALL of the 22.5 tires will be "too small" in terms of gearing - lowering your top speed and increasing your fuel consumption. A set of 24.5 aluminum wheels would be perfect - but check very, very closely around the bolt holes for egging and/or cracks.
Bridgestone makes a 11R24.5 drive tire that turns 470 revs/mile. That tire (or another brand that's very close, rpm-wise) will give you an overall gearing almost identical to OEM.
FWIW & HTH. . .
;)
I ran both 11 R and 12 R on my 4106, with a standard transmission I could tell little difference, I wore the 11 r s out and went to 12 r s the bus would run better than 80 mph with either. handeled well with both. for what it is worth
Frank Allen
What is the gearing ratio difference between a 4106 and the 4905 all the 40 ft GM buses used the 12R x 22.5 I thought as standard issue std or automatic
That's correct. 4905s came with 4.375 ratio as standard. 4.11 was optional. Afaik, 4106s had 4.11 as standard.
Quote from: luvrbus on June 19, 2015, 02:10:26 PM
What is the gearing ratio difference between a 4106 and the 4905? All the 40 ft GM buses used the 12R x 22.5 I thought as standard issue, std or automatic.
Quote from: chessie4905 on June 19, 2015, 02:31:56 PM
That's correct. 4905s came with 4.375 ratio as standard. 4.11 was optional. Afaik, 4106s had 4.11 as standard.
The 35' GMs came with a 4.125:1 rear axle.
The 40' GMs came with a 4.375:1 rear axle.
Except:If the operator purchased a 40' with the V-730, GM automatically installed a 4.125:1 rear axle, in order to make up the difference because of the lower bevel gear ratio of the slush box. (0.875:1 vs 0.808:1)
FWIW & HTH. . .
;)
There is a big difference between diameter of the tire on paper and loaded radius. The previous figuring of the 11R-24.5 on bare diameter is correct. Except, when mounted and the bus resting on the tire, the tire flexes and that is called "loaded radius". So what figures to be a 463rpm tire by raw diameter, actually is a 476rpm tire by loaded radius. I have 11R-24.5 Michelin XZE 16ply all around. With 4.56 rears, V730, I cruise at 1800rpm which is 58mph. I can bump it up to 65mph which is 2150rpm. At 2400rpm I'm doing 76mph-which I've only tried once-entirely too fast. Good Luck, TomC
My tires are the same as TomC's and I have very similar road speeds at rpm with Allison 740. I am not sure of my gear ratio.. governed at 2250.
Donald-with my 4.56 ratio but with the V730 built in overdrive, it works out to be 4.01 ratio. So you probably have 3.90's which were common Eagle ratio. Good Luck, TomC