| [GMCnet] Tires (again) [message #198613] |
Sat, 16 February 2013 13:17  |
|
|
OK, kids, looking for opinions/advice. It is time for tires
(mine are approaching 10 tears old (yeah, I know, co
comments about age)).
I am NOT looking for brand/model answers, I can make my own
decisions there (the old tires are Big O house brand and
have been JUST FIN, thank you!).
The question of the day is what is the consensus on going to
a larger size (245vs225 75 R16)? I like the idea of more
tread on the ground and don't care about speedo calibration
(I can handle that in my (feeble) head).
Considerations, I have a Manny 1 ton front end, Eagle wheels
and JimK Quadabag.
Thoughts?
tt
74 (ex)Eleganza SE
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Terry Taylor
'74 ex-Eleganza SE
San Lorenzo, CA
http://www.n6mon.org
http://dldesignstore.com
|
|
|
|
| Re: [GMCnet] Tires (again) [message #198630 is a reply to message #198613] |
Sat, 16 February 2013 14:21  |
tphipps
Messages: 3005
Registered: August 2004
Location: Spanish Fort, AL
Karma: 9
|
Senior Member |
|
|
You will find that larger tires may cause serious clearance problems, especially in the rear. Stick with the LT225/75 R 16.
No sense in adding additional work.
73's have clearance problems. I suspect that some early 74's may have the same problems.
Sticking with the 225 tire means that you really do not have to worry about the speedo being off (very much).
Just my take on tires.
Tom, MS II
with LT225/75r16s
2012 Phoenix Cruiser model 2552
KA4CSG
|
|
|
|
| Re: [GMCnet] Tires (again) [message #198637 is a reply to message #198630] |
Sat, 16 February 2013 14:52 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
|
Senior Member |
|
|
I agree with Tom. When a certain anonymous "Used to be Skinny" individual
bought his first coach, it came with oversized tires (I don't remember but
probably 235's). We saw right off the evidence of them having hit the
fender flares, but the real catastrophe came when he, not then knowing how
to manage ride height, made the first 3 mile drive from his house to mine.
Before he got here, the right center tire had contacted the apparently new
air bag and worn a 1/2" X 3/4" hole in it. Need I say more?
Ken H.
On Sat, Feb 16, 2013 at 3:21 PM, Thomas Phipps wrote:
>
>
> You will find that larger tires may cause serious clearance problems,
> especially in the rear. Stick with the LT225/75 R 16.
> No sense in adding additional work.
> 73's have clearance problems. I suspect that some early 74's may have the
> same problems.
> Sticking with the 225 tire means that you really do not have to worry
> about the speedo being off (very much).
> Just my take on tires.
>
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
|
|
|
|
|
|
| Re: [GMCnet] Tires (again) [message #198643 is a reply to message #198637] |
Sat, 16 February 2013 16:35 |
|
|
For what it's worth,and I really respect the opinions on here, I have run the 245's since 2003 and mine are nine years old. BFG TA's bought at Costco; I know that Dan (and others) runs the same but he won't argue that on here. I've spent a lot of time working on my coach and only have maybe 5000 miles on them. My coach has a wonderful ride with no rutting and good steering;
I haven't done much front end work 'cept bearings and lube. I did set the ride height several years ago and have no way to adjust the pressure in the bags (new in'03)except manualy. My tires look good and I probably will sell my coach this year; I'm 85 and slowing down. Good luck w/your decision.
geo groth '73 260 Sequoia
Carson City Nevada 89703
|
|
|
|
| Re: [GMCnet] Tires (again) [message #198644 is a reply to message #198613] |
Sat, 16 February 2013 17:03 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
If you run wider tires you will have a wider contact patch but a shorter one. So you actually end up with about the same amount of tread on the ground. The only way to end up with a larger contact patch is to reduce the amount of air in the larger tires.
If you want more weight carrying, go to a higher load range like LRE. If you want more traction go to an AT tire like the Kuhumo KL78. Otherwise an all season tire is your next best option. If you want a softer ride and better handling go to a ragwall radial.
I would stay with the correct size tire and run them at the correct pressure determined by the weight on each axle.
Wider is not necessarily better.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
| Re: [GMCnet] Tires (again) [message #198648 is a reply to message #198644] |
Sat, 16 February 2013 17:15 |
tphipps
Messages: 3005
Registered: August 2004
Location: Spanish Fort, AL
Karma: 9
|
Senior Member |
|
|
Second Ken's comment on using Polywall tires. Since during the development of the coach, bias-ply were the heavy duty tires of the day. The Polywall more closely offers similar flexibly to bias-ply. Others prefer all-steel.
I have poly-wall tires, with steel thread. I am happy with the ride and handling of the coach. Prices of Poly-wall also appear to be more friendly.
Get your coach weighed at International, and set your tire pressure to the actual weight that each tire supports.
Tom, MS II
2012 Phoenix Cruiser model 2552
KA4CSG
|
|
|
|
| Re: [GMCnet] Tires (again) [message #198664 is a reply to message #198613] |
Sat, 16 February 2013 19:03 |
bryant374
Messages: 563
Registered: May 2004
Location: Pleasant Valley, NY 12569
Karma: 1
|
Senior Member |
|
|
FYI: At TZE# 4V101022 the rear wheel housing inner panel changed from poly plastic to SMC/fiberglass.
The rear suspension pins/bushings had changed from 1 1/4" to 1 1/2" 12 units before at TZE 4V101010.
Bill Bryant
PO 1976~PB (owned 34 years)
1914 Ford (owned 70 years)
1965 Corvette (owned 39 years)
GMC Motorhome History
|
|
|
|
| Re: [GMCnet] Tires (again) [message #198721 is a reply to message #198613] |
Sun, 17 February 2013 10:55 |
John Wright
Messages: 118
Registered: September 2008
Karma: 0
|
Senior Member |
|
|
Terry,
On our present coach (the Buskirk stretch) we run a 225 on the front to take advantage of the final drive ratio that we have. We have a 3.66 ratio final which is a combo of a 3.21 final drive and a 3.50 chain drive. A larger tire sizeThe rears are a 245 size tire that were originally sized because of the heavier weight of the coach. We finally got the coach weighed and it came out to a gross of 13,360 with a 4,880 to 8,480 balance. The 245 tire works with our coach because of the modified 4 bag suspension which is a heavier version of a Leigh Harrison with larger bags and thicker and raised support arms and that the body is raised 2" on the frame.
The 245 tire is a difficult fit although there are some that run it with success. In the 73/74 coaches you have issues with the wheel wells and you can damage your air bags with all year coaches if your ride height is incorrect or you lose air pressure. Some have had issues with the early designed replacement air bags. I made an emergency run to help a fellow GMCer who had installed an replacement airbags system and tore up 2 of the air bag with the 245 tire which. We had to reinstall two of the old style air bags for clearance. He was on his way to Alaska.
I see no need or real advantage (JMPO) in using a larger size tire. The 225 tire has plenty of load capacity for our coaches, but if you decide that you must use a bigger tire I wouldn't go any larger than the 235 on the back and leave the 225 on the front.
Here is the chart that compares tires size and ration changes.
http://www.gmceast.com/technical/Brown_Drive_Tire_Ratios.pdf
J.R. Wright
GMC GreatLaker
GMC Eastern States
GMCMI
78 Buskirk 30' Stretch
1975 Avion (Under Reconstruction)
Michigan
On Feb 16, 2013, at 2:17 PM, Terry Taylor <n6mon@pacbell.net> wrote:
> OK, kids, looking for opinions/advice. It is time for tires
> (mine are approaching 10 tears old (yeah, I know, co
> comments about age)).
>
> I am NOT looking for brand/model answers, I can make my own
> decisions there (the old tires are Big O house brand and
> have been JUST FIN, thank you!).
>
> The question of the day is what is the consensus on going to
> a larger size (245vs225 75 R16)? I like the idea of more
> tread on the ground and don't care about speedo calibration
> (I can handle that in my (feeble) head).
>
> Considerations, I have a Manny 1 ton front end, Eagle wheels
> and JimK Quadabag.
>
> Thoughts?
>
> tt
> 74 (ex)Eleganza SE
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
| Re: [GMCnet] Tires (again) [message #198775 is a reply to message #198721] |
Sun, 17 February 2013 19:07 |
John Sharpe
Messages: 489
Registered: February 2006
Location: Texas
Karma: 1
|
Senior Member |
|
|
| Quote: |
.....what is the consensus on going to
a larger size (245vs225 75 R16)?......
|
If you loose air in the rear bags 245's have been known to wear holes in the air bags.
John Sharpe
Humble,TX
'78 Eleganza TBI
'89 Spectrum 2000 MPI V-10
'40 Ford Panel Delivery TPI
johnasharpe@gmail.com
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
)