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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: mung on November 10, 2014, 07:14:57 AM

Title: Another Tire Question
Post by: mung on November 10, 2014, 07:14:57 AM
So we have discussed tires and the rotations per mile in relation to their impact on top speed and fuel consumption.  One thing I haven't seen mentioned is the relationship of tire size to ease of turning.  Given that we need every bit of help we can get turning in tight spaces especially with older buses that have no or weak power steering (if mine is working at all, it doesn't do much), does tire size make any difference on the ability to turn the bus?  I would think that a the less width on a tire the easier it would be to turn at slow/no speeds. 

Thoughts on this?
Title: Re: Another Tire Question
Post by: wg4t50 on November 10, 2014, 07:39:43 AM
Having the integral power steering on the MC7, never noticed any change between the 11R22.5 and the 11R24.5 but for mountain climbing the 11R22.5 did better with the 8V-71 than the 11R24.5 due to difference in ratio, 20 rev per mile makes a difference.
Other than that I am clueless.
Dave M
Title: Re: Another Tire Question
Post by: Ed Hackenbruch on November 10, 2014, 04:37:23 PM
Wider the tire, the more effort to turn it. 
Title: Re: Another Tire Question
Post by: luvrbus on November 10, 2014, 04:49:49 PM
There no difference in the width between a 11R 2 x22.5 and 11R 24.5 the 12Rx22.5 will be wider higher air pressure in the front will make it turn easier
Title: Re: Another Tire Question
Post by: wg4t50 on November 10, 2014, 06:03:20 PM
I try to never turn wheels while stopped, hard on the rubber also with or without power steering.
Dave M
Title: Re: Another Tire Question
Post by: HB of CJ on November 10, 2014, 06:36:07 PM
I am not sure if it makes that much difference in turning effort.  However some Bus Conversions may not have enough front wheel well clearance to handle a much taller or wider tire, especially when the front wheels are hard over AND the front suspension compresses or works. 

Fortunately, my old Crown Supercoach "almost conversion" had lots of wheel well clearance front and rear.  Even sloppy loose tire chains did not seem to bang the wheel wells.  However, I do not know if such would handle a "super single" wide front tire or similar.   HB of CJ (old coot)
Title: Re: Another Tire Question
Post by: PP on November 11, 2014, 02:06:06 PM
Tire height shouldn't have any effect on turning in a campground or at low to no speed because the pivot points haven't changed. However, tire width will have an impact as it creates more rubber to road contact surface which will increase turning resistance either from side to side (turning) or rolling forward. That's physics. Higher tire pressure reduces the amount of contact surface (outer edges curl up and rubber won't fold over objects as easily) which lessens surface resistance and makes it easier to turn and roll. Again, physics. HTH
Will
Title: Re: Another Tire Question
Post by: mung on November 11, 2014, 03:18:25 PM
Right, so is there an option of thinner tires that will work with our coaches?
Title: Re: Another Tire Question
Post by: solodon on November 11, 2014, 06:19:33 PM
I can't even imagine trying to turn the front wheels if they had super singles mounted.  Yuch and better eat about 30 bowls of wheaties.
Title: Re: Another Tire Question
Post by: mung on November 12, 2014, 07:38:00 AM
I already need spinach to turn it now.
Title: Re: Another Tire Question
Post by: TomC on November 12, 2014, 11:49:18 AM
I have 11R-24.5 tires, but only 10,500lb on the front axle. My Sheppard steering is finger tip-whether rolling or stopped. Good Luck, TomC
Title: Re: Another Tire Question
Post by: mung on November 12, 2014, 12:09:31 PM
I have the original power assist on the 4104.  It was totally out of fluid when I got it and I put some in, did the whole turn the wheel while jacked up procedure, but it doesn't seem to really be working.  So I need to figure out how to determine if the pump is even pumping fluid.
Title: Re: Another Tire Question
Post by: eagle19952 on November 13, 2014, 09:24:29 PM
that would be crack the pressure hose and start the steering wheel turn....lotsa oil it's pumping...a dribble it's not... ;D

Quote from: mung on November 12, 2014, 12:09:31 PM
I have the original power assist on the 4104.  It was totally out of fluid when I got it and I put some in, did the whole turn the wheel while jacked up procedure, but it doesn't seem to really be working.  So I need to figure out how to determine if the pump is even pumping fluid.
Title: Re: Another Tire Question
Post by: TomC on November 13, 2014, 10:42:41 PM
Sheppard power steering needs pressure. When I put the power steering on my bus, the old pump was putting out only 1,500psi. Couldn't turn the wheel when stopped. Put a new Vickers pump in at 2,200psi-and works great. Also uses 15W-40 engine oil. Good Luck, TomC
Title: Re: Another Tire Question
Post by: wg4t50 on November 14, 2014, 01:46:29 AM
Same thing on the MC7 when changed from the old power steering system to the integral Shepard, needed to change the spring in the pump, made a huge improvement.
Dave M
Title: Re: Another Tire Question
Post by: mung on November 14, 2014, 05:09:15 AM
Don is there a way to do that without spraying fluid everywhere?