Mixing tire sizes steers and drives

[kotflb]

If you have 22.5 rims, you may not have to change the rims in order to go with the larger 11:22.5 tires. Unless your rims are only 6.5 inches wide. The preferred rim for a 11:22.5 is 7.5 to 8 inches wide but some tire brands say a 7 inch rim is ok.

There is nothing wrong with running different size tires on the front axle vs the rear axle. Many semis do it, the only drawback is needing two different size spares, and that's even if you plan to carry a spare at all. Once your rear tires wear down, than you can upgrade the rear to match the steer axle tire size. The 11:22.5 is plentiful and easy to find, in the event you need to buy one on the road. Most truck stops carry them in stock.


As far as new vs used tires, I, myself would put the best virgin tire I could afford on the front. Recapped tires on the rear
are pretty much standard on school buses and most do hold up very well. If your having a tire recapped, or looking to buy a recap, look for the one piece or continuous cap w/o the slit across the tread. Goodyear calls theirs Circle Caps, Bandag calls them something else, but the concept is the same. Hopes this helps, safe travels.

[Redbear]

Originally Posted by kotflb

. . . .There is nothing wrong with running different size tires on the front axle vs the rear axle. . . .

I agree. Just don't mix them on the same axle. The only vehicles I know of where identical front/rear tires are a must is for "full-time" All Wheel Drive cars operated on hard pavement. Using "part-time" 4-Wheel Drive assumes you are on a slick surface, and the wheels can slip some if turning different speeds.

[bapos]

kotflb

I just recently got out of the commerical tire business and what they are say prior to me is spot on. No issues with different sizes on the same axle. The rims (if the bolt pattern is the same and widths are the same) should work on either size. So when you wear one set out you can put on a matching size of the other tire.

I would suggest the 11r225. You will find it a little more often at tire stores than the 10r225. The 10r225 is not super common. A lot of bigger shipping fleets still used the 11r225 so lots of dealers stock that even if various load ranges.

I would ALWAYS go with a virgin on a steer axle and possibly caps on the rears when it comes that time.

If I can help some more please let me know.


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[grampsbutler]

I have a 1984 bluebird flat front. It currently has 11R22.5 all around.

I bought it a couple of years ago, and the first thing that I had to do was replace the steerers. I did this with new tires.

Now the drive tires are perished, and will need to be replaced within the next year or so. I was thinking of replacing them with a bigger size, to try and gain higher gearing. Does anyone have any experience with this?

One of the biggest problems with the bus is cruising at 65 I am reving the hell out of the engine which could really use another gear. I figured that instead of messing with the rear end reduction (which sounds like a can of worms). Bigger tires could give me a 10% reduction at the road. Any thoughts on this? Has anybody tried this...what tire size would you recommend?

Graham


Intrepid Cycles
http://www.intrepidequipment.com Handcycles and recumbent trikes

[bapos]

Graham

I use to work in this line of business this past job. Your 11r's are about the same in height to LP 245s. So there is not a huge improvement. The only real option you have is going to an 11r245. It will help but on the flip side.... they are harder to find.... more expensive... and you will have to replace all of the rims (since you would be going to a 24.5 rim) so I think the cost and down sides are way higher then the reward. You can find cheap tires out there but they suck in quality, your gas mileage will go down, and they will wear quick. I dont work in the tire business anymore so I have no vested interest in selling you a expensive tire but I am dead sold on michelin tires hands down.

As much of a pain in the ass as gear change would be.. I think its in your best interest to stay where you are in tires and work on the gear side? Just my opinion. I am fighting the same issues you are. I have a set of LP 24.5 on the front and some 9.00r 20's on the back. I went to my old job to see if they can hook me up with some 24.5 budd rims. Once I have the conversion done, by then I should have a full set of lp24.5's on it, and if the rpms are still mucho high I will make the gear change. I want the weight to be where its going to be so I dont under gear it.

Hope this helps. If you need more techinal if I would be glad to show you the math ok?

[grampsbutler]

Thanks! That is excellent info. I also did a little research and came to the same conclusion. By going to a 24.5 I would only gain about 5% based on the tire circumference. That is definitely not worth the cost.

I am also looking at auxiliary under/over drive options. There is a Spicer brownie box for sale locally here in San Diego which would give me an under, 1:1 and a 0.83 overdrive. This sounds like it might be the ticket. It is old and heavy, and will be a pain to install, but it should give me the range that I am looking for. I will also carry the original drive shafts with me, in case for some reason it blows up on the road, I can just put the originals back and be on my merry way.

Thanks again
Graham

Intrepid Cycles http://www.intrepidequipment.com Handcycles and recumbents

[bapos]

No problem.

Im glad yours and my math came out the same. I think its a good idea but the investment will not be worth the steps involved.

I think the OD unit is a good idea but again lots of work and fab to make it happen. I still think the gear change will be more of a one step process.

As said I would wait to the every end when your conversion is done to make sure your gross weight wont change that much and determine how to get closer to the rpm and fuel range your looking for.

Let me know when you do this. I am interested in your results.


Bapos