Has anyone downsized their 15" Tires to a smaller diameter?

tinglebellstinglebells Member Posts: 14
edited September 2022 in Trailer & Towing
We have a 2019 T@B 320 S Boondock Edge with 15" wheels running 235/75R15 (28" diameter) tires.  We are wanting to lower the overall height about 4" when we replace our tires.  We are wanting to fit into a standard garage without partially deflating the tires each time.  Has anyone downsized their tires yet and if so, what size is your new replacement tire?  At the bottom is an email from DEXTER AXLE that discusses the extra spin caused by smaller tire.  Below is the chart for 15" wheels from https://tiresize.com/calculator/

Tire Size Calculator Chart for 15" Wheels

20" Tire Diameter

105/70R15 = 20.8X4.1R15

21" Tire Diameter

115/70R15 = 21.3X4.5R15
125/70R15 = 21.9X4.9R15
165/50R15 = 21.5X6.5R15
195/45R15 = 21.9x7.7R15

22" Tire Diameter

125/80R15 = 22.9X4.9R15
145/65R15 = 22.4x5.7R15
155/60R15 = 22.3x6.1R15
165/60R15 = 22.8x6.5R15
175/55R15 = 22.6x6.9R15
195/50R15 = 22.7x7.7R15
22X8R15
22.5X4.5R15
245/40R15 = 22.7X9.6R15
275/35R15 = 22.6x10.8R15

23" Tire Diameter

135/80R15 = 23.5X5.3R15
165/65R15 = 23.4X6.5R15
175/60R15 = 23.3x6.9R15
185/55R15 = 23x7.3R15
185/60R15 = 23.7x7.3R15
195/55R15 = 23.4x7.7R15
205/50R15 = 23.1x8.1R15
205/55R15 = 23.9x8.1R15
225/45R15 = 23x8.9R15
225/50R15 = 23.9x8.9R15
295/35R15 = 23.1X11.6R15

24" Tire Diameter

135/90R15 = 24.6X5.3R15
155/80R15 = 24.8X6.1R15
175/65R15 = 24x6.9R15
185/65R15 = 24.5x7.3R15
195/60R15 = 24.2x7.7R15
205/60R15 = 24.7x8.1R15
225/55R15 = 24.7x8.9R15
235/50R15 = 24.3x9.3R15
24X4.5R15
24X5R15
24.5X8R15
245/50R15 = 24.6x9.6R15
345/35R15 = 24.5x13.6R15

25" Tire Diameter

165/80R15 = 25.4X6.5R15
185/70R15 = 25.2x7.3R15
195/65R15 = 25x7.7R15
195/70R15 = 25.7x7.7R15
205/65R15 = 25.5x8.1R15
215/60R15 = 25.2x8.5R15
225/60R15 = 25.6x8.9R15
265/50R15 = 25.4X10.4R15
275/50R15 = 25.8x10.8R15

26" Tire Diameter

205/70R15 = 26.3x8.1R15
215/65R15 = 26x8.5R15
215/70R15 = 26.9x8.5R15
235/60R15 = 26.1x9.3R15
245/60R15 = 26.6x9.6R15
26X10R15
26X10.5R15
26X11.5R15
26X6R15
26X7.5R15
26X8R15
26X8.5R15
295/50R15 = 26.6x11.6R15

27" Tire Diameter

205/75R15 = 27.1x8.1R15
215/75R15 = 27.7x8.5R15
225/70R15 = 27.4x8.9R15
255/60R15 = 27x10R15
27X10.5R15
27X9.5R15
27.5X4.5R15
295/55R15 = 27.8X11.6R15
325/50R15 = 27.8x12.8R15
E78-15 = 27x6.5R15

28" Tire Diameter

225/75R15 = 28.3x8.9R15
235/70R15 = 28x9.3R15
*235/75R15 = 28.9x9.3R15* (what I currently have on the T@B320 BD)
245/70R15 = 28.5X9.6R15
255/65R15 = 28.1x10R15
275/60R15 = 28x10.8R15
28X10.5R15
28X11.5R15
28X12.5R15
28X13.5R15
28X4.5R15
28X7.5R15
28X9R15


DEXTER AXLE

Mr. Tingle,

I didn’t see your axle size stated. If it’s a 10” drum or smaller the 14” wheel will fit without issue. As for your question regarding the tire size affecting the bearings. The minimal change in rolling radius will not have an effect on bearing life or heat.

Dexter would always suggest following regular maintenance to ensure long product life.

https://www.dexteraxle.com/docs/default-source/default-document-library/light-duty-maintenance-schedulee47a839d2ba463c18d7aff64007a4014.pdf?sfvrsn=30dee048_0

 

Kind regards,

 

Mark Nave | Market Manager

Dexter – Corporate Headquarters

mnave@dexteraxle.com  

direct tel: (574) 295-7888 | cell: (574) 370-2661

 

2900 Industrial Parkway East, Elkhart, Indiana 46516, USA

fax: (574) 000-0000 | main tel: (574) 295-7888

a DexKo Global Company  ■  Together is Better





Comments

  • falcon1970falcon1970 Member Posts: 754
    I suspect that would add some level of stress to the wheel bearings.  I wouldn't think Dexter engineered the bearing for the higher speeds you would incur.
    What do you hope to accomplish with smaller wheels?
  • Denny16Denny16 Member Posts: 5,420
    You could replace the 15-inch wheels with the stock 14-inch wheels that come with the non Boondock version.  But why pay extra for higher ground clearance and then lower the trailer back down with smaller wheels?
    cheers
    2018 TaB400 Custom Boondock,  Jeep Gladiator truck, Northern California Coast.
  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 9,461
    Is this to help get the TaB into your garage?
    Sharon / 2017 T@B CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • DougHDougH Member Posts: 1,110
    edited November 2020
    Some folks go to smaller rims, mount higher sidewall tires, and vary the inflation to manage traversing interesting backwood pathways?
    2021 Jeep Gladiator, 2021 tiny toy hauler, Austin TX
    Former steward of a 2017 T@B S Max

  • tabiphiletabiphile Member Posts: 423
    edited November 2020
    The difference in height at the step is only one half of an inch....the aspect ratio of most 14 and 15 inch tires is the same so the only change is the wheel diameter. Is it worth the trouble of making the change for half an inch?
    If you are using a tire size calculator be sure to take into consideration the availability of tires that are suitable for trailer use...the side wall characteristics and load ratings are not the same as for standard vehicle tires.
  • Denny16Denny16 Member Posts: 5,420
    I could see mounting the original non Boondock wheels to get the road tires vs the off road tread for a smoother ride for the trailer whilst going down highways.
    I have considered this also, as I have both sets of wheels, but on the TaB 400, both wheels are 15-inch.  However, the sidewall height is a little less on the 15-inch road tires vs the more aggressive tread AT tires used on the Boondock axle.
    cheers
    2018 TaB400 Custom Boondock,  Jeep Gladiator truck, Northern California Coast.
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