Differences

This shows you the differences between two versions of the page.

--- cars:wheels [2025/02/10 20:03] – created - external edit 127.0.0.1
+++ cars:wheels [2025/02/13 06:52] (current) – Nedra
@@ Line 1: / Line 1: @@
 ====== Wheels ======
-Just buy the cheapest wheels that Harbor Freight sells.
+There are a variety of sizes and configurations of the assorted wheel, rim, hub, tire etc that people will use on different vehicles, powered and unpowered. it can feel overwhelming at first to take a first stab at setting up the wheel assembly for a Power Racer; hopefully this document will help.
-**KIDDING!**
+Typically a Wheel assembly is made up of three distinct components:
+  * the Tire -- the rubber bit that is in contact with the pavement
+  * the Rim -- the formed sheet metal bit or bits that the tire seats against and gets bolted to the Hub.
+  * the Hub -- the machined hunk of metal which the rim bolts to to attach the tire to the axle.
-You can use the cheapie Harbor freight wheels, but you'll need to do some <del>welding</del> reinforcing of the rims, as they are not built to take any lateral force, and will just rip themselves apart. If you're after the Crash & Burn award, go for it. Also, you should replace the bearings. Probably.
+Each of these pieces are characterized with a variety of measurements which let you know if they are compatible with each other. let's examine a test-case example:
-Alternately, better wheels will last longer.
+I've found a stack of cheap racing slick tires buried in a box which is printed 10x3.5-4 on the side.
+this measuring schema lets me know that this tire has a nominal 10" outside diameter, a nominal width of 3.5" inside side wall to outside side wall, and a 4" internal diameter nominal hole for the rims.  (just like how the cheap HF tires are printed 4.10/3.50-4 -- note the difference between X and / in the reporting: 4.10 refers to the total sidewall height. 4.10+4=8.10" total nominal diameter, actual will be a little larger.)
-(Add links below to where you get your wheels)
+at this point you can know that, if you want to run this 10x3.5-4 tire, you'll need a rim which can accommodate that tire: a 4" nominal diameter rim, which is close to 3.5" in overall width.
+Rims are available in a variety of pricepoints with these and other specifications for those two data-points. importantly, rims also will contain a "bolt hole pattern" which is used to connect the rim or rim halves to the hub. For wheels of the typical size in this league, this bolt hole pattern/circle with often be either a 3-bolt or a 4-bolt circle. consider this table for common sizes within the league:
+^ Bolt hole count ^ Bolt hole diameter ^ bolt specs ^ common rim diameter ^
+| 4               | 2-13/16"           | 5/16"-NF   | 4"                  |
+| 3               | 55mm               | 8mmx1.25   | 5"                  |
+| 3               | 2-1/2"             | 1/4"-NF    | ???                 |
+| 4               | 2-7/8"             | 3/8"       | 5"                  |
+Do not consider this table to be comprehensive, just a light selection of options that have been run before.
+In our rolling example, we'll select a split 4-bolt hole pattern 2-13/16" 4" rim, so it will fit onto the 4" ID tires we have, and will bolt up to a 4-bolt 2-13/16" circle hub with 5/16"-NF bolts. We can select a hub of whatever ID is appropriate to connect to our axle, and congratulations, you've successfully built a wheel.
+===== Further Notes =====
+While some consider it a rite of passage for first-time teams to run and break the crappy Harbor Freight "10 in. Pneumatic Tire with White Hub" wheels, it's generally not recommended to trust your kart to the cheap stock HF setups. Some teams [who?] have had success with reinforcing the 4" rims that come on the cheapest 4.10/3.50-4. They are not built to take any lateral force, and will just rip themselves apart without these modifications.
+Linked [[https://rasterweb.net/raster/2017/06/18/wheels-of-improvement/|Here is a 2017 guide from racer Pete Prodoehl about adapting the HF wheels with a "proper" hub.]]
+here is a selection of other sources teams have bought wheel parts from previously:
-===== Links =====
   * [[http://www.harborfreight.com/10-in-pneumatic-tire-with-white-hub-62409.html| Harbor Fright Wheels]]
   * [[http://www.northerntool.com/shop/tools/product_18845_18845|Northern Tool Wheels]]
@@ Line 23: / Line 46: @@
 ===== Models =====
-  * 3D Printed Hubs by Matt for the Orange Truck
+  * 3D Printed Hubs by Maddie for the Orange Truck
    * {{:cars:prs-front-hub.sldprt|PRS-front-hub.sldprt}}
    * {{:cars:prs-front-hub.stl|PRS-front-hub.stl}}