Wheel Offset

There seems to be a lot of confusion between wheel offset and backspacing. This video will explain the differences and why and when you need to care about both.
Chapters:
Introduction 0:00
What is Offset? 0:52
How to determine the Offset of a wheel 1:04
What is Backspacing? 1:53
How to measure Backspacing 2:07
Why we care 2:27
8" wheel example 2:49
10" wheel Example 3:03
Same backspacing example 3:13
What to consider when choosing wheels for a car 3:40
Other potential problems 4:23
Be sure to check out my video on wheel spacers and their effect on suspension geometry here: • Wheel Spacers: Good Id...
Huibert Mees
Suspensions Explained

[@Sussy-hotdog]

By far clearest explanation I've seen by using live tire as well as CAD diagrams to demonstrate ramifications to consider in modifications to either BS or OS to rim sizing.

[@MatheusSSchmitz]

Great video! This is the best channel about suspensions, with the most effective teaching method! Could you make a video about steering, scrub radius, mechanical trail, caster angle, king pin angle, and Ackermann?

[@CanadaLuke]

Great video! One topic I haven't really heard much discussion about over the years is bushing designs in different positions of the control arms. A lot of aftermarket companies sell harder bushing without much engineering or thought. I'd like to learn more about that and if some bushings might be ok to replace with harder ones or if they're usually a bad idea.

[@suspensionsexplained]

Thanks for watching. I have bushing design on my list of topics to cover in the future.

[@PS_on_youtube]

Thank you for this video & explanation. I remember leaving a comment on your wheel bearing video about 'if i change out my 7in wheel for a 8in wheel (and i used a 0.5in spacer) would that be OK..' I thought about it a week later and remembered that offset is determined from the centerline, not the outside face of the wheel. Silly me.. Back spacing is something i did not know about. i learned something new. *I have been looking into doing a complete overhaul of my cars suspension system. I have Macpherson suspension in the front and multi-link with trailing arm in the rear. I am researching converting both to double wishbone and pushing the wheels out 2in in the front, and 3in in the rear. I have spent the past 2 years working on a replica of Ken Blocks Ford Focus RS RX (video's on my channel). The car will never see racing or off-roading, so the custom suspension doesn't need to be super crazy dialed in for professional level events.. as long as the car drives comfortably in a straight line and handles daily driving at normal speed limits i'm good.

[@suspensionsexplained]

Thanks for watching. If your car is only meant for daily driving and needs to be comfortable then why change the suspension unless you just want the challenge (which I can totally understand!). The stock suspension does both quite well already. I can assure you Ken Blocks cars are VERY uncomfortable, as is any race car. Stiff springs and no rubber bushings make for a very harsh ride. Fine on a race course, but not so good on the street.

[@bushrod6258]

My question is once you find out your offset than what is the calculation to figure out the minimum and maximum offset allowed?

[@suspensionsexplained]

There is no hard a fast answer to that question. IT depends on the rest of the suspension design. I really wouldn't change the offset more than a few mm without risking changing other suspension parameters and performance too much.

[@mry82]

I've only bought aftermarket wheels once, out of necessity rather than aesthetics (though I did like the new wheels better!); I went from a stock +55mm offset to +45mm and cannot say I noticed any difference driving wise... 2006 Mazda MX-5

[@user-cp3ps5pi4b]

Very enjoyable video! Please, can you recommend any books about suspension systems?

[@suspensionsexplained]

The book that every suspension and vehicle dynamics engineer has on their desk is Race Car Vehicle Dynamics by Milliken and Milliken. It is the suspension engineer's bible. The other book that is very good to start with is Fundamentals of Vehicle Dynamics by Thomas Gillespie. Both are excellent books although the Gillespie book is a bit more approachable. Race Car Vehicle Dynamics is more like a university level textbook. Excellent, but very deep and technical.

[@user-cp3ps5pi4b]

@@suspensionsexplained Big thanks, I appreciate it!

[@needadate]

Steering radius, anyone?

[@krishnas525]

hello sir can you post a series on DESIGNING A SUSPENSION GEOMETRY FOR A FSAE CAR - DOUBLE WISHBONE, DAMPER TO LOWER ARM TO BODY or PUSH ROD SUSPENSION, I will be waiting sir i request you sir