Richard Quinn
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| posted on 26/3/09 at 10:34 PM |
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Toe - mm v. degrees
I have figures of 1.5mm toe in (front) and 3mm toe in (rear) to work to. What would this be roughly in degrees (14" wheels)?
Cheers
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adithorp
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| posted on 26/3/09 at 10:52 PM |
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Varies depending on your wheel size but not by much.
Roughly speaking 1'=6mm or 1mm=10"
adrian
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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NS Dev
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| posted on 26/3/09 at 10:57 PM |
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take it your measurement is overall toe not per wheel?
If so,
Front, toe per wheel = 0.75mm
Wheel dia = 356mm
Toe in deg = inverse tangent of 0.75/356 = 0.12 degrees
rear = 0.24 degrees
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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MikeR
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| posted on 27/3/09 at 08:54 AM |
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can someone explain that in more noddy terms. ....
When i do the maths i get a fraction over 0.10 degrees for the front wheel.
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NS Dev
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| posted on 27/3/09 at 02:48 PM |
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yea, 0.12 degrees as I said!
That is exactly right
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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NS Dev
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| posted on 27/3/09 at 02:50 PM |
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PS adithorp's rule of thumb is spot on, 6mm is about 1 degree, 1mm is 10 minutes of a degree, just thought I'd show where it comes from.
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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MikeR
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| posted on 27/3/09 at 06:26 PM |
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ok,
0.75/356 = 0.0021067415730337078651685393258427
(windows calculator)
inv tan of above = 12 degrees.......
no idea what i was doing when i tried it in the office, everyone ignore me.
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NS Dev
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| posted on 27/3/09 at 10:06 PM |
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lol you mean 0.12 degrees...............
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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MikeR
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| posted on 27/3/09 at 11:10 PM |
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[cough]
i dropped the 0. ..... whats a 0. between friends? 
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907
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| posted on 28/3/09 at 12:25 AM |
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IMHO
The thing is, with normal workshop tools, you can measure in mm, but not in degrees.
So is it not more practical to quote toe figures in mm?
Paul G
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Richard Quinn
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| posted on 28/3/09 at 06:31 AM |
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Probably, but someone had lent me an optical alignment gauge which reads directly in degrees!
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rusty nuts
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| posted on 28/3/09 at 07:30 AM |
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quote:
Originally posted by Richard Quinn
Probably, but someone had lent me an optical alignment gauge which reads directly in degrees!
Some of the optical tracking gauges , Dunlop for one , has both degrees and mm/in. Just rotate a dial to set wheel diameter and read off
whichever
PS Make sure you calibrate the gauges before using if they are the Dunlop type. Put the gauges together and take a reading, centralise the scale to
zero.
[Edited on 28/3/09 by rusty nuts]
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Richard Quinn
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| posted on 28/3/09 at 08:45 AM |
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quote:
Originally posted by rusty nuts
quote:
Originally posted by Richard Quinn
Probably, but someone had lent me an optical alignment gauge which reads directly in degrees!
Some of the optical tracking gauges , Dunlop for one , has both degrees and mm/in. Just rotate a dial to set wheel diameter and read off
whichever
PS Make sure you calibrate the gauges before using if they are the Dunlop type. Put the gauges together and take a reading, centralise the scale to
zero.
[Edited on 28/3/09 by rusty nuts]
Ahhh, wondered what the black dial contraption was for. How does that work then? I guess it's
something to do with setting the wheel diameter and the mm you want to allow you to convert?
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rusty nuts
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| posted on 28/3/09 at 09:14 AM |
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Yes , set the dial to the wheel diameter , take a reading from the scale at the end of the gauges and compare with the rotary scale. To centralise the
gauges place them on the car and adjust the contacts that rests on the wheel so they touch the wheel rim (avoiding any balance weights) then place the
gauges together making sure the contacts touch and look down the periscope, move the scale arm until the line visible lines up with the marks on the
face of the gauge then take a reading. If the reading is not zero slacken the nuts under the scale and adjust. place the gauges on the car and away
you go.
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Richard Quinn
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| posted on 28/3/09 at 09:27 AM |
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Is the "wheel diameter" considered to be the distance between the two points where the arms touch the rim?
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rusty nuts
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| posted on 28/3/09 at 09:31 AM |
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yes.
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NS Dev
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| posted on 30/3/09 at 05:39 PM |
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quote:
Originally posted by 907
IMHO
The thing is, with normal workshop tools, you can measure in mm, but not in degrees.
So is it not more practical to quote toe figures in mm?
Paul G
totally agree, but most "quoted setups" are in degrees, so you have to convert at some point, though a general purpose setup of about 3mm
overall toe at both ends of a locost ain't going to be very far off.
Think that's about what mine has iirc, it was a while ago now
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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craig1410
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| posted on 11/4/09 at 11:10 PM |
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Hi guys, just been looking at my setup as I just set it by eye previously.
I get 5mm of overall toe out measured at the surface of the tyre which is 591mm diameter. I make this 0.48 degrees in total which is 0.24 degrees per
wheel. Correct?
What I am unsure of is whether, when discussing toe angles, do people tend to talk about overall angles or per-wheel angles? For example, if someone
said that 1 degree toe-in was considered a good starting point then would this be 1 degree overall or 1 degree per wheel?
In Des Hamill's book he talks about having up to 3.2mm of toe-out but I'm not clear if he means 3.2mm per wheel or 3.2mm total. Anyone
know?
Cheers,
Craig.
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rusty nuts
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| posted on 12/4/09 at 08:03 AM |
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The quoted angle or mm is normally total degrees/mm and the measurement is taken at the wheel rim not the tyre . IMHO 1degree toe in is a bit
excessive although there is always the exception , I would start at around 1/2 degree .
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craig1410
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| posted on 12/4/09 at 11:08 AM |
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thanks for that, that's what I thought. The 1 degree figure was just for illustration, I believe a small amount of toe out is actually better,
especially for a non ackerman setup like mine. I'm probably not far off optimal where I am. Once I get it on the road (hopefully this week...) I
can play with the settings.
Thanks again,
Craig.
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