Outside diameter Insa dakar

Outside diameter Insa dakar

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Discussion

James-lw83o

Original Poster:

2 posts

72 months

Monday 2nd April 2018
quotequote all
I’m doubting myself with tyre diameter, hoping someone can help.
I’m currently running 17x7” with 235/65r17 road tyres and want to drop to 16x8” with 235/70r16, likely with an Insa Dakar.
Using aspect ratio I get the following:
Current set up- 29” diameter
New set up- 28.95”

So it shouldn’t be an issue, however I keep doubting it. Am I right or am I missing something?
Does anyone run 235/70r16 Dakar’s on 8j wheels, if so what’s the outside diameter?


InitialDave

11,901 posts

119 months

Monday 2nd April 2018
quotequote all
An aggressive tyre's extra tread depth may make it larger in diameter even if it ha the same nominal carcass size as another tyre.

I'd get a tape measure out.

Is your concern gearing/speedo reading, or clearance against arches etc?

Greener Jim

Original Poster:

2 posts

72 months

Monday 2nd April 2018
quotequote all
Cheers mate thanks. Arch clearance is the concern, don’t mind the speedo being a little out.

If needs be I will go 235/60r16 which would help quite a lot

Edited by Greener Jim on Monday 2nd April 15:07

PhillipM

6,520 posts

189 months

Wednesday 4th April 2018
quotequote all
Use this size on the buggy - the Goodyears of the same pattern as the Insa's in 235/70R16 were just shy of 30.5" new - the 235/70R16 Fedima Extreme's we run now are closer to 31"

KevinCamaroSS

11,635 posts

280 months

Thursday 5th April 2018
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You are not missing anything, the difference is actually a nominal 0.08" in diameter with the 16" being smaller, differences in tread depth excluded.

Darkslider

3,073 posts

189 months

Thursday 5th April 2018
quotequote all
What vehicle is it on? The pistonheads answer is to go to a 235/85/16 and trim off whatever catches. It'll look the dogs!