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sp250 tire size

rkhmarin
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Location: Tampa, Florida, USA

sp250 tire size

Post by rkhmarin »

Does anyone use 165 80 15 tires on sp250? will they fit?

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migray
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Re: sp250 tire size

Post by migray »

Yes they fit the standard, rather narrow, wheels.
I got these ones which are H rated for speed. They drive okay in my opinion and look suitable.
https://www.mytyres.co.uk/rshop/tyre/Re ... H/R-361170

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Ian Slade
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Re: sp250 tire size

Post by Ian Slade »

Yes but your speedometer will over read and fuel economy will suffer, the ideal is 175/80 R15 but seem to be no longer available, the nearest size to the original if you have 5.5J rims is 195/65 R15
Owner since the 70's, Genghis is slightly to my left.

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migray
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Re: sp250 tire size

Post by migray »

Useful article here on tyres for the dart https://www.longstonetyres.co.uk/classi ... /dart.html
The standard steel wheels were only 4" wide, the wire wheels half an inch wider which helps accept wider tyres.
Longstone seem to recommend 180 x 15 or 165 x 15
Last edited by migray on Wed Apr 28, 2021 4:28 pm, edited 1 time in total.

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John-B
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Re: sp250 tire size

Post by John-B »

migray wrote: Wed Apr 28, 2021 3:00 pm Useful article here on tyres for the dart https://www.longstonetyres.co.uk/classi ... /dart.html
The standard steel wheels were only 5" wide, the wire wheels half an inch wider which helps accept wider tyres.
Longstone seem to recommend 180 x 15 or 165 x 15
Are you sure steel wheels are 5"? Mine were 4" and suitable for 165 or 175 tyres but not 185. Manual says steel rims 4J x 15".
It's OK to fit 175 or 185 tyres on 5" or 5.5" rims.

Ozzsp250
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Re: sp250 tire size

Post by Ozzsp250 »

Here is an interesting tire size calculator that compares the result in mph between two tire sizes and gives RPM for a known final gear ratio.

https://www.tacomaworld.com/tirecalc?ti ... -175-80r15

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migray
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Re: sp250 tire size

Post by migray »

You are right John-B 4"is the original size - I have edited my post.

Chris_R
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Re: sp250 tire size

Post by Chris_R »

Blockley Tyres also do these https://www.blockleytyre.com/product/550-x-15 which are recommended for 4" rims but will fit rims between 3.75" and 5.5".
Whether they are suitable for the SP250 or not I don't know but the size is probably about right.

peterbee
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Re: sp250 tire size

Post by peterbee »

Tyre size is governed by rim size. If you are running original steel rims, these are 4J rims. The "4" means that the dimension between the tyre bead seatings is four inches. The overall width of the rim is five inches. If you are running wire wheels then the rim size will be between 4J and 5.5J. If you are running alloys then the smallest I have found is 5.5J and I doubt if you can run anything greater than 6J. I have calculated mph at 1000rpm for various gearbox/tyre combinations. If you want a spare wheel to fit in the spare wheel well I am told the maximum size is a 5J rim.
Attachments
Mph calculator.xlsx
(13.93 KiB) Downloaded 58 times

rkhmarin
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Re: sp250 tire size

Post by rkhmarin »

My rims are original steel rims. They are 4" between inside 5" outside.

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