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Discussion Starter · #1 ·
I’m currently in the process of doing a small restoration on a 2008 KTM 85 SX BW. I can’t for the life of me find a set of road legal tyres in sizes 70/100-19 and 80/100-16.

I’ve searched endlessly for hours on the internet but have failed to source anything. Does ANYONE have any ideas for me please.

Thanks,

Shaun
 

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Maybe your search text is wrong... usually put the tyre width/profile-size 100/70-19 100/80-16
Yep, the first numbers are the width of the tyre in millimeters. The second numbers are how many % the height of the tyre is of the width of the tyre. 100/80 means 100mm wide and tyre height is 80% of that.
 

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Discussion Starter · #4 ·
Yep, the first numbers are the width of the tyre in millimeters. The second numbers are how many % the height of the tyre is of the width of the tyre. 100/80 means 100mm wide and tyre height is 80% of that.
I can find the sizes just can’t find any that are road legal
 

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Im searching as it’s written on the tyre like I have always done for my car tyres
You are correct in the way you write the MX tyres. 19" 85cc MX tyres are quite narrow, normally only 70mm wide giving you the 70 wide and same height 100 (means 100% of width and gives you the 70/100x19 description). As the road tyres are not knobblies and they need to get as much grip as possible from the tarmac they are often lower profile but wider. And if you check Supermoto bikes (often dirt bikes converted to also being able to ride on tarmac) you find that they have smaller wheels fitted with wider tyres.

But if you could not give a hoot about all that and you want to keep the wheel sizes you have then your tyre selection becomes very limited. And a 70mm wide/70mm high front tyre is not much to keep a motorbike glued to the road... so the closest you might get is a 100mm wide tyre with 90% height for a 19 inch wheel... (100/90x19). And for the rear you will most probably have to make similar compromises. https://www.boydmotorcycles.co.nz/s...ridgestone-H50-100-90x19&p=120219&t=4&c=71574
 
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Not sure any of my US feedback helps except to offer our federal department of transportation dictates certain tire requirements to allow road usage. Dunlop and Michelin and Bridgestone all build street legal tires in common sizes for larger bikes. My experience with them for off road use is pitiful. They are tolerable for careful road use but dont ask them to push fast corners or brake hard on wet roads. I would expect your unique build to find few or no suitable road legal tires. I have resigned myself to using motocross knobbies on my dual sport and dont care. I can be cited for non compliance but it's not much of a concern to me for my usage. I dont recertify or inspect my bike annually as required. I risk citation if pressed by law enforcement. I don't worry much about police following me through woods on goat trails and rabbit tracks and cleaning mud from my tires to look for certifications on tire. You may find it's easier to suit the tire to your usage and simply swap your legal tires on bike for your inspection certification and ignore the tire regulations until your reinspection is required if possible. Another possibility would be to swap rims to another size to which a legal sized tire was available. May be less expensive to find or build another wheel set and mount street tires on your bike. That little smoke rocket would make one pisser of a supermoto bike.
 
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Discussion Starter · #8 ·
Not sure any of my US feedback helps except to offer our federal department of transportation dictates certain tire requirements to allow road usage. Dunlop and Michelin and Bridgestone all build street legal tires in common sizes for larger bikes. My experience with them for off road use is pitiful. They are tolerable for careful road use but dont ask them to push fast corners or brake hard on wet roads. I would expect your unique build to find few or no suitable road legal tires. I have resigned myself to using motocross knobbies on my dual sport and dont care. I can be cited for non compliance but it's not much of a concern to me for my usage. I dont recertify or inspect my bike annually as required. I risk citation if pressed by law enforcement. I don't worry much about police following me through woods on goat trails and rabbit tracks and cleaning mud from my tires to look for certifications on tire. You may find it's easier to suit the tire to your usage and simply swap your legal tires on bike for your inspection certification and ignore the tire regulations until your reinspection is required if possible. Another possibility would be to swap rims to another size to which a legal sized tire was available. May be less expensive to find or build another wheel set and mount street tires on your bike. That little smoke rocket would make one pisser of a supermoto bike.
Thank you for the reply.
The police around here are pretty tough on road legal dirt bikes. It has crossed my mind to go super motard with my 85 but not really sure what wheel set I’d need. I was just trying to keep the dirt bike look but road legal so I can ride to the local green lanes etc.
 

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Discussion Starter · #9 ·
You are correct in the way you write the MX tyres. 19" 85cc MX tyres are quite narrow, normally only 70mm wide giving you the 70 wide and same height 100 (means 100% of width and gives you the 70/100x19 description). As the road tyres are not knobblies and they need to get as much grip as possible from the tarmac they are often lower profile but wider. And if you check Supermoto bikes (often dirt bikes converted to also being able to ride on tarmac) you find that they have smaller wheels fitted with wider tyres.

But if you could not give a hoot about all that and you want to keep the wheel sizes you have then your tyre selection becomes very limited. And a 70mm wide/70mm high front tyre is not much to keep a motorbike glued to the road... so the closest you might get is a 100mm wide tyre with 90% height for a 19 inch wheel... (100/90x19). And for the rear you will most probably have to make similar compromises. https://www.boydmotorcycles.co.nz/s...ridgestone-H50-100-90x19&p=120219&t=4&c=71574
ooooh I see now thank you. Do you know what other sizes would Fit my rims I.e. can I put a 90/90-19 on there etc?
 

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ooooh I see now thank you. Do you know what other sizes would Fit my rims I.e. can I put a 90/90-19 on there etc?
I would expect that a 90/90 would fit. But for road I would recommend a lower profile tyre as you then get more tyre on the ground. Perhaps a 90/70-19, or even better, if it stays on the rim, a 100/70-19 (and the tyre does not rub against forks etc. But there should be more than 100mm between the forks). You are up for some testing to find out what works best. When MX bikes are converted to Supermoto bikes they get smaller and wider rims.

There is a Supermoto category here. Perhaps put up a post there asking what the Supermoto guys recommend you do...
 

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Discussion Starter · #11 ·
I would expect that a 90/90 would fit. But for road I would recommend a lower profile tyre as you then get more tyre on the ground. Perhaps a 90/70-19, or even better, if it stays on the rim, a 100/70-19 (and the tyre does not rub against forks etc. But there should be more than 100mm between the forks). You are up for some testing to find out what works best. When MX bikes are converted to Supermoto bikes they get smaller and wider rims.

There is a Supermoto category here. Perhaps put up a post there asking what the Supermoto guys recommend you do...
Thank you so much for all your help
 
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