Hey everyone !
Is there anyone who knows how to help these two new members figure this tire size thing out ?
The initial request was from January, but no replies...I figure someone here is bound to have an idea :shrug:, but probably didn't see the thread....so I'm "keepin' it alive" in hopes someone will see this time.
Thank You in advance for your help ! :thumbsup:
Is there anyone who knows how to help these two new members figure this tire size thing out ?
The initial request was from January, but no replies...I figure someone here is bound to have an idea :shrug:, but probably didn't see the thread....so I'm "keepin' it alive" in hopes someone will see this time.
Thank You in advance for your help ! :thumbsup:
My BAJA mb165 has 3/4" space between the rear wheel and the chain when using a 7 inch wide OEM tire of 19x7.00x8 .
So I see there are some 20 inch dia tires which are only one half inch larger in diameter which will not cause a problem.
I do not think a one inch wider ( 8") wide tire will rub because it will be just one half inch wider on each side. You should
still have a quarter inch clearance between chain and tire.
So I see there are some 20 inch dia tires which are only one half inch larger in diameter which will not cause a problem.
I do not think a one inch wider ( 8") wide tire will rub because it will be just one half inch wider on each side. You should
still have a quarter inch clearance between chain and tire.
No... there is a guy on this forum who has converted to a rear swing arm with shocks and hid pictures look fantastic.
AND... It must result in a gigantic world of comfort when riding over pot holes. I would guess that if mass
manufactured like that the cost might be $100 more and I would gladly pay it. One of the outstanding
features of the BAJA mb165 and mb200 series is the shock absorbed front forks. Adding some movement
for the back wheel would be greatly appreciated.
AND... It must result in a gigantic world of comfort when riding over pot holes. I would guess that if mass
manufactured like that the cost might be $100 more and I would gladly pay it. One of the outstanding
features of the BAJA mb165 and mb200 series is the shock absorbed front forks. Adding some movement
for the back wheel would be greatly appreciated.
For the larger Baja minibikes, they come with 7 inch wide tires (19x7.0x8) as standard with 3/4" space on each side
between the shock forks. I dont think adding a half inch to each side when upgrading to an 8 " tire could make much difference.
What I think would cause a lot of trouble is making the mistake of using a square flat profile as used as rear tires in ATVs
in the front of a minibike. When you turn the handle you would transfer contact point from one square side of the tire to the
other side.
I even think that could cause a bit of a problem in the rear but others will have to comment on that who have tried it.
Some of those flat tread tires sure look good and when on the back would seem to offer some better traction depending
on the tread type. All the lawn tractor tires have that square edge shape it seems.
between the shock forks. I dont think adding a half inch to each side when upgrading to an 8 " tire could make much difference.
What I think would cause a lot of trouble is making the mistake of using a square flat profile as used as rear tires in ATVs
in the front of a minibike. When you turn the handle you would transfer contact point from one square side of the tire to the
other side.
I even think that could cause a bit of a problem in the rear but others will have to comment on that who have tried it.
Some of those flat tread tires sure look good and when on the back would seem to offer some better traction depending
on the tread type. All the lawn tractor tires have that square edge shape it seems.
You can use a larger diameter of tyre, but your ratio will have to increase to compensate for the size difference.
You gain speed or loose climbing ability ( just try and climb with a big set of boots and shoe clutch and see how badly that ends for you lol )
You can compensate for that with a TAV, but you will need to lower the ratio by using a 9 tooth primary and secondary with 58 or more teeth.
If your going the TAV route then a 7 inch secondary is a nice thing to have but that means a custom jack shaft.
If you go with a wider tyre you are in trouble now.
You need to shim out your drive sprocket and find a way to line up your chain.
This is how I did it.
Tyre used is a 20-8-8 turf saver.
It crowns up nice on the narrow rim ( but still handles bad )
Its hard enough for resist rocks, but soft enough for good traction in a groomed clay track
No good for mud or sand ( use softer tyre with deeper groves ).
All this adds weight and now you need more power, lot more.
So you can lighten things up flat track style by cutting the front end off a small Chinese dirt bike and grafting it to the front of the 165 frame.
This works good and handles better, but the weight is too far back on the bike for climbing.
There are 21 and 20 tyres that fit the 8 by 7 rim.
https://www.youtube.com/watch?v=EkxXqkF9YiE
You gain speed or loose climbing ability ( just try and climb with a big set of boots and shoe clutch and see how badly that ends for you lol )
You can compensate for that with a TAV, but you will need to lower the ratio by using a 9 tooth primary and secondary with 58 or more teeth.
If your going the TAV route then a 7 inch secondary is a nice thing to have but that means a custom jack shaft.
If you go with a wider tyre you are in trouble now.
You need to shim out your drive sprocket and find a way to line up your chain.
This is how I did it.
Tyre used is a 20-8-8 turf saver.
It crowns up nice on the narrow rim ( but still handles bad )
Its hard enough for resist rocks, but soft enough for good traction in a groomed clay track
No good for mud or sand ( use softer tyre with deeper groves ).
All this adds weight and now you need more power, lot more.
So you can lighten things up flat track style by cutting the front end off a small Chinese dirt bike and grafting it to the front of the 165 frame.
This works good and handles better, but the weight is too far back on the bike for climbing.
There are 21 and 20 tyres that fit the 8 by 7 rim.
https://www.youtube.com/watch?v=EkxXqkF9YiE