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KFunk

Tires for my '81 xs400?

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its for the ugly '81 Yamaha XS400-SH, and my current tires are all dry rotted and cracked. I'm really picky on my car tires, but I'm new to motorcycle tires. I just want something safe...

The rear is a 120-90-16, and front is 3.00S-18. It's got 'mag' wheels or whatever (not wire), and it currently has tubeless tires.

It looks like all I can find are chinese/taiwanese brands unfortunately... and I'm pickin from Cheng-Shin, Duro, and IRC.

I'm thinkin of goin with Duro from http://www.americanmototire.com/

It's $41 for rear, $26 for front, and $11 for a tube for the front.

...but, that leads me to.... everything I can find is for tubed front tires. Can I put tubed tires on a tubeless/mag wheel?

..and my front would be bias ply, while the rear is belted, is that OK? I've found that its wrong to mix a radial front with a bias ply rear, but not sure if its bad to mix bias ply and belted.

I'm tryin to stick with both as Duros instead of mixin brands, should I worry about that? Other affordable brands don't have the 3.00S-18 (apparently the S means lower aspect ratio of like 82%).

and... is it possible for me to change any of these myself? Local bike shop wants $20 per tire, if I bring them in just the wheels.

Thanks if you can help!

Kevin

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its for the ugly '81 Yamaha XS400-SH, and my current tires are all dry rotted and cracked. I'm really picky on my car tires, but I'm new to motorcycle tires. I just want something safe...

The rear is a 120-90-16, and front is 3.00S-18. It's got 'mag' wheels or whatever (not wire), and it currently has tubeless tires.

It looks like all I can find are chinese/taiwanese brands unfortunately... and I'm pickin from Cheng-Shin, Duro, and IRC.

I'm thinkin of goin with Duro from http://www.americanmototire.com/

It's $41 for rear, $26 for front, and $11 for a tube for the front.

...but, that leads me to.... everything I can find is for tubed front tires. Can I put tubed tires on a tubeless/mag wheel?

..and my front would be bias ply, while the rear is belted, is that OK? I've found that its wrong to mix a radial front with a bias ply rear, but not sure if its bad to mix bias ply and belted.

I'm tryin to stick with both as Duros instead of mixin brands, should I worry about that? Other affordable brands don't have the 3.00S-18 (apparently the S means lower aspect ratio of like 82%).

and... is it possible for me to change any of these myself? Local bike shop wants $20 per tire, if I bring them in just the wheels.

Thanks if you can help!

Kevin

Hi Kevin,

In the UK the XS400SE (your SG, from pics I have seen) did not have tubeless wheels (in 81 they were few & far between) so you may find tubes in both, normally the rims of the wheels will state on them if they are tubeless or not. To fit tubes in tubleless wheels you need an adaptor to sleeve down the hole that the valve fits thro so the valve is not torn from the tube under braking/acceleration. Can you give me the info on S being the aspect ratio ? 120-90 give width & aspect (i.e 90% aspect) but I'm not getting the older system ? From memory the letter used to signify the speed rating and the aspect was cast in stone ... but its so long since I did this at collage I could be wrong. To change the tyres yourself you will need something to break the bead from the rim (there are tools to do this but it can be done with a big vice and lots of strength) then (if tubed) you stand a chance of pinching the tube on the refit (if you use levers) or lots of effort to push the tyre on with your feet, so my guess $40 is cheaper than buying the required tools

Regards Jim

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SOHC xs400's are tubed tyres but you can use tubeless tyres with tubes in them.

I can't recommend anything other than BT45's they are the best, Merv will confer with me as they also suit the RD's. I use them on my xs and can say they rock. I used them at wombwell kart track and they never kicked out even when grinding the footrests.

drewps

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both my tires on my bike say 'tubeless' on them. not sure if thats odd for an'81.

but anyways, perhaps i just need that adapter.

i did some research, and the 3.00S-18 is just an older system. 3.00 is the width in inches, and apparently the S means an aspect ratio of like 82%. If there were no S, it would be an aspect ratio of 100%.

I've seen the bridgestones listed, but seem a bit pricey. I just want something a little bit better than cracked tires, as i can't afford much more really, and will end up just running on the cracked tires if i have to.

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3.00 = 90/90x18" = 90mm with the height of the tyre 90% of the width and 18" wheel

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I just replaced my rear.

i could do with mine changing, wife said its too fat :lol:

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I guess I got confused on the 'S' thing, and thats just the speed rating like any other tire...

So anyways, I'm thinkin of goin with this:

Rear: DURO HF261A 120/90B-16: $41.41

Front: DURO HF918 90/90B-18 $37.04

+$19/shipping from http://www.americanmototire.com/

Both are belted/tubeless.

Bike Bandit doesn't have the same brands/prices.

I also thought about ironpony.com (Ohio preference for me). They've got similar Cheng Shin Hi-Max tires for almost identical price, but they're regular bias ply. I thought the belted Duro tires might be a bit stronger... plus they want to add an Ohio sales tax. I could cut shipping cost and buy from the store, but thats a long drive and I don't have another excuse to go up there...

So yeah, AMT for 100 bucks. As soon as I secure some extra funds, I'll prolly place the order.

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I guess I got confused on the 'S' thing, and thats just the speed rating like any other tire...

So anyways, I'm thinkin of goin with this:

Rear: DURO HF261A 120/90B-16: $41.41

Front: DURO HF918 90/90B-18 $37.04

+$19/shipping from http://www.americanmototire.com/

Both are belted/tubeless.

Bike Bandit doesn't have the same brands/prices.

I also thought about ironpony.com (Ohio preference for me). They've got similar Cheng Shin Hi-Max tires for almost identical price, but they're regular bias ply. I thought the belted Duro tires might be a bit stronger... plus they want to add an Ohio sales tax. I could cut shipping cost and buy from the store, but thats a long drive and I don't have another excuse to go up there...

So yeah, AMT for 100 bucks. As soon as I secure some extra funds, I'll prolly place the order.

The mags on my '78 XS 400 are set up for tubes, got the front to seal without a tube but wound up going with a tube on the back. Running a Duro on back, the one that's the repro of the old Dunlop TT100. Softer rubber than the Dunlop, but I'm happy with it.

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Running a Duro on back, the one that's the repro of the old Dunlop TT100. Softer rubber than the Dunlop, but I'm happy with it.

I have a durex at the front, really soft rubber with good ribbing!! ;)

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I guess I got confused on the 'S' thing, and thats just the speed rating like any other tire...

So anyways, I'm thinkin of goin with this:

Rear: DURO HF261A 120/90B-16: $41.41

Front: DURO HF918 90/90B-18 $37.04

+$19/shipping from http://www.americanmototire.com/

Both are belted/tubeless.

Bike Bandit doesn't have the same brands/prices.

I also thought about ironpony.com (Ohio preference for me). They've got similar Cheng Shin Hi-Max tires for almost identical price, but they're regular bias ply. I thought the belted Duro tires might be a bit stronger... plus they want to add an Ohio sales tax. I could cut shipping cost and buy from the store, but thats a long drive and I don't have another excuse to go up there...

So yeah, AMT for 100 bucks. As soon as I secure some extra funds, I'll prolly place the order.

Just an update: I placed that order on Thursday night (from AZ), and received the tires here in Ohio on Tuesday. I found a friend that owns a motorcycle shop and he mounted them for $15 each.

I've been takin it easy on them since you're supposed to give them 100 miles to get broken in. But its been 50 miles yesterday and they seem fine. I didn't like a strange little seamline protrusion down the center of the front tire, but thats wearing off quickly.

I really can't compare these tires to anything so I'm not a good judge. But they seem to fit fine.

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I guess I got confused on the 'S' thing, and thats just the speed rating like any other tire...

So anyways, I'm thinkin of goin with this:

Rear: DURO HF261A 120/90B-16: $41.41

Front: DURO HF918 90/90B-18 $37.04

+$19/shipping from http://www.americanmototire.com/

Both are belted/tubeless.

Bike Bandit doesn't have the same brands/prices.

I also thought about ironpony.com (Ohio preference for me). They've got similar Cheng Shin Hi-Max tires for almost identical price, but they're regular bias ply. I thought the belted Duro tires might be a bit stronger... plus they want to add an Ohio sales tax. I could cut shipping cost and buy from the store, but thats a long drive and I don't have another excuse to go up there...

So yeah, AMT for 100 bucks. As soon as I secure some extra funds, I'll prolly place the order.

I would not recommend chen chin, they seem to grip fine but they wear really fast. And they don't wear evenly either.

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a case of "wear today, gone tomorrow" you could say!! :D

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I would not recommend chen chin, they seem to grip fine but they wear really fast. And they don't wear evenly either.

Lots of the vintage guys around here run Cheng Shins. In my experience on a fairly low powered small bike like what we're talkin' about just about ANY tire will dry rot before it wears out. Aside: I have had my Duro HF-314 on long enough to make 3 oil changes (@6000 miles) and I can't tell any wear.

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