Topic: CB750 Rear Tire Suggestions

[Simpson]

I'm looking for suggestions to replace my rear tire.
Interested in finding a vintage looking tire that will be good for touring.

Considering the DUNLOP K70 VINTAGE MOTORCYCLE TIRE REAR 4.00-18 TT
But wondering if that will be a mistake for 2up and luggage?

[Simpson]

Bump
Wow, I've never seen people not have an opinion on tires.

[MCRider]

As the name implies, the K70 pattern was common back in the early 70s. Perfectly fine for all purpose use. It came on Triumphs incl their semi "off-road" Trophy series. But also on the street series. I had them on my 67 Bonneville until Dunlop came out with the K81 which was all the rage for street.

As far as wear, there is no way of knowing as the 70s reputation cannot carry to now. We don't know what plant they come from, what compound they are using etc. All we know is it looks like the tire we used to buy. If its anything like the original it should be fine.

Muy recuardos: I had a K70 on my Bonneville in the summer of 1970. I rode it from Indy to Big Sur and back, BWO Phoenix. 6,000 miles in 6 weeks. I had a bobbed rear fender. About 50 miles into the trip, my makeshift tent came unhooked, hit the tire and rolled up to the swingarm, locking the wheel and sliding to a stop from 60mph. Made a heck of a flat spot on a brand new K70. Still made the trip though. The flat spot was bald when i got home. The rest of the tire had some life left.

Oh yeah, I was 17 years old.

[Kevin D]

What is on the front? Wouldn't you want the same brand/style as on the front?

[MCRider]

What is on the front? Wouldn't you want the same brand/style as on the front?

Back in the day, whether OEM or choice, we ran K70s front and rear. The other choice would be a rib on the front, which pretty much goes with anything. There were no radials, so mixing bias ply with radials was not a question. Probably shouldn't be done.

The OP wants a vintage look and the 2 big choices would be K70s, or K81s, front and rear. Or a rib on the front.

Remember our OEM tires from Honda were a Bridgestone of mild tread design on the rear and a ribbed front. Not too much going on back then by way of tires.

[Duke McDukiedook]

Hondaman suggests ribbed pattern on the front (for everyone's pleasure) and a symmetrical blocked pattern on the rear. I have Spitfires front and back and they seem to work fine on my bike 2+ years and running.
 

[MCRider]

Hondaman suggests ribbed pattern on the front (for everyone's pleasure) and a symmetrical blocked pattern on the rear. I have Spitfires front and back and they seem to work fine on my bike 2+ years and running.
 

Spitfire is probably most popular bias ply modern tire, perfectly suitable for our CBs. i have them on my HawkGT.

But OP was looking for the period look. Nixes the Spitfire.

[Simpson]

What is on the front? Wouldn't you want the same brand/style as on the front?

Back in the day, whether OEM or choice, we ran K70s front and rear. The other choice would be a rib on the front, which pretty much goes with anything. There were no radials, so mixing bias ply with radials was not a question. Probably shouldn't be done.

The OP wants a vintage look and the 2 big choices would be K70s, or K81s, front and rear. Or a rib on the front.

Remember our OEM tires from Honda were a Bridgestone of mild tread design on the rear and a ribbed front. Not too much going on back then by way of tires.

I'd prefer the K81 but they are very expensive and hard to find. They seem to be commanding 150-200 dollars a tire. That's a lot of money for vintage rubber. Heck, I can get Pilot Power CT2 cheaper for my Speed Triple. I've got a ribbed front tire and now I just looking for rear that will take some miles. Sounds from your description, it will be fine. I bought some enduro Golden Boy Shinko's for my CL this summer and I am very happy. Just didn't know if there was something else out there or vital information I was missing. Thanks much

[Simpson]

Hondaman suggests ribbed pattern on the front (for everyone's pleasure) and a symmetrical blocked pattern on the rear. I have Spitfires front and back and they seem to work fine on my bike 2+ years and running.
 

Who makes the symmetrical blocked pattern tires? Is the K70 a symmetrical blocked pattern?

[MCRider]

Hondaman suggests ribbed pattern on the front (for everyone's pleasure) and a symmetrical blocked pattern on the rear. I have Spitfires front and back and they seem to work fine on my bike 2+ years and running.
 

Who makes the symmetrical blocked pattern tires? Is the K70 a symmetrical blocked pattern?

I would say the K70 is. Looking at each side from the centerline it is symmetrical, but shifted a tad. And blockie.

The K81s and later went to a V profile.  The origianl Bridgestone rear wasn't blocked in my memory, but it wasn't much of anything, sort of ambiguous. I don't know if Bridgestone has that in their Vintage line up or not.

[Simpson]

Hondaman suggests ribbed pattern on the front (for everyone's pleasure) and a symmetrical blocked pattern on the rear. I have Spitfires front and back and they seem to work fine on my bike 2+ years and running.
 

Who makes the symmetrical blocked pattern tires? Is the K70 a symmetrical blocked pattern?

I would say the K70 is. Looking at each side from the centerline it is symmetrical, but shifted a tad. And blockie.

The K81s and later went to a V profile.  The origianl Bridgestone rear wasn't blocked in my memory, but it wasn't much of anything, sort of ambiguous. I don't know if Bridgestone has that in their Vintage line up or not.

I will probably order a new tire tonight then...

[ofreen]

The Metzeler ME88 has been around so long it looks like it is vintage to me.  You mentioned 2 up and luggage.  That is what the ME88 is made for.  120/90 x 18 works fine on the 750.

[MCRider]

Hondaman suggests ribbed pattern on the front (for everyone's pleasure) and a symmetrical blocked pattern on the rear. I have Spitfires front and back and they seem to work fine on my bike 2+ years and running.
 

Who makes the symmetrical blocked pattern tires? Is the K70 a symmetrical blocked pattern?

I would say the K70 is. Looking at each side from the centerline it is symmetrical, but shifted a tad. And blockie.

The K81s and later went to a V profile.  The origianl Bridgestone rear wasn't blocked in my memory, but it wasn't much of anything, sort of ambiguous. I don't know if Bridgestone has that in their Vintage line up or not.

I will probably order a new tire tonight then...

At age 36, I don't know if you hang around with oldtimers. But if you do, and you show up with a K70, you'll get a lot of reminiscing like I did. Truly THE vintage tire. IMO of course.

[Simpson]

I'd prefer the K81 but they are very expensive and hard to find. They seem to be commanding 150-200 dollars a tire. That's a lot of money for vintage rubber. Heck, I can get Pilot Power CT2 cheaper for my Speed Triple. I've got a ribbed front tire and now I just looking for rear that will take some miles. Sounds from your description, it will be fine. I bought some enduro Golden Boy Shinko's for my CL this summer and I am very happy. Just didn't know if there was something else out there or vital information I was missing. Thanks much

Correction: It's the K87 that's expensive and hard to find. k70 and K81 can be purchased cheap through motorcyclesuperstore really cheap.

K70


K81


K87

[MCRider]

I'd prefer the K81 but they are very expensive and hard to find. They seem to be commanding 150-200 dollars a tire. That's a lot of money for vintage rubber. Heck, I can get Pilot Power CT2 cheaper for my Speed Triple. I've got a ribbed front tire and now I just looking for rear that will take some miles. Sounds from your description, it will be fine. I bought some enduro Golden Boy Shinko's for my CL this summer and I am very happy. Just didn't know if there was something else out there or vital information I was missing. Thanks much

Correction: It's the K87 that's expensive and hard to find. k70 and K81 can be purchased cheap through motorcyclesuperstore really cheap.

K70


K81


K87

I couldn't remember what was stock on the CB750, but looking at that K87 I think that was it. And that;s why the high price I'll bet. THe K70s and K81s are period tires, but more on the British bikes I think. Still, they are very recognizable tread patterns. And often used for CB750s when the original wore out. THe K81s don't have the blocks like the K87 does. Still I ran them a lot.  I remember our feelings were that the K70 was more of the touring tire putting a lot of rubber flat on the road. THe K81s were for the racer crowd, more rubber when leaned over. And since most of us don't really lean a lot, the K81 tended to get real flat on the bottom from wear and would feel funny transitioning onto the sides of the tire in the turns. The 87 was a blend of the two.

All pulled from distant memory...

[Simpson]

I couldn't remember what was stock on the CB750, but looking at that K87 I think that was it. And that;s why the high price I'll bet. THe K70s and K81s are period tires, but more on the British bikes I think. Still, they are very recognizable tread patterns. And often used for CB750s when the original wore out. THe K81s don't have the blocks like the K87 does. Still I ran them a lot.  I remember our feelings were that the K70 was more of the touring tire putting a lot of rubber flat on the road. THe K81s were for the racer crowd, more rubber when leaned over. And since most of us don't really lean a lot, the K81 tended to get real flat on the bottom from wear and would feel funny transitioning onto the sides of the tire in the turns. The 87 was a blend of the two.

All pulled from distant memory...

I won't be doing much leaning, espically with the extra load. The bike drags hardware too easily and the girl's foot tends to scrape the road on the back pegs. She is never particularly impressed and gets mad her shoes get marked up. Your description makes a lot of sense looking at the pictures. I have a theory that today's reproduction tires are probably pretty good due to rubber technology in comparison to the old days. So even a cheap reproduction probably is better than 40 years ago tires. Just a theory, no real data there.
Thanks for the input!

[Jonesy]

I've always liked the Continental K112 rear/RB2 front combo. The front has the blocked rib pattern and the rear has a tread akin to the old Bridgestone Super Speed (OE fitment)

[CycleRanger]

Just for the heck of it here's an original OEM Bridgestone Superspeed 4.00x18 that came from the back of a 6000 mile CB750K4.  Almost identical to the K87.




Personally I went with Pirelli MT66 front and rear on my 750K5.

[Simpson]

I was real tempted by the Continental K112 rear/RB2 front combo. They look like a real nice compromise between modern and vintage for durability. Ended up ordering the K70 for 66 bucks shipped from motorcycle super store. Depending performance, I might try the Continental K112 rear/RB2 next tire change.

[lowmileage]

I've always liked the Continental K112 rear/RB2 front combo. The front has the blocked rib pattern and the rear has a tread akin to the old Bridgestone Super Speed (OE fitment)

That's the duo I put on mine this summer.  Selected them from reviews on this board.  Worked for me FWIW.

[Old Scrambler]

From my experience, the current K70 tires will get good looks and conversation, but they will not last on the highway. Had one on a CB750 last year and it showed wear at 4,000 miles. If you are running with a load it may be best to get some heavy-duty springs or use stronger shocks for the trip. Even on full pre-load, the stock springs were soft when new and now tend to ride like a pogo-stick. I like the Contenentals and also have good mileage on IRC modern treads.

[prisonchef]

since you are doing what we like to do in the touring thing take a look at dunlop d404. they have a good weight rating and we got ours from dennis kirk. front and rear tires, new tubes and new rim strips came to about 150 bucks. myself unless a 100 points concours bike was involved i prefer to go with what works best.

[Kevin D]

In pursuit of vintage perfection

  
I went back and watched your video Simpson, thats a smooth runnin' CB you have there. I also read a few of the magazine articles we have attached at the front of the website. One article even mentioned k70 as the OE tire, but the pictured tire attached to the article is clearly not k70. The bike may have been one of the early prototypes or preproduction, I dunno. The k87s and the Super Speeds were the OE tires on my K0 and K1, as I recall it.
 I wonder what the manufacture date is on the k87s you might get today?....but thats a different issue. $145 at Yamiya + $108 shipping...ouch!!!