Author Topic: need rear tire recommendations for CB750K2  (Read 4163 times)

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Offline hotelstationery

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need rear tire recommendations for CB750K2
« on: October 19, 2014, 03:34:13 PM »
I knew my tire wasn't great but upon inspection today it would appear that it is totally gone and needs to be replaced immediately.  As far as I know the rim is stock with a 120/90-18 on it.  Naturally I would like a tire that retains the original look but has good performance.  I'm not racing or anything but I would like it to be grippy in the corners and capable of handling rain, since this bike is currently my daily driver.  What would you guys recommend?  What do you use and how do you like it?

Also, I was planning to just take the wheel in.  Is it easier to break the chain at the master link or undo the rear sprocket?

jeremy

Offline Whaleman

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Re: need rear tire recommendations for CB750K2
« Reply #1 on: October 19, 2014, 04:10:46 PM »
You do not need to break the chain to remove the rear wheel. Download a manual. Dan  EDIT: I also have BT-45's and love them.
« Last Edit: October 19, 2014, 05:48:17 PM by Whaleman »

Offline Stev-o

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Re: need rear tire recommendations for CB750K2
« Reply #2 on: October 19, 2014, 04:16:38 PM »
I have Bridgestone BT45's on my K4 and really like them. 

+1, don't break the chain. 
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline seanbarney41

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Re: need rear tire recommendations for CB750K2
« Reply #3 on: October 19, 2014, 06:11:10 PM »
110 is gonna work a lot better than 120 if you have a stock rim...or factory correct 4.00x18 if you can find that in a tire you look.  I have had good success with Metzeler Lasertec, Avon Roadriders, Pirelli Sport Demons.
If it works good, it looks good...

Offline hotelstationery

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Re: need rear tire recommendations for CB750K2
« Reply #4 on: October 19, 2014, 10:24:03 PM »
I looked at some 4.00 x 18 and saw the Dunlop K70 and K81.  I love the way they look but I'm impressed with the performance of the BT45.  I can't decided, looks or performance.

jeremy

Offline PeWe

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Re: need rear tire recommendations for CB750K2
« Reply #5 on: October 20, 2014, 03:09:53 AM »
Use the Search function of this forum, threads with very good answers and experiences will pop-up.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Stev-o

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Re: need rear tire recommendations for CB750K2
« Reply #6 on: October 20, 2014, 07:42:25 AM »
I looked at some 4.00 x 18 and saw the Dunlop K70 and K81.  I love the way they look but I'm impressed with the performance of the BT45.  I can't decided, looks or performance.

jeremy

I think you would be happy with the K81, it is better than the K70. But, then what what will you put on the front?
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline Dunk

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Re: need rear tire recommendations for CB750K2
« Reply #7 on: October 20, 2014, 08:34:43 AM »
I am running Continental K112 rear and RB2 front, these are a period correct look. They seem to grip pretty well, though I haven't scraped pegs yet on this bike. Rear slid out a little once when leaned over pretty far moving quick, but it was over a tarred seam that it slid and immediately hooked back up. Got my heart going but that's more road condition than tire issue.


Offline 70CB750

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Re: need rear tire recommendations for CB750K2
« Reply #8 on: October 20, 2014, 09:08:36 AM »
I used Bt45s before. Good tires, grippy, 12000 miles out of 1 front and two rears.

Since the K0 is before a rebuild I went with Shinko 712 for the rest of the season and just finished  round trip from North Virginia to Barber and back - 1800 or so miles - and Shinkos held fine on the Tail of Dragon and during all the rain I encountered on my way home. 
Prokop
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Pure Gas - find ethanol free gas station near you

I love it when parts come together.

Dorothy - my CB750
CB750K3F - The Red
Sidecar


CB900C

2006 KLR650

Offline hotelstationery

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Re: need rear tire recommendations for CB750K2
« Reply #9 on: October 20, 2014, 05:08:03 PM »
With an Isle Of Mann victory behind it and a higher speed rating the K81 is the clear winner over the K70.  The bike came equipped with a virtually new K70 on the front and I was planning on leaving it on.

The bike shops are open again tomorrow, so I will call around and see who was what in stock.  Otherwise I guess I will order online.

jeremy

Offline Stev-o

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Re: need rear tire recommendations for CB750K2
« Reply #10 on: October 20, 2014, 05:26:29 PM »
Order a new tube and rim strip too.
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline hotelstationery

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Re: need rear tire recommendations for CB750K2
« Reply #11 on: October 20, 2014, 06:30:59 PM »
You have preempted my next question, thank you.

jeremy

Offline Stev-o

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Re: need rear tire recommendations for CB750K2
« Reply #12 on: October 20, 2014, 07:26:00 PM »
You have preempted my next question, thank you.

jeremy

You're welcome
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline TwoTired

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Re: need rear tire recommendations for CB750K2
« Reply #13 on: October 20, 2014, 09:56:30 PM »
I'd recommend a Metzeler in 4.00 x18.  Has the same aspect ratio the designers intended for the rim and suspension, rather than 90% most of the metrics have.  Tire wear patterns are better too, for the life of the tire.  Pretty much all brands feel good when new.  But, if/when they wear off the crown, not so much.  The folly of wider tires on stock rims.
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline Johnie

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Re: need rear tire recommendations for CB750K2
« Reply #14 on: October 21, 2014, 07:19:33 AM »
I have Conti's on all my 750's. Very happy with them.
1970 CB750K0 - Candy Ruby Red
1973 CB750K3 - Candy Bacchus Olive or Sunflake Orange
1970 Chevy Chevelle SS396 - Cortez Silver
1976 GL1000 Sulphur Yellow

Oshkosh, WI  USA

Offline PeWe

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Re: need rear tire recommendations for CB750K2
« Reply #15 on: October 21, 2014, 10:44:47 AM »
The Search function of this forum is not as good as before. Cannot take an expression like 'xxxxx + yyyyyyy'

Anyway, here is one of the useful posts Tower has written. http://forums.sohc4.net/index.php?topic=56494.msg609309#msg609309

The thing here is that front and rear tire angles match each other so the bike will react correctly when leaning the bike in curves.

I have read on other forums that original dimensions give best handling. (Different thing if the bike is totally redesigned with different rims, fork, swingarm, shocks....)

OEM dimensions  front rim, tire: 1.85"  3.25-19 Rear: 2.15 4.0-18
I went for wider  matching tire alternative that is OK to use according to the chart and others. 100/90-19, 120/90-18.
My choice was Metzeler Lasertec H (max 210kmh) when I had good experience of Metzeler from the middle of 80's with ME99 rear and later 80's ME33 front. Much better grip without sudden yerky loss of grip on my bike than Continental, Dunlop K81 (TT100), Michelins that were used earlier on most bikes here.

For older look, Metzeler has ME77 still in production.
« Last Edit: October 21, 2014, 11:07:13 AM by PeWe »
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Vinhead1957

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Re: need rear tire recommendations for CB750K2
« Reply #16 on: October 21, 2014, 12:18:06 PM »
It matters what you have on the front. In the day, we wanted a matched pair for the bike.  continental was preferred but there are newer ones today !   I love the Avons I have but I'm not. That aggressive in the twisties.

Offline hotelstationery

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Re: need rear tire recommendations for CB750K2
« Reply #17 on: October 21, 2014, 06:26:46 PM »
I went ahead and ordered a K81 from a local dealer and picked up some brake shoes, just in case, since the old ones are of unknown age.  Anything else I should do or examine while it's off?  How likely are the rubbers for the cush drive going to need replacement?

jeremy

Offline hotelstationery

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Re: need rear tire recommendations for CB750K2
« Reply #18 on: October 21, 2014, 10:14:30 PM »
I pulled the wheel off in accordance with the manual and it went smoothly enough.  The brakes were worn down to 2mm in some places but still as thick as 4mm in others.  I guess it's time for new shoes.  Whoever took the retainer bearing out before just drove it out with a punch and it's as mangled as it is stuck.  Looking under there may be a project for the future...

jeremy

Offline 70CB750

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Re: need rear tire recommendations for CB750K2
« Reply #19 on: October 22, 2014, 03:07:22 AM »
You can find new old stock retainers on hebay and other places.
Prokop
_______________
Pure Gas - find ethanol free gas station near you

I love it when parts come together.

Dorothy - my CB750
CB750K3F - The Red
Sidecar


CB900C

2006 KLR650

Offline Johnie

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Re: need rear tire recommendations for CB750K2
« Reply #20 on: October 22, 2014, 05:02:35 AM »
Good idea to check out those wheel bearings. Lots of age and dirt can take a toll. I routinely change my front and rear bearings mainly for peace of mind. I would hate to have one fail on the highway. And with the sealed bearings that you can get nowadays they surpassed what was available back in the day.
1970 CB750K0 - Candy Ruby Red
1973 CB750K3 - Candy Bacchus Olive or Sunflake Orange
1970 Chevy Chevelle SS396 - Cortez Silver
1976 GL1000 Sulphur Yellow

Oshkosh, WI  USA

Offline hotelstationery

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Re: need rear tire recommendations for CB750K2
« Reply #21 on: October 22, 2014, 09:33:40 PM »
I will likely change them in the future for the peace of mind but not right now.

Is there a way to torque the axle on without removing the mufflers?

jeremy

Offline Johnie

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Re: need rear tire recommendations for CB750K2
« Reply #22 on: October 23, 2014, 11:11:49 AM »
Not if you have the OEM mufflers on there. I just give it a good tighten with an open end wrench and put the pin in.
1970 CB750K0 - Candy Ruby Red
1973 CB750K3 - Candy Bacchus Olive or Sunflake Orange
1970 Chevy Chevelle SS396 - Cortez Silver
1976 GL1000 Sulphur Yellow

Oshkosh, WI  USA