Topic: Tire Decision

[Rosinante]

Did a number of searches.  Hit the "Back" button if you're thinking of wasting your time scolding me for asking a controversial or subjective question.

I accept that my spoke wheels are not appropriate for tubeless tires.  Darn.  Perhaps I will get some alloy wheels.  But in the meantime, I need to make a tire decision.  With cars (and I presume this is at least as true with motorcycles) tires are easily the most important performance parts on the vehicle.  EVERY other performance part on a vehicle works its magic through the contact patch between the tire and the road surface.  Noticing that my physical body is hanging in the balance, I am going to apply the same strategy to my new (1978 CB750K) bike as I do to my street cars and my performance cars.  I am interested in using the absolute finest, most effective tire I can buy.  Price is not important.  Traction is important.

So.......what is the best tire I can mount onto my vintage spoke wheels?  Does Metzeler make a tire for my wheels?

[cameron]

You can mount ANY tire on. You just need a tube inside.. which they TOTALLY make for your wheel.

http://www.motorcycle-superstore.com/1/0/Motorcycle-Tire-Finder/Street-Bike-Tires.aspx


As far as 'best'? Totally subjective.
I use Bridgestone Spitfires.
I like them
THey feel good.
They look true-to-era.

I don't like flashy new-school tires, because I value a stock look.
But I am not a high-performance guy.

YMMV.

[TwoTired]

  Does Metzeler make a tire for my wheels?

Yes they do, and quite fine ones at that.  The local shops probably won't stock the correct inch sizes.  But, if you threaten to walk, they will order them for you.


I'm using the Lasertec on the front and the ME77 on the rear.  But, they do make the Lazertec for the rear also.

Cheers,

[brewsky]

I've been looking for a "matched set" also, but the 17" rear/ 19" front narrows the field considerably.
So far I've found only the following available as matching sets in modern sizes:
Bridgestone Battlax BT 45
Avon Roadrider AM 26
IRC Durotour RS-310
All the above are 100/90/19 and 120/90/17 which are as close to the original as you can get in modern sizes, however, they do not have the "rib" front/ "block rear" recommended elsewhere on the forum.
At least its not as bad as my Honda Dream which takes 3.25/16 narrow whitewalls....unobtainium anywhere...

[camelman]

I highly recommend the Avon Roadriders.  I just had a great weekend stomping on a new BMW GS800 and a new Triumph Thruxton 900.  I was on my 350F, and had the maneuverability on the crazy mountain bike path style roads we were on to get away from them.  The tires were very predictable, and allowed me to lean far enough to either side to drag metal on the ground.  The rear tire has about 2000 miles on it, and barely shows any wear, although that might be from only have 34 HP and weighing 350lbs.

These are tubeless tires too.  You have to run tubes in tubeless tires unless you opt for tubeless conversion, which will save some significant weight.

Camelman

[Alan F.]

Personally I can't say enough good things about Michelin Pilot Activ no matter what bike they're fitted to.

http://www.motorcycle-superstore.com/1/28/396/6158/ITEM/Michelin-Pilot-Activ-Rear-Tire.aspx?sst=RR|6158

http://www.motorcycle-superstore.com/1/28/396/6158/ITEM/Michelin-Pilot-Activ-Rear-Tire.aspx?sst=RR|6158

Cheers.

[TwoTired]

I forgot the 78K has a 17 inch rear wheel.
Meztler does make the 3.50 19 front.  But not the 4.50-17 rear.   Probably have to sub a metric 120 tire for the rear.

[swellguy]

Dunlop K70's

[cameron]

I forgot the 78K has a 17 inch rear wheel.
Meztler does make the 3.50 19 front.  But not the 4.50-17 rear.   Probably have to sub a metric 120 tire for the rear.

My impression is that switching metric/english re: tires is totally OK.
 That there is a range of fitment on any rim.
Does anyone disagree?

[BobbyR]

I went with the Battleaxe BT45s and have been happy on my 78K. On my first pair I went too wide in the rear which looks good, but they square off at midway through their life and develop a step you can feel when you lean it over. This time I went down a size as was recommended here and she is more responsive all around.    

[TwoTired]

I forgot the 78K has a 17 inch rear wheel.
Meztler does make the 3.50 19 front.  But not the 4.50-17 rear.   Probably have to sub a metric 120 tire for the rear.

My impression is that switching metric/english re: tires is totally OK.
 That there is a range of fitment on any rim.
Does anyone disagree?

Yes, I disagree.  And there have been prior discussion and explanations post in this forum before.
The range of fitment on a rim is in part determined by the sidewall angle allowance.  (See post references below.)
Also, I believe tire "expert" salesmen have obscured relevant details about the switch over in the interest of profit. (Had to say it.)

Inch size tires were generally 95-100% aspect ratio.  Modern metrics are not.  So you can get close to what Honda intended w.r.t. contact patch size and position in relation the frame components, but not exactly what was designed when using metric conversions.

I.E. a 3.50 front tire is/was also about 3.50 tall.  Which is about 87 mm.  A 90 size tire is pretty close to proper width.  However, the metric tire height is only 90% of width (90/90 tire) which is only 78.3 height which is just over 3 inches.  So, you have a shorter tire.  To get the height back you can go to a 100/90 tire.  But, then when you lean the bike over the contact patch is offset, it no longer handles neutral in the turns.  You can adjust the contact patch with over-inflation.  But that causes the tire to wear in the center more rapidly and that wreaks further havoc with handling as the tire wears unevenly.
Everyone seems to like whatever new tire they have put on the bike, with their glowing reports coming while the tires have little wear on them.  The handling changes are gradual, and riders adapt.  But, then the new tire works so much better than the old worn tire (even if it is the exact same tire).

So, it may not matter as much when the tires are are totally brand new with no wear on the crown.  It will matter when the tires wear down.  On my bikes, it effected handling and how much you have to fight the bars to hold your line in the curves.

Tower had some pretty good write ups.
See also:
http://forums.sohc4.net/index.php?topic=32886.msg340259#msg340259
http://forums.sohc4.net/index.php?topic=56494.msg609309#msg609309
http://forums.sohc4.net/index.php?topic=31345.msg322927#msg322927
http://forums.sohc4.net/index.php?topic=19346.msg274511#msg274511
http://forums.sohc4.net/index.php?topic=19346.msg274490#msg274490

In fact, this entire thread is a good read:
http://forums.sohc4.net/index.php?topic=19346.0

[fatmatt650]

This is so reminiscent of my own first post. It seems like it was just a week and a half ago.

http://forums.sohc4.net/index.php?topic=70954.0

BTW I've put about 250 miles of all sorts of riding on these things and I am totally stoked. Also found out that my good buddy Dreyzar had also come to the same conclusion independently and I totally trust his judgment.

[Frostyboy]

I know that my 550 takes different sizes to what you are chasing, but I found that Bridgestone still offer 3.25x19 BT45 for my front but I had to go metric for the rear. (110/90/18) I think it's because of the dual compound thing.
Maybe they still offer 3.5 for your front as well?? It might be worth asking the question.

[KRONUS0100]

I think its personal preference.  I too am looking for new tires for my Cb750F.  It has Cheng Shin Barracudas on it now that are wore out.  My 90 GS500E had Dunlop Gt501's and they were great in all weather.  My GL1100I had the Bridgestone Spitfire's and they were great for a very heavy bike.  My GS1100E is gonna get the Dunlops.  I am currently looking at the BT45 or the Bridgestone Spitfire's for the 750.  I say it depends on how you are planning to ride the bike more than 75% of the time.....winding roads...riding 2 up...long straights at speed...etc.

[TwoTired]

I think its personal preference. 

No offense meant.  But, what does personal opinion have to do with a technical subject?

You will NOT change the laws of physics or geometry just because you prefer that it does.
It's my personal preference that I fly simply by flapping my arms.  Care to guess what my ETA is going to be?  Or, if my beard will cause too much drag?

I should probably point out that all brand loyalty is a misapplied concept.  Companies sell product under the guise of a brand.  Once they have you loyal to the brand, they can switch the product specs around as it benefits them.  But, you still buy the same brand.
The product you bought 5 years ago is almost certainly different than what is available today.  It is an artifact of production that the construction technique and materials used in production are constantly tweaked and changed to improve profit margins.  It still gets the same label, unless the consumer appearance facade changes.  Then it is labeled "NEW" or "improved" to attract new buyers.  I'm convinced most consumers aren't even aware they are being manipulated.

To me, it is still about matching the maker's specs to the application requirements, and not about the shade of black the tire comes in.
I did a quick search and found that Continental still offers the correct size tires for the 78 CB750K.
http://www.conti-online.com/generator/www/de/en/continental/motorcycle/themes/motorcycletires/classic/tk22_44/tk22_44_en.html

I would go with those rather the stuff something close to what is required around the axles, even though I've had/have good experience with Metzlers.  But then, I'm an engineer, not a fashion/style maven.

It is what it is, not what I'd prefer it to be.

Cheers,

[cameron]

That is interesting, TwoTired!

I never knew that about tires.

Can you tell me why Honda chose English-size tires, when everything else is metric?
I also never really understood that!

And FTR, I HATED my new tires when I first got them. It took me weeks to get used to them.
Now they feel just like my old ones. But again, I am not a performance guy

[TwoTired]

Can you tell me why Honda chose English-size tires, when everything else is metric?
I also never really understood that!

In the 70s metric MC tires were not generally available  Inch sized tires were available world wide, ASAIK.
The changeover to metric for car tires began in the 60's when European made radial tires began their rise to popularity.
It wasn't until the 80's that metric tires for motorcycles began entering the US market and were specified for new motorcycles (I think due to DOT requirements and the US pledge/ movement to convert America to the metric system).

From:
http://www.unc.edu/~rowlett/units/usmetric.html
In the 1970's there was a major effort to increase the use of the metric system, and Congress passed the Metric Conversion Act of 1975 to speed this process along. However, American consumers generally rejected the use of metric units for highway distances, weather reports, and other common measurements, so little was accomplished except for the encouragement of faster metric conversion in various scientific and technical fields.

In 1988, Congress passed the Omnibus Trade and Competitiveness Act, which designates "the metric system of measurement as the preferred system of weights and measures for United States trade and commerce." Among many other things, the act requires federal agencies to use metric measurements in nearly all of their activities, although there are still exceptions allowing traditional units to be used in documents intended for consumers. The real purpose of the act was to improve the competitiveness of American industry in international markets by encouraging industries to design, produce, and sell products in metric units

[brewsky]

Dunlop K70's

I would love to have a set of those on my K8.
Where can I get them in a 4.50/17?

[swellguy]

Where can I get them in a 4.50/17?

I did not realize that you were running a 17" rear wheel. They're only made in 18 and 19 inch diameter.

[swellguy]

I forgot the 78K has a 17 inch rear wheel.
Meztler does make the 3.50 19 front.  But not the 4.50-17 rear.   Probably have to sub a metric 120 tire for the rear.

Dunlop also does make the D103 Rear which is a 4.50-17 tire.

[BobbyR]

Dunlop K70's

I would love to have a set of those on my K8.
Where can I get them in a 4.50/17?

Probably the easier way to find them is do a Google search on the tire. Or go to the company website they usually have a list of sizes, easier way.

[dave500]

my 500 has a spitfire on the rear and a battlax on the front,i did have a battlax rear but went the spitfire when it was replaced(i had the battlax new) because the centre tread isnt a zig zag type,i think these wear out faster on the drive tyre.i live in a great hilly area,and as posted above can hold my own against heavier bikes in these twisty areas.

[brewsky]

Dunlop K70's

I would love to have a set of those on my K8.
Where can I get them in a 4.50/17?

Probably the easier way to find them is do a Google search on the tire. Or go to the company website they usually have a list of sizes, easier way.

I've Googled till I'm Google-eyed....that's where I got the recommendations for my reply above.
I missed the Continentals though that Two Tired found and may use those if I can't find other better options, since I prefer the stock sizes over substitutes.
By the way, this site has the rear for one heck of a price, but doesn't show the front.
http://www.klr650.com/continentaltire.htm
The Avon Roadriders are the only ones that are V rated of the bunch mentioned so far I believe.
As important to me is the manufacture date code on the tire, thats why I like to see the tire in person that I'm buying, hard to do online.

[Operator]

I run Bridgestone Accolades. I have found them to last a long time, handle really well in the rain, and have had no issues with slippage when laying into corners. Fitted with tubes, on Comstar rims on a K3.

Had Dunlops on my CB350, found them to be good all around tires but I didn't have a huge amount of confidence with them in heavy rains. Can't explain precisely why, they just seemed a bit off.

[Rosinante]

I am in travel status at the moment, but I plan to check out these links and resume my research soon, as the tires on this (new to me) bike are not acceptable (WAY old).

I VERY MUCH appreciate the input and discussion.