Topic: shoot me ..... cb550 tire size (s)

[xsmooth69x]

now im usually pretty good with lurking and searching before i ask redundant questions.....

anyways searching for the tire size for a 1975 cb550k1 i cant get a good answer..... this is what i came up with....

Front 110/90/19, 100/90/19, and 90/90/19
Rear 120/90/18, 100/90/18, 130/90/18

Front 4.10
Rear 4.25

^ all those sizes where recommended by other threads in this forums and caferacer forums.... so what is it?

i want good handling..... i dont know why else anyone would get different sizes to not make it handle?

[lone*X]

My opinion is that bigger tires are an aesthetic option only.  The factory engineers didn't just slap a set of wheels and tires on because they were available or cheap.  They were sized to complement the chassis dynamics.  Rake, trail, wheelbase, spring rates, lean angles all were considered when selecting the factory tire sizes and then road tested for handling.  The best handling for a stock suspension and chassis is going to be the factory sizes in my opinion.  Stock for your 550 are:
Front    3.25 x 19in
Rear    3.75 x 18in

You can cross reference the metric sizing of current offerings.

Of course if you are modifying the suspension then all bets are off.

[bollingball]

For you to get what you want you need to know what the numbers mean. Do you? You don't want a tall tire if you lay over hard all the time. Also read up on compounds. How long do you want them to last? FAQ has a lot of tire info. What do you have now and how did they work for you and your type of riding?

[singedebile]

The bike was made for a 3.25 front and 3.75 rear
...unless you go with cheng shin etc.. you wont be finding exactly these sizes. Some close to the original size and highly rated options include

Michelin Pilot Activ 3.25-19 4.0-18 (what i will likely be getting but i really wish either the front was slightly larger or the rear slightly smaller as HondaMan recommends not having more then 10mm or .5inch difference between the front and rear, but I may just be nitpicking)

Avon AM26 90/90-19 100/90-18

Metzeler Lasertec 3.25-19 4.0-18


and incase you were wondering
90 millimeters = 3.54330709 inches
100 millimeters = 3.93700787 inches

[xsmooth69x]

For you to get what you want you need to know what the numbers mean. Do you? You don't want a tall tire if you lay over hard all the time. Also read up on compounds. How long do you want them to last? FAQ has a lot of tire info. What do you have now and how did they work for you and your type of riding?

how tall/ wide/ rim size

metric only has 2 numbers thats... rim width x rim diameter

[xsmooth69x]

i want to get the continental rb2 / k112 combo but from what ive searched they are hella expensive.... unless someone can point me in the right direction

i might just get the dunlop k81 tt100 since they are cheaper

might go avon too i really like the block tread in the front the super vintage look. the k81 dont really have that.... the rb2 / k112 deff has that look but can anyone justify the price !?!?!?!

but whats with these cheng shin they are dirt cheap and they dont look half bad. whats is the story with these? are they legit?

[TwoTired]

The best handling for a stock suspension and chassis is going to be the factory sizes in my opinion.  Stock for your 550 are:
Front    3.25 x 19in
Rear    3.75 x 18in

You can cross reference the metric sizing of current offerings.

Good advice.   However, the metric conversions don't take the aspect ratio into account.  So, you can pick an equivalent width in metric, but it won't be the same 95-100% aspect ratio of he original specification.

If you want the superb stock handling the original bike had over the entire life of the tire, get nearly the same stock size as the original rims demand.
Any new oversize tire with the original crown profile will work ok when brand new.  But, as the crown flattens, the handling gets progressively worse.  Leading you to be oh so happy you replace them...    ...often.

I've done the oversize tire routine with the Cb550.  I've learned that the stock sizes work best over time on the stock bike.  The crown profile remains far longer than with the oversize fitment.
I now use Metzeler Lasertec 3.25-19 front and ME77 4.0-18 rear.  I'll probably go Lasertec rear next time as they weren't available during the last replacement interval.

[singedebile]

The best handling for a stock suspension and chassis is going to be the factory sizes in my opinion.  Stock for your 550 are:
Front    3.25 x 19in
Rear    3.75 x 18in

You can cross reference the metric sizing of current offerings.

Good advice.   However, the metric conversions don't take the aspect ratio into account.  So, you can pick an equivalent width in metric, but it won't be the same 95-100% aspect ratio of he original specification.

If you want the superb stock handling the original bike had over the entire life of the tire, get nearly the same stock size as the original rims demand.
Any new oversize tire with the original crown profile will work ok when brand new.  But, as the crown flattens, the handling gets progressively worse.  Leading you to be oh so happy you replace them...    ...often.

I've done the oversize tire routine with the Cb550.  I've learned that the stock sizes work best over time on the stock bike.  The crown profile remains far longer than with the oversize fitment.
I now use Metzeler Lasertec 3.25-19 front and ME77 4.0-18 rear.  I'll probably go Lasertec rear next time as they weren't available during the last replacement interval.

so you would say its better to end up with a slightly larger rear and have the proper front size then have a set that are more proportional one to the other?

[xsmooth69x]

ya i going with 3.25x19 F and 4.00x18 R

no i have to pick the tires

im really curious about these cheng shin's

[Bankerdanny]

Keep in mind that the stock 550 rims are very narrow, 1.85" front and rear. Based on every manufacturer's chart I looked at when getting new tires for my bike that is too narrow for a 4" rear.

I picked up a 3.25x19 Michelin for the front and put a 110/90-18 Kenda 671 on the back.

The 110/90 is a pretty easy size to find, Michelin, Avon, and Bridgestone all offer tires in this size in addition to the less expensive options from Cheng Chin and Kenda.

[vames]

ya i going with 3.25x19 F and 4.00x18 R

no i have to pick the tires

im really curious about these cheng shin's

Cheng Shin doesn't make street bike tires any more -- I believe they're now called Maxxis. You can search for a number of threads in which there was heated debates on these. The short version is some say "you get what you pay for and these are crap" while others say "i'm not a knee dragger/thrill seeker and these tires are economical and work well for me."

[Bankerdanny]

Sheng Shin sells in the US as Maxxis and also CST

[Gordon]

Avon Roadriders are available in 3.25/19 and 4.00/18, and they're great tires. 

[Bankerdanny]

I had Roadriders on my Enfield and my FJ and was very please with them.

[xsmooth69x]

ya i wanted to keep to more period looking tires....

can anyone tell me if the rb2/k112 any good and if you can justify the price for these things. are they really that amazing. sure they look very cool but 100ish for the front and 130ish for the rear worth that cost?

also when fitting new motorcycle tires to i need to bring them to a motorcycle shop or can i just bring it to any automotive shop?

i also need stems tubes and rim strips right? should i buy all this before hand or just buy it from the shop.... or will they even have this stuff in stock at the tire places?

[Kevin400F]

If you're insistent on staying with a more period look, do a search for IRC GS-11 tires.  An added benefit is that they have them in the period "inch" sizes.   I would go with 3.25-19 front and 4.00-18 rear.   

Yes, you need tubes and rim strips.  You should be able to pick them up from the motorcycle shop that does the mounting.  Automotive tire shops probably won't be capable of dealing with the motorcycle wheels.

Finally, a "130-ish" rear tire is way too big for the stock 1.85" wide rim.  Even a 120 is too big, in my opinion.

Kevin

[JBMorse]

Here are a couple suggestions:
IRC GS 11 tires are a good choice and come in the sizes you need.  I had them on my bike but didn't like them as much as my Dunlop K70s because I ride on lots of dirt roads ( I live in New Hampshire) and the K70s have a nice blocky tread pattern.
If you have a little more money to spend, try the Metzelers mentioned above.  They're supposed to be excellent.  Someday soon I want to try those or the aforementioned Avons on one of my bikes.

And I don't know if you were already planning this or not, but mounting these tires is pretty easy and will save you a lot.  I order my tires online for about 1/2 what they cost at the dealer and mount them at home, saving the $20 or so it cost to mount them.

[Bankerdanny]

$20 to mount them? Hah!

A local independent I was referred to by another forum member will do it for $35. But the local dealers all charge $60-$80 per tire.

I did the front and rear tires myself with assistance from my sister's boyfriend, although I have done other bikes on  my own. It requires some care to make sure you don't pinch the new tube (I recommend a spare on hand just in case), a good set of motorcycle specific tire irons, some patience and some muscle, but it can be done with some practice.

It's a skill that everyone with a motorcycle should have as far as I'm concerned. Every small town has a garage that can do car tires, but finding a shop that can do motorcycle tires can be a challenge.

[crazypj]

ya i wanted to keep to more period looking tires....

can anyone tell me if the rb2/k112 any good and if you can justify the price for these things. are they really that amazing. sure they look very cool but 100ish for the front and 130ish for the rear worth that cost?

also when fitting new motorcycle tires to i need to bring them to a motorcycle shop or can i just bring it to any automotive shop?

i also need stems tubes and rim strips right? should i buy all this before hand or just buy it from the shop.... or will they even have this stuff in stock at the tire places?

 I can highly recommend the Conti's. RB2/K112
 Used them multiple times on my 550 (when I had cash)
 Front has a 'limited slip' capability to let you know your close to the limit (damn scary the first time it happens, but, you can keep leaning over and it sticks like you know what to a blanket

PJ

[xsmooth69x]

If you're insistent on staying with a more period look, do a search for IRC GS-11 tires.  An added benefit is that they have them in the period "inch" sizes.   I would go with 3.25-19 front and 4.00-18 rear.   

Yes, you need tubes and rim strips.  You should be able to pick them up from the motorcycle shop that does the mounting.  Automotive tire shops probably won't be capable of dealing with the motorcycle wheels.

Finally, a "130-ish" rear tire is way too big for the stock 1.85" wide rim.  Even a 120 is too big, in my opinion.

Kevin

sorry when i said 120is and 130is i ment the cost of these tires

$120ish front and $130ish rear for the price. and i was wondering if they are justified since i think they are kind of expensive or am i looking in the wrong place?

[Bankerdanny]

$ signs are your friend. Most tire sizes are metric these days, so when you say 120 or 130 without the dollar sign we all will assume you are talking tire size, not cost.

There is no reason to spend more than $100 (before shipping) on the tires for your bike. These are not adventure bikes or bleeding edge sport bikes sporting giant radials.

[xsmooth69x]

you can mount tires by myself?!?!?!?! i thought u need a machine to do it?!?!?!?!

anyone know any reputable places that sell tires cheap?

k70, k80, k110, rb2, k112, avon ribbed, avon sm mark 2?

[xsmooth69x]

found a sweet walkthrough for changing your own moto tires

http://www.motorcyclecruiser.com/tech/0706_crup_how_to_change_a_motorcycle_tire/motorcycle_rotors.html

i might just do this myself i love learning and possibly mastering new traits 

[Bankerdanny]

found a sweet walkthrough for changing your own moto tires

http://www.motorcyclecruiser.com/tech/0706_crup_how_to_change_a_motorcycle_tire/motorcycle_rotors.html

i might just do this myself i love learning and possibly mastering new traits 

Sure, it's like changing a very heavy duty bicycle tire.

Like I said, proper levers are essential, I have a pair of 16" long tire irons that I bought from Competition Accessories. It takes practice and some muscle, but it's a great skill to have if you are going to do any touring on a tube type tires like the ones on our bikes. Be prepared to sacrifice a tube or two as you learn though.

[TwoTired]

They still need to be balanced.  And MC shops do that after mounting.