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Discussion Starter · #1 ·
Can I fit 18 4.00 firestones on my stock cb450? I understand performance will suffer but I'm more concerned if its physically possible...
 

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It will definately fit on back (I've run 4.25 x 18).... As to the front it MIGHT not clear the fender (depending on fork year) ..... BTW, Your K7 has (came with) a 19" front wheel, so, NO a 4.00 x 18" won't fit physically......
 

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Discussion Starter · #4 ·
Awesome. Thanks for clearing that up. Can't wait to get this thing roadworthy.
-Mike
 

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4.00x18 on the rear on my bike. Fit's perfect and looks great I think. They are dunlop k70 tires...really nice and pretty cheap.
 

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I been looking into this as well, some sites say the 74 k7 came with 3.25-18 front and 3.50-18 rear so that would make the direct replacent a 100/90/18 for both front and rear. When I went out and looked at my bike however it had a 3.25-19 front and a 400.18 rear. So as I am try to stay as close to stock size as possible would I be correct in using a 100/90/19 front and a 110/90/18 rear as a tire size.
Thanks for any input

Dan
 

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I ran a 4" for years on the K0 450, no problems, and still good clearance. I did keep to the 3.25" front profile though.
Th K0 had 18" wheels both front and back. Which is apparantly why you cant buy Dunlop TT100's for the BB. The TT100 refer to 19" wheels, which the Triumph had.
 

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I was looking at avon am26 as they have both 3.25-19 and 4.00-18 tires. These tires are tubeless, any thoughts on tube or not and as I am new to wire spoke wheels do they require a tube?

thanks again

Dan
 

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Hi All I'm going to step in and dissagree with most of the posts above...

if you want to know what tires work on your bike the best place to check is with the tire manufacturers...based on what RIM SIZE their tires are recommended for.

for example if you cross reference (and there is some debate on the cross reference but bear with me) a 4.00 x 18 to a 110 x 90 x 18 and you look up what rim size (width) the tire manufacturers recommend for their tires...Avon for example recommends an 2.50 x 18 rim to run with their 110 x 90 x 18 tire. so unless you plan to put wider rims on you are not recommended to put this tire on.

when deciding what tire to run on your bike, pick something that fits your RIM, not something that you can physically cram between the fenders. I'll never understand why so many people feel the need to put the fattest tire they can fit on their bikes.

If you'll excuse the rant, Here's a quick overview of the ways bigger tires hurt your performance
* shoehorning wide tires on rims that are too narrow will pinch the tire profile and actually reduce the contact patch your tire has on the road
* it also changes the overall profile of the tire with effects the hight and roundness of the tread patters with compromises wet wether traction, stability and turn in effort
* a bigger tire is heavier than a smaller tire with all the extra mass at the outside of the radius which requires the most leverage to change it's velocity...it takes more horsepower to accelerate, takes more brakes to stop (leads to faster brake fade from the extra heat, adds to unsprung weight which effects your suspension's ability to control the vehicle.
* these old bikes don't make enough hoursepower to need larger rear tires. so there's no upside.

so to sum; bigger tires hurt traction, rob horsepower, rob breaking, are heavier to stear, perform worse in the wet, and overpower suspension.

On the bennefit side we have...they look cool :cry: :lol: :lol: :?

if you simply have to look cooler go buy a new pair of sunglasses or some fashion jeans and stop ruining your bikes with these silly tacky dangerous ideas.
 
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Thanks for the input. I am trying to get the correct size tire for the bike. I would like a tire like the am26 for its handling and sticky factor but I want the correct size. I will contact bikebandit and ask them based on my rim size. My bike has 9400 miles on it so I am pretty positive the 3.25-19 front and 4.00-18 rear were not original. I have the original owners manual for my 74 cb450k7 and it list the tires as 3.25-19 (4PR) front and 3.50-18(4PR) rear.

Dan
 

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I plan on a 16" rim & 5.00 tire on the back of mine.

I simply don't like the 18" rim that looks like it should have a dirt bike knobby for street use. ;)
 

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fairjoeblue said:
I plan on a 16" rim & 5.00 tire on the back of mine.

I simply don't like the 18" rim that looks like it should have a dirt bike knobby for street use. ;)
apehangers and forward controls to match?
 

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" apehangers and forward controls to match? "


Medium high bars & stock controls.

I think apehangers are absolutly the most unattractive thing a person can put on a bike.

[Not to mention they are unsafe, poor control & after awhile arms start getting nimb.]
 

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nevermind...
 

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Discussion Starter · #17 ·
outobie said:
On the bennefit side we have...they look cool :cry: :lol: :lol: :?

if you simply have to look cooler go buy a new pair of sunglasses or some fashion jeans and stop ruining your bikes with these silly tacky dangerous ideas.
You could have stopped at your explanation on how going bigger affects handling and your opinion would have been much appreciated. I simply wanted to know if I could use a slightly bigger tire on the rear of my bike...I'm not looking for the biggest tire that will fit.
This bike is being built to cruise around town, not go wide open on the vintage racing circuit. The other posts have given me confidence that the tire won't unseat itself as I leisure around town doing 40mph...but thanks anyway.
 
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