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Discussion Starter · #1 ·
what is the largest tire size you could fit on stock 1971 cb450 rims? would Firestone Deluxe Champion 4.00 x 19 fronts - 4.50 x 18 rears fit? i am ABSOLUTELY IN LOVE with everything these guys in denmark do, particularly this yamaha chop/rebuild. this is just a basic beautiful motorcycle in my opinion. i'm really considering borrowing some of these ideas for my bike...

http://wrenchmonkees.com/monkee10.html

speaking of, thoughts on running without a battery? maybe i'll start a new thread for that one.
-seth
 

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The stock rims will actually be somewhat too narrow...Not much, but enough, and here is a quote from the Dunlop tire site...
"Correct rim width may be crucial to handling and stability. A tire that is installed on a rim wider than recommended (for its sizing) will have a flattened profile, and a rider may easily reach the edge of the tread during cornering. A narrow rim will alter the tire profile, concentrating tire wear in a very small area during cornering, with a smaller contact patch during braking. Remember: Tire clearances are important."

....If you relace to the next size wider rims you should be within recommended sizing guidelines.....
Steve
 

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Discussion Starter · #3 ·
relace to the next size, meaning keep my hubs but up the rim size? hmm, smart steve. where do you think i might find that "next size up," and what exactly would that be, off hand?

and most importantly, how are you man? hope your (at least a little bit) happily wrenching and riding!
seth
 

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Seth, I believe the "stock" 450 rims are WM-1 (1.60 width)..... (Might be 1.60 front, 1.85 rear) Size is stamped into the rims....
The "next size up" would be: to WM2 (1.85 for the 1.60 rims), and/or to WM3 (2.15 if they are the 1.85 rims)
BTW... Those "Firestone Delux Champions" were "old style" Harley tires (in the 1960's)and I'd recommend more modern compounds/tread patterns....
IF I was going so far as to relace to new rims, I'd have to bite the bullet and run Excel Shouldered alloy rims (vintage racer style)... About $200 EACH unlaced.....add $$$ for lacing/truing, and of course, even more $ for Stainless spokes............. AT least all you have to do is polish up the hubs, and mail them to Buchannons..... :lol: :D

http://www.buchananspokes.net/products/ ... m_rims.asp


JMHO..... Steve
 

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Discussion Starter · #5 ·
steve...

and anyone else who cares, buchanan's came thru for me. just had the beefy new tires put on professionally to protect my fresh powdercoat job. and yes i did pay a pretty penny but i'm really happy with my quick mockup in the kitchen so far. keep you all posted. yep i'm leaving my dented tank as is (for now), adds character don't you think?


firestone deluxe champions...
4.00x19 front
4.50x18 rear

buchanan's bare steel raised nipple something...
1.85x19 front
2.15x18 rear
 

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Seth... Good job!... I see you followed the rim size for tire size guide, (The 1.85 and 2.15 rims were a perfect choice for those tire sizes) and the tires look VERY "old style fat", yet are just narrow enough to allow chain clearance..... Can't wait to see future progress.... What did the rims, spokes, lacing, and tires actually cost?... I'm sure someone else would consider a similar mod if they knew what you paid.... (not everyone is broke like me...LOL...) :D Steve
 

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Buchanans charged me about 700 for two 18" vm3 aluminum rims (anodized black) and matching spoke kits, full stainless spokes and nipples I laced em myself, not hard, just need patience. I went with narrower tires (stock sizes) front and rear avon listed vm3 for ideal rim width for am 26's Stock rims on my bike were 1.85 front and rear 19" and 18" respectively
 

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The improved tire designs and radial belting often specify/require wider rims... (the WM3's are 2.15's)... The preference/suggested size seems to allow a tad narrower rims for the bias ply tires.... Regardless of what I believe might be acceptable or correct sizing, ALWAYS DO as the Manufacturer specs...... , and Don't forget to install new rim bands and correctly sized new tubes...... :D :D ;) Steve
 

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Discussion Starter · #9 ·
yeah i'm in at about 550 for bare steel rims and stainless spoke kits. powdercoat was a deal i thought at about 60/rim including corresponding (existing) hubs. i too laced myself, a little hard but patience paid off and i'm stoked i figured it out! maybe 4 different attempts for the rear then on a quick second try i was a pro for the front. paid to have them trued and tires put on. this IS going to be my biggest expense for this bike and i knew that going in. i'm just gonna keep telling myself that...
-seth
 

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?

Seth... Good job!... I see you followed the rim size for tire size guide, (The 1.85 and 2.15 rims were a perfect choice for those tire sizes) and the tires look VERY "old style fat", yet are just narrow enough to allow chain clearance..... Can't wait to see future progress.... What did the rims, spokes, lacing, and tires actually cost?... I'm sure someone else would consider a similar mod if they knew what you paid.... (not everyone is broke like me...LOL...) :D Steve
Okay so a few things:

1. Where can a newbie like me get a definitive answer on what size my 72 Honda CL450 rims are? Is there an online manual or spec sheet that will list this information? I see several sizes here and but not a confirmation as to exact rim sizes for this bike. I've checked my rims (tires, tubes and strip removed) and don't see a stamp anywhere denoting the rim size. It might be somewhere under the rust.

2. It seems mounting 4.00 and 4.50 size tires on this model/era of bike/rims goes against a lot of what I'm hearing in other places on this board; namely that those wide tires are bad for safety and ride-ability. Yet I see here that mounting tires that big on stock rims was seen as okay. Honestly, I'd love for this to be true because I like the larger tires, but I'd like to de-conflict some of the info I'm seeing on the boards regarding this subject.

Thanks!
 

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Wider tires in and of themselves are not problematic when mounted on correctly sized (width) rims for those tires.....IF they have appropriate clearances to frame, chain, forks, fenders, and swingarms, etc....
The problems arise in that the wider tires usually chosen are strictly for aesthetics purposes, not performance, and do not fufill the needs of the bike as a SYSTEM.....
Do they "look" cool?....Sure.....But do they contribute to the handling, stability, safety, and functionality of the bike? ... NOT USUALLY....Because the other changes required to run larger, heavier, wider tires to advantage are usually not done as well....
 

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okay thanks

Wider tires in and of themselves are not problematic when mounted on correctly sized (width) rims for those tires.....IF they have appropriate clearances to frame, chain, forks, fenders, and swingarms, etc....
The problems arise in that the wider tires usually chosen are strictly for aesthetics purposes, not performance, and do not fufill the needs of the bike as a SYSTEM.....
Do they "look" cool?....Sure.....But do they contribute to the handling, stability, safety, and functionality of the bike? ... NOT USUALLY....Because the other changes required to run larger, heavier, wider tires to advantage are usually not done as well....
So in your opinion, mounting the 4.00 and 4.5 tires on stock rims for this 450 is okay assuming proper clearances, etc?

Is there a source that the pros like you on these boards use for reference? Like if you wanted to definitively find the stock rim sizes for a 72 Honda CL450? My barn find didn't come with manual and I've checked the rims all over and can't find any stamps.
 

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NO!......The STOCK rims are TOO NARROW!......Those running that size tires are relacing to WIDER rims.....
Still, without signifigant changes to weight bias and suspension at the minimum, those tires become a disadvantage rather than an improvement....
You have missed the point of this entire discussion.....
 

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NO!......The STOCK rims are TOO NARROW!......Those running that size tires are relacing to WIDER rims.....
Still, without signifigant changes to weight bias and suspension at the minimum, those tires become a disadvantage rather than an improvement....
You have missed the point of this entire discussion.....

Yes, until now I did miss the fact that the original poster had gone to wider rims in order to accommodate the larger tires.

With us newbies some assumptions go right over our heads. If that's frustrating, I apologize. I'm still trying to figure out the best way to learn what I need to know.
 

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My frustrations notwithstanding, just continue to ask and we'll continue to answer until you "get" what we are trying to say.....
We ALL can learn when the reasons are required to be stated using differing wordings.....I try to be succinct, but sometimes forget that the questioner is not asking from the same technical level or with the same base knowledge....For instance, you CAN ascertain your existing rim widths by measuring between the insides of the "bead" lips with the tire dismounted.....There was an excellent pictorial I'll post a link to when I can find it......:D
 

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In case you don't know, the key to handling and response is matching the suspension parts (spring rate, shock absorption) to the unsprung weight, which is everything NOT riding on top of the springs. Increasing this weight, by adding a larger tire or other hardware, means the shock absorbers have to work harder to control how much the wheels bounce. Is a 4" tire enough heavier than a 3.25" tire to really feel this difference? It is for some.
 
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