Author Topic: cb400f ultimate rim size  (Read 4354 times)

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Offline kajtek

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cb400f ultimate rim size
« on: March 21, 2010, 08:10:13 AM »
hi all,

a recently purchased cb400f has mismatched and quite old tires so i plan to fit avon am26 when funds allow. i have been considering lacing the hubs to alloy rims, to resist any corrosion and for better handling/acceleration etc. looking around morad seems to be a good choice. any other suggestions welcome that are not expensive!

looking at this website: http://home.comcast.net/~eyhonda/1975_honda_cb400f.htm

the chap has fitted plus size rims, 1.85f and 2.15 rear, with a 90 front tire and a 110 rear. as i understand the 90 size tire is a little larger than the original 1970s tire, so a 1.85 rim would suit it better? also he has gone up a size on the rear to match the rim i assume?

what i want to find out is what is the best combination in terms of handling. should i consider wider rims? i dont want the front to go wider than 90, i prefer sharper handling as i imagine everyone else does. but whats best on the rear? and whats the best choice in rim width?

thanks for any advice....

ashley :)
1978 honda cb400f supersport

Offline kghost

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Re: cb400f ultimate rim size
« Reply #1 on: March 21, 2010, 10:58:32 AM »
I like my Avons on the 400.

I'm not quite sure why you think an alloy rim is going to be corrosion resistant.

Aluminium rims tend to corrode and oxidize faster than chromed steel.

Thier nice because thier lighter but they'll still need something to prevent corrosion.

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Offline wannabridin

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Re: cb400f ultimate rim size
« Reply #2 on: March 21, 2010, 11:20:13 AM »
why do you say they're going to corrode faster than chromed steel?  the electronegative differences between aluminum and steel are substantial.  the only thing that can cause bad enough corrosion with an aluminum wheel is with the use of non-stainless spokes, and due to the dissimilar materials at the spoke/wheel interface, you will induce galvanic corrosion, but as long as you keep your wheels dry after you wash them, you won't have to worry about much!
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Offline kghost

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Re: cb400f ultimate rim size
« Reply #3 on: March 21, 2010, 12:02:45 PM »
why do you say they're going to corrode faster than chromed steel?  the electronegative differences between aluminum and steel are substantial.  the only thing that can cause bad enough corrosion with an aluminum wheel is with the use of non-stainless spokes, and due to the dissimilar materials at the spoke/wheel interface, you will induce galvanic corrosion, but as long as you keep your wheels dry after you wash them, you won't have to worry about much!

Yes you'll have corrosion problems associated with galvanic corrosion (Electrolytic) and dissimilar metals.

Additionally if your looking for a shiny or reflective surface...aluminium will dull faster due to its surface oxidation characteristics. Its actually one of the ways that aluminium protects itself from worse corrosion.....but surface oxidation will occur faster than with chromed steel.

Aluminium is also susceptible to Exfoliant, Intergranular, and Stress corrosion (Certain Heat treated alloys) in ways steel is not.

Now the last three are pretty extreme cases. But I've seen a fair bit of it on Vintage rims. Takes a fair bit of neglect to achieve the state.

I guess the point I was trying to make is that without a barrier the alloy wheels will be dull due to surface oxidation much more quickly.

Personally I find the alloy wheels much more difficult when it comes to the breakdown of the barrier on the surface then Chromed steel.

Its fairly challenging to polish and protect Alloy when the barrier has been compromised. Short of polishing and reapplying a protective coating.

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Offline kajtek

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Re: cb400f ultimate rim size
« Reply #4 on: March 21, 2010, 12:07:43 PM »
ok, i was just thinking about my currently chromed and pitted steel rims! i was planning on powder coating / painting black if i got the alloy rims which would hopefully prevent any surface problems. the main reason for the alloy rims is obviously weight.

any ideas on best rim sizes and tire choices?

thanks

ashley
1978 honda cb400f supersport

Offline kghost

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Re: cb400f ultimate rim size
« Reply #5 on: March 21, 2010, 12:25:08 PM »
ok, i was just thinking about my currently chromed and pitted steel rims! i was planning on powder coating / painting black if i got the alloy rims which would hopefully prevent any surface problems. the main reason for the alloy rims is obviously weight.

any ideas on best rim sizes and tire choices?

thanks

ashley

What I was getting at was....depends what you want the surface to look like and for how long.

Polished and cleared alloy look great.....when the clear breaks down its problematic.

Now if you want bare alloy....you'll polish more than chrome to keep it shiny.

Chrome is great if maintained and its really easy to maintain...Alloy is great if your not concerned about a dull surface and want lighter weight.

The stock tire size is pretty good.....rim size depends on your need.

Stock I'd not see alot of benefit from a wider tire front/back...but if your going to track days or do serious riding...then yeah you'll probably enjoy a wider tire.

I like the avons that are on my bike.
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Offline strynboen

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Re: cb400f ultimate rim size
« Reply #6 on: March 21, 2010, 12:35:41 PM »
alternative are gold metallic or silver..just made this on my yamaha,,,,tjek my self made vheel maker..
« Last Edit: March 21, 2010, 12:37:17 PM by strynboen »
i kan not speak english/but trying!!
http://forums.sohc4.net/index.php?topic=60973.0
http://forums.sohc4.net/index.php?topic=144758.0
i hate all this v-w.... vords

Offline Kevin400F

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Re: cb400f ultimate rim size
« Reply #7 on: March 21, 2010, 12:59:32 PM »
I'd recommend a 1.85 with a 90/90 tire, and 2.15 rear rim with 100/90 tire if you're running at stock power levels.  You really don't need a bigger rear...it just represents more weight and rotating inertia, but if the fatter look appeals to you a 110/90 would be equally happy on the 2.15 rim.  You'll just accelerate a bit more slowly due to the taller effective gearing and the increased tire mass.


Offline kajtek

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Re: cb400f ultimate rim size
« Reply #8 on: March 21, 2010, 01:17:08 PM »
cool, thanks for all the advice, and i love those gold rims!

if all goes to plan (i.e if all my ebay sales go to plan...) will go with the morad 1.85 front and 2.15 rear, with 90 front and 100 rear. hadnt considered the extra weight of the 110, seems pointless to fit alloy rims with a heavier tire!

will post up some pics of my bike in the current week. i love it very much but it doesnt seem to be running great, pods are coming off and all the service stuff needs to get done.

thanks

ashley
1978 honda cb400f supersport