Need some help

[Drmskul]

I have a CB 750 K3 front tire i want to change out the bearing and spacer so it will fit a 3/4" axle.
has anyone done this? if so what bearing did you use and what did you use for a spacers. hope someone has done this to save me sometime

[Re-run]

Have you made sure the axle will fit in the clamps? I would make sure of that first. Otherwise, I have not come across anyone that has done that. Most people will just re-lace the hub to whatever rim they want.

[TOOLS1]

The standard bearing for the wheel is a 6302UU radial ball bearing. The inner diameter is 15mm. You need to find a radial ball bearing with an inner diameter of 3/4" or 19.05mm.
For a new spacer you can just use a piece of 3/4" pipe cut to length.



 "d" (shaft or inner diameter) = 15mm (.5906")

"D" (outer diameter) = 42mm (1.6535")

"B" (width) = 13mm (.5118")

"r" (radius) = 1.5mm (.059")

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[Re-run]

I would still make sure it safely clamps in the fork legs though. Bearings are easy enough to find and spacers can always be made for inside the hub. The spacer for the fork has to hold the axle solid so it can't move and still be secure enough to not slide out or break the bolts.

[TOOLS1]

I am assuming he is wanting to install a Honda wheel on a different set of forks that use a 3/4"axle, and not trying to install a 3/4" axle on a Honda front end.
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[Lucky 1]

He is not telling us the whole story so it makes it hard to help him.

He may not realize how experienced some members are.

[shinyribs]

Well,it's pretty simple; he wants to run a 3/4'' axle.  Why? I dunno. We don't really need the whole story.  

Since the original bearings are sized in metric it might be tough finding a standard-sized bearing to do a simple bearing conversion to adapt to a 3/4'' axle. You might wanna play around on Google doing some inch-to-mm conversions and compare that to what is available in a bearing.

3/4'' = 19.05mm so you are not too far off. That may actually slip inside a bearing with a advertised 19mm bore, but the proof is in the pudding. A quick search showed bearings with 42mm O.D. are only available with 18mm or 20 mm bores. But like I said, it was just a quick search.


McMaster Carr has an awesome database of bearings to look through.

As far as the inner bearing spacer goes I'd just hit up a hardware store. That piece doesn't to be a precisely fitted item, just needs to be there. Black iron pipe would do just fine and it easy to cut.

[Drmskul]

Here is a Pic

and the rest of the story i am going to put a DNA Springer front end on the bike and want to use the front wheel I have.
i have got the bearing now and will use 3/4 id pipe to make the spacer seems simple.
thanks for all the help.
Now the next problem i took the speedo drive apart so i could Machine it to fit the 3/4 inch axle when i took out the top gear that the tack cable goes to 2 small washes came out with it does anyone know that order they go back in?

[shinyribs]

A springer would look cool on there

You need one of these fuel caps. http://www.ebay.com/itm/Petrol-Gas-Fuel-Tank-Cap-Chrome-Large-Krommet-Bobber-Chop-Custom-/271153435948?pt=UK_Motorcycle_Parts_13&hash=item3f2201152c&vxp=mtr


I can't help with the speedo drive washers. I've never really had one apart. Are the washers flat or curved? Maybe they are used for preload somewhere to keep the gear from jumping around.

[shinyribs]

Looking at this now, needing a 3/4'' axle for a HD front end, some axle mods may have been the way to go. You could have built up(welded) the ends of the axle that fit into the fork legs and had them machined to fit your forks. That way all your bearings and speedo drive could have retained the original sizing. Just a thought. :)

[Drmskul]

Here are a few pics the frist one is the parts the washers are flat and I just can't tell if they are there just to be spacers or not it works the same if I put it together with both washer on the long shaft or if I put one in front of the gear and one on the back

[TOOLS1]

One front, and one back.
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