Topic: Harley Sportster Forty-Eight Wheels on CB500/4

[bassboy3313]

Hello everyone! I am new to these bikes and just acquired a CB500/4 for practically free. I am planning a street scrambler style build. I want fat tires on it, which made me look at the wheels on the Sportster Forty-Eight I have sitting in my garage. They are 16" laced wheels with 170 rear & 150 front tires. This is the exact look I want for the CB as well.

My question is, will the hubs on the Sportster wheels mount right up to the CB500? Or will custom hubs be needed due to axle size, etc. I know the brakes would need to be sorted out, but is there anything else preventing the Forty-Eight wheels from mounting right up? Otherwise could I lace up the CB hubs to the Harley wheels/spokes and be good or will the wider wheels prevent that from working? Thanks in advance!!!

[newday777]

Welcome to the forum

Many have put Harley 16" rim on the rear over the years.
Front will probably be too narrow spacing of the forks for a wide rim and tire.

[bassboy3313]

Thanks! Happy to be here. I found this bike online that is a good representation of what I'd like to do wheel/tire wise. Any info or help in achieving this fitment would be awesome!!

Welcome to the forum

Many have put Harley 16" rim on the rear over the years.
Front will probably be too narrow spacing of the forks for a wide rim and tire.

[newday777]

You will need to obtain a set of bigger width triple trees.  Those might be from Cognito Moto

[HondaMan]

Get longer front forks along the way: these bikes had little trail up front, and having even less will make for pretty spooky handling!

[gearsoup]

Get longer front forks along the way: these bikes had little trail up front, and having even less will make for pretty spooky handling!

I've got a '78 750K that I'll be tearing into this winter. Any suggestions on what would be a viable longer fork swap option? Triple trees aren't an issue, as I'm planning on machining anything I need (assuming I can get some openings in my shop schedule)

[bassboy3313]

You will need to obtain a set of bigger width triple trees.  Those might be from Cognito Moto

Ah that's a good point. I didn't think about that. I will have to do some research on what width triple tree would be required. I'll do some comparative measuring on the Sportster and CB500. Thanks!

[bassboy3313]

Get longer front forks along the way: these bikes had little trail up front, and having even less will make for pretty spooky handling!

How much longer would you suggest?

[carnivorous chicken]

Don't know what the limit is for the rear, but the swing arm might also prevent something too wide.

But... nobody wants to try to talk him out of this? His bike, his ideas, sure. But a bike like that is going to handle like 5hit. It's definitely "just for looks" but people who know these bikes will be giving it a different kind of look.

[bassboy3313]

Don't know what the limit is for the rear, but the swing arm might also prevent something too wide.

But... nobody wants to try to talk him out of this? His bike, his ideas, sure. But a bike like that is going to handle like 5hit. It's definitely "just for looks" but people who know these bikes will be giving it a different kind of look.

This bike IS going to be more so "for looks" honestly. I have my Sportster Forty-Eight that is fully built for racing/street riding as well as a Triumph Bonneville. I got this CB500/4 for practically free already cut into, so now is my chance to build a "show" bike that I have wanted to do for awhile.

Mainly looking for ideas on how to most closely match that balloon retro tire look from the image above. If there is a way to do it with the stock wheels, I am all ears. Just don't think that's possible without going to a smaller diameter rim.

[Shtonecb500]

I think the fattest tire ur gonna get into a cb500/550 swing arm is a 130/140 tire and thats with modifying the brake stay/stabalizer bar...might even get some rub when the tire gets wide.

[seanbarney41]

I still don't get it.  What is it about a crippled, useless motorcycle that looks "good".

[Stev-o]

I still don't get it.  What is it about a crippled, useless motorcycle that looks "good".

Some guys just like oversize tires for looks.  I get it for muscle cars but not for my bikes that I ride.

[Bankerdanny]

I've got a '78 750K that I'll be tearing into this winter. Any suggestions on what would be a viable longer fork swap option? Triple trees aren't an issue, as I'm planning on machining anything I need (assuming I can get some openings in my shop schedule)

A GL1000 swap would get a longer fork with bigger fork tubes for a more rigid front end and better brakes if you want to run twin front rotors. It is almost a direct bolt on. You need the complete front end, including the triple trees and have to press out the GL steering stem tube and replace it with the 750 tube.

[Bankerdanny]

Thanks! Happy to be here. I found this bike online that is a good representation of what I'd like to do wheel/tire wise. Any info or help in achieving this fitment would be awesome!!

Welcome to the forum

Many have put Harley 16" rim on the rear over the years.
Front will probably be too narrow spacing of the forks for a wide rim and tire.

I will not deny this looks cool. But it will handle like a pig and not be very enjoyable to ride.

[newday777]

Thanks! Happy to be here. I found this bike online that is a good representation of what I'd like to do wheel/tire wise. Any info or help in achieving this fitment would be awesome!!

Welcome to the forum

Many have put Harley 16" rim on the rear over the years.
Front will probably be too narrow spacing of the forks for a wide rim and tire.

I will not deny this looks cool. But it will handle like a pig and not be very enjoyable to ride.

It might fo OK on gravel roads though.....😎

[calj737]

I think the fattest tire ur gonna get into a cb500/550 swing arm is a 130/140 tire and thats with modifying the brake stay/stabalizer bar...might even get some rub when the tire gets wide.

A 150/17” tire fits.  The tire in his reference photo is not nearly that wide. Regarding the rear tire fitment, clearance to the subframe above is the place to be mindful of when the suspension is under compression.

Wider spread triple trees require spacers for the hub. One thing affects another with respect to modifications. The tires shown “appear” wider, taller etc but I think mostly it’s due to a taller sidewall. So before you go chopping things up, get a set of tires and lay them between the stock forks and trees. Then see what you might need to do (could be less than you think).

[bassboy3313]

I still don't get it.  What is it about a crippled, useless motorcycle that looks "good".

Good thing this isn't your bike then, huh?

[bassboy3313]

Thanks! Happy to be here. I found this bike online that is a good representation of what I'd like to do wheel/tire wise. Any info or help in achieving this fitment would be awesome!!

Welcome to the forum

Many have put Harley 16" rim on the rear over the years.
Front will probably be too narrow spacing of the forks for a wide rim and tire.

I will not deny this looks cool. But it will handle like a pig and not be very enjoyable to ride.

Different strokes for different folks... 🤷‍♂️

[bassboy3313]

I think the fattest tire ur gonna get into a cb500/550 swing arm is a 130/140 tire and thats with modifying the brake stay/stabalizer bar...might even get some rub when the tire gets wide.

A 150/17” tire fits.  The tire in his reference photo is not nearly that wide. Regarding the rear tire fitment, clearance to the subframe above is the place to be mindful of when the suspension is under compression.

Wider spread triple trees require spacers for the hub. One thing affects another with respect to modifications. The tires shown “appear” wider, taller etc but I think mostly it’s due to a taller sidewall. So before you go chopping things up, get a set of tires and lay them between the stock forks and trees. Then see what you might need to do (could be less than you think).

That definitely makes sense. From research on Shinko's site, I think the below tires are what's on that reference bike. I would just need to see what size would work and what size wheels would be needed to make it all come together as well. More research will be had for sure.

https://shinkotireusa.com/product/super-classic-270-tire/211905

[Bankerdanny]

Different strokes for different folks... 🤷‍♂️

Agreed. You build the bike you want.