Wheel interchange question.SOHC to a DOHC

[slownugly007]

i measured my front axle, its about 10 1/4", the inside dimension of my fork tubes is 6 1/8", just curious what a SOHC measures?

[shinyribs]

I'll be pretty busy tomorrow but i will measure mine as soon as i get the chance.

Tools...guess what...i didnt test the controlssorry  maybe ill have time tomorrow after work  its been a rough week over here. I just wanna ride!

[slownugly007]

yea no biggie ribs, just whenever you get a chance and think about it, like i said i was just curious? im almost 98% sure that im gonna take the wheels, shouldnt be too hard of a swap, plus im picking up my parts bike this weekend so i can tear it down and get the wheels to fit without having to tear down my. just let me bud! thanks for all your help

[slownugly007]

Im gonna bump this up to the top so maybe we can get this resolved shiny? If I end up getting them from you Id like to post the details on here to help anyone looking to swap their wheels.

[Piute]

 Good Idea Slow ,I'm interested just to understand                                                           TANK ...

[shinyribs]

Good idea Slow. I PM'ed you back,but for sake of sharing. We need to see if your rear alxe is 20mm. That is what the SOHC rears run on. Also,I'm not sure if you can reuse your speedo drive or not.I know on the SOHC's that the spokes vs Comstars are totally different speedo drive. Also,we need to check the whole 5 bolt/6 bolt rotor deal,too.

I'm sure all this could be sorted out real easy if all the parts were right in front of you.Just sucks relaying it long distance.We'll get it figured out,though. Sink or swim,we'll figure it out!

[slownugly007]

Im definitely down to give it a shot! I want to get my bike able to fit any SOHC wheels. If I cant have a kickstart....by god I'll have the wheels!

Let me know what measurements or info you need and we can relay and make some leadway. On my bike Im running an electronic speedo so Im not using the speedo drive, but its on there for spacing sake. My rotors are 5 bolt.

Im wondering if it wouldnt be easier to swap my rear setup to drums, I know you did this Shiny, and swap the front setup over to SOHC suspension? Ive been wanting to get rid of my air forks. I know my forks are 37mm so id basically need the entire front end.

How big of a pain was it to change over to drums? Do you like it compared to rear discs?

[slownugly007]

so i searched around to see if anybody in the wide world of google had any advice. What I found was that the 80-82 750K had spoke wheels but I believe rear drum and single front disc. I want to be able to fit SOHC wheels because I hate the "newer" comstars on my bike and Im a huge fan of the earlier comstars and spokes. So my idea was to setup my bike for SOHC wheels to have a choice.

But if Im just gonna go for spoke wheels it looks like an easy fix would be to get a K model rear frame (swingarm, brake pedal, and all the drum brake stuff) and just do an easy swap...if a swap between K and F are possible...Tools, might need you to shed some light? As for the front I could just eliminate one brake, which wouldnt be terrible because now Id only need one front brake line instead of 3. I wonder if it would cause any problems running just one brake?

[TOOLS1]

It would be easy to change the front to a SOHC. Just use a set of All Balls tapered roller bearings, and it is a bolt on. Also, you could do the same with a 75-76 Gold Wing front end. They had spokes. The later ones had Comstars.
TOOLS

[slownugly007]

So the front would be a simple swap, if I just swapped over to a complete SOHC front end. Are SOHC forks shorter than DOHC? If so that option might help me with a few things. So I guess right now Im on a search for a SOHC front end...anybody willing to maybe trade? My front ends got brand new fork seals and dust seals (not installed) and both calipers are completely rebuilt (new seals, bleeders, pads, banjo bolts, crush washers) and the rotors are still in good condition...so its basically a new/rebuilt front end

[TOOLS1]

Yes the SOHC forks are shorter. The 500-550 forks are the same, but even 2 inches shorter yet.

slownugly007 wrote

So the front would be a simple swap, if I just swapped over to a complete SOHC front end. Are SOHC forks shorter than DOHC? If so that option might help me with a few things. So I guess right now Im on a search for a SOHC front end...anybody willing to maybe trade? My front ends got brand new fork seals and dust seals (not installed) and both calipers are completely rebuilt (new seals, bleeders, pads, banjo bolts, crush washers) and the rotors are still in good condition...so its basically a new/rebuilt front end

Wish, you had made that offer a few weeks ago. I just got a set off Half calf.
TOOLS

[shinyribs]

I cant keep up,Slow! I thought you wanted the rear disc wheel! I have a drum and a disc spoke wheel. The disc wheel is in pretty good shape.Only one small area of pitting and it is not severe.It is an 18" wheel.The drum rear I havent looked over real good but I know it is a 17" wheel.

I never rode with my disc on the rear.I swapped straight over to the drum. I had to weld a piece of tube on the frame for the brake pedal to mount in.You could fab something off your existing brake pedal to work,I just wanted to get rid of the big clunky brake pedal bracket on mine.The other tab with the hole in it is for a bolt that you need to stop the pedal on the up-stroke. So not sure what all you have available for welding.You might be able to fab up a stop off your existing hardware for that,too.


The disc rear holds a 6 bolt rotor. Measured across the studs,outside-to-outside,is 5".The cushions are there,and good,but i dont have the drive plate that goes in it and I don't have a rotor for it,either.I cleaned one spot and the chrome looked real good.The rest doesn;t have any bubbles or sign of rust.Spokes are tight and it turns true.


Here is the only bad spot on the rear disc wheel.

The front wheel is rougher than I thought.All the spokes are rusty,and there is some pretty bad rust areas pretty much all over it. It has an axle,speedo drive and rotor on it. So if you swap all you will need is the spacer for the rotor side and it'll go right on a set of SOHC forks.I only have one disc for this wheel.I checked this tonight,too.Spokes are good and it turns true,also.

I have 3 SOHC swing arms.I know at least one of them is a drum s-arm if you go that route.You will need a brake stay rod for a drum setup,but you can make one out of anything.Not a big deal.When i went to drums I didn't fool with all the fancy hardware the factory uses.I just used two heim joints and threaded a piece of 1/4" rod. The heim joints let it pivot like it's supposed to.

The difference in the disc and drum s-arm is the tab for the brake stay arm to mount to.You probably already knew that.

Did I forget anything? Holler if I did.

[shinyribs]

Hold on.I Just saw this. Tools says the SOHC and DOHC front axles are the same. That means you dont have to swap your forks,right? How is that possible if the DOHC forks are set wider,though?

http://honda-cb750-s.456789.n3.nabble.com/Sale-over-750-and-900-parts-td3943019i20.html#a3979045

Y'all are gonna force me to go buy a dang DOHC just so I can measure one.You know that,right?

[cdaiscool]

What do you need measured? If you don't need something removed, I may be able to get a measurement for you...

Or look it up in the FSM.

[slownugly007]

Im not entirely sure if I want disc or drums on the rear, right now Im open to whatever will be the easiest swap. If I was back in Tennessee with my garage and all my tools Id be open to fabbing up anything. But all I have available is basic tools and a screened in porch that I use as my garage!? So the easier route is my objective.

Those wheels dont look too bad....well except for that front one!? hahaha Would it be good to get it sandblasted and coated, that was my plan originally?

Im totally confused on the axles now! Ill take mine out either tonight or tomorrow and go from there. Im kinda wanting to swap over to SOHC for a few reasons, get rid of that stupid looking hose/air assist crap, if the forks are shorter that lowers my bike without any other mods and I can order gaiters that FIT my bike!

I was planning on getting an all ballz kit for mine and I still need to rebuild the forks so really it wouldnt be too much extra work to swap since Im tearing it down anyways. I just need the parts

[TOOLS1]

That wheel would be perfect, for sandblasting, and powdercoating.
TOOLS

[shinyribs]

I am starting to get fed up with my SOHC front end to be honest.Well,at the brake system.It works great and is dependable,but I am tired of having to fool with it constantly. Every 3-400 miles I grease my chain and sand my rotor.It's getting old.If the rotor/brakes on your dohc are cool I would consider keeping them.This squeaky bastard has to go.

[TOOLS1]

Slow is looking, for a swap.
TOOLS

[shinyribs]

Yeah,I know. But I'd feel guilty pawning these brakes off on anybody. Hell,I'm looking for a swap too at this point!

[slownugly007]

Not sure if we were still trying to determine axle dimensions, but I took my front one off and it measures 8 7/8" long, the part the clamps sit on is 20mm and the axle itself is 15mm. The inside of the chrome forks measures at about 6 1/16", the "shock" part of the forks inside dim. is ~5 11/16", inside dim of clamps is ~6 3/8" and outside dim is 8 3/8".

From the dimensions Shiny sent me, the 81F front end is roughly 3/8" wider, or 3/16" on each side, than a SOHC front end. Really not a huge difference, but apparently enough that its not a direct bolt on.

Shiny, do you not like the SOHC front end just because of the brakes? or is there other problems you dont like?