Topic: Looking for Gordon frame mod equivalent 1975 CB750f

[willbird]

The weight difference is neglible, the strength is massive.

Just how much do those solid aluminum bars weigh?

Each leg weighs less than 1#. Heavier than thin steel tube, but you’d never ride the difference.

One can get super heavy wall aluminum tube intended for suspension rods too, has an ID close to the correct size and maybe the exact tap dril size for spherical rod ends. Friend used it on a Sprint Car. That would be a .578"  ID for 5/8 rod ends. of course then it cannot be milled on the ends like a solid bar. Tying the two bars together is interesting for sure, makes things simpler. Gives me something to ponder in my drive time LOL.

I had planned on milling up a solid jig out of 1" square solid steel to hold the parts getting welded into the frame in alignment...it would need an area for RH and LH side gusset fixturing to bolt on. Thinking out loud the whole bolt in portion could maybe be plasma cut out of plate as one piece with some thought. Not sure where plasma cut drops the microphone with aluminum as far as thickness goes. Just saw a guy cut some 3/16" on a youtube channel and it looked really nice as far as cut quality goes. Quick look says it takes 300 amps to plasma cut 1" aluminum :-).

[willbird]

If you used tube aluminum, you’d still need to mill and weld the lug into it so that you could connect to the steel frame. Hence, I went with solid bar and simply milled the lug end. Super simple. Chucked the rod into a collet block, milled it, spun it 180* in the vise and pushed “repeat”. Did the same collet block milling on the steel lugs after I turned a shoulder for fit into the stock tube.

Put the steel lugs into the stock frame, bolt the aluminum bar in place, align it as needed, tack the steel lugs. Weld it out, unbolt it, massage as needed. I doubt it took me a full 2 hours from raw frame to done.

I did add some shim stick between the round bar and steel lugs when welding in the cross tie to prevent it from pulling the bars too tightly and not allowing removal.

Indeed, there are several ways to skin that cat :-).

Bill

[kingrabbit]

Hey I’m back into this project after a year. I have several other bikes in various states. In this case I went ahead and cut the rails off. I haven’t had her pulled the cam cover off.
Now what?
Is there a way to assess the oil delivery without taking anything else apart? I kicked it over but didn’t see any oil moving anywhere. Should I just start it? Wear a rain coat? I want to see if oil is being equally distributor to the valves and cam.

[bryanj]

Take the end bearing caps off the towers, you will soon see if its been short on oil

[kingrabbit]

Bryan which ones are the end bearing caps? I assume it’s the caps on the very end on the cam which has 2 nuts on top and a an oil port in between?

[kingrabbit]

Ok I pulled that cap off and there is definitely evidence of metal transfer there on the cap aluminum cap end. The cam looks fine underneath but there was burnt material on there.
Everything on the other side of the cam looks healthy and well oiled. It’s the starboard side 3 and 4 that looks like it was starved of lubricant.
What’s my next move? I would love a DIY pipe cleaner fix here.
The diagram I saw showed the oil coming up both sides of the cam chain and moving outboard to lube the valves, lifters, camshaft.
How do I get into the gallery?

[bryanj]

You have to remove the cam shaft along with rockers and shafts, then the cam towers to remove the oil restrictor jets.

The only way to be certain of clean oil ways is to remove the head and barrelles to thouroughly clean out all the oil passages.

Then rebuild super cleanly with new gaskets, rubber pucks and appropriate seals, you will need at least 1 new cam tower, probably a cam and a few rockers, ANY discoloration of parts(blue) means they are scrap
This was and is a common problem after poor rebuilds and/or insuficient oil changes or wrong oil

[Don R]

 Under the cam holders there are two oil jets, they can become plugged by silicone or other debris in the oil system. They can be removed, sometimes it's difficult but mine seem to fall out at the machine shop.
 It isn't just a jet that can be drilled, it's more like a reversed shower head.

[kingrabbit]

So am I hearing the only way forward here is to pull the head off completely? No other way to get at those passages and jets?

[Don R]

 The oil jets can be removed from the top, maybe someone that has actually done it will chime in.

[Don R]

 Here is a discussion om the subject
http://forums.sohc4.net/index.php/topic,175940.0/all.html

[bryanj]

The jets come out from the top when they are not jammed in BUT in my opinion the only way to guarantee the oil pathways clean is to remove heas and cylinders to physicaly clean them

[crashmaster]

I am sorry to resurrect this post, but the info is pertinent to my question. Do any of the frame kits currently available allow for splicing the 3 straps that tie the 3 horizontal main tubes together? I see Carpy has one as well as Cycle X make a kit . Do Frank or RRRTool Solutions still do a kit? Thanks

[newday777]

I am sorry to resurrect this post, but the info is pertinent to my question. Do any of the frame kits currently available allow for splicing the 3 straps that tie the 3 horizontal main tubes together? I see Carpy has one as well as Cycle X make a kit . Do Frank or RRRTool Solutions still do a kit? Thanks

Unfortunately  Frank passed a few years ago now.

[crashmaster]

Sorry, I didn’t know

[newday777]

Sorry, I didn’t know

It was before you joined.

[Alan F.]

You can join us in a thread inspired by Frank's New Year's resolution to get out riding more.
http://forums.sohc4.net/index.php/topic,206303.0.html