Topic: Cycle X Posi-Lock Frame Splice Kit Review - SOHC CB750

[86FJNJ]

I really like these weld in slugs to make the lower backbone tubes removable on my SOHC 1978 CB750. I got frustrated realizing you cant remove the valve cover while the engine is installed and then the acrobatics to remove the engine was something I wanted to avoid for future engine work I plan to do...so I got these. Very easy to install, just cut out the triangle brace between the top tubes, then cut the tubes where you want to install the splice kits, file the tube ends down so they're clean, the slugs actually fit inside the tubes making it really easy to mock up. Then just make sure to cut the bridge tube really tight so you don't have any play. Tighten the bolts. I did need to clamp a level to it to ensure it's 100% straight when I tacked it place because despite my best efforts it did have a very small amount of play. Be sure the orientation of the front and rear split kit are identical so the tube can easily be removable. I did one small tack on each joint, then made sure the piece was removable, then did several more tacks, made sure it was still removable, then ran a couple longer beads. I'm leaving it alone for now but I'll finish fully welding it in the future.

Once I do the final assembly on the bike I'll throw some blue thread locker on the bolts. The kit seems great so wanted to share it with the group in case anyone was considering it.

https://www.cyclexchange.net/frame__end.htm

[dusterdude]

I like that

Sent from my SM-S711U using Tapatalk

[scottly]

just cut out the triangle brace between the top tubes,

The triangle brace adds a fair amount of rigidity, forming a truss with the three tubes. Standard procedure with either a weld in kit or a weldless kit is to cut the triangle on both sides and add bolt on plates or straps to retain the rigidity. Curious, how much did the Cycle X kit cost?   

[newday777]

just cut out the triangle brace between the top tubes,

The triangle brace adds a fair amount of rigidity, forming a truss with the three tubes. Standard procedure with either a weld in kit or a weldless kit is to cut the triangle on both sides and add bolt on plates or straps to retain the rigidity. Curious, how much did the Cycle X kit cost?

More than you were charging for the bolt on kits. $220

[86FJNJ]

just cut out the triangle brace between the top tubes,

The triangle brace adds a fair amount of rigidity, forming a truss with the three tubes. Standard procedure with either a weld in kit or a weldless kit is to cut the triangle on both sides and add bolt on plates or straps to retain the rigidity. Curious, how much did the Cycle X kit cost?

Thanks and good point, I was thinking they put the triangle there for a reason, I suspected it may have been to reduce vibration from the longer spans of those straight tubes. I may take some flat stock, or angle stock and some bungs and create a bolt together triangle or T truss to recreate it in a removable way like what you show.

[BenelliSEI]

just cut out the triangle brace between the top tubes,

The triangle brace adds a fair amount of rigidity, forming a truss with the three tubes. Standard procedure with either a weld in kit or a weldless kit is to cut the triangle on both sides and add bolt on plates or straps to retain the rigidity. Curious, how much did the Cycle X kit cost?

More than you were charging for the bolt on kits. $220

These are really cleaver. The “interlock” feature is a plus. I’ve never been a fan of this frame cutting, but with the triangle maintained and this kit my opinion is changing.

[BenelliSEI]

just cut out the triangle brace between the top tubes,

The triangle brace adds a fair amount of rigidity, forming a truss with the three tubes. Standard procedure with either a weld in kit or a weldless kit is to cut the triangle on both sides and add bolt on plates or straps to retain the rigidity. Curious, how much did the Cycle X kit cost?

Thanks and good point, I was thinking they put the triangle there for a reason, I suspected it may have been to reduce vibration from the longer spans of those straight tubes. I may take some flat stock, or angle stock and some bungs and create a bolt together triangle or T truss to recreate it in a removable way like what you show.

Nicely done and thanks for sharing!

[MauiK3]

Looks like, with the triangulation, it will be very stiff.

[86FJNJ]

just cut out the triangle brace between the top tubes,

The triangle brace adds a fair amount of rigidity, forming a truss with the three tubes. Standard procedure with either a weld in kit or a weldless kit is to cut the triangle on both sides and add bolt on plates or straps to retain the rigidity. Curious, how much did the Cycle X kit cost?

More than you were charging for the bolt on kits. $220

These are really cleaver. The “interlock” feature is a plus. I’ve never been a fan of this frame cutting, but with the triangle maintained and this kit my opinion is changing.

That's why I went with this kit because of the interlock, the stress is not just on the bolt. I do agree that adding triangulation would be best so I'll work on adding that. The way how I orientated the side tubes is so the tubes slide out laterally, that kept the bolt access on top and bottom rather than inside and outside. So I need to configure the triangulation to work with that and keep bolt access easy.

[scottly]

just cut out the triangle brace between the top tubes,

The triangle brace adds a fair amount of rigidity, forming a truss with the three tubes. Standard procedure with either a weld in kit or a weldless kit is to cut the triangle on both sides and add bolt on plates or straps to retain the rigidity. Curious, how much did the Cycle X kit cost?

More than you were charging for the bolt on kits. $220

Ouch.
https://lowrangeoffroad.com/chromoly-interlocking-tube-clamps.html

[86FJNJ]

just cut out the triangle brace between the top tubes,

The triangle brace adds a fair amount of rigidity, forming a truss with the three tubes. Standard procedure with either a weld in kit or a weldless kit is to cut the triangle on both sides and add bolt on plates or straps to retain the rigidity. Curious, how much did the Cycle X kit cost?

More than you were charging for the bolt on kits. $220

Ouch.
https://lowrangeoffroad.com/chromoly-interlocking-tube-clamps.html

nice find, those look the same as the ones I got...... $40 X 4 = $160

[BenelliSEI]

just cut out the triangle brace between the top tubes,

The triangle brace adds a fair amount of rigidity, forming a truss with the three tubes. Standard procedure with either a weld in kit or a weldless kit is to cut the triangle on both sides and add bolt on plates or straps to retain the rigidity. Curious, how much did the Cycle X kit cost?

More than you were charging for the bolt on kits. $220

These are really cleaver. The “interlock” feature is a plus. I’ve never been a fan of this frame cutting, but with the triangle maintained and this kit my opinion is changing.

That's why I went with this kit because of the interlock, the stress is not just on the bolt. I do agree that adding triangulation would be best so I'll work on adding that. The way how I orientated the side tubes is so the tubes slide out laterally, that kept the bolt access on top and bottom rather than inside and outside. So I need to configure the triangulation to work with that and keep bolt access easy.

That will be slick.

[Don R]

 You can find the 1" weld in connectors on ebay for around $20 each. The triangle splice is easily made from a piece of flat stock either drilled and bolted or tapped for a bolt.
 
 I had some time and counter bored my Gordons kit to reduce weight before plug welding them in, the boring was admittedly a little obsessive. It got used like that for a season before the bike came apart for powder coat when the kit was finish welded. Usually, I'm replacing bars that someone else removed, making good use of rusted, wrecked, and untitled frame pieces. I've even put an F super sport section into a K0 frame, that took a little finesse.
  I have one K2 drag bike left to go. It might get bent tubes so the head can come off without removing them. Fortunately, I have one already done to copy.

[Don R]

 Here is an alternative to the kit for the adventurous types. I'm unsure how the coils fit, this bike had a magneto. The stock tank fits fine though.

[86FJNJ]

Here is an alternative to the kit for the adventurous types. I'm unsure how the coils fit, this bike had a magneto. The stock tank fits fine though.

I thought about that, bending tube like the DOHC frames, but I just got a new welder so any excuse to use it lol

[Don R]

https://www.ebay.com/itm/256582942447?_skw=1%22+weld+in+tube+connector&itmmeta=01KFY9MN9T6026PF8D8GJTTA1V&hash=item3bbd88feef:g:AuIAAOSwKZ1hN8yM&itmprp=enc%3AAQALAAAA4O7PUuNWmJ%2B%2BUShgI9tQz%2FqlUVS0KInJNrA8a64GzCjnDNC5zlhXF4qreCFiMqJqGeUGeO1jf6q6GN6yq4fxrShGq8EgZJfyHrtVjyOwmKBm6OsX0nrTK0%2BhkZzYZKchNBVIRE0KAB54%2B9lGP0fkhRlDK%2FXdGGopCDmqGRCFlfh%2BZYFeZ8oaooQ%2FNayhgNaXCS5%2FODK6QvvNWqlArc1EAeLP2XQB9M6CFiMAeAzPBUlWRFm7X%2FjOb3N8Sv3GJXrY5b0GgpVmFfJIDL2dHb1vmc%2F7Uk82v9MUXzSouTLQwPW%2B%7Ctkp%3ABk9SR6zV0sn_Zg

[86FJNJ]

https://www.ebay.com/itm/256582942447?_skw=1%22+weld+in+tube+connector&itmmeta=01KFY9MN9T6026PF8D8GJTTA1V&hash=item3bbd88feef:g:AuIAAOSwKZ1hN8yM&itmprp=enc%3AAQALAAAA4O7PUuNWmJ%2B%2BUShgI9tQz%2FqlUVS0KInJNrA8a64GzCjnDNC5zlhXF4qreCFiMqJqGeUGeO1jf6q6GN6yq4fxrShGq8EgZJfyHrtVjyOwmKBm6OsX0nrTK0%2BhkZzYZKchNBVIRE0KAB54%2B9lGP0fkhRlDK%2FXdGGopCDmqGRCFlfh%2BZYFeZ8oaooQ%2FNayhgNaXCS5%2FODK6QvvNWqlArc1EAeLP2XQB9M6CFiMAeAzPBUlWRFm7X%2FjOb3N8Sv3GJXrY5b0GgpVmFfJIDL2dHb1vmc%2F7Uk82v9MUXzSouTLQwPW%2B%7Ctkp%3ABk9SR6zV0sn_Zg

Nice find! The price is def right. Personally I’m not a fan that it has a nut that can get lost rather than the bung being threaded. That is why they are cheaper. But $20ea X 4 = $80 and that is a great deal.


I’m working on my triangulation concept now and think I have a plan.

[BenelliSEI]

https://www.ebay.com/itm/256582942447?_skw=1%22+weld+in+tube+connector&itmmeta=01KFY9MN9T6026PF8D8GJTTA1V&hash=item3bbd88feef:g:AuIAAOSwKZ1hN8yM&itmprp=enc%3AAQALAAAA4O7PUuNWmJ%2B%2BUShgI9tQz%2FqlUVS0KInJNrA8a64GzCjnDNC5zlhXF4qreCFiMqJqGeUGeO1jf6q6GN6yq4fxrShGq8EgZJfyHrtVjyOwmKBm6OsX0nrTK0%2BhkZzYZKchNBVIRE0KAB54%2B9lGP0fkhRlDK%2FXdGGopCDmqGRCFlfh%2BZYFeZ8oaooQ%2FNayhgNaXCS5%2FODK6QvvNWqlArc1EAeLP2XQB9M6CFiMAeAzPBUlWRFm7X%2FjOb3N8Sv3GJXrY5b0GgpVmFfJIDL2dHb1vmc%2F7Uk82v9MUXzSouTLQwPW%2B%7Ctkp%3ABk9SR6zV0sn_Zg

Nice find! The price is def right. Personally I’m not a fan that it has a nut that can get lost rather than the bung being threaded. That is why they are cheaper. But $20ea X 4 = $80 and that is a great deal.


I’m working on my triangulation concept now and think I have a plan.

You also initially pointed out the “interlock” feature that really adds a major benefit. If I ever decide to do this I’ll definitely follow your lead. Post some pics of you triangle solution when you’re done. Thanks.

[86FJNJ]

This is my current concept, which would simplify the triangulation down to one bolt instead of several bolts from the designs I've seen pictures of. The bolt would not be centered between the three tubes so that should eliminate twisting torsion (compared to if the bolt was perfectly centered in between the three tubes).

There would be one tab off the top backbone with a threaded bung welded to it. Then one tab welded to each of the removable side pieces. The center bolt goes through all three tabs connecting them.

The drawing is a bit crude, I would cope the tabs where they weld to the tubes and likely round the tabs where they bolt in the center. And likely add gussets to each tab to prevent lateral movement of the tab

This would also keep some space for me to route wiring.

I'm open to feedback.

[willbird]

Yea those look pretty good, I made up some that used an interlock but my fear was that I made them really close tolerance and they would have to end up welded in utterly perfect within a few .001" to actually work.


Bill

[Don R]

Yea those look pretty good, I made up some that used an interlock but my fear was that I made them really close tolerance and they would have to end up welded in utterly perfect within a few .001" to actually work.

 I welded mine in while bolted up tight, they work awesomely.


Bill

[BenelliSEI]

Looks good, noting that a “T” does not add the bracing built into an “A” (triangle).

[willbird]

Yea those look pretty good, I made up some that used an interlock but my fear was that I made them really close tolerance and they would have to end up welded in utterly perfect within a few .001" to actually work.

 I welded mine in while bolted up tight, they work awesomely.


Bill

Yea I can always go back and remove a bit of metal from the section that comes out. I made mine to replace the triangulation with round tubes. Cleaned the bench enough the other day to reveal them. Need to get back onto that project.

Here are the ones I made up. I have a local friend who bought a Haas mini mill, these could be made entirely on a mill, need to talk to him about it. When I worked cnc tool and die I did a lot of "lathe" stuff on a 3-4-5 axis cnc mill because it was quicker than having the lathe guys make it up. This could be setup with jigs that would allow loading parts up and a complete frame kit would come out of each run of the CNC program leaving him free to do other stuff while it ran.

Bill

[86FJNJ]

Finally got back to this.

Based on your feedback I ditched the single bolt idea and went a more traditional route. I made two female brackets for the top backbone tube that have a threaded bung and front and rear mounting plate that is coped to the tube. Then for the removable side tubes I have gravestone tabs with a hole to allow the bolt to go through it. Locking washer and regular washer between the bolt heads and the gravestone tab. I just put a few spot welds for now and tested the removability and both pieces are removable, although very tight fitting, which is fine because they won't be removed too often and they should be tight to be strong.

Once those are fully welded up I may add two horizontal tabs to join the side tubes together for a complete triangle brace....although that would probably be overkill as it sits even with just the spot weld this thing is rock solid so I doubt I even need to add the other lower brace. I also pushed the brackets back a bit further than the stock bracket location to allow me more space behind the coils and they still clear the tank just fine. I also have plenty of meat on the tombstone tabs that if I need to cope then in to make space for wiring I would still have plenty of metal left.

[BenelliSEI]

Very “trick” and looks perfect!