Topic: Aftermarket frame - group purchase

[MessnerMoto]

Yep... aware of that but taking out the engine in this design is job of 1h max..You can just drop it down... . and you dont need to actually take the engine out you need to pivot the frame around swingarm pivot. Like it is done on CBX

On my current bike I made a special frame kit.. it is special in the sense you cant see from side of the bike where the tubing is cut.

http://forums.sohc4.net/index.php/topic,149894.msg1869266.html#msg1869266

But to disconnect all the wiring etc is more then 1h in my current setup

... always some compromises

[slikwilli420]

I love the design but its still pretty busy. You said it yourself, the appeal is stock-looking frames, which is why the Rickman and Seeley are so attractive, yet have advantages over stock.

Aluminum is tricky and presents a host of flexibility issues that are not ideal, not to mention that a jig to hold it while heat treating would be cost prohibitive in itself. That frame looks extremely complicated to build with all of the joints between tubes. Im not saying you should steal a design but much of the work has been done in classic frames for our bikes. Take elements from those and make something your own. It will be difficult to improve on a design and still keep a classic look.

[calj737]

It’s a pretty looking frame, but I don’t understand why you’d specify thinner walled tubing than stock, especially using aluminum. Ally is already lower in strength, so at least a 30mm Tube with at least 3.2mm wall would be needed.

I see some concerns in the frame geometry for hanging the motor on butt welded tubes (looking at the front particularly). I suspect this joint would be very weak, and the stress on it very high.

The highest backbone “appears” to be much higher than the stock backbone, so that would prevent stock tanks from being used. You’d need to angle that backbone or lower it to run parallel to the upper side rails.

I don’t see the jig to weld it being a terribly difficult chore. The triangulated pieces on top get welded in once the 3 rails are in place. The real trick, is to drill vent holes in the intersecting joints to enable the tubes to be fully welded closed without blowing out.

I like the looks of it. Similar to something I’m working on too-

[754]

He did mention 1.5 mm  wall, same as Stock.
I think if you can tip the motor and access top  that would be good enough.

[Medyo Bastos]

I think if you can tip the motor and access top  that would be good enough.

I agree.




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[turboguzzi]

mirko, look at it form a business side...
for classic racing in most countries you cant "invent a frame", it has to be period. no business.
for road bikes, in most european countries it'd be a nightmare to run legally (TUV, etc...) USA might be easier, not so sure. 
the only way would be then what Sanctuary are doing, i.e. become a legal manufacture and sell complete bikes. their superb frames require (like yours) all custom body parts, so it makes sense in any case. but you'd need VERY deep pockets to go into that...
the beauty of the sanctuary frame is of course that form the outside bike looks quite stock...

[MessnerMoto]

This is a frame for me not for selling it. Built according to my needs and preferences. I stated that in my post

Lets just say it is a grey zone.... for riding this frame on streets.

[calj737]

He did mention 1.5 mm  wall, same as Stock.
I think if you can tip the motor and access top  that would be good enough.

1.5mm is 0.059. Stock is 0.063. He would need to bump to 1.8mm to match stock. The difference in weight between the wall size is 0.21#/ft for 1.5mm vs 0.22#/ft for 1.8mm.

[MessnerMoto]

He did mention 1.5 mm  wall, same as Stock.
I think if you can tip the motor and access top  that would be good enough.

1.5mm is 0.059. Stock is 0.063. He would need to bump to 1.8mm to match stock. The difference in weight between the wall size is 0.21#/ft for 1.5mm vs 0.22#/ft for 1.8mm.

Cal maybe you are correct. I would probably need to bump to 2.0mm wall thickness... It will probably take me to 7kg of weight.... before optimization....

The goal is to offset less stiff al with full triangulation.... but FEA will tell if 25x2.0mm is good or if triangulation is good   

Also there will be some bracing to address front engine mounting point

[754]

 The heat treating , raises the price and involves some time, like a week or more turnaround. Probably same as paint or plating.
 A local guy built A few aluminum frames,  but no longer does. One big concern was buyers wanting to add or modify a frame after the  sale. His reasoning was no matter who did the work , if it failed, it still comes back to his name.

Also In hestvtreat things move sround a bit, so you may want to finish neckbores after treatment.  And expect to maybe have to tweak the frame a bit..

[scottly]

Any precision work is always done after welding or heat treat.

[Captain]

 It might be of interest but I'm underway building a new frame for our Pre 82 DOHC Superbike.
 The point of difference.........."Titanium" 
 Not for the faint hearted and all the analyse has been done and we will have a frame to perform at least equal to our current.

 Captain

[calj737]

Cal maybe you are correct. I would probably need to bump to 2.0mm wall thickness... It will probably take me to 7kg of weight.... before optimization....

I doubt it will raise the overall weight that much, but it will still be awfully light. 

The one issue that causes me the most concern is the front engine hangars. The bosses at the end of the tubes, where the moaning bolts pass through, those would be welded to the hollow tubes running above. That's a lot of force and stress on those welds. Suspect the bosses would be 30mm solid, drilled/reamed for 10mm bolts, but then welded above to 25mmx2mm wall. Aluminum welds aren't the strongest in that type of orientation. Will your FEA allow you to adequately evaluate that?

One possible solution would be to use solid that is sleeved by the tubing, then butt and plug welded above. It would add some weight, but it might solve the stress issue...

Anyway, curious to see what you discover in your evaluations 

[turboguzzi]

Captain, you never fail to impress!

Mirko, ok, must have missed thats it's a single copy.

Nevertheless, where are you going to put a decent volume of fuel with that spine taking up all the place?

[754]

Cal  there are ways to deal with the front hanger strength issue.
 For one, wall thickness could be increased on those 2 tubes.
 And yes mount milled from  solid and plug welded , is a good idea. But drill out the middle.

I have seen frame pieces where the axle plate had portions that went into the frame tube  for several inches.
 But not a solid tube  more like 2 spears that tapered off. 
 This on a brazed frame made a HUNDRED years ago..
 So they been on this problem from before any if us were born..

 And they had no FEA then..

[MessnerMoto]

Captain, you never fail to impress!

Mirko, ok, must have missed thats it's a single copy.

Nevertheless, where are you going to put a decent volume of fuel with that spine taking up all the place?

My current tank has more room under the tank than needed for this design... Holds 17L-19L. If I make it tight around back bone of this design it will go to 22L

[calj737]

Cal  there are ways to deal with the front hanger strength issue.
 For one, wall thickness could be increased on those 2 tubes.
 And yes mount milled from  solid and plug welded , is a good idea. But drill out the middle.

I have seen frame pieces where the axle plate had portions that went into the frame tube  for several inches.
 But not a solid tube  more like 2 spears that tapered off. 
 This on a brazed frame made a HUNDRED years ago..
 So they been on this problem from before any if us were born..

 And they had no FEA then..

Yes, there are solutions. To your point though, these brazed frames were steel, not aluminum  It’s the nature of the aluminum weld in that very particular application that I am focused on.

Mirko’s frame is very reminiscent of the HB-1, right? Look at the end of the motor hangar bosses in the frame. With 2-3mm wall, I suspect aluminum tube would not be viable. I may well be wrong. I’m just pointing that out to Mirko.

[turboguzzi]

as per the original title of this thread, im still curious as how folks deal with potentially making a kit frame road legal
here in italy, ASFAIK, you have to be a certified manufacturer of complete road worthy bikes with the ministry of transportation and even then, engine wise you'd be relying on the homologation of the engine unit of the donor bike in terms of emotions, etc. That's what Bimota did all along their lifetime...
how is it around your area?

[calj737]

as per the original title of this thread, im still curious as how folks deal with potentially making a kit frame road legal
here in italy, ASFAIK, you have to be a certified manufacturer of complete road worthy bikes with the ministry of transportation and even then, engine wise you'd be relying on the homologation of the engine unit of the donor bike in terms of emotions, etc. That's what Bimota did all along their lifetime...
how is it around your area?

There seems to be 2 crowds here; 1 interested in racing and the other “street” customs. Regarding street, frame modifications in many of the US states is not heavily regulated. So it’s fullly possible to make a “kit”, use a donor neck and VIN and be on your way. You could also register the bike as a builder custom and obtain a new, custom VIN. That creates some insurance issues and a DOT inspection locally in many states. Not insurmountable any way you do it.

As to the racing blokes, they are most likely regulated by specs in the class and organization in which they race.

[turboguzzi]

Ok, interesting.... round here many register italian bikes in germany, get TUV test and then register again in italy, for some reason germans seem more lax but quite a costly procedure.
My neighbour took the donor neck shortcut with a crazy guzzi he built.

[gschuld]

https://www.rbracing-rsr.com/aboutrb.htm

I’ll just throw this in for food for thought.

Very Elgi like, parts count petty low.

George

[754]

That last pic.  BULTACO clip ons  like my Matador..

I just thought up another alternative  for the  engine front bolt hanger mount..
 Weldless  of course..
 Thread the tubing end like a tie rod and slit. Make the hanger with threads(like a tie rod end), then install and clamp externally.,

[scottly]

Ok, interesting.... round here many register italian bikes in germany, get TUV test and then register again in italy, for some reason germans seem more lax but quite a costly procedure.
My neighbour took the donor neck shortcut with a crazy guzzi he built.

Yes, interesting. Seeley had to make some mods to get his bikes accepted in Germany? When I bought my Seeley, there was a delay of 2-3 months before I received the California title, which listed it as a 1971 CB750, but with the Seeley frame VIN. I don't know if the delay was caused by a paperwork issue, or the incompetence of the seller/PO, who had proven himself mechanically incompetent several times already.    

[eli]

Ok, interesting.... round here many register italian bikes in germany, get TUV test and then register again in italy, for some reason germans seem more lax but quite a costly procedure.
My neighbour took the donor neck shortcut with a crazy guzzi he built.

Yes, interesting. Seeley had to make some mods to get his bikes accepted in Germany? When I bought my Seeley, there was a delay of 2-3 months before I received the California title, which listed it as a 1971 CB750, but with the Seeley frame VIN. I don't know if the delay was caused by a paperwork issue, or the incompetence of the seller/PO, who had proven himself mechanically incompetent several times already.

Well, I wouldn't exactly call TÜV lax!
The mods to the seeley frame for the german authorities were simple: A support for a steering lock (don't know the technical term, in german it's "Lenkradschloss"). With this little mod, the SH GER-series of frame numbers was made

[simon#42]

In England it's called a lock stop