My first 440 "cafè'ish" build.

Great looking fabrication, and I like what you're doing with the bike, but that rear brake is worrisome.

Whereas the rear brake stay originally had a good lever advantage over the rear wheel torque by virtue of the fact that the stay was holding the hub from several inches away from the center, the new setup gives the wheel a huge lever advantage over the spacer-attached stay. Secondly, the original stay was a bar under tension which is very strong, whereas the new stay is a bar under torsional stress, which is far more prone to a tearing action where the majority of the load is at one point, initially (much like the difference in tearing a piece of paper versus pulling the paper apart all at once).

I've seen a few ill-engineered stays result in the hub rotating and wrapping the brake rod around the hub during a hard stop.

I would have to agree.
Steve

loudhvx wrote: Great looking fabrication, and I like what you're doing with the bike, but that rear brake is worrisome.

Whereas the rear brake stay originally had a good lever advantage over the rear wheel torque by virtue of the fact that the stay was holding the hub from several inches away from the center, the new setup gives the wheel a huge lever advantage over the spacer-attached stay. Secondly, the original stay was a bar under tension which is very strong, whereas the new stay is a bar under torsional stress, which is far more prone to a tearing action where the majority of the load is at one point, initially (much like the difference in tearing a piece of paper versus pulling the paper apart all at once).

I've seen a few ill-engineered stays result in the hub rotating and wrapping the brake rod around the hub during a hard stop.

Thanks loud for the compliment I totally understand what you're saying and sure as hell don't wanna be another statistic to that category. I've seen and repaired a fair share of head scratching fabrication whoas (like, whoa is that gonna be safe or work how intended?)that has come through my shop and I always take mental note. If you ever have the chance to look over the entire chassis of a sandrail or long travel in person, you'll see a few areas questionable. The material I used was 1" x 1/4" chromoly plate and round stock. Now the way I fit the pieces together before welding further strengthens the joint. In the round stock, I machined a channel for each arm to sit in, then I chamfered the edge of where the weld would be so I'll get maximum penetration. I made a 10x1.50 steel bung and welded it to the arm that gets bolted to the swing arm to fill in the gap. I'm pretty confident that it should hold up just fine. Once finally I get this bike on the road I'll definitely keep my eyes on it. I should've taken a picture of how I did, but I was antsy and wanted to finish that part and move on.
I do appreciate your concern though loud none the less. I know problems will surely present themselves once the bike gets on the road, I'm hoping and trying to keep it from being fabrication problems caused by me. Chances are, the way I have the rear brake set up now, it may change? I didn't cut the tabs for the original setup just in case.


ed

I'm going to chime in here.
2 reasons you should reconcider.
1) Unsprung weight, how much do the fabricated mounts and axle spacer
along with filler rod used weigh compared to the stock spacer and rod?
This issue is minor and the lesser of the two.
2) The more serious problem will be when the axle bolt is tightened down.
The friction will prohibit the rotation of that axle spacer. This will affect both
directions of travel. Both in the application and the release of the brake.


.

Well I hope you don't get hurt, but here are some numbers to consider:

Lets assume the OD of the tire is 22 inches, the stock brake stay location is 4 inches from the center of the axle, and the fabricated stay is 1/2 inch from the center of the axle.

The wheel/tire has a 11:4 lever advantage over the stock brake stay. That is 2.75.
The wheel/tire has a 11:1/2 lever advantage over the fabricated stay. That is 22.0

That is an 8 fold increase in the torque the fabricated brake stay has to handle. But that is only part of the story.

Look at how much aluminum is used on the hub to reinforce the bolt that holds the brake stay. That ensures the stock brake stay merely has to handle the torque in a purely tensile load.

The fabricated arm is designed such that the arm has to handle the torsional load with no reinforcement. This means the backside of the arm is holding all of the tension while the front is acting like a fulcrum. This is another lever trying to tear the arm from the base metal.

The way it is set up is analogous to having a wheel with one single large spoke to handle the torque.

Can you at least box section the two arms together so they help each other?
Imagine if you made the spacer about 8 inches in diameter, then simply bolted the spacer to the hub and swingarm at the same points you have them now, then milled away all of the excess metal. You would end up with a pie-shaped wedge attached to the spacer. Then you would hollow it out. This way the torque is transferred from hub to frame somewhat directly.

You could put the attachment point on the underside of the swingarm so the box section could be more like a rectangle than a wedge.

As a side note, will the brake lever still work even though it will be pulled the opposite direction? Some levers can go either way. Or were you going to make the brake rod a push-type instead of pull?

Something that just occurred to me is, when the bike is being ridden, power is applied to the wheel, stress is present at the end of the swing arm at the axle. A certain amount of flex can occur. If braking is applied, the end of the arm is under more stress. With the break arm fastened close the pivot and frame, the braking force is transferred there, not to the end of the arm.
If that makes any sense.
Steve

Subscribed! This build has definitely grabbed my curiosity!

Didn't forget about you forum! Life took me away from you guys. JK..well not too much really. As to not bore anyone with my life the past month or so, I m gonna stay on topic and fill you in on that. Sadly I haven't been able to get hardly anything done on my bike which pisses me off! thanks personal life..another story. Just been picking at things here and there when I had the time. I don't have all the pics on hand, but I'll get them up ASAP..Make a small list of things so far..

Front brake is finally 100% Has fluid and bled. Goodridge lines (purchased from 79MKII, thank you) replaced the stocks. (I did however change 2 hose ends out for a 45 and 90 banjo for a better fit (sorry Mike ) No pic on hand, but I'll get it.
Months ago, I did an impulse buy on some forktube headlight mounts.
eBay forktube headlight mounts..


Didn't like how much it made the light stick out so made me some new ones.


sucked in a lot more..


That's really all the progress I've made the past month. Aside from finishing/shortening the harness since I removed the self canceling signal unit and the new electrical box/tray under the (soon to be where my ass is suppose to) seat. Secured the throttle and clutch cable to the frame. New chain put on, Got the clip-ons under the top triple (which reminds me of something). Still a bunch of work left. I still need to get some rearsets on. The stock ignition switch is buggin me how it sticks up so high now? A concern a few post ago of how I have the rear brake setup is still not set in stone. That will be addressed later on before the bike gets underway. Need to finish a seat and a clever(or not so clever)way to mount it. The tail section, I have to get that mediocre cowl looking thing I got going on, into aluminum or other easy working material after I finalize a shape of it. So far it's just a cover for the battery. So yeah...bunch of work left. I'm looking forward to it also! Now I just have to turn off the nice guy be that asshole when some needs MY help?

Don't know if you can see what's going on here? lol

A guzzi in the back of fords new transit?

remade the tire chock to bolt down..


couldn't say no to this guy since he was the one that gave me the bike in the first place.

Any progress is still progress!

I like the headlight mounts. Nice fab as usual. However, I think I'd like to see the headlight a little bit lower if at all possible. I prefer the headlight to flow with the tank profile so the "mass" of the headlight is in line with the "mass" of the tank.

Keep up the good work!

loudhvx wrote: Any progress is still progress!

I like the headlight mounts. Nice fab as usual. However, I think I'd like to see the headlight a little bit lower if at all possible. I prefer the headlight to flow with the tank profile so the "mass" of the headlight is in line with the "mass" of the tank.

Keep up the good work!

I see what you mean there loud, Didn't really get a good side view for myself and now that you mention it. Thanks?!..lol jk. I can see what's going on and have to agree that it does look outta place. Looked good from the front? I've got the ears pointing up atm, so I'll get them flipped and see how it is.

Couldn't find my post for a second there..lol So another update and another question. Got some rearsets in place finally but totally air headed on how much room I was gonna have on the left for the new shift linkage and muffler. Crude pics coming up, I'm gonna have to update them with better ones later on once the bike gets underway.
New rearset shift side..It looks like the side stand is in the way, but I actually have a lot of room for up shifting. If anything, I'll relocate the spring behind the stand.


some random pics of left side progress.

had to machine and weld in a spacer inside my pegs so the m10x1.5 allen has something to tighten on.
Prepped and ready to weld..

The shift linkage and first smell of burning raining brain cells.



First tab fabbed up to weld in it's new home to support my left footness.


Where its presumably gonna live now.


Original shift lever cut and cleaned up a lot. Seemed so damn bulky? More eye pleasing now. Wish I woulda took a before shot though.


Another shot. 6mm hiems. Even have a left hand thread one on there. Shift lever came off my buddies BMW RR. Had to cut the ear where the hiem goes and re-weld to the bottom.


Here's the right side mocked up..


This was gonna strain a little more of my brain cells to attach the pull rod for the brake. But got it sorted! and I thought this side was gonna be the pita..


Driver side with the muffler on..

Yeah that's a total fail shot to even see what my problem is. But hopefully I'll get it sorted outsell this week.

Shot from the back with stock muffs and new sets.


Oh and I took your advice Loud and flipped the ears for the headlight. Thanks for catching that for me. Looks waaaay better! I'll post a pic of that tomorrow, since my idevices are having wifi syncing issues with my photo stream..

My next biggest hurdle that's gonna keep me from starting this thing is my gas tank. From the get go, I saw brown inside, Don't know how bad yet cause I didn't use a flashlight to get a good look, just the light over my shoulder. I'm sure I can get away with cleaning the inside out then using one of them handy sealing kits. My question is.. recommendations? I know there's quite a few different brands out there. Red-kote, Kreem, eastwood, caswell and por. All run about the same price and some have more steps than others. I did a little reading on all of them, but not enough to decide. So far I'm liking the caswell cause it's a 2 part mix. I could fab a tank inside of the KZs. Hmmmmm? naaaaah..that's more down time, and I still need to finish my seat.

Ok so I'll once again get better pics of this series and the headlight pic as well Loud, get your approval in the meantime...enjoy, I'm gonna let my brain cells cool off and get ahold of some 3/16 tungsten in bulk! I'm dangerously low :ohmy:

ed

I think the obvious solution to your problem Ed, is that you need to fab up a badass custom stainless exhaust. Nice work on the rear sets are you gonna put some rubber on them or something? I would try cleaning out the tank with oxalic acid before doing any coating regardless of whether you plan on coating or not. you may not need to deal with coating, but if you do, the Caswell has my vote. I have used it twice and seems like good stuff. Like all liners prep is very important. .Any more flicks of the guzzi? that front drum looks huge.