| Author | Message | ||
     Crusty |
There's a thread over on the XL forum from a shop building an aluminum framed Sportster. I'm really getting a kick watching the build progress. The CNC machine work is just beautiful, and while I don't believe it'll work as well as a Buell, I still think that the finished product will be pretty sweet looking. You can check out the thread here: http://xlforum.net/vbportal/forums/showthread.php? t=2057545 | ||
| Pwnzor |
Very cool indeed. | ||
| 86129squids |
Slick so far! | ||
| Tootal |
They're using Rapidcut endmills. I love those things. Not as pretty of a finish but man do they cut fast with a lot less pressure on the tool. I only have 2 of them left and I save them for when I have to remove a lot of material. Enjoyed it Crusty, thanks! | ||
| Greg_e |
Cool stuff, wish I had the machines and skills to do something like that. Even if I could design my own frame, I could probably find places to machine it within a budget. Need a little lighter and little bigger frame from my race bike, and move the weight distribution around a little. Should be easy, but I don't really have the knowledge to design it right now. Heck I'd even do steel tubes and crappy flux core welding if I thought I could figure it out. One more thing on my to learn list (that list never seems to get shorter). | ||
| Rick_a |
I'd be worried about the long term longevity of that front engine mount, but it certainly looks interesting. | ||
| Ducbsa |
Here's another aluminum V-Twin frame: https://www.classicmotorbikes.com.au/news.html | ||
| Rick_a |
Spondon has been making an XL frame forever.  | ||
| Hootowl |
"I'd be worried about the long term longevity of that front engine mount, but it certainly looks interesting." Exactly my thought. Those bolts going into the front head are going to break unless they can keep the engine from moving front to back and the frame from flexing. I didn't notice any triangulation there. Sure is pretty though. | ||
| Natexlh1000 |
Wooooah there. Is that a dry clutch? What lubes the gear case? Does it have a belt or a chain? So many questions! | ||
| Hootowl |
It looks like it will try to pivot here, especially with the forks attached and weight on wheel.  | ||
| Hootowl |
"Wooooah there. Is that a dry clutch?" Yes. There's a kit. Belt primary. Sure makes it easy to tell when your crank seal goes! There's a similar seal between the clutch basket and the oil-bathed transmission. I don't see the value, other than being different. | ||
| Crusty |
I'm enjoying watching someone build a Sportster into a bike that will handle better than stock. To me, it's a welcome breath of fresh air after seeing so many Customs that look and handle like this bike:  And I love how the machined pieces look. | ||
| Rick_a |
Ya. I was thinking the same thing. I ain't no expert or engineer, but it looks a bit hingey there. All the backbone style frames I've seen are dead stout, full diameter there all the way to the swingarm pivot. Maybe there's going to be more to it? | ||
| Natexlh1000 |
I see the hinge there too. Especially if they go with a conventional rear suspension mounting arrangement. There are actual REASONS that Buell put a pull shock under there  | ||
| Ratbuell |
Just for the sake of argument...all Indian motorcycles have aluminum frames. Scouts and heavyweights. I've said it before - a Scout is everything a sportster should have been from day one. Light, low center of gravity, good geometry, boatloads of accessible power, high rev limit, and liquid cooled. | ||
| Crusty |
The Scout would be a pretty decent bike if it only had mid controls and a seat that didn't lock you into one position. It's a nice cruiser, but I'd hate to ride it to the Arctic Ocean. | ||
| Natexlh1000 |
Agreed. Same goes for the Vrod. That engine would have been great in a touring rig or a sportster-like chassis. Nope Vrod is Vrod and only Vrod. | ||
| Ratbuell |
Scout is too low for mid controls, your heels would be up your a$$. We outfitted one with RSD mid controls and that's exactly where my heels ended up. Good thing the buyer was 5'-nothing, he could actually fit on it. Maybe they could do a taller version, such as the VRSCR...shame HD killed that one after only a year. | ||
| Sifo |
I kind of agree about the potential hinge point too. Beyond that, I'm not so sure about the welding. Admittitly, I've just started playing with a TIG welder, but every thing I see about TIG welding aluminum says it needs to be very clean if it's a critical joint. Those are certainly critical joints IMO, and they are certainly not well cleaned. I hope they know their stuff on heat treating too. So is the backbone going to serve as the oil tank? | ||
| Ducbsa |
That joint at the back of the top spine held up for these bikes at the IOM: https://egli-vincent.net/2016/08/27/the-vincent-re sults-on-the-2016-classic-tt/ The unit construction engine should be stiff enough to not put too bad of a bend in the frame. My concern would be the narrow attachment at the rear of the engine, allowing twisting. | ||
| Rick_a |
We've progressed a bit since then. A heavy gusset such as this would likely help.  | ||
| Hootowl |
"That joint at the back of the top spine held up for these bikes at the IOM" I didn't see a frame in any of those pictures. Is the frame attached to the front of the front head using two bolts that have bending stresses from the non-triangular load path created by the bracket? If the "hinge" was stronger, it might ameliorate the inherent weakness of the four sided polygon arrangement that the bracket creates, or if there were three mounting bolts in that bracket, one further down, that would eliminate the bending stress. It will be interesting to see what the finished frame looks like. | ||
| Ducbsa |
They look like Rick's frame above. you are right, that Sportster front bracket isn't the strongest. You can sort of see the centerline head bracket here:  (Message edited by ducbsa on January 26, 2018) | ||
| Hootowl |
The difference with that frame/engine is that there is a gusset there at the "hinge". They've not left room for such a gusset on the other frame. There may be enough for a small one. It will be interesting to see what the finished frame looks like. | ||
| Sifo |
I just read a few posts in that thread trying to get an idea of the intentions of this build and got to this...
That last part seems to be a driving force in the engineering. Build it from billet because you can. I think there's better ways. Oddly, they didn't do the joint above the rear head that way though. They also didn't gusset the joint. That joint certainly looks suspect for flex, especially with a paint shaker bolted to the frame. Aluminum doesn't play well with those conditions. I think it may be intended as a show piece, so maybe it's not that big of a deal. If they plan any real riding with it, I hope they have done a good analysis of the stressed involved. My personal gut feel of it doesn't give me the warm fuzzies. | ||
| S1owner |
Interesting but I see issues right away with the front iso mount. It only provides rocking in a foreard backward motion and these motors shake all directions. Also aluminum has no to very little flex it just fractures thats wht the tubers are chromly | ||
| Hootowl |
There's no isolator. It's hard mounted. | ||
| Greg_e |
Does Dan Moto do anything that they don't intend to sell? if it is decent, there is a market. Especially if they can turn it out for reasonable prices. | ||
| Natexlh1000 |
If it's hard mounted, the engine makes a good frame brace, I suppose. They'll have to buy a 55 gallon drum of threadlocker though. |
