| Author | Message | ||
     Fuzzy |
almost done and nephew stole it out from under me! xr750 dirttrack tail from airtech. wasn't going to do any cutting on the frame but ended up taking off the tabs for the fuse block and flasher.... (dying the seat now and think the black tail is only temporary)      | ||
| Nevrenuf |
now what about a cafe racer front end(fairing) on it | ||
| Guell |
looks nice, how comfy is it though? | ||
| Beachbuell |
What did you do with the stock tail? Is it available? | ||
| Fuzzy |
Nevrenuf: nah, a fairing would violate the "Minimalist Principle"  Guell: well. the seat is on the firm side, but expecting it to soften up a bit after it gets oiled. the leather is still hard as a rock from the molding.... Beachbuell: hmm, so you're saying your butt fits the stock seat better? planned on keeping all the stock parts in case it got sold. now it got sold. i'll check with the nephew and see if he wants it. | ||
| Beachbuell |
I must say that my M2 Cyclone is the most comfortable and best suited bike for me. I have owned a variety of motorcycles and none have felt better than my M2. Mine is pretty much stock with the exception of a Vance & Hines stage one. | ||
| Djkaplan |
"What did you do with the stock tail?" I have a brand new, flawless early model 'slim' tailsection and an excellent used seat for it. It fits any year M2. PM me if you're interested. | ||
| Djkaplan |
"I must say that my M2 Cyclone is the most comfortable and best suited bike for me." Then you be severely dissapointed by the comfort of the slim tailsection and seat... like I was. That XR tailsection looks a lot more comfortable... | ||
| Naustin |
That's dead sexy. Nice job! | ||
| Fuzzy |
Beachbuell: been riding vfr's for 20 some years and then a firebolt for almost a year now and the M2 felt like apehangers and dragging feet. nephew likes the firebolt and seems to agree with the new setup on the M2. says make him an offer on the tail. complete minus tailight. seat has a crack in the upholstery at the bottom of a pleat. manta tank also available (blue)... | ||
| Fuzzy |
Naustin: thank you!!!! seat is black now and tail and flyscreen are getting painted to match the tank. Djkaplan: That XR tailsection looks a lot more comfortable i probably should have gone with more than 5/16" of foam, with feet on the ground the edges are still too square where they hit your inner thigh. | ||
| Fuzzy |
and nobody even mentioned the bsa! sniff! my next project | ||
| Dwardo |
I was gonna mention it! I can spot one from a mile away! If my experience is any guide, it will give you a vibration treatment you won't believe. | ||
| Road_thing |
Nice Beezer! Waht's the story on the aluminum tailpiece? rt | ||
| Fuzzy |
cranking the motor over with the head off and watching both pistons going up and down at the same time just seems wrong! don't see how it could not shake!!! but i ride a buell supposedly it was a Bonneville bike back in the day and had an aluminum boattail like that but the salt ate it, so the guy i got it from tried to copy it. it's pretty rough and not very symmetrical but i think i can do something with it. that and the tank are what got me... | ||
| Beachbuell |
PM sent Fuzzy. | ||
| Dwardo |
Most vertical twins have pistons that go up and down together. Some Jap twins didn't. The advantage is that it gives an even firing sequence, 360 degrees apart. The disadvantage is obvious, particularly on Britsh bikes which don't have a center main bearing. The Honda 450 was made with both kinds of crank depending on whether it was the CB or CL model. My Dad had one of each and I couldn't tell any difference in vibration as both were fairly bad that way but not like a BSA. The later BSA had a pretty short stroke for a Brit bike but for some reason they seem vibrate worse than anything else I ever rode. Go figure. | ||
| Djkaplan |
"The advantage is that it gives an even firing sequence, 360 degrees apart." Another advantage (a very important one as displacement increases) is a 360 degree crank doesn't create a rocking couple vibration like a 180 crank does. This keeps the vibration in one plane and makes it easier to deal with. The engines in XL powered Buells shares this advantage because of the knife and fork rod arrangement. | ||
| Fuzzy |
was thinking my yamaha xs 650 was a 180 crank, but just looked it up and it's 360 too. i don't remember it shaking. just looking and they've played around with rephasing them quite a bit. 270 and 277 degrees anyway. v twin sounds know about the rocking couple thing and it can actually break things. like cranks and frames. mostly what dynamic balancing is about. seems like the right counter weights would take care of it? bsa put the damn things in the middle! maybe i need a knife and fork beamer!!! | ||
| Djkaplan |
"seems like the right counter weights would take care of it?" Balance shafts are typically used to quell rocking couple vibration (to varying degrees of success). Crankshaft counter weighting won't do much for a rocking couple; it's more effective on a 360 crank at changing the amplitude of vibraton from up-and-down to fore-and-aft. I've seen a 277 degree XS650 before. I wish I had spoken more to the fabricator/owner about how he did it and why 277 is better than 270. The bike was nicely tarted up as a streettracker with Omar's goodies. | ||
| Dwardo |
If you compare the insides of your XS650 to your BSA you will see that the Yamaha is way stronger (but much wider). It's pretty near bullet-proof. All Brit bikes that I am aware of (except some AJS models I don't really know about) have that flywheel in the middle. What DJ said about the balancing is right. It just changes the direction of the vibration. I've seen some intriguing data about cranks for Brit bikes with odd offsets. I love my Norton but I would never think of revving it over 7000 and it's all done by then anyway, even with cam and head work. | ||
| Beachbuell |
Thanks Fuzzy, I got the email. I'm still kicking it around inside my head. Just planning a line of attack and need to see what route I'm going first. | ||
| Fuzzy |
Beachbuell: no hurry, let me know if you want them... | ||
| Fuzzy |
wouldn't the counter weights straddling the rods drop the imbalance into one plane? can't be that simple but seems like...damn reciprocating engines anyway! the 277 is just easier i think, 13 splines and just modify some stock parts. somebody made a bunch of shafts to do 270 though. still need custom cams either way. haven't seen anything on goofy clocked limeys, would be interested to see how they did it. have a bunch of 4.5" pistons at work and don't mind making a cylinder block and rods, but don't think i want to be making a crank. or heads either for that matter. but getting it balanced would be something i would have to deal with. don't think i'll be spinning even that fast! | ||
| Dwardo |
No, it's in two planes. If you put enough weight on the counterbalance to completely compensate for the weight of the piston and rod, then when the crank is a 90 degrees the counterweight is pulling in one direction and the only thing pulling the other way is the big end of the rod and the journal etc. So it would move backwards and forward rather than up and down. 4.5" pistons? Wow! | ||
| Fuzzy |
ding! now it makes sense, the rotating mass only has to balance the reciprocating mass twice and the rest of the time it's proportionately less. the 50% rule isn't just a compromise, it's an average. don't see anyway to get the bore spacing out far enough to take that big a bore. even cutting the rods down to half width on the bigend, the crank won't let them out that far. would be a monster though |
