Hello forum, I am have almost finish my SF2, I got new mufflers from Wolfgang and got the headers re chromed, I got a guy in Australia to make me a cross over but not impressed how it sits, (hangs low) any one know of where I can get a crossover. I asked Wolfgang but he doesn't make them. Just thought I'd ask before I go and see another fabricator of pipes.
Laverda SF2 Cross over
- Thread starter JasonB
- Start date
mik667
Senior member
- Location
- San Francisco, Ca
Humm I got one from Wolfgang - though I have to admit when I compared the bike to with and without it I found no discernible seat of the pants difference, it just made the exhaust a small bit quieter
Tippie
Hero member
- Location
- Dr?bak, Norway
Isn?t Wagner?s one empty? The factory ones were sort of a mixer crossover type of thing. They both scrape like f*ck in corners though.
chrisk
Hero member
- Location
- Brisbane, Australia
Tippie said:
You blokes need beaches with sand instead of rocks. Balls in sand don't get scraped as bad as, balls against rocks.
Shamrock
Hero member
- Location
- Miami, Florida USA
The banana. 
tyelav13
Hero member
- Location
- Wales (gods own country)
I have heard loads of conflicting information on this and as I am hoping to renew the silencers on my SF1 later this year maybe some of the people on here with lots of twins experience can push me in the right direction. Cross over pipe or not? Is there a big difference?mik667 said:
Regards
Tyrone
Tippie
Hero member
- Location
- Dr?bak, Norway
It is a bit like a tyre or oil thread this one.
There are those of us that have run for decades without the crossover, generally having removed it due to cornering issues. For myself there has never been an issue as regards tuning or power. My own SF2s pull like a diesel from low down and rev out fine with no tuning issues.
Others here maintain from experience that it is absolutely impossible to get the bike to run well at lower revs and that you also lose most of your bottom end power.
For me the benefit of the crossover is that the bike goes as well as it will, with no seeming restriction, and is fantastically quiet, something I do value these days. The downside is the cornering clearance if like some of us you never grew out of the cornering addiction.
The benefit of no crossover is the cornering issue. The downside is that the exhaust system can be prone to vibration cracks as it is a long section without support from the manifold to the muffler supports. This can be fixed with another rubber mount at the join of the header and muffler. I have not had cracking problems since I have been unable to tour at 6000rpm type riding.
It is also possible to bend the header even higher when eliminating the crossover for maximum clearance with pipes at the side. The SFC went from side pipes to under motor twin muffler and 2 into 1 for the same reasons. Both of these systems require new centrestand lugs, an SFC type centrestand and at least in the case of the 2 into 1, no side stand.
There are those of us that have run for decades without the crossover, generally having removed it due to cornering issues. For myself there has never been an issue as regards tuning or power. My own SF2s pull like a diesel from low down and rev out fine with no tuning issues.
Others here maintain from experience that it is absolutely impossible to get the bike to run well at lower revs and that you also lose most of your bottom end power.
For me the benefit of the crossover is that the bike goes as well as it will, with no seeming restriction, and is fantastically quiet, something I do value these days. The downside is the cornering clearance if like some of us you never grew out of the cornering addiction.
The benefit of no crossover is the cornering issue. The downside is that the exhaust system can be prone to vibration cracks as it is a long section without support from the manifold to the muffler supports. This can be fixed with another rubber mount at the join of the header and muffler. I have not had cracking problems since I have been unable to tour at 6000rpm type riding.
It is also possible to bend the header even higher when eliminating the crossover for maximum clearance with pipes at the side. The SFC went from side pipes to under motor twin muffler and 2 into 1 for the same reasons. Both of these systems require new centrestand lugs, an SFC type centrestand and at least in the case of the 2 into 1, no side stand.
markQLD
Hero member
- Location
- QLD Australia
Reckon the 'balance bulge' is an apt description that i've nicked from Tippie. (bigthumb)
It was going to be the first item i trashed when Seffie, my standard SF2, was delivered a couple of years ago. I had an SF3 in my younger years and can recall how the balance bulge got regularly bashed into the tarmac when cranked down into a turn. Probably rode a bit more like Lee and Quentin back then?
Anyhow, two years later, and it still remains fitted to SeFFie. Is not an issue with my current riding technique. :-[ yes, sad but true
Much has been commented on before and i can understand both sides of the debate.
http://www.laverdaforum.com/forum/index.php/topic,91579.msg325899.html#msg325899
My question is: has anybody opened up a standard factory balance cross-over ?? If i had a junk surplus item i would peel it open as i'm curious to know exactly what pipework is hidden within. I can only see the start of inlet 90? bends. Photos anybody ??
I guess a bloke is just going to have to do a couple of dyno runs, with and without. Unless it's already been done?
It was going to be the first item i trashed when Seffie, my standard SF2, was delivered a couple of years ago. I had an SF3 in my younger years and can recall how the balance bulge got regularly bashed into the tarmac when cranked down into a turn. Probably rode a bit more like Lee and Quentin back then?
Anyhow, two years later, and it still remains fitted to SeFFie. Is not an issue with my current riding technique. :-[ yes, sad but true
Much has been commented on before and i can understand both sides of the debate.
http://www.laverdaforum.com/forum/index.php/topic,91579.msg325899.html#msg325899
My question is: has anybody opened up a standard factory balance cross-over ?? If i had a junk surplus item i would peel it open as i'm curious to know exactly what pipework is hidden within. I can only see the start of inlet 90? bends. Photos anybody ??
I guess a bloke is just going to have to do a couple of dyno runs, with and without. Unless it's already been done?
markQLD said:
Mark,
Both inlets turn in towards the centre of the big tube where they exit next to one another. The exhaust gases can expand and distribute themselves into both silencers through short exit tubes. Actually allows for more free breathing than each header into its own individual silencer. This effectively simply increases header length because the gases have not much room to expand on their way out due to the absorber type construction of the silencers.
Wolfgang once spoke of having a simple crossover tube made, similar to the Guzzi setup. Don't know how far that has progressed.
piet
markQLD
Hero member
- Location
- QLD Australia
Thanks Piet, so my next question is;
If smoke puffs out more from the left pipe, is the smoke coming from the left or right cylinder ??
confused Mark :-\
If smoke puffs out more from the left pipe, is the smoke coming from the left or right cylinder ??
confused Mark :-\
G
Grant
Guest
Yes
You can do without the cross over. A lot more noise though
However, you need to ridify the system somehow, either by mounting it rigid with the risk of breakage, or by using a system with a linkage tube somewhere. No performance advantage or loss whatever but if you don't fix the system, the headers will grind into the copper exhaust gaskets due to rotation leading to endless leaks. I spent a few weeks last winter learning that.
Paul
However, you need to ridify the system somehow, either by mounting it rigid with the risk of breakage, or by using a system with a linkage tube somewhere. No performance advantage or loss whatever but if you don't fix the system, the headers will grind into the copper exhaust gaskets due to rotation leading to endless leaks. I spent a few weeks last winter learning that.
Paul
markQLD said:Thanks Piet, so my next question is;
If smoke puffs out more from the left pipe, is the smoke coming from the left or right cylinder ??
confused Mark :-\
Your guess is as good as mine...
When my mate burnt a piston of his SF3 at around 150kmh right in front of me, sparks, and then smoke came out of both silencers, quite spectacular in the failing light at dusk!
piet
piranha-bro2
Hero member
- Location
- Melbourne
Lemme guess? Plugs too hot?sfcpiet said:
As for 'the debate' - ran my SF1 without the crossover for probably 15 years before going SFC 2/1. Have set my mate's SF1 up with 'joiners' into the Staintunes - I took the liberty of bending the stock headers as high as poss without fouling the gear lever on the right and the brake pedal on the left, plus very solid aftermarket rubber silentblocks x 2 for each muffler - I've covered about 2000km on it - no issues, and has seriously good cornering clearance. if it were mine I'd fit the extra mid-way mounts as suggested by Senor Tippie. No crazy tuning issues. Bike flies, no flat spots, revs cleanly. Never had an issue with how the SF ran with the Bulge, just didn't like that sensation of a very hard metal object that was part of my bike whacking the tarmac when nicely committed in a bumpy corner. Tendency to lift the rear wheel ... you tend to discover you don't like the box at times like these.
Piranha Brother 2 said:
No. Chose to stick with the points, reckoned the bike had survived up till then, why shouldn't it continue? Anyway, first thing I said when we rescued ourselves to a lay by was "Told you so!"
Almost wet myself from laughing. Downside, it was getting dark, was already cold and we were about 300km from home. Left the bike where it was, loaded him and his gear on mine and others and headed home. He picked it up next day, surprisingly, still in one large bit! Goes to show Laverdas were generally un-loved back in 1992, a Honda would have vanished by the time he returned.When taking the engine apart, we found the ignition timing was way off on the offending cylinder. DMC time after that.
piet