Modern Vespa

Howdy,

So my SIP Road v1.0 had a good 20,000km's on it, and one de-coking, and that honeycomb stuff was starting to fall out, so I just got my hands on one of these SIP Road 2.0 exhausts. It's acquired two exhaust spring hooks, which is a good feature, methinks, because my previous SIP Road had been held on by, variously, shims made from beer cans, coke cans, tomato paste tins, grease cans, and even the 0.15mm shims that SIP sell. Even then it was hard going to get the thing to seat properly right up at the base of the exhaust stub.

I understand the bit about putting the 2-holed steel extender bit on the cylinder shroud screw, and attaching one spring to that, and for the other spring I'm supposed to drill a little hole at the bottom end of the outermost cooling fin and hook it in there.

I see, though, that for the forward spring to connect to the cooling fin, that spring's gotta be massively stretched out. Adding to my concern is that this is a Polini 210 nikasil barrel. The thing just feels so light and so brittle. Also, I seem to remember reading elsewhere about people having trouble attaching springs to aluminum cylinders. Breaking fins and so on. And now I can't find that information for some reason.

Does anybody have any experience with this? Also, would it be feasible to just hook up the one spring to the cylinder shroud screw and leave it at that? Or would that exert any damaging lateral force on the exhaust stub? (Sorry if that sounded paranoid. Just trying to be thorough here.)

After a decade of Sito+ with a clamp versus a recent convert to expansion chamber header pushed to exhaust stub on (Pinasco) aluminum barrel, I'm SOLD! It fits firmly with no leaks. Best of all since there's no wiggle (like the Sito w/ clamp) then the stub won't get worn down.

I'm using the factory stainless springs with that metal tab that extends from the screw hole at the bottom of the shroud. I drilled a hole in the top and second fins so the spring fits as low as possible (don't want the head fighting it).

At some point I had an auto exhast clamp on my Sito and one spring going from it to the shroud screw. Helped quite a bit but the Sito+ just cracked apart all over. It served me well but I'm in expansion chamber heaven/hell (tuning) right now.

I don't have any concerns with the springs at this point. I used this as my guide but don't forget to drill through the top TWO fins so the spring seats:

http://www.scooterhelp.com/tuning/sip.pipe.html

Also, after I installed the header only I installed the one spring that pulls the chamber snug to the header, then loosly screwed in all the bolts and made sure the alignment was good before snugging them all down.

Oh and for sure get one of those T-handled spring pullers. Probably preaching to the choir here. I got mine at Harbor Freight locally for like 8 bucks and change. Totally worth it.

Use both springs. I have no worries about the fins breaking. I think the holes I drilled were approximately 1/4" in from the edge or perhaps a bit more. I just eyeballed the alignment, pretty much lines up with the middle of the header pipe.

Hey Jimmy... If you want to use both springs and one of your is ''massively stretched out" either get a longer spring.. just long enough to give a little holding tension.. or just use the cylinder shroud spring... I've never had a hole in a malossi aluminum fin break from the spring tension... i've also run several pipes with only the shroud spring... if you get the pipe bracket onto the swingarm up tight where it wants to be, it'll be doing the heavy lifting anyway..

If you drill the fin, just don't do it RIGHT at the edge... go in as far as your spring end will alow, and don't use a spring that's too short..

Ok fellas, thanks for this. I'll be hooking this up tomorrow and will take pictures!

If you need the hole in one of the inner fins, just drill holes through all of the outer fins to get down to it. On my first malossi kit, I stuck the drill in at weird angles trying to get in there. It was a waste of time. As pointed out above, do make sure you stay away from the edge. I LOVE the spring hangers on my 226 Hot Wing. SO much nicer than clamp-on exhausts!

Hojo

Yeah I'm a bit disappointed with the fit of the SIP road... it's WAAAY loose on my Polini stub. Why didn't they just fix it rather than adding springs? German engineering my $#@%&.

If the spring is too short, make a neat wire lengthening bit... hooks or loops on both ends, job's right.

People take exhausts to have cracks welded, have EGT probe mounts welded on... take it to a welder and have a couple hooks welded on for springs!