Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

I am deep down the Vespa rabbit hole because of Eric in QCB and the "Epic Vespa Thread." I have always wanted to build a really fast Vespa (faster than 43MPH). I went back and forth on building an MP-One full Malossi build or going the Simo route. I decided it will be fun to do a head-to-head comparison with the help of other QCB members. Yes, I am stupid and spending too much time, effort and money on this but here we go. Starting with this Si and then I will move on to the Bravo.

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Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

I’m excited to see the results, I’m thinking the simo will be faster in the end. Which bike is getting which engine?

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

I'm currently building a Si with a full Malossi MP-One 4 stud deps kit. Slippin and sliding down the money pit I go! That MHR Malossi pipe is absolutely dreamy, and I will be buying one

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

The Si will get the MP-One and the Bravo will get the Simo.

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

Si Build: I am starting with MP-One 4 stud cases. The casting on these is nuts. I have decided to run a 21 Moparts Racing intake and a Malossi VL8 rubber-lined reed block.

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Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

Si Build: I am using a full circle Malossi 12pin crank (pictured is a 10 but I exchanged that). I am also running the Malossi CDI

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Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

I think you may be right - we will find out at testing when we use the same jockey - Ryan from QCB who is dreamy.

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

Si Build: Malossi Overrange and Malossi 9:1 gearing. MHR pipe as well and 21PHBG.

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Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

You and I are pretty much doing the exact same build, but I will likely go with the Polini variator instead if the Malossi, but we'll see. I'm doing small chunks at a time, because I keep coming home with new bikes. I can't pass up good deals haha

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

Awesome man! I totally understand the bike issue.

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

campeona del mundo /

man i don't know, i think it will be a pretty close call. the 4 stud mp one is serious business plus I THINK malossi will make some sorta liquid cooled bolt on cylinder at some point....maybe not though

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

But the simonini has 3 more mm of stroke.

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

Si Build: Got a subframe, front and rear disc kits, pull start, and over-range protection from GP Racing in Italy. I checked around and asked if anyone had bought stuff from them and kept hearing no. I pulled the trigger regardless and took the chance. Turns out the owner Giovanni was great to work with and he shipped to the US in a week. You can find them at: https://www.gpracingparts.com/

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Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

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Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

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Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

Oooo shiny parts 😲 I heard those deps kits are ripper can’t wait to see this thing ! But damn I don’t even wanna know the cost of this build 😅

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

Daaaaaaamn dude, you’re going all out 🤤

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

🦺🥇b to the eff /

Goddamn.

Shame about the pull start. 😅

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

Well it's good he shipped something to you, he refused to ship me a brake kit in spring of '21.

Anyone wanna take bets?

Also, that subframe looks nice as shit. You're definitely going to want a disc brake. Also Also, are you going to just swap the engines on the same bike? Or have 2 bikes with all these fancy bits?

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

Fuck, I've been following them on insta for a while. This is rad af.

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

Two bikes with all this stuff. I will never financially recover from this. 😅🚀

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

Woah, fuck yea. This is what the people have been waiting for. You da man.

That being said, my bet is the bravo will be faster with the simo but the si will be easier to control off the line.

Also, I had to cut my mcproparts subframe to get the simo to fit. The transfers are wider than a mp-one engine so they get stuck on the frame on the pedal chain side of the subframe. I think I had to cut part of the cylinder fins also. The simo comes with the worst instructions ever too, they pretty much just say make it fit and what the 2 tabs on the ignition coil are and good luck. Grab a treats hobbit belt for the bravo subframe for it to work. Unless you got 2 of those gpracing subframes. Then in that case use the si length malossi belt the overrange comes with, it's a little bit less stiff than the Treats belt imo

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

Thanks for this advice! I will be doing another subframe, set up specifically for a Simo engine.

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

🦺🥇b to the eff /

FWIW, aluminum isn't great for ground connections; aluminum oxide forms on the surface very rapidly and is an insulator.

If it were me I'd run ground wires, but you can also scratch up the surface and bond immediately.

This is less of an issue with things like cylinder heads grounding a spark plug because you have both sharp edges and a ton of surface area to conduct through. (edited)

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

Subframe is on. Next up is transmission work.

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Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

EH 📣FCC of the QCB /

This is all so awesome, so stoked I get to be part of all of this.

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…..4 Blake

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

Is there enough space in the subframe to run a airfilter? That subframe looks sick on it

Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

Thanks man. I think it looks great too. Yes, there is enough room. I am thinking of running a go cart airbox. You can see in the picture, I mocked up a 90 rubber elbow from an old blue Polini foam filter. That won’t be the final part, but I have a reference point to sizing now.

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Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

Added adjustable footpegs for maximum tuck. Definitely not a moped now.

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Re: Vespa Si / Malossi MP-One vs. Vespa Bravo / Simo

What kind of forks are you going to run? I read somewhere that pit bike forks fit the massive head tube on the si frame.

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