Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

You thinkin a 90 degree hose bend to the intake?

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Also, damn, I wish I had known that before - I just bought this Polini carb and thought 21 was the way to go. Might be able to sell it on the forums and upgrade.

Re: Crazy Custom Frame Hobbit

either way works but you gotta make the 90 bend flow well. I’m always partial to straight shots if I can do it and you can in this situation.

I’d use a spigot mount because they’re the best for high power shit to stop carb vibrations and weird overflow issues.

Re: Crazy Custom Frame Hobbit

Could you run a smaller front sprocket to give yourself more room? You really boxed yourself in here. I’ve done it before with designs then changed numerous other things like engine position and/or making room by repositioning the gearbox to make something so stupid like a short intake be put “right”

I think right now you won’t get 3/4in away from that sprocket. You’ll be lucky to get 1/4 inch, which is still fine. Any wiggle room on that gearbox to push it back?

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

No wiggle room, really, sadly. I'll play around with the intake and see what I can do. What if the intake comes out angled to the side and blended? Bad idea?

Polini is spigot mount - the CP21 is what I picked up, BUT, I'm wishing I had gotten a CP24

The sprockets are midsized, so could probably go smaller in the front (assuming that I'll want a gear ratio > 1).

Might post up the CP21 or see if I could return it to Treats (I ran it for about 2 minutes and then back to the VM24).

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Or hell, maybe just the TM24? Dunno why I haven't just gotten that

Re: Crazy Custom Frame Hobbit

I’ve found that with a 24 you can often just crack the throttle and rip where you have to give much more throttle on smaller carbs to do the same. Pinball run was a joy with that 24. Before I left I tried a 21 oko vs the 24 and it was a no brainer. I gotta upgrade at least one more bike I have to the 24, has a 21 and it works ok and really revs out but I feel like it would give me more with just a lil more carb.

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

what 24 are you running?

Re: Crazy Custom Frame Hobbit

Tweaker trash /

That bike belongs on the 🧂

Re: Crazy Custom Frame Hobbit

I run whatever I get. Oko and polini, weird 26mm mikuni from a motorcycle. Oko/polini style carbs are great and mostly cheap. Just buy a needle set because tuning them is all needle.

Not really but the needle type is super important to getting a good tune.

Re: Crazy Custom Frame Hobbit

What about cutting off the top elbow on the intake you have and run a diaphragm carb that sticks up? No jets to buy and the intake would be half the length and can still point up?

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Ahhh that's an idea but I hate diaphragm carbs. I'm looking to see if there are any carbs with adjustable float angles or anything of that sort

Re: Crazy Custom Frame Hobbit

Old Dellorto UB carbs have multiple different angled float bowls. They're a little tricky to work with sometimes, and not cheap.

Dellorto_002.jpg

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Going back to Daniel's idea ages ago, wondering if this is a solution:

ScreenShot2021-02-02at8.55.57AM.png

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Something like this? Doesn't save a ton of distance, but removes some of that bend etc.

ScreenShot2021-02-02at9.07.13AM.png

Re: Crazy Custom Frame Hobbit

You sure you can’t tilt that engine forward at all?

Looks like there’s room and you’re still running the ball joint so exh would just accept it.

Even 30 deg would give you better intake options

The diaphragm carb is a great idea actually (edited)

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Yeah I'll check the engine bracketry and see if it won't cause trouble to rotate it. I agree that there's a good dose of room there, and honestly would look good to have the cylinder line up with the downtubes of the frame

Re: Crazy Custom Frame Hobbit

Btw, are you measuring wheelbase from where each tire touches the ground? And it’s 54in?

Re: Crazy Custom Frame Hobbit

Tweaker trash /

Just my opinion

Imagine the entire engine flipped

Blue in intake

Red is exhaust

I suck @ photoshop

D7F23BBE-597C-48E8-A837-93DD18722D0F.jpeg

Re: Crazy Custom Frame Hobbit

There’s a ton of problems with your idea so I’ll just let you figure out what they are

Re: Crazy Custom Frame Hobbit

> JBOT Admin Wrote:

> -------------------------------------------------------

> There’s a ton of problems with your idea so I’ll just let you figure out

> what they are

Ha!

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

I think I am going to table the short intake for now. The long intake doesn't seem to be a deal breaker, and I'm thinking that the short intake can be something I circle back on as an improvement in 6 months. Nothing I do with it will change other things I do at this time.

Re: Crazy Custom Frame Hobbit

Hey man it’s your build. Do whatever works for you. That being said I put your motor into my brainhole and that tilt forward would make it look amazing. Might have to change the rear pipe mount

I’ve been thinking of my shock comment and looking at other bikes and I think should clarify. I run them at more angle because I ride on the streets and use beefy scooter shocks.. On a track the more upright would be fine and maybe even preferred. When I do a more upright angle on the streets my ass gets destroyed due to so much spring resistance. Like riding on a rigid.

Excited to see what this looks like in a few months of tinkering and refining.

BTW, get a really bright taillight or multiple ones if you can as your lowered riding position makes it slightly harder to see you from behind.

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Oh I totally agree. I think it's a great idea and a solid next step, I just think I'm getting stuck on solving for that, when there's a lot of easier things to knock out that will also have a larger impact (fork springs, etc). I'm going to sell the CP21 I think and make the VM20 work for now, and down the road will go to a bigger carb.

I think finishing the seat, shortening the springs, loctiting the hell out of everything, and getting it coated in something so it doesn't rust are key. If I just get some big boy jets for the VM that should take me where I need to go for now. Then it's just riding it a ton to iron out the kinks and gain confidence that nothing will fall off while I'm going around town!

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Made the seat! Going to go with a different taillight in the future, but I had this lying around and now it's street legal!

PXL_20210205_200029659.jpg
PXL_20210205_200024151.jpg

Re: Crazy Custom Frame Hobbit

Right on. Looks good.

I was looking into making those acrylic domes for cool moped windshields. Are you planning on fairings?

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Wasn't sure at the moment - with the gsxr I already have a pretty sweet fairing bike, and I wanted this one to be something that worked both with and without one.

Definitely at some point I want to do one, but for now kinda into the Cimatti Sagittario look

Re: Crazy Custom Frame Hobbit

Tweaker trash /

Pa50 engine

Tomos engine as transmission

Game over!

Edit: 6 speed dirt bike engine as transmission (edited)

Re: Crazy Custom Frame Hobbit

you can also just use map gas and a ts8000 torch for brazing as a cheaper alternative.

https://www.amazon.com/dp/B0019CQL60/

That is what snordley taught me and it has worked great for intakes, pipes, and gas tanks.

Re: Crazy Custom Frame Hobbit

oops sorry my computer stoped on page 6 I realized that topic was from a long time ago sorry.

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