IZIP to GAS Scooter Project

[lowracer]

Here are the latest pics and news.
I sold the IZIP to GAS project & have an offer on this Scooter.
I just added the small motorized bicycle muffler today to allow the engine to reach higher rpm's without added noise. It works really well so far (3 test drives) & I only had to cut a small hole in the shroud to fit the header pipe through.
I may need to brace the pipe to the engine block like I did on the 2 motorized bicycles to keep the header bolts from loosening (hanging weight).
enjoy
-Lowracer-

 

[d_gizzle]

Good deal! Once I finish '5150' I will be doing a 20" bicycle conversion.



In-frame of course.

 

[16v4nrbrgr]

I like it a lot Lowracer, looks like its a blast to ride!

 

[lowracer]

If this one sells, I may try to 'scooterize' one of my full suspension motorized bicycles ('The Beast').
I think I can drop the height of the bike with the 12.5" scooter wheels & still have enough ground clearance for the suspension to compress without touchdown. That would be pretty cool scootering around on a full suspension stand-up...
-Low-

 

[16v4nrbrgr]

Hey lowracer, I was wondering what 76mm clutch settings have worked out for you on these small two strokes. Mine on my BMX has a two shoe clutch with the hook spring in between. I drilled out my lightening holes by 1/4" through in 4 spots and that gave me a about a 7000 rpm lockup for the 10500 redline engine.

Any insight into clutch setups that worked for you with these scooters or with your mountain bikes would be greatly appreciated. You're one of the most experienced on here at putting these centrifugal clutches to work.

 

[lowracer]

16V,
The only trouble I had with my 78mm clutch springs were with the 3 spring clutches found on the cags. The one spring clutches have never broken on me & work well. From my experience they shoes last longest when incorporating a freewheel into the motorized drivetrain.
I just ordered some new parts & will be going forward with a new project turning 'The Beast' into a full suspension stand-up scooter with 8" disc brakes & 2 engines (front & rear drive) both on freewheels. I'll probably gear the front engine for rapid acceleration up to around 18 mph, & the rear engine for up to 40 mph. Once up to a speed of 20 mph or so, the front engine can then just idle & freewheel along while the rear engine is in its powerband. We'll see how the gearing progresses (changes) once I get it all together. I'm just waiting on some neat thread-on 6 bolt rotor conversion pieces to arrive.
-Lowracer-

 

[16v4nrbrgr]

Huh, that sounds awesome! I'm glad I ordered more two shoe clutches, and yeah I'm using a free wheel so it doesn't stretch the springs like you talked about.

The major problems are that I'm getting a harmonic or something that causes pulsing cruise and mid accel if not wot, and I need a clutch setting that will allow this little utility motor to zing yet have enough bite and weight hillclimbing to not burn up. I have a good combo now but my top speed is about 25 mph at 10500, when I geared it taller it overheated the clutch (smoke!), it works great but once I blast up to the top its BZZZZZZ maintaining 7000 rpm to keep engaged or bwa bwa bwa! with freewheeling in between.

I've watched a lot of pocket bike and goped vids with engines similar to this with the same carb that are 33-52cc and they all sound like they run better part throttle and have better power and clutch bite. Maybe it's because all the people's machines online are all tuned up and ported, I dunno.

I'm wondering if the inertia of the 20" wheels and drivetrain are why I can't have fast accel AND good top speed like a goped, or the weight (200~ lbs me and bike total) , or that the motor really is only 1.5 HP, dunno, lol. I gotta WOT it to make the accel not pulse, thinking maybe I need a boost bottle, or a different chain.

 

[lowracer]

Sounds to me like the carb is causing the problem.
I've never had those issues with the Japanese engines I've been using lately.
Perhaps China is to blame...lol
-Lowracer-

 

[16v4nrbrgr]

Maybe it really is only around 1.5 HP even though its a big bore 52cc model, dunno? I found the wowowowowow source, it's my drive chain since it has a tight spot and I'm turning it at low rpms. On second thought it might be a wonky chinese freewheel sprocket...

 

[lowracer]

16v,
I like to put a rear derailleur into the drivetrain using it as a chain tensioner.
It would keep the chain tight even if the sprockets are slightly out of perfect round and by using the top out adjustment screws the derailleur can be fine tuned left & right to maximize a straight chain line onto the rear drive cog. I havent had one derail on me yet.
-Lowracer-

 

[16v4nrbrgr]

Did the derailleur stop the oscillation? I think part of my problem is that im running a rhd sprocket lhd, so it butts against the lockring and may be true if its seated tight against the wheel side of the hub, so I'm going to torque a sprocket on and just weld it to the wheel, since its a $20 wheel.

A true testament to the high heat capabilites of red moly synthetic wheel bearing grease, I tack welded a lockring to a greased hub yesterday and it didn't boil, lol. I didn't fix the problem, but it gave me an insight into what would with the sprocket.

 

[lowracer]

If the chain gets too tight at some point between the two sprockets spinning around then the addition of some extra chain & a spring loaded rear derailleur could solve that.
-Lowracer-

 

[lowracer]

Bicycle to Scooter

I read somewhere that a stand-up scooter fork trail should be different than for a seated bike due to weight distribution & that there is a simple yet effective solution to increase high speed handling. Forks can be flipped around to give more trail. I tried it today to see how it would affect handling.
Conclusions:
At very slow maneuvering it feels 'weird' kinda like 'wheel flop'.
At high speeds it rails corners & feels like it was supposed to be this way.
I'll keep taking it on test drives to compare handling, but so far I like it better this way.
see pics
-Lowracer-

 

[d_gizzle]

Looks like its meant to be that way. And did it level out your footboard? I'm out of words for your builds mang!




Unless you ship?

 

[lowracer]

D Gizzle,
I guess it should theoretically raise the front end of the bike a little?
I never thought about that but if it went slightly higher, I'd be good with that.
Anything to prevent bottoming the bottom bracket shell on large curbs.
-Lowracer-

 

[lowracer]

I swapped engines off this scooterbike so that I could have 2 matching engines for my other scooter project I'm working on (2 wheel drive scooter).
Now this puppy has a Tanaka 47r and a Dax friction drive w/1.25" roller (changed out the 1.5").
This thing now screams from a dead stop up to about 32 mph and has roll on power at any speed in between. I'll probably wear out the tire if I dont end up selling this one.
-Lowracer-

 

[lowracer]

Scooter from Bike

This little scooter rips with the friction drive 1.25" roller & Tanaka 47r engine, but is a tad loud. I added a meter of silicone exhaust hose I bought from DDM racing.
It might be a slightly quieter (not much) so I'm thinking most of the noise is intake related.
I'm not going to work on it since its not 'Cag loud', but its just an observation.
Here's the latest pic showing the exhaust.
-Lowracer-

 

[lowracer]

I've since cut down the extra long silicone hose so it isn't so ugly...
Just haven't taken any photos yet
-Low-

 

[maniac57]

I'd leave it as is just to mess with people's heads.

 

[16v4nrbrgr]

Hey Low, I used a plastic coffee can and the end of an old grip for the airbox and stack on my BMX and it quieted it down considerably. Something maybe worth a try because its almost free.