What would your dream build consist of?

[Rusty_S85]

You have obviously not ridden one of these bikes yet!If you want to do 50 mph in the top end and cruise at 30 and also from a standing start you need to make some serious torque and it still will probably be spinning around 7000 rpm at 30 mph!

I haven't. this is my very first build and I might be trying to blend my automotive knowledge in on this with unrealistic goals. Why I am doing as much reading as I can and asking opinions where possible to try and make a decision. Ideally I feel that lower rpm will provide longer life and less wear on the engine but at the same time I realize we are talking about a single cylinder engine that is making 3 hp maybe 4hp with tuning. So it might be harder to find a balance that I am looking for.

Right now how ever I am just looking at buying one of the GT5 Skyhawk engine kits and then go from there. I am starting to think maybe I shouldn't worry about what RPM the engine is turning at what speed just try to build it to meet my main goal which is to have enough power to take off from a stand still without requiring pedaling or lugging the engine too hard.

At least going this route I can give a try at modifying the engine to make it better for me. After all I would be happy with around 30 to 35 mph I just have never been a fan of the whole engine screaming its guts out at that speed. Maybe mine wont be as bad since I am looking at the long muffler two piece exhaust to use on my build.

 

[Carl Walichnowski]

Isn't that just a standerd 1" steering tube and old school quill?the bar is also an everyday regular bar not tapered or anything!

I have no idea what's the sizes are just looking at em but I'll take your word for it. I have to order new forks and a handle bar due to my accident. I just wanted to be sure 1" forks is what I need to buy.

 

[Rusty_S85]

Yup going to need some torque and a 36 at least!And a good pipe staged low to use the power gain where the load is!

I am looking at buying another sprocket in the area of 30T. Not sure which one just yet. I have a 44T right now which from my reading is a good all around gear. For now I might be able to swing a higher gear as the roads are pretty much level here. After I move how ever with hills I might have to switch back to a 44T.

I think if I buy the GT5 kit from Bicycle-Engine I think I will pick up their 36T sprocket for my Grubee HD axle.

Yea I see that paint job is very nice!going to be a cool looking bike!I didn't read all of the thread is he planning on using a jack shaft or single gear?

Orignally I was leaning towards a shift kit with a sbp shift kit but since settled on a single speed. Two reasons was cost as I realize it would raise my cost quite a bit for sourcing the proper parts. Second reason was that from my reading I found out that you lose power going through multiple chains.

 

[gary55]

I am looking at buying another sprocket in the area of 30T. Not sure which one just yet. I have a 44T right now which from my reading is a good all around gear. For now I might be able to swing a higher gear as the roads are pretty much level here. After I move how ever with hills I might have to switch back to a 44T.

I think if I buy the GT5 kit from Bicycle-Engine I think I will pick up their 36T sprocket for my Grubee HD axle.



Orignally I was leaning towards a shift kit with a sbp shift kit but since settled on a single speed. Two reasons was cost as I realize it would raise my cost quite a bit for sourcing the proper parts. Second reason was that from my reading I found out that you lose power going through multiple chains.

OK now that I know that you are looking for a bike that will take off from a stand still I can fill you in on some things you need to know.
1. You will not be able to do this and reach speeds of 30 to 35 mph with a single speed unless you build or purchase a extremely souped up engine with a bad assed pipe, and a minimum 41 to 44 tooth sprocket. The 2 strokes just don't have the low end torque without either a shifter or a large sprocket and additional power.

2. A 4 stroke will let you take off without pedaling but still would need a large sprocket to make this reasonable on a regular basis to give the clutch any kind of a life span. With such a set up 25 to 30 mph would be it at best.

3.So If you want to be able to take off from a stand still with a 2 stroke my advice would be to plan on building a bike with a jack shaft and either a 4 or 5 speed internal hub, or a nuvinci hub. you will still need a moderately enhanced engine and pipe. Other wise you will need to go with a 4 stroke jack shaft setup.

4. If you chose the 4 stroke their are 3 ways to go. KC Val has what he calls a 10G multi speed kit. Good design, but requires fitting to frame for welding and heavier gauge materials. GruBee has a similar set up with a bolt on mount. Though not as elegant as KC's the materials are stronger but it is not offset like KC's to allow for narrower pedals. Then their is sickbikes shifter kit for 4 strokes. I don't see you going 4 stroke anyways because of aesthetics.

 

[KCvale]

3.So If you want to be able to take off from a stand still with a 2 stroke my advice would be to plan on building a bike with a jack shaft and either a 3 or 5 speed internal hub, or a nuvinci hub.

Yep.
Gears change everything and you should look into them, you can rocket off the line and still do ~40mph.

I have built a couple for customers...

These are my 2-stroke shifter builds.
http://kcsbikes.com/KCsBuilds.asp?motor=2-stroke&shifter=Yes

These are my 4-stroke shifter builds.
http://kcsbikes.com/KCsBuilds.asp?motor=4-stroke&shifter=Yes

And all my electrics are shifters.
http://kcsbikes.com/KCsBuilds.asp?motor=Electric&shifter=All

A 2-stroke shift kit is ~$150 at Sick Bike Parts.
http://sickbikeparts.com/standard-2-stroke-shifter-kit/

NOTE: I do not recommend this for kids building a bike in their backyard with a Crest wrench, old screw drivers, and a pair of pliers, you folks will have a hard enough time making a direct drive go, but if you build in a shop and have decent tools they aren't that hard to install properly.

Just a thought.

 

[6blueoval9]

4130 chrome moly steel frame with built in tank...similar to some designs we see now...maybe slightly stretched.

Lightweight triple tree front suspension with clip on style handle bars.

All premium made accessories like throttles and cables and sprockets brackets etc...

Lightweight carbon mag wheels

Front and rear hydraulic disc brakes

Zeda 50mm reed case motor built to the hilt

Custom built/tuned expansion chamber for the particular set up of the motor.

Analog tachometer

Essentially a full on drag style motorized bike.

Or maybe just be happy with something like this and add to it as i see fit...this is so my style of bike build which will be a reality

 

[Daniel1801]

I know the answer to this may be quite lengthy but I always wondered what others dream build would consist of?? Even if you can list a dream part or two that'd be great! Would you go with a Grubee frame with the built in tank, maybe a chopper build? 2-cycle or a 4-cycle motor? How about the expansion chamber or frame? Please feel free to share!

What's the diff between the grubee and kmb frame?

 

[gary55]

What's the diff between the grubee and kmb frame?

Grubee is a better design, has disc brake mount, rear stays allow larger tire, stronger drop outs, and claims to be made of as I remember 6169 alum.. Good stuff.

 

[Daniel1801]

Is

Grubee is a better design, has disc brake mount, rear stays allow larger tire, stronger drop outs, and claims to be made of as I remember 6169 alum.. Good stuff.

the grub the original design of the frame?

 

[bikejock]

I think I'd go with the Grubee frame and a Zeda motor.

The Zeda is a great 2 stroke. Been using one for a couple months up untill my rear wheel got damaged (waiting on a new wheel this week) I am kinda hesitant about using a 2 stroke on an aluminum frame though which is what the grubee frames are made of. Aluminum is light & cheap but it can crack due to vibrations from a 2 stroke. I prefer the old GT Dyno beach cruisers from the 90's & early 2000's, they seem to be the best 2 or 4 stroke motors mostly because they are made of steel which really takes the beatings of 2 stroke motors & plenty of frame space for a wide variety of engine sizes. I've even seen a 212 predator on a GT Dyno.