Need help for deciding on personal bike

Gerard Andrade

New Member
Joined
Nov 3, 2016
Messages
14
Hello, so anyone who has seen my previous post knows I have built a bike before but now I pose the question of which configuration is the best for me. Here is what I have laid out, I have a La Jolla street cruiser from Next that I will be using as my frame of choice. While it isn't the best choice I decided to use it because of how the bike rides. Personally I have ridden lots of bikes but beach cruisers I didn't like as much as I thought I would. I settled for the street cruiser because of the tires and aluminum build. My concern right now is which engine to use. I have experience with the 48cc and I love the pep it has. However today I want to look at everything before I buy. First some background of my commute. I currently ride the 48cc to school daily and work when needed. Both are within 30 minutes of engine riding so I settled for a two stroke engine (plus the 4 stroke doesn't fit). But I live in more hilly areas and the two stroke bogs when going up hills. I'm not exactly a light person weighing over 220. I do have a few questions in regards to which seems more logical. First is there a major external size difference between the 48cc and 66cc engines? Second which is better for pulling hills? And finally which is the more reliable? I know for a fact that the 48cc fits the frame when I was building the other bike however I saw through some of the flaws of that engine and want to know, if I get a normal 66cc engine and don't modify anything will it be better than if I get a 48cc engine and add performance parts to it. I want to make sure I get the most out of my little engine and I don't want to end up making the wrong choice and it biting me in the a$$ later. I am considering a lot but would like some help narrowing it down. (And anyone who read the whole paragraph thanks, I like to talk... a lot)
 


crassius

Well-Known Member
Joined
Jul 23, 2012
Messages
4,575
aluminum frames can sometimes be a problem in that they are subject to cracking from the vibration (something to look out for)

I've recently switched to 40mm stroke engines, and find them much better for hilly areas (though, with slightly more vibration at low speeds).
 

Gerard Andrade

New Member
Joined
Nov 3, 2016
Messages
14
Update: Scrap the aluminum frame the rear axle fell apart so I'm not using it anymore. I'm going for the Kent male beach cruiser from Walmart. (Has steel frame)
 

Steve Best

Well-Known Member
Joined
Sep 22, 2012
Messages
1,236
I have 4 motors at this time. An older 48cc Grubee, a new Grubee 66cc that I modified and put 1000+ miles on over the summer, a very old no-name 66cc and a brand new Grubee 66cc that is getting a more powerful 49cc cast iron cylinder. I've learned a bit about them in the past year.

Both are the same reliability, which is mainly dependent on the care you put into your bike and motor.

The 48cc Grubee with larger 56t sprocket has about the same vibration and hill climbing ability as the stock Grubee 66cc with the smaller 44t sprocket. Only the top speed varies (25mph vs 30mph +-5mph) when they are geared this way. The 48cc seems a bit more frugal on fuel. Their outside dimensions are pretty much identical, with various models of each having wider or narrower front mount bolt spacing of M6 or M8. The Grubee 48cc is more powerful than the no-name 66cc and has better hill climbing capability and top speed even with the same 56 gearing.

If you were looking to buy with an eye to future modifications, I would buy the 66cc because of more potential.
If you are asking should you buy a 66cc instead of modifying the 48cc you have now? MODIFY THE 48CC!
No need to buy a lot of expensive parts. Some cheap head mods and light porting will really liven it up.
The exhausts are the same 40mm pattern, and most of the intakes are 40mm bolt pattern now too. Lucky if your 48cc is.
Sanding some squish into the head, replacing the headgasket with teflon, maybe a double base gasket, match the exhaust pipe/port and widen the exhaust port will give a huge boost in your 48cc hill climbing capability at little to no cost.

Steve
 

Gerard Andrade

New Member
Joined
Nov 3, 2016
Messages
14
Ok update I purchased a jackshaft along with a 66cc engine. My question now is what should I do to keep my bike from falling apart when I build it and does anyone have any tips about installing it?
 

crassius

Well-Known Member
Joined
Jul 23, 2012
Messages
4,575
inspection, adjustment, greasing, and just being careful will keep the bike from falling apart too quickly, but it will fall apart

the bike was not made to go this fast or to handle the vibration of a motor - over time, you'll see freewheel pawls worn to nubs, wheel grease baked to crust, spokes bent or broken from hitting potholes at 3 times the normal speed

keep an eye on everything
 

gary55

Well-Known Member
Joined
Nov 27, 2012
Messages
3,947
I am guessing you are considering the kent bayside. Poor choice because of the braking system. The caliper type brakes are very weak and take forever to stop. This will be multiplied because you are j shafting to a derailuer ( which is as cheap as they come, and will not last) that is going to have you going 40 + mph. Braking system should be one of the leading concerns when deciding which bike to build on. Front and rear v brakes at the least for safe stopping, rear v brake and front disc even better. Just my opinion.
 

Gerard Andrade

New Member
Joined
Nov 3, 2016
Messages
14
Ok update, my engine has arrived and I ditched the new bike idea and have decided to use another frame right now I can't open the screws for the clutch arm cover (where the sprocket is) and I can't open the magneto cover either. The screws were too tight I stripped the Phillips screws and can't still open the cover what can I do?
 

Street Ryderz

Well-Known Member
Joined
Oct 14, 2016
Messages
3,271
extractor bits called grab it! the best one I have ever used!And they are cheap under 20 bucks,I use them in my electric impact driver but also work in regular drill!They have a reverse drill on one end and the extractor on the other and takes only seconds to remove the bolts!
 

Gerard Andrade

New Member
Joined
Nov 3, 2016
Messages
14
extractor bits called grab it! the best one I have ever used!And they are cheap under 20 bucks,I use them in my electric impact driver but also work in regular drill!They have a reverse drill on one end and the extractor on the other and takes only seconds to remove the bolts!
Where can I get those?
 
Thread Status: Hello , this thread is over 3 years old. You can still reply if relevant, but sometimes it's better to create a new thread to get more replies!
Top