Sprockets 36T sprocket and heavy riders

[Alan]

Jekem ?
What ever happened to good old fashioned......................

 

[Irish John]

Expected top speed

I weigh 275, and I am satisfied with the 44T sprocket. I do have to peddle to help it up real steep hills, and it bogs when going against a strong wind. Other than that, it flies up to the top speed! I had the 50T sprocket and did not like it for normal riding. The top soeed on 26" wheels was only 23 mph. I am going to use the 50T in the winter. I dont need to be going faster than 23 mph on ice. I don't think I am going to go with a 36T. I think it will bog too much. I might get one someday to play around with.

I've ordered a Grubee 4-stroke kit. I weigh 198 pounds. I forgot to ask what size sprocket comes with the kit but the one in the picture on bicycle-engines.com shows about 56 teeth (it's hard to count them on such a small image). My question is what speed can I expect - the web site says top speed of 35mph but I want to know if she does that comfortably without revving its guts out. I have a 48 tooth sprocket and I have a 44 tooth I could use from the HT kits that litter my garden. Would the 48 tooth be the best?
I'm presuming the Honda GXH50 and the Hua Sheng F142 49cc have a very similar performance - is this right? I'm getting both motors.

 

[starkm32]

Jekem. A new high?

OH, "me thane"?

 

[Marktur]

You know, I never actually COUNTED the teeth on my BGF sprocket, but I wonder if that's why I feel the need to back off at 25mph???

My 40t is on the way from the LiveFastMotors eBay upgrade special...and now I'm VERY anxious to put it on...

I weigh 220...but working on it. I have NEVER pedalled my bike on a flat road faster than maybe 20-23mph....can't imagine a 275lb, beer drinkning, non-exercising guy pump out 45mph on a bike! You must be a super-hero, Simonator!

Seriously, man, if you're intentions are to go that fast, get a real motorcycle or scooter, that is well-lit, has suspension, and most importantly all parts are made to withstand that kind of stress...oh, and did I mention BRAKES that will stop your 275 moving at 40mph? I'm not trying to be mean or rude, but you are going to get yourself killed on this path you're taking.

I actually took a long ride yesterday, and did some tests braking at 23.5 mph....and I was not able to lock up the rear brakes, and my stopping power went down quite a bit from 15mph - that's for sure. At higher speeds, you need more time for everything because the equipment is not made to handle these speeds....these bikes were made to "cruise" from about 5-15mph and that's really it.

Be safe and have fun!
Mark

 

[Simonator]

I thought about all that stuff, and decided against the 36T a long time ago. Even when I am going 30-35 mph down a hill it gets scary. What if the chain came off and got caught in the wheel? What if the engine siezes? The last thing I want is the tire locking up at 35 mph! I'll stick with my 44T and cruise at 20 mph everywhere I go. At least I feel safe at that speed.

 

[losenup]

I have a 37 sprocket and a 28 inch backwheel (with fat tires) and mine can do prox 40-45mph.
Its totally hasardous going that speed, but its quite fun

Usually I only cruise 20mph with very low throttle and rev, its beautiful. Thats why i changed. Im a lightweighter, I weigh less than 10 stone.

 

[fastboy9]

What if the chain came off and got caught in the wheel? What if the engine siezes? The last thing I want is the tire locking up at 35 mph! I'll stick with my 44T and cruise at 20 mph everywhere I go. At least I feel safe at that speed.

Exactly what I was thnking, lately my chain keeps falling off my engine sprocket, and locking the back wheel up, I had this happen to me at about 27 mph. The whole back end was skidding all over the road and I think it was more luck that I didnt come straight off, scared the **** out of me. I think I'll just stay with a 44 tooth. I only weigh 10 stone + tuned pipe + ported engine + 36 tooth + unreliable drivetrain = Not even worth thinking about.

 

[Norm]

I've ordered a Grubee 4-stroke kit. I weigh 198 pounds. I forgot to ask what size sprocket comes with the kit but the one in the picture on bicycle-engines.com shows about 56 teeth (it's hard to count them on such a small image). My question is what speed can I expect - the web site says top speed of 35mph but I want to know if she does that comfortably without revving its guts out. I have a 48 tooth sprocket and I have a 44 tooth I could use from the HT kits that litter my garden. Would the 48 tooth be the best?
I'm presuming the Honda GXH50 and the Hua Sheng F142 49cc have a very similar performance - is this right? I'm getting both motors.

I have been riding the same kit for a little over a month. I'm loving it! I'm about the same size as you. I think if you build the bike right you could approach 35mph. The sprocket is 56t. It's my understanding that the Grubee gearbox is designed for high-end speed and thus I think it matches pretty well with the 56T to give you well rounded performance.
Here's what I get out of it: when the clutch is dry it prefers to go into gear at about 7mph. Pick-up is great on a flat. It doesn't take long to break 30mph. I get a high frequency vibration at about 27mph. The vibe makes me a little uncomfortable but I feel like the engine tolerates it okay. On a slight down-grade I do reach 35mph when wide-open. On a steep downhill run it will rev pretty fast so I give it a lot of throttle at the top of the hill then I idle the motor at 25 or 30mph coasting to the bottom. Hill climbing is not as good as I expect from a 56T. I usually help a little (very little) if I have to climb a steep hill from a stop at the bottom. Again I attribute the lack of low end torque to the high gearing of the Grubee box.

I have debated getting a smaller sprocket so I could get to higher speed without that vibration but have decided the 56T suits the terrain I ride (lots of stop and go) just about perfect. If I were doing rural roads and long stop free runs I would want a smaller sprocket.

Hope this helps,

norm

 

[Norm]

I have gone at least 40 mph peddling, I am not afraid to do the same with a motor

I'd like to echo blackmikey "you DO NOT want to go over 40mph on one of these bikes" How afraid you are is irrelevant. It's what your mom has to look at when she identifies your faceless body that matters.

A motoredbike is a very different animal than a regular bike. There are handling issues caused by the extra weight and center of gravity difference. A motored bike is not a bike (nor is it a motorcycle) and should never be confused with either. The stopping distance for instance is much longer on a motored bike (a lot longer than a car in fact).

Please forgive me for being preachy. I mean no offense. As I work in nursing I get to take care of a lot of young people who also were "not afraid".

just my 2cents,

norm

 

[starkm32]

Well stated, Norm.

One has to adjust to one's machine accordingly.

A bicycle is not exactly a Hummer wannabe, powered. Or not.

One is still potential roadkill, or an accident waiting for a bike(cycle), on steroids.

Just my tuppence (two pee, or not to pee).