Working on my trike. Doing test fitting, nothing bolted down or welded. What do you think. Will it work? Thanks Joe
Here's where I'm at. need input good or bad
- Thread starter yellowbeard
- Start date
I have a smaller back sprocket a 31 tooth, would it work? The one on there is from a go cart. Joe
See this thread:
http://motorbicycling.com/showthread.php?t=4820
http://jimsitton.net/ratiocalc/
The bottom of the three downloads ratiocalc uses engine rpm, clutch teeth number, and (IF you use a jackshaft those input output gears teeth numbers) tires diameter size, you get speed.
Note that other factors are not included that will affect the speed, but to find a calculator that is more involved with horsepower, torque, friction...ect this is something yet to come across and understand fully.
Is that 26 inch rear drive wheel and no jack shaft?
Since I guess the 31 teeth you mention to be smaller than whatever is the go-kart sprocket that is on there now, I just make some quick estimates.
You can also instead of teeth count use diameter for either pulley or gear measuring diameter furthest point to point.
I say 2inch dia for clutch and 10 inch dia for sprocket (not the 31 teeth one not shown). That is gearing down by ratio 10 / 2 = 5 or 5:1 ratio.
The calculator does this and the next part I know the steps but to do this the calculator does it just the same quicker.
Note I see the centrifugal clutch and I am guessing clutch engine idle speed with the Briggs 5hp can idle OK at 1750 rpm and it won’t be engaging the clutch until starting at 2000 rpm and fully engaged the clutch at 2200 rpm.
What this means with the 26 inch wheel at 2200 rpm when clutch is fully engaged and should not be slipping, the speed is 35mph. At a maximum rpm of engine maybe 3500 rpm 54.1mph.
Note these speeds which would be less for the other factors not taken into account, but still useful.
My thinking here is that there is way too little gearing down. Speed of 15 mph starting at clutch fully engaged at 2200 rpm on my 3hp Briggs motor bike was bogging it down to get started I will be using a ratio of 20:1 for dirt biking and a 40:1 for parade speeds most people not going to be using, but I made my system able to switch between the two ratios.
Just so you get an idea of how the use of the go-cart went was 10 inch sprocket and a wheel on the go-kart being practically the same size as the sprocket say 12 inches wheel. The numbers come out as 2200 rpm equate to 15.7 mph and 3500 rpm equates to 25 mph. Going with the same sort of speed range with a similar vehicle weight and engine horse power see below what I think can be done.
What would equate to the 2200 rpm speed equating to near 15.7 mph on a 26 inch wheel the ratio of 5:1 would have to change and be greater like a 10:1 ratio.
10:1 ratio gets 2200 rpm going 17 mph and max at 3500 rpm 27.1 mph. This is I think realistic with a 5hp Briggs.
A jack shaft with like a 2 inch and a 4 inch makes a ratio of 2:1. You then multiply both ratios 5 times 2 equaling 10:1 ratio. You have it.
Just what I think, but see the calculator and try some actual numbers to see what you can find.
MT
http://motorbicycling.com/showthread.php?t=4820
http://jimsitton.net/ratiocalc/
The bottom of the three downloads ratiocalc uses engine rpm, clutch teeth number, and (IF you use a jackshaft those input output gears teeth numbers) tires diameter size, you get speed.
Note that other factors are not included that will affect the speed, but to find a calculator that is more involved with horsepower, torque, friction...ect this is something yet to come across and understand fully.
Is that 26 inch rear drive wheel and no jack shaft?
Since I guess the 31 teeth you mention to be smaller than whatever is the go-kart sprocket that is on there now, I just make some quick estimates.
You can also instead of teeth count use diameter for either pulley or gear measuring diameter furthest point to point.
I say 2inch dia for clutch and 10 inch dia for sprocket (not the 31 teeth one not shown). That is gearing down by ratio 10 / 2 = 5 or 5:1 ratio.
The calculator does this and the next part I know the steps but to do this the calculator does it just the same quicker.
Note I see the centrifugal clutch and I am guessing clutch engine idle speed with the Briggs 5hp can idle OK at 1750 rpm and it won’t be engaging the clutch until starting at 2000 rpm and fully engaged the clutch at 2200 rpm.
What this means with the 26 inch wheel at 2200 rpm when clutch is fully engaged and should not be slipping, the speed is 35mph. At a maximum rpm of engine maybe 3500 rpm 54.1mph.
Note these speeds which would be less for the other factors not taken into account, but still useful.
My thinking here is that there is way too little gearing down. Speed of 15 mph starting at clutch fully engaged at 2200 rpm on my 3hp Briggs motor bike was bogging it down to get started I will be using a ratio of 20:1 for dirt biking and a 40:1 for parade speeds most people not going to be using, but I made my system able to switch between the two ratios.
Just so you get an idea of how the use of the go-cart went was 10 inch sprocket and a wheel on the go-kart being practically the same size as the sprocket say 12 inches wheel. The numbers come out as 2200 rpm equate to 15.7 mph and 3500 rpm equates to 25 mph. Going with the same sort of speed range with a similar vehicle weight and engine horse power see below what I think can be done.
What would equate to the 2200 rpm speed equating to near 15.7 mph on a 26 inch wheel the ratio of 5:1 would have to change and be greater like a 10:1 ratio.
10:1 ratio gets 2200 rpm going 17 mph and max at 3500 rpm 27.1 mph. This is I think realistic with a 5hp Briggs.
A jack shaft with like a 2 inch and a 4 inch makes a ratio of 2:1. You then multiply both ratios 5 times 2 equaling 10:1 ratio. You have it.
Just what I think, but see the calculator and try some actual numbers to see what you can find.
MT
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I am learning still with my welder. I have to see next time of short quick short weld and let metal cool for sheet metal an see if no punch through. Seems simple enough, but with a torch welder would be easier and quicker.
Say what is the horse power of the engine that you have intended on using with those gears?
With more horsepower a higher ratio can be used without bogging down. I saw a book with the HeathKit Boonie-Bike GT18 which used a 5hp two speed and 18 inch wheels. I have to see if I can find more about the ratio it used. The fascinating thing I saw was that it had a stick shift. It was an automatic I suspect for two gear ratios. I saw where two chains from a shaft that turns from the centrifugal clutch has another clutch for switching between a primary 1:1 ratio or a 2:1 ratio. Then it goes to what looks like a 2 inch to 12 inch sprocket on an 18 inch tire. This bike has 12:1 low gear and 6:1 high gear maybe with 5hp Briggs on 18 inch wheel.
That’s 2200 rpm 9.8 mph and 3500 rpm 15.6 mph on the low gear 12:1 ratio.
That’s 2200 rpm 19.6 mph and 3500 rpm 31.2 mph on high gear 6:1 ratio.
A pretty sweet deal!
That beast has not quite twice the horse power of my engine and so with that I suspect I would be using a ratio of 24:1 twice that of the low gear on that bike. My engine is near ½ the horse power of this HeathKit Bonnie-Bike. I would be at 2200 rpm 7.1 mph and 3500 rpm 11.3 mph which should do hills OK.
In the link look below the sled for the Boonie-Bike and see where it also comes not only with a stick shift, but front ski to use as well. Ah da 70”s!
http://books.google.com/books?id=Pa...&hl=en&sa=X&ei=57_GUP3BJ4P02QWW2YHQCw&ved=0CF
MT
Say what is the horse power of the engine that you have intended on using with those gears?
With more horsepower a higher ratio can be used without bogging down. I saw a book with the HeathKit Boonie-Bike GT18 which used a 5hp two speed and 18 inch wheels. I have to see if I can find more about the ratio it used. The fascinating thing I saw was that it had a stick shift. It was an automatic I suspect for two gear ratios. I saw where two chains from a shaft that turns from the centrifugal clutch has another clutch for switching between a primary 1:1 ratio or a 2:1 ratio. Then it goes to what looks like a 2 inch to 12 inch sprocket on an 18 inch tire. This bike has 12:1 low gear and 6:1 high gear maybe with 5hp Briggs on 18 inch wheel.
That’s 2200 rpm 9.8 mph and 3500 rpm 15.6 mph on the low gear 12:1 ratio.
That’s 2200 rpm 19.6 mph and 3500 rpm 31.2 mph on high gear 6:1 ratio.
A pretty sweet deal!
That beast has not quite twice the horse power of my engine and so with that I suspect I would be using a ratio of 24:1 twice that of the low gear on that bike. My engine is near ½ the horse power of this HeathKit Bonnie-Bike. I would be at 2200 rpm 7.1 mph and 3500 rpm 11.3 mph which should do hills OK.
In the link look below the sled for the Boonie-Bike and see where it also comes not only with a stick shift, but front ski to use as well. Ah da 70”s!
http://books.google.com/books?id=Pa...&hl=en&sa=X&ei=57_GUP3BJ4P02QWW2YHQCw&ved=0CF
MT
Joe,
Would it help if you were to weld a small sprocket with the teeth ground off it to the spocket mount so you could bolt different sprockets to it. Looks like there would be enough of the mount left if you weld it from the back so the sprocket would center it's self.
Your going to like the welder. Silverbear has the Handler 125 and I have a Miller 140 which is the parent company for Hobart.
Steve.
Would it help if you were to weld a small sprocket with the teeth ground off it to the spocket mount so you could bolt different sprockets to it. Looks like there would be enough of the mount left if you weld it from the back so the sprocket would center it's self.
Your going to like the welder. Silverbear has the Handler 125 and I have a Miller 140 which is the parent company for Hobart.
Steve.
good idea, Going to look into that, i have a smaller sprocket I could weld to it and bolt my bigger sprocket to the smaller one. Thanks
I looked at the pictures of the sprocket already on the bike. It seems it is almost as big as can fit in the space without the sprocket and chain hitting the frame.
Still the idea that Fasteddy mentions to use a sprocket that otherwise you could not attach easily any other way is useful, but the sprocket has to fit in the space provided.
I was thinking you might take the approach to use the gears you have as long as welding it up would not make extra work of undoing welds to change this if it does not work right. I know that is quite a task to remove welds!
Then if you can see if that would be OK, then trying it out as is may be workable with the gear ratio as is. I know that the speeds seem a bit unreasonably high for both clutch engagement and also top speed. Those are numbers are without all the factors included. We yet have an easil a way to figure the speed and engine loading exactly so the calculator is as good as it is.
Maybe I misunderstood and you would be using this method of utilizing a large sprocket on a jackshaft and would be figuring where it would go.
I don’t want to sound like I am designing your project and saying exactly what works and what does not, so I hope I’m helping anyway.
MT
Still the idea that Fasteddy mentions to use a sprocket that otherwise you could not attach easily any other way is useful, but the sprocket has to fit in the space provided.
I was thinking you might take the approach to use the gears you have as long as welding it up would not make extra work of undoing welds to change this if it does not work right. I know that is quite a task to remove welds!
Then if you can see if that would be OK, then trying it out as is may be workable with the gear ratio as is. I know that the speeds seem a bit unreasonably high for both clutch engagement and also top speed. Those are numbers are without all the factors included. We yet have an easil a way to figure the speed and engine loading exactly so the calculator is as good as it is.
Maybe I misunderstood and you would be using this method of utilizing a large sprocket on a jackshaft and would be figuring where it would go.
I don’t want to sound like I am designing your project and saying exactly what works and what does not, so I hope I’m helping anyway.
MT
