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dta
08-23-2011, 01:03 PM
I'm going to school for my Motorcycle repair technician. I have a question on a take home assignment and I'm stuck. Also I didn't know where to post this. Maybe one of you can help.

Question.
A technician wants to increase the torque produced at the rear wheel in all gear ranges. Which of the following changes will produce this result.

a. Replace the primary drive with a larger diameter gear
b. Replace the clutch outer with one having a smaller diameter
c. Replace the counter shaft sprocket with on having a larger diameter
d. Replace the rear wheel sprocket with one of a larger diameter

Shouldn't A and D be correct. My book says that decreasing the rpms of the primary drive gear will increase torque. Also the same should apply on the rear sprocket. Am I missing something?

rexazz2
08-23-2011, 01:35 PM
http://www.grimmjeeper.com/gears.html


go look at a bicycle

bigger front smaller back for speed
smaller front bigger rear for torque

dta
08-23-2011, 01:45 PM
I know that much but making the primary drive gear will also increase the torque unless I'm mistaken.

dta
08-23-2011, 02:52 PM
The gear reduction system used for
transferring the power from the crankshaft to the clutch is called the
primary drive.

This if what I'm referring to as primary drive

arsenic
08-23-2011, 03:04 PM
I figured that. That gear on the crank is not a gear you can just change. You need a different crankshaft. Than you need a different clutch. So, IMO, that's not a very viable option. But changing the sprocket ratio is a viable option. Are you going to MMI? If so, I'd go with the most ridiculous option they give you. :bigthumb :lol:

dta
08-23-2011, 03:26 PM
I figured that. That gear on the crank is not a gear you can just change. You need a different crankshaft. Than you need a different clutch. So, IMO, that's not a very viable option. But changing the sprocket ratio is a viable option. Are you going to MMI? If so, I'd go with the most ridiculous option they give you. :bigthumb :lol:

Haha nope, not MMI. Just a little bit pricy since I'm paying out of pocket. So I'm doing the motorcycle repair tech program a Penn Foster with on the job training that should start soon.

I'll put down D and if I'm counted off I'll just email them my reasons for the credit. Thanks for the help though. :bigthumb

steves
08-23-2011, 03:34 PM
D. You would go DOWN teeth on the front to increase torque.

It's why all the stunters run 4 tooth fronts and 99999 tooth rears.

Blackdog
08-23-2011, 07:38 PM
4 teeth on the front sprocket and the Kat will power wheelie in 6th gear with a top speed of say 25mph, damn sarcastic bunch:bunny2

you would need a velocity stacks and a k&n and a wider rear tire.

oh ya "D" is the answer.:bigthumb

dta
08-23-2011, 09:55 PM
100% on it. Thanks guys. Also arsenic we were right both answers were correct they were just looking for D since it was the choice any tech would have made rather than get inside the case.


BTW Blackdog what going through the thumb??????

HemiKat
08-23-2011, 10:11 PM
These are like my ASE tests. Let me give you some advice. Dont look for the right answer. Delete the wrong answers one by one until you realize the last viable option is left. Even if you dont know the correct answer, but deleting the obvious incorrect answer you will arrive at the right conclusion without even knowing it.

And D is the correct answer. :bigthumb (Edit, just saw you did get answer D correct, lol)

Mojoe
08-23-2011, 10:23 PM
I am going with A. that is off the top of my head.

spatula6554
08-23-2011, 10:27 PM
You would...

dta
08-23-2011, 10:31 PM
These are like my ASE tests. Let me give you some advice. Dont look for the right answer. Delete the wrong answers one by one until you realize the last viable option is left. Even if you dont know the correct answer, but deleting the obvious incorrect answer you will arrive at the right conclusion without even knowing it.

And D is the correct answer. :bigthumb (Edit, just saw you did get answer D correct, lol)


Thanks for the Advice. Have you encountered to possible correct answers before in your tests? For example another one I had last week was

"In a 2 stroke engine the intake valve is located where?

-top of the cylinder
-middle of the cylinder
-bottom of the cylinder
-Crankcase (my choice and was correct)"

But in the chapter that the test was on said "The intake valve is located in the bottom of the piston or the crankcase in some models." I Quadruple checked and that was the only info related to location. So I picked my favorite answer.

Will I run into this a lot based on your experience?

arsenic
08-23-2011, 10:38 PM
There are two correct answers a lot. I'm certified, and Hemi is ASE certificated. I'm sure his tests are a lot like mine where. They phrase them just like that. There are two options, both will achieve the same result. But one no one in the history of forever would ever do. :bigthumb Remember making money as a tech is about speed. There is book time for each job. For example a carb clean is a 4 hour book job. Well, if you do it in 2 hours, you still get paid for a four hour job. So, your still making money on that job while your on another job. So, which do you think is faster? Changing sprockets or splitting the cases and changing the crank?

Mojoe
08-24-2011, 12:10 PM
You would...

meaning? care to elaborate on that comment?

if you care to know why I picked A, it is because the primary gear is not a direct connect to the the front drive sprocket. there is a secondary gear in between, so if you enlarge the primary gear, you would slow down the secondary gear...thus creating more torque. however, if there is a 3rd gear in there somewhere before the output shaft to the front sprocket, then you would have to go in size. I just assumed there were only 2 gears involved. if there are 3, then you would use a smaller primary gear for more torque. even number of gears, you would go up. odd number of gears, you would go down. that's the basic principal with reduction. it works with everything.

but hey...that is just how I am visualizing it in my head. I am not a tranny expert by any means, so I can not say with 100% certainty. If this was a real life situation someone needed help with, I would not even bother answering because I am just not certain.

arsenic
08-24-2011, 12:13 PM
meaning? care to elaborate on that comment?

if you care to know why I picked A, it is because the primary gear is not a direct connect to the the front drive sprocket. there is a secondary gear in between, so if you enlarge the primary gear, you would slow down the secondary gear...thus creating more torque.

but hey...that is just how I am visualizing it in my head. I am not a tranny expert by any means, so I can not say with 100% certainty. If this was a real life situation someone needed help with, I would not even bother answering because I am just not certain.
There are a whole lot of gears between the primary gear and the front sprocket. Like the clutch and entire transmission. :lol:

Mojoe
08-24-2011, 12:26 PM
umm, a clutch is not a gear. it is driven by gears, but not a gear itself.

like I said....I am not a tranny expert. I have never had the need to crack open one of my engines, period....nor anyone elses.

I am still going to stick with A. if I am wrong, no big deal. but if I am right, I will be the only one, it appears.

KatKrak
08-24-2011, 12:27 PM
These Multiple choice tests all normally follow the same formula. There will be correct answers and answers that are, well, MORE correct. What ****es me off about alot of these is that they will try to fool you with grammar and reading comprehension, often not having anything to do with the topic in question.

Anyway, in this case , the most correct answer IMHO is D)

arsenic
08-24-2011, 12:30 PM
the clutch basket is a gear, and then there is the primary gear on the back of it. :bigthumb The part of the clutch that the primary gear contacts is, in fact, a gear.

Mojoe
08-24-2011, 12:35 PM
the clutch basket is a gear, and then there is the primary gear on the back of it. :bigthumb The part of the clutch that the primary gear contacts is, in fact, a gear.

this part I am aware of.

arsenic
08-24-2011, 12:39 PM
And the correct answer is D. That was established last page. :lol:

Mojoe
08-24-2011, 12:59 PM
D is a given. it's been common knowledge on this site since forever.

I didn't see the OP mention the right answer(s) from his test. figured there might be more than one right answer.

one thing for certain, D is not the only way to do it.

arsenic
08-24-2011, 01:03 PM
I'm aware of that. :bigthumb

Mojoe
08-24-2011, 01:07 PM
although D is the only practical answer. can't see any real world application where one would feel the need to rip into his tranny when he could easily achieve the same thing with D....or going down with the front sprocket.

superbike
08-24-2011, 01:43 PM
Hemi, thats good advise...

spatula6554
08-25-2011, 09:05 AM
I just thought it would be Mojoe's style to take the more complicated path towards the solution.

Glad we could all get another 5 posts from this.

Mojoe
08-25-2011, 01:47 PM
I just thought it would be Mojoe's style to take the more complicated path towards the solution.

Glad we could all get another 5 posts from this.

only time my solutions get complicated is when I am dealing with close minded people who tend to believe that their way is the only way. :bigthumb

also, I goofed in my other response. the number of gear does not mean anything except the direction of rotation in regards to the primary drive gear. I used to be quite efficient in this stuff when I was working as a machinist, but alas, that was quite some time ago.