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Discussion Starter · #1 ·
Bike is '02 620, currently stock gearing, and I was debating going 1t larger in front sprocket, did this on my Yamaha and dropped the amount of shifting I had to do around town alot, and eased the buzziness at highway speed. Wondering if anyone has done this on their monster and if so was it worth it? Also will be replacing rear with stock, and chain at same time, no idea how old any of those pieces are and would like to start fresh.
 

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don't do it, **** even mine with stock gearing, (15/42) is too high and im revving the thing like a ferrari at slow street speeds. gearing it down this weekend with a new 14/42 520 chain.

IMO it will be way high with a 16 front.
 

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If the shifting into 1st is OK for you, why not try it? I think a front sprocket thru Chris K is only about $15.
 

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Bike is '02 620, currently stock gearing, and I was debating going 1t larger in front sprocket, did this on my Yamaha and dropped the amount of shifting I had to do around town alot, and eased the buzziness at highway speed. Wondering if anyone has done this on their monster and if so was it worth it? Also will be replacing rear with stock, and chain at same time, no idea how old any of those pieces are and would like to start fresh.
everybody's doing 14/XX on their Ducatis; I have a 15/48 set, so, I think it would be the best for you to go 14/42...I'm waiting on my 14T front sprocket...'05 M620D
 

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I think 15T is the largest front sprocket available
from what I know...it is...tested a 50T rear on mine...didn't like the feeling, either stay OEM 15/48 or fo 14/48...
 

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I mostly use a 15t, but yes, 16t is available. One of the most important factors in controlling squat/antisquat characteristics of a bike is the swingarm geometry which involves the angle of the chain over the top of the 2 sprockets. The determining angle is generally referred to as "Q" and is in most frame geometry books. If you can't find a diagram on line, I'll try & post it for you. This is a REALLY important angle.
 

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I mostly use a 15t, but yes, 16t is available.
Norm, didn't know there were 16T front sprockets available; haven't seen them advertised in the usual places.

What I meant with 'I didn't like the feeling' is, at least for me, hard to describe, the bike "asked" for a quick shift from first to second and from there on, it was like a CVT...didn't like that.

It would be interesting to see the diagram for "Q"
 

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I'm not very good at this but I pulled an image from my photobuck account.

<a href="http://s239.photobucket.com/albums/ff154/motomaxy/?action=view&current=swingarm-poleofthemoments.jpg" target="_blank"><img src="http://i239.photobucket.com/albums/ff154/motomaxy/swingarm-poleofthemoments.jpg" border="0" alt="Photobucket"></a>


If anyone knows how to post the actual image, feel free to help.

"Q" is the bottom line angle to the ground. The steeper it is, the more anti squat the bike will have under acceleration. The shallower it is, the more the bike will squat. The result is the the more antisquat, the earlier and harder you can get on the gas coming out of corners without running wide.
 

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I'm not very good at this but I pulled an image from my photobuck account.

If anyone knows how to post the actual image, feel free to help.

"Q" is the bottom line angle to the ground. The steeper it is, the more anti squat the bike will have under acceleration. The shallower it is, the more the bike will squat. The result is the the more antisquat, the earlier and harder you can get on the gas coming out of corners without running wide.
to attach an image you,
or, click on insert image and right click on image's properties and copy paste .....

so, the line you talk about, is it, the thick one? How do we manage to get a steeper angle then? Cause with my 15/48, I get on the gas midway thru corners and haven't gone wide... and if the bike wanted to go wide, I'd control with throttle...
 

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Thanks. Yeah, the dark one. You can easily see how changing the front or rear sprocket will change the pole of the moments. Swingarm angle is also very important. I try to set up swingarms at about 12+%, but clearance is frequently a limiting factor, especialy with a small front sprocket.
The idea is to be able to stay on the throttle hard, without having to modulate or slide in order to maintain the line you want.
 

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So how do I make the angle steeper???
 

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The easiest way is to measure your swingarm angle and increase it as much as you can with your ride height. Put an inclometer on it (unloaded) and tell me what it is.
 

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Discussion Starter · #16 ·
Busy weekend for this post. I like it. My shifting is fine, have no issues lugging around town in first or 2nd, even at low rpms. I mostly wanted it slightly mellower on the highway, and perhaps a touch slower taking off at lights, got pulled over already :) and or :( no ticket but still. Or I guess I could just be responsible...
 

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Discussion Starter · #18 ·
Yes it is used, to the best of my knowledge, only aftermarket stuff is Sargent seat, smoked turn signal covers, and bikini fairing
 
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