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Ninjasmoker

Low gearing/sprocket sizes: more torque for the inner city commute

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stickshift
7 hours ago, Pursuvant said:

Chemobrain is a real thing, I attributed the extra tooth with speedo change, but you helped me see it takes a change in wheel with tire diameter to affect speedo that reads off wheel(s) rotation.

My non-ABS bike gets it's speed from the gearbox, so sprocket size changes do affect speedo accuracy.

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shinyribs
12 hours ago, stickshift said:

My non-ABS bike gets it's speed from the gearbox, so sprocket size changes do affect speedo accuracy.

Same here. 

 

Are the ABS equipped bikes getting speed signals from the wheel sensors for the speedo? I assumed they left all that alone and just tacked on the ABS system independentaly. 

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DewMan

I'm still looking for confirmation but I'm pretty sure the ABS sensors aren't doing double duty as speed sensors. The sensors are sensing the rpm of each wheel so they can be compared to each other to tell when a wheel has lost traction. 

I believe the ABS model uses the same sensor as the ones who do not have ABS.

The easy way to tell is find one of us that has made final gearing change that didn't require speed healer.

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DewMan
 
Just shut up and ride.

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klx678

If it's around town figure out if you need to actually gear down or gear up.  It is all about the rpm you will be running.   If you need to gain 500 rpm at 45 mph and a downshift won't cut it, go up two or three teeth on the back.  It might also be accomplished by gearing taller and running one gear lower.   As said, the 700 has great power range.  I am also one who is considering gearing taller to maybe pick up a few mpg.

I actually made an rpm/speed/gear spreadsheet to compare what happens with changes based on exact gearing and tire diameter.   I was doing it with two calculators on one sheet so I could compare gearing when I was looking at SM wheels for my KLX650, did I need to change the rear sprocket size or not, to stay close to the same gearing, etc.  I wanted to have a roll in set of wheels without any chain adjustment preferable.

I can email a copy of the Excel sheet if interested.  You would need to learn the tooth count of the primary drive and all six gears to do the job.   I got the ones for the KLXs in the parts lists for the gear boxes, they were listed.

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Pursuvant
4 hours ago, shinyribs said:

Same here. 

 

Are the ABS equipped bikes getting speed signals from the wheel sensors for the speedo?

I can't say where I read it, but somebody had identified the 3 fuses that control abs. And he noted he could pull two of them to disable the abs, but he left the third fuse in because without it he lost his speedo display. 

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ElGonzales
Posted (edited)

There is no speed sensor at the gearbox of ABS bikes. You can't find it in reality, not in the wiring diagram and service manual tells you to check the rear wheel sensor in case of problems with the speedo.

The ABS system needs three fuses:
-ABS solenoid fuse
-ABS motor fuse
-ABS control unit fuse

Edit: I strongly believe that your speedo is gone if you remove the ABS control unit fuse. The wheel sensors are connected directly to it.

Edited by ElGonzales
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bartman5impson

Speaking of sprockets, how do we know which side of the front sprocket faces out? I got a JT rubber dampened sprocket and just put the side with words facing outwards. There were no instructions included and I haven't found any online. I've heard of people who installed it reversed and it ended up wearing horribly due to being misaligned.

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DewMan
34 minutes ago, bartman5impson said:

Speaking of sprockets, how do we know which side of the front sprocket faces out? I got a JT rubber dampened sprocket and just put the side with words facing outwards. There were no instructions included and I haven't found any online. I've heard of people who installed it reversed and it ended up wearing horribly due to being misaligned.

Yes, I've asked this question here before when I did a 520 conversion.  The writing facing out is the correct orientation. 

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DewMan
 
Just shut up and ride.

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ElGonzales
Posted (edited)

This is the JT sprocket, the orientation is correct I guess? I was also worried when I installed it and threw a coin :D ...IMG_20200502_161310.thumb.jpg.ff57e702c0913fe9d684a6e8e7091734.jpg

Edited by ElGonzales

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Sirbacon

Okay so I just created this account and idk how to do things yet but my dumb a just bought like a 15/50 with minimal research and now I'm like what have I done so I'm going to stick with the 15 but what should I change it to in the back for medium torque and speed 

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longrider1951

You just bought a wheelie monster.  I hope you know how to quick shift, you're going to need that skill. Your top speed will be under 90 and your MPG are in the toilet.  What were you trying to accomplish?

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mossrider

Get a 42, 43 or 44 for the back and you'll be ok and your chain should't have to be replaced or cut.  A 15/43 and a 16/46 are the same basic ratio. Either will give you a bump in your jump. 

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