Thinking of changing gearing. Read some posts... questions...

[Danny500]

So, my chain has had it and under inspection, the front sprocket has a sort of "shark-fin" appearance to all of the teeth, so it's time to get a new one. Rear sprocket still looks good.

Now, my bike is a 2000 GS500E... yet, my front sprocket is stamped "17" and, sure enough.. is a 17 tooth. So, I'm guessing this is a PO add-on.

I like my bike where it is... but I do want more... not crazy... but MORE low-end.

I've read about dropping in a 15' but coming down from a 17 would that be a huge jump? My other thought would be to simply keep the 17 as 'stock' replacement and bump the rear up to a 45.

From experience, I've noticed that running a slack chain (as I do run about 3/4 inch to 1 full inch of slack due to the Katana shock) as the chain stretches and bounces under acceleration that the chain gets thrown outwards from the valley of the sprocket and the chain runs out towards the tips.... thus causing the bend that I've got.

Also.. horsing around... I tried to do a VERY hard acceleration (almost just a pop-up wheelie) and simply drop the clutch, full stop from 6500 rpm... and the front sprocket just spun and bounced inside of the chain... Now, this could also be because the chain is TERRIBLY worn. But that's neither here-nor-there.

Everything aside... I think I'd rather keep the largest sprocket possible up front and just bump-up the rear to compensate. Also, from a lot of guys on other forums the only way to go is to go big in the rear... going smaller in the front causes pre-mature wear and link-skipping as I previously encountered.

But I just wanted to see what everyone else has tried or if they've tried this at all.

My choices would be the following:
45/17: 2.64
43/17: 2.52
43/16: 2.68

These are the closest in relation to 39/15: 2.6... which most everyone seems to like.

Considering stock is 39/17: 2.29 (my bike) any of these would merit a vast improvement.

Something considered, but might be a tad insane would be:
45/16: 2.81
43/15: 2.86

But I think a solid 45/17 is safer than a 39/15 as far as chain wear, slack reaction due to suspension travel, and protection against link-hop.

Thoughts? 

[mach1]

17 front is not stock. for the best gearing people use 15/39 that will give you a good low rpm ooommpphh. a bigger rear will make the work a little more harder changing the front is faster than the rear and much cheaper. you can use the stock 110 link chain also. but when its all said and done its your bike and money and with the shotty econ do what will save you moolahh.

[Big Shot]

So far i've run a 39t rear with a 12, 15, 16, and 17t front...

I prefer the 17t like you were already running on your bike

And if you want to changing gearing, do it up front and not the back 


Life after people? - Bob!

[sledge]

Decreasing sprocket size leads to an increase in chain speed variation as a %. Its a condition know as Chordal action or Chordal effect. This in turn increases vibration and accelerates chain/sprocket wear. Not a problem short term or if you are racing but for long term use.......well work it out yourself.

Look at the graph and see how it starts to shoot up at about 15 teeth, its why you very rarely see stock bikes with less than about 14 teeth on the front. 2% speed variation is regarded as the maximum for any well designed chain drive. Go with 12 teeth on the front and you are up to about 4% and the life of the chain and sprocket will be dramaticaly shortened against the 2% variation a 15 tooth setup will give you.

Increasing the size of the rear sprocket is aways the better option.......but its your bike, your money and your choice 

[lopee]

I run a 15 front and a 42 rear, non-o-ring chain( thats what i wanted), got it all for 70-75 with shipping. I love it, same chain size, plenty of power

[Danny500]

I just picked up a 45 rear and a 17 front with a 114 link chain. I'll let you know how it works out when I do the install...

Sledge, thanks for making perfect sense out of my thoughts...

Also... Kneedraggers.com has Vortex rear sprockets for 46 bucks... any tooth, free shipping... Boo-yea.

Dan

[average]

I've always been curious about this: what would be the optimal gearing for someone that scoots around town but also loves to get on the highway?