Ducati Monster Forum

Moto Board => Tech => Topic started by: rideserotta on January 03, 2011, 06:18:18 AM

Title: -1 up front or +2 in the back?
Post by: rideserotta on January 03, 2011, 06:18:18 AM
I know this has been discussed quite a bit but I'm still not sure which route I want to take on this. First, most of my riding is commuting. I do most of my weekday miles at 45mph and under. I have a fair amount of traffic lights on the 7 mile route. The terrain is rolling hills, nothing steep.

On the weekends I like to go to the foothills (Smokey Mountains) or the Blue Ridge Parkway. There's spirited riding but not a lot of high speed. Getting there on the interstate takes me up to 75mph but that's about it.

I have a couple questions...
1) would I be better off going with a 14 up front or up in the back?
2) if up in the back, do you recommend 1 or 2 teeth?
3) is it easier to change the front or the back?
4) will moving to a 14 require a chain adjustment? how about +1 or 2 on the back?
5) how hard is a chain adjustment?
Title: Re: -1 up front or +2 in the back?
Post by: ducpainter on January 03, 2011, 06:33:55 AM
Quote from: rideserotta on January 03, 2011, 06:18:18 AM
I know this has been discussed quite a bit but I'm still not sure which route I want to take on this. First, most of my riding is commuting. I do most of my weekday miles at 45mph and under. I have a fair amount of traffic lights on the 7 mile route. The terrain is rolling hills, nothing steep.

On the weekends I like to go to the foothills (Smokey Mountains) or the Blue Ridge Parkway. There's spirited riding but not a lot of high speed. Getting there on the interstate takes me up to 75mph but that's about it.

I have a couple questions...
1) would I be better off going with a 14 up front or up in the back?... I think going up in the back is better. Less wear on the chain rubbing block
2) if up in the back, do you recommend 1 or 2 teeth?... At least 2
3) is it easier to change the front or the back?... The front
4) will moving to a 14 require a chain adjustment? how about +1 or 2 on the back?... It will require an adjustment either way
5) how hard is a chain adjustment?... Not difficult. You can do it in about 15 minutes

Keep in mind if you have over 10K on the chain and sprockets it would be a good idea to change all the parts for best longevity.
Title: Re: -1 up front or +2 in the back?
Post by: Howie on January 03, 2011, 06:57:52 AM
Quote from: rideserotta on January 03, 2011, 06:18:18 AM
<snip>


I have a couple questions...
1) would I be better off going with a 14 up front or up in the back?
Personel preference, the 14 front will gear you down a little lower.  In theory it could reduce chain life, in practice I don't think you will see a difference.
2) if up in the back, do you recommend 1 or 2 teeth?
Figure about 250 RPM a tooth.
3) is it easier to change the front or the back?
Changing the back requires removing the rear wheel, changing the front does not
4) will moving to a 14 require a chain adjustment? how about +1 or 2 on the back?
Both will require a chain adjustment.
5) how hard is a chain adjustment?
You need to know how to do this as an owner. 
Here is a good link:
http://www.ducatitech.com/info/wheelchange.html (http://www.ducatitech.com/info/wheelchange.html)
Good folks to buy chain and sprocket stuff from:
http://www.ca-cycleworks.com (http://www.ca-cycleworks.com)  both a board sponsor and the person responsible for the fine Ducati Tech stuff.



Quote from: humorless dp on January 03, 2011, 06:33:55 AM
Keep in mind if you have over 10K on the chain and sprockets it would be a good idea to change all the parts for best longevity.

Yep [thumbsup]
Title: Re: -1 up front or +2 in the back?
Post by: rideserotta on January 03, 2011, 07:08:06 AM
Awesome... thanks. The bike only has 4300 miles on it so the chain should be good. It sounds like the front will be a little easier and get me to where I want to be.  [thumbsup]
Title: Re: -1 up front or +2 in the back?
Post by: Jarvicious on January 03, 2011, 08:55:14 AM
Front is a cinch.  The part that took the longest was cleaning out all the goop from years of chain lube deposits :)  On that note, PJ's black label really protects the chain well but god is it messy.  I think I'll be changing brands.

(http://i6.photobucket.com/albums/y239/Jervisaurus/Bikes/DSC01533.jpg)

And yes, you will have to adjust your chain if you put a new front on.  My chain was borderline too loose when I put on the new one and now it's unrideable until I get it tightened.  Is that a 695 I see in your avatar?  Someone else will have to chime in on chain adjustment :)
Title: Re: -1 up front or +2 in the back?
Post by: rideserotta on January 03, 2011, 09:47:26 AM
It's a 620. I cleaned all the goop out a few days ago. I'm fairly handy with bicycles. I've taken apart/put back together bikes, adjusted chain tension, replaced chainrings/hubs/cassettes. But for some reason I'm intimidated by things with engines. Doesn't look like too tough of a job.
Title: Re: -1 up front or +2 in the back?
Post by: stopintime on January 03, 2011, 01:07:27 PM
15 to 14 equals 3 up rear. Both very close to 7%.
Your revs will be 7% higher at any time.
At 3,000 that's 210 rpm. At 6,000 it's 420 rpm.
Not a lot on paper, but very noticeable.
Title: Re: -1 up front or +2 in the back?
Post by: scduc on January 03, 2011, 06:08:17 PM
What "stopintime" said. If I had to do it over, I would go up 3 on the rear. A little (well alot) more $ upfront, but less stress on the chain. If the funds are tight, then going to 14 up front is not a bad option, there will be more wear and in the big picture not something to worry about.
Title: Re: -1 up front or +2 in the back?
Post by: Slide Panda on January 05, 2011, 10:17:31 AM
If you really want to hash the math, you can use:
http://www.gearingcommander.com/ (http://www.gearingcommander.com/)

It has the factory gearing and you can punch in any combination you want and see all the ratios.
Title: Re: -1 up front or +2 in the back?
Post by: seevtsaab on January 06, 2011, 11:13:25 AM
for your miles, I'd do a -1 on the front. Adding on the rear will necessitate a new chain *I think*.

I replaced my P.O. neglected chain at ~12K and dropped a tooth in the front then, rear sprocket looked
fine despite the chain neglect. I'm at 26K miles now.

I also added a case saver (Desmotimes iirc).

Next change I'll replace both sprockets, 15 front, +2 or 3 rear with longer chain.

I'm using Dupont Teflon dry lube, treats me well considering I live on a dirt road.

Oh - dude you need to find the long way to get to work.