14T Swap

[Fruity]

hi there,

was wondering if anyone can give their differing opinions for those who have done this swap.

i recently did the swap on my monster s4r (04) and found it a little faster on the acceleration on 1st and 2nd gear and marginally on 3rd. but what a difference riding it on the tight twisties. acceleration out of corners was much much better and turning in and in mid corner too gives a lot better feel. inspires a lot of confidence on the ride. then i took it out on the highway. boy, do i notice a big difference. the bike rides with a lot of vibration now (feels bad for the engine to me). so i quickly pulled in to a local mechanic, not a ducati one, and he said it's not good for the engine. that's why i'm posting on this forum to get more info.

for your info, the bike still runs on the old chain and rear sprocket. maybe that ''s why?

TIA for any advice.

[stopintime]

You're reading too much into the swap. It's mathematics, not magic.

Bikes will run at 6.67% higher revs at all times - that's it. In some situations it will result in a more suitable gearing - in other situations not.

I think you should check/have checked that the front sprocket is put on correctly and that the chain/rear sprocket are in good condition. This mod shouldn't result in more vibration - other than the slight increase due to the higher revs (which aren't much)

[Fruity]

thanks for the feedback SIT. ok, i may be overreacting a bit and the ride certainly wasn't magical but this is a road that i've ridden a thousand times over and i genuinely feel that the bike rides a lot better  [moto]. i did say on the straight in low gears it pulls only marginally better. in heavy traffic so far i haven't noticed any difference between 14t and 15t, it never bothered me to begin with  .

but my main concern is the vibration on highways. the chain did show some uneven tightness whilst on the stand but not too terrible a lash (after tightening it with the new 14t sprocket). my worry is the new sprocket with the old chain and old rear sprocket, although the rear sprocket still looks very goood. like you said there shouldn't be any vibration.

[Howie]

Is the vibration road speed related or engine speed related?  Different with the clutch engaged or disengaged?  If the vibration is engine speed related or disappears when the clutch is disengaged the problem is probably not the chain.  If you change a sprocket, theory is you should change all three parts together since they have run in together.  Would you always do this in real life?  No, too cost prohibitive.  But, if there is significant mileage or noticeable wear, absolutely.   Try loosening the chain a little first.  A little loose is OK, a little too tight is bad. 

[TJR178]

I have the same set-up on my '04 S4R - factory rear sprocket and chain w/ a 14T front.  I've never had an issue, so you'll want to do what Stopintime says and make sure it was installed correctly, i.e. flush against the shaft.  I keep my chain tightened with 1" of slack which is the factory setting.

If you want to get rid of highway vibration, do yourself and your bike a favor and skip the highway    Monster's don't like highways.

[seevtsaab]

Is you motor trying to tell you to sync your TB's?
You might be running a slightly different RPM now?

Along with superior ridability, the rpm's and speedo seem easier to decipher what gear I'm in
when I want that info (05 620).

[Fruity]

TJR - thanks i'll double check if the sprocket is installed correctly tomorrow. i hear you, i usually try not to ride on the highways but no choice sometimes. will double check chain tension too and loosen at any tight spots.

howie - the vibration is not all that bad it's where the whole bike shakes. it's like a very light chatter and it's present throughout the gears till 3rd with the clutch disengaged. didn't have a chance to go all the way to the 6th gear ie top speed. don't know for sure, just a funny feeling for me. sorry howie but how can one tell if the chain is bad. it's old, since the bike came out of the workshop (04) and when i did the tension check there are some tight and loose spots, between them, the tightest spot and the loosest spot i would say there a difference of about an inch. the rear sprocket still looks good and it's still stock from factory.

thanks for all the input guys. appreciate it. cheers.

[Howie]

To determine if your chain should be replaced, look for the following:
  Rotated pins
  Missing O rings
  Tight links that don't free up
  Fine brown rust around pins
  Excessive "stretch"*
If any of these conditions exist you need a new chain.  If you find you need to adjust your chain frequently, you need a new one.

There are two ways to determine "stretch", the hard way and the easy way.  The hard way is to measure a 16 link section of the chain under tension from pin to pin.  If it is 256 mm. or longer, you need a new chain.  The easy way is to pull the chain away from the back of the rear sprocket.  If you can expose more than a half tooth you need a new chain.

The OEM chains rarely last more than 14,000 miles.

My best over the internet is either your chain is adjusted too tight or your chain is too worn to be happy with the new front sprocket.



*Chains don't really stretch.  As the pins wear the chain gets longer.

[Fruity]

thanks howie, you da man. 

[Speeddog]

I've seen two OEM chains go over maybe 12k, one went 14k and the other 20k.

The guy with the 20k chain was a bit frosted that it needed replacement.
I told him most folks get 10k or less.... 

Are you saying that the slack difference in the chain is 1" between tightest and loosest?

[Fruity]

yes, speed. the tightest and the loosest spot (this is rolling the wheel around looking for it) on the chain is bout an inch or a bit more. the mileage on the bike now is about 19,000km. but i'll use howie's method and check if the chain is bust anyways. thanks mate.

[Speeddog]

If you've got 19,000 km on the OEM chain, I'd say it's likely used up.

[Fruity]

any new chain suggestions? DID x-ring 525? how many links? can't seem to find the info. thanks.

ok, did the chain wear test. measurement of 16 links is less than 256mm at various points and as for the easy test couldn't pull the chain to expose the rear sprocket at all, however i did a rough measurement the tightest spot in the chain slack is about 15mm and the loosest part is about 40mm. how come? some tight links? change of chain in order???

[Howie]

Yes, rear sprocket too.  I didn't understand the difference in tension varied by that much. 

You can shop here:
http://www.ca-cycleworks.com
Chris ships internationally and can answer all your questions, plus he is a sponsor.

[Fruity]

ok, time for shopping, couldn't have come at a worse time. 

Merry Christmas you guys.