Ducati.ms - The Ultimate Ducati Forum banner
  • Hey Everyone! Enter your bike HERE to be a part of this months Bike of the Month Challenge!

1 - 13 of 13 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter #1
Just out of curiousity on normal running of the st4 who ride in 3rd and above at the 30mph speed limits? My previous bike was an in-line 4 and could potter around in 3-4 at 30mph however with the ST I find myself wanting and needing to use 1-2 gears? 1, I love the roar of the induction when rolling off! And 2 it doesn’t seem to like running at low revs! Also who actually manages to get in to top gear?
 

·
Still needs a life.
Joined
·
12,619 Posts
Factory gearing of the ST4s is way too high, especially if you live in an area will you will be doing a lot of starting and stopping on hills. Most of us have swapped the 38T OEM rear sprocket for a 42T or 43T one. This lets the bike cruise comfortably in its 3,000-4,000 rpm sweet spot in the higher gears at our North American posted speed limits. Your speed limits in the UK are probably similar.

Installing a larger rear sprocket will entail the use of a longer chain. I forget the exact length but I'm sure other members will know.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #3
Bigger rear sprocket , how does that affect acceleration and top end?( don’t ever think I will ever see topend!) lol
 

·
Retired Pipe Polisher C2H6O+
Joined
·
19,081 Posts
Bigger rear sprocket , how does that affect acceleration and top end?( don’t ever think I will ever see topend!) lol
It will make the bike feel quicker and probably will be. It will have virtually no effect on top speed as the bike with the stock gearing won't pull 6'th anyway.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #5
Interesting!! This may be a dense question but where do I find a bigger sprocket? Are the bolt hole in a different configuration to other bikes?
 

·
Retired Pipe Polisher C2H6O+
Joined
·
19,081 Posts
Interesting!! This may be a dense question but where do I find a bigger sprocket? Are the bolt hole in a different configuration to other bikes?
The ST3 came with a 42T sprocket and the correct length chain for it. That's all you need to buy.
 

·
Premium Member
Joined
·
2,072 Posts
where do I find a bigger sprocket?
First thing to do is see if your front/rear sprocket is the OEM 15/38 configuration. Some people take the 15 off the front and replace it with a 14 (I did for a while) until the chain begins to wear and the whole system can be replaced. Various ideas, but the general consensus is that the 15 front and 43 rear is the best solution for the ST4s. I've run with that for the last several years and can recommend it. Some maintain that 42 or 44 rear is better, but these are outlier opinions. The 15 front 43 rear (superlite) with the DID gold 525 chain is the best, 102 links. You might want to read this post: http://www.ducati.ms/forums/80-hall-wisdom/28202-sprocket-gearing-recommendations.html. As already mentioned, your 6th gear system is already an overdrive. I wouldn't worry about top end, since 15/43 will already get you thrown into prison if you decide to seek out absolute speed.

You need to change the chain, the front and rear sprockets. Sprocket Center provides a good package: 525 Chain Kit - SUPERLITE RS7 Steel Sprocket Set with Your Choice of X'ring Chain - DUCATI 996 ST4S '02-05 - 996 ST4S 2002-2005 - Ducati - STREET. The Sprocket Center people fill their orders promptly and are reliable.

The DID chain comes with (if I recall) maybe 120 links, so you will need to cut some off to get to 102 links. There is no reason to go with a 520 chain when your bike is as heavy (relatively) as the ST4s. If you don't have a chain breaker/riviter, then you want to get a reasonably priced unit (Motion Pro sells these). If you don't have some way to get the old chain off, many of us use the Dremel tool, which can be had at Home Depot. Alternatively, an angle grinder will do the job in half the time, but you want to be careful of the sparks and gas in the garage. If you haven't done this before, you will want to watch a video on UTube or Vimeo on how to replace a motorcycle chain. The Sprocket Center package comes with a master link to be riveted in, and it is easy to do if you're careful.

There is a whole friggin' mystique about working on your bike that should be set aside right away. Replacing a chain is one of the most straight-forward items of maintenance that can be imagined. Just pay attention to the process and it will be fine.

Ron

Ron
 

·
Just Visiting Your Planet
Joined
·
10,217 Posts
I'd like to add that with today's chains, there's really no reason not to go with a 520 conversion and save the weight. A high-end 520 actually has more tensile strength than the OEM 525 stuff and will be plenty strong. Just check the specs on what you purchase. I ended up going with EK chains and I'm very happy with them.
 

·
Registered
Joined
·
853 Posts
1 - 13 of 13 Posts
Top