Rear Sprocket Change : LUSENET : MV Agusta F4 : One Thread

Greetings All- Itís cold and wet here in the Puget Sound area. The perfect opportunity to have fun in my garage! I found a Ferracci quick change rear sprocket hub on ebay last month and ordered up a new 43 tooth rear sprocket. My goal was to get more torque and power at slower road speeds. Most of my riding is below 100 MPH so the loss of top end speed is no consequence to me. How many of you have seen 175 MPH on your F4? I made the same change to my 748 last year with only a two tooth jump so I figured three teeth would definitely improve the 2000 models power delivery. I also replaced the chain because the jump in teeth required one additional link. The entire process took me about an hour. I could have cut the time in half but I was in no hurry to ride and wanted to clean everything while I was there. The difference is amazing! Today (Sunday) I got a break in the weather and the streets were relatively dry. I took the MV out for a test ride and found a noticeable difference in power delivery right away. At 6,000 RPM it wants to lift the front end if you crank open the throttle too hard (just like my Ducati). With a few more revs at cruising speeds the engine sounds great. Just the right amount of exhaust note to make me smile. The down side to the sprocket change is the speedometer is off a little and may need re-calibrating. It takes its reading from a sensor located near the front sprocket. I donít believe the gauge can be re-calibrated. When the weather gets better I will check the actual difference for myself. I found the speed indicated on the gauge was always a bit faster than the actual road speed. Aside from the speedometer issue the rear sprocket change is a relatively simple and cost effective performance modification that transformed my F4 and will no doubt make riding more enjoyable.

-- Tim Willard (, December 29, 2002


hello tim, please let us know, once you figured out the speedometer issue, how you (or workshop) calibrated for the right speed read- out. Seems a cheap and effective performance modification. You're right driving at topspeed is not a daily business anylonger. Kris

-- kris hoffelinck (, December 30, 2002.

Is this the sprocket carrier that allows you to change sprockets without taking the whole hub out? I'm semi interested in looking into that. It just so happens though that at that track I ride at, the gearing is pretty close to being perfect, although it may be able to be a bit shorter. On the street I don't care much, gearing isn't an issue.

If you had a picture, that would be great.

-- Andy Ruhl (, December 30, 2002.

European owners might be interested in visiting as they do seperate carriers and sprockets for the F4; haven't used them yet, but when I need replacements it's definitely worth a look.

-- Ralph Goldstein (, December 30, 2002.

Not try to piss you off. When I rented a F4s the second day I went to germany and hit 286km/h (178,75Mph) easy on an EVO 2! No sprocket mod involved! Together with the looks and feel made me buy one for myself month's later!

-- hb (, December 30, 2002.

I read a few months ago about a power commander type product that plugs into speedometer cables and allows full adjustment for sprocket changes on late model sportbikes. I will try to find out where I read about it at and if they have it for a MV.

-- Doug Chism (, December 30, 2002.

Did you put a spacer on the rear chain guard ?? I put the 43 tooth sprocket from MV-SP and they included a spacer but even with that the chain was hitting the top of the guard (I found out after it broke the insert of the guard).

-- Matt Thompson (, December 30, 2002.

AFAM ( also make a sprocket carrier for the MV. If you go to their www site look under "news".

-- Matt Thompson (, December 30, 2002.

The hub carrier from Ferracci does allow sprocket changes without removing the hub. If a one tooth change was made you could probably use the stock chain. There are five 8mm Allen head bolts that secure the sprocket to the hub. For me the great thing about the Ferracci set up is the sprockets. They are the same for both the Ducati hub carrier and the F4 carrier. Having both bikes allow me to stock one set of sprockets. The carbon fiber chain guard installed on my F4 was very close to the chain with the standard sprocket. I used a couple of washers to space it up and away from the chain. When I installed the larger 43 tooth sprocket I made up a 1/4" long aluminum spacer from some 1/2" bar stock. A longer 6mm bolt replace the tiny button head Allen. Thanks for the great response. I love to share my F4 excitement with fellow enthusiasts.

-- Tim W (, December 30, 2002.

I hit 150 mph (indicated) with the stock rear sprocket, 38t. The Senna came with a 37 and 39 tooth rear sprocket neatly wrapped in the crate. That 150 mph was achieved in 5th gear with a little room left on the tach., I was not looking at the tach for long, the road and distance ahead was more important.

-- greg petersen (, December 31, 2002.

Just an insight into speedo accuracy in STD form,The police have a mobile radar speed device which shows you your speed as you approach it-i suppose to remind you how fast your going-anyways i came across it a few weeks ago so had acouple of `flybys`-when my Mv showed 51mph the radar thing showed 49mph,and when showing 70 mph the radar thing showed 67mph-did`nt want to try any quicker as it was parked in a 50 limit

-- mike tilston (, January 01, 2003.

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