I know I know search well i did and couldnt find the answers i was looking for. I have an 06 F4i and i know the rear sprocket needs to be replaced but what i need to know is how can i tell if the chain needs to be replaced too? Any visual signs to look for? The chain seems to have the right amount of slack in it but i dont want to change the sprocket and then the sprocket get messed up or something. Any help or pictures would be great. Thanks.

 

Generally, if you've gone through a steel rear sprocket with the existing chain... it's best to replace the chain and the front sprocket while you're at it. Many people forget the front sprocket. Don't do this. They're the cheapest part.

Any stretch in the existing chain will mate itself to the new sprocket/s rather quickly (ie: chew up the new sprocket)

A rule of thumb for checking chain wear is grabbing the chain at the very back of the rear sprocket and pulling on it. If the chain comes off the sprocket enough to show light between the bottom of the teeth and the rollers, it's getting worn.

However, the best way to check a chain is to measure the links. In the service manual, it will tell you how to do it.
Basically, you measure a set length of chain (say 17 links), and the manual will give you a length that it should be. We'll say it's supposed to be like 10.5" max or something. If it's over that, it's out of spec and needs replaced.
You can download the manual and have a look.

 

Thanks. I forgot to menstion the bike has a vortex aluminum sprocket in the rear and im guessing the front is also vortex the chain is a D&D? Im not sure. When i got the bike it had that on it and the chain was a bit loose so i tightend it and oiled it and it seems to be fine. I checked the front sprocket today and it seemed to be pretty good but im getting a new front and rear sprocket next week i just dont have the cash for a new chain right now so if my chain will work for a few weeks then that would be great. From what a few people have told me my chain looks good i just dont wanna get new sprockets and it F them up. Oh im getting steel sprocket to replace the aluminum one if that matters.

Thanks again.

 

Front sprockets are always steel. The chain is DID. Without seeing the chain and measuring it, I can't be sure how worn it is. Same with the sprockets.
You may very well be fine with just changing sprockets, but they won't last as long as if you changed the chain with them. How long? Who knows.
I would keep an eye on them for wear, and keep the chain slack set properly. You don't want to be too tight, or you'll chew stuff up real quick.

 

Thats what it was DID. The front sprocket had a little wear but i didnt think it was bad the rear on the other hand is pretty well done. I have been babying the hell out of it because of the rear sprocket. If it matters the little indicator thing on the swing arm isnt in the replace chain zone yet. Im gunna get new sprockets next week and ill probley get a new chain the week after or so. Would running a slightly worn chain on new steel sprockets for maybe 2 weeks be such a bad thing? If so ill just have to not ride it for that time. Thanks again. You are a ton of help. My 2 riding buddies dont know enough about bikes to give me accurate answers. Oh you wouldnt happen to know the stock sprocket gearing would you? I have seem front 16 and rear 45 and a few other combos saying different OEM gearing.

 

thats easy, if one needs replaced they all 3 need replaced.

 

the general rule of thumb is if you have more than 4000 miles on your set of sprockets and chain, do not put on a new chain or new sprockets. As KG was saying, they sprockets and chain wear together, and introducing a new component to the system will have a different pattern that the chain or sprocket will not match, which will result in much faster wear.

I would change the whole set at once instead changing one, then the other the next week. I would replace the chain and both sprockets at the same time.

The stock gearing should be 16/46. I think..

 

Alright thanks guys. I found an RK chain and sprocket kit so i may order that. Comes with steel sprockets and thats what i want. Oh how bad would my speedo be off if i put a 15 tooth sprocket up front? They have 3 kits ones and OEM kit but its about 40 bucks more the other 2 are quick acceleration kits which i honestly dont care about but the one with the steel sprockets is the cheapest one and it has a 15 tooth front and 46 rear. Thanks guys

 

It would be off about an additional 3%. keep in mind stock speedo's are off about 8% to begin with, so your speed would be off about 11% all together. With the new sprocket, Your speedometer would read around 61-62 mph when your actually going 55mph.

If your concerned with accuracy of the speedometer, you can always put a speedohealer on the bike. They are about $115, but are very nice to have. My only regret with having a speedohealer is waiting so long to get one.

On another note, you didn't mention if you were going with a 520 chain. If I were you, I'd stick with the stock set up. The 520 set up will wear out faster and the little bit of weight savings is not worth it to me.

 

Wow didnt know it would be off that bad. Speedohealer will be my first i guess you could call it an upgrade. lol. The only reason im getting the 520 is because its the cheapest kit i can find and from what i know RK is a pretty good brand so it seems like a good deal to me. I dont care to much about weight saving. This is my first bike so its way faster then i need right now anyway. lol. If you know of a good OEM kit that cost about 150 to 160 bucks please let me know. Thanks again. I really appreciate all the help you guys are giving me.