I know I need to get a new chain, but the back sprocket looks ok but the front shows some wear... so buying both sprockets and chain... if I change them to get a little more acceleration how bad will it affect the top speed? I do not want to hurt the top end speed of my bike, what there is of it.
16/39 with a 520 110 link is stock... what would be a decent alternatives for sprockets and chain size ?
just buy a 15 front and a new chain
and you will be happy
I've been inactive here for a long while, so you may not want to trust me, but...
I run my GS with a 15T in front and stock 39T in back. Top end hasn't suffered at all, of course the GS can break 100 but not by much, and it takes a good bit of road to do it. Generally speaking the motor is spinning 500rpm higher than when I was running stock gearing.
Now for some opinions and advice. Replace both sprockets and the chain at the same time. Any one of these pieces, if worn, can accellerate the wear on the others. Also go ahead and buy a good quality chain (O-ring or X-ring). It may be overkill but good chains last longer, and trust me having to constantly adjust your chain, cause it stretches like the waistband of your under-britches, sucks! With the gearing I have I would suggest a shorter chain (108), although others on this site will definately know better than I. I currently have a 110 chain on, and it is a bit stretchy, but my rear axle is adjusted a far back as it will go, so I figure a slightly shorter chain will fit perfectly.
Hope this was helpful.
Oh, and for any who remember me:
I graduated college, worked a crappy QC Tech job, got a new job in Durham, NC as an FTIR analyst (analytical chemist), and I'm doing well. If anybody is in this area and wants to go riding give me a hollar. Oh, and to all the ladies out there, I'm still single. Surprising. I know.