Sprocket mod reviews in a nut shell

[CDNRatMan]

Phoebe5150, the chain length will not be an issue other then you might have to shorten it. When I changed mine toi a 18 / 38 I had to shorten the chain as it was way to long.
Chain wear, not sure as I have changed mine when I swapped sprockets......but a good chain will last a long time......or one that is looked after properly.

[Phoebe5150]

Based on that thought, I did a quick Google search and it seems it is legit.  In sprocket combo's, best to worst are:  odd/odd, odd/even, even/even.  With that being said, I would like to ask another question to those of you running 18/40:  What kind of chain life are you seeing?    TIA

[allstateguy]

I'm posting this as the oddball (gearing joke) in the group.
Somewhere a few decades ago I remember reading that you should have sprockets that are either odd/even, even/odd, or odd/odd. And the BIG no-no was an even resultant ratio, read that as 18/36 or 1:2 ratio should not be run, if you could even find a 36 rear. This was because the same chain rollers are going to be pushed on by the same teeth all the time, causing increased wear.

So, I decided to run 18/39 and am more than pleased with the result. Cleaned the muck out of the area around the front sprocket (and a 19 tooth would be a VERY tight fit if it would even go) and the chain, when readjusted was just fine for length. No clutch slipping, since the grampsizing, I just give it a whiff of throttle, let the clutch out and I'm on my way, no noticeable difference other that each gear lasts longer while street riding, and 5th is now just fine at my normal hiway cruising speed of 70.

[Phoebe5150]

So, if I replace my 17T with and 18T is there typically enough chain length, or is a new chain necessary?   Thanks!

[CDNRatMan]

  Ok I have done the pictures and such for the front sprocket, I will be doing the rear in the next few weeks so I'll do that as well for the mods section.

D1 I was really happy with the 18t front sprocket and going to say before hand that the 38t rear is going to be a huge improvement, and once I run to 0hi0 I'll let you know what the change is like.......

[Drift1]

greenbarn great points ! I was very close to go with the 19 front and thought I read somewhere on here about it , but that was some time ago . My only concern with this is how much "clutch riding" is going on if any at all ?

[greenbarn]

You know now that I think about this more , yes it would be less time consuming to just change out one sprocket , but it makes sense changing both sprockets , and chain of course , for wear purposes and safety .

Another reason to change the front sprocket - if you haven't had that cover off and cleaned it, I Guarantee it's quite full of crud... .   And for all the trouble to find a 36 tooth, it's almost identical to 18/38.   Now, on the other hand, I have considered bumping the front one more tooth - to a 19.   Somebody on here has done that and they said it's great.  If I convert a 800 to a solo bike, I might consider that.

And, glad to here from you again Troll....thought for a minute we might have to send somebody to look for you.

[Drift1]

Thanks for the interesting links troll , they were very helpful . I would also like to thank greenbarn and ratman for their input on this as well .
Well after two days of searching for a 36 tooth rear I came up empty handed . That being said I would assume one would have to special order this item or search maybe over seas to try to find one . It's no wonder so many went with the 18/38 set up . You know now that I think about this more , yes it would be less time consuming to just change out one sprocket , but it makes sense changing both sprockets , and chain of course , for wear purposes and safety . For those of you who have not read trolls post above take a few minutes and please read that .
So guys I'm another rider who is doing the 18/38 set up and should be expecting all my ordered parts on Tuesday . Ratman no write up on this project needed being you have done so already  Thanks LOL

[Troll]

  HUH? There is some advantage to having the ability to just lurk...I ran a 24/48 combo on both my last 2 H-Ds. supposedly the smaller the front sprocket, the faster the chain will wear due to higher turning velocity...but I think this is more a problem with the people who don't take care of chains. I did a little calculation, and the 18/36 is an even 2:1. The 17/36 and the 18/38 are almost identical at 2.11:1. I'm thinking that the big thing here is going to be availability of the parts. The stock 1st gear ratio is 5.52:1 considering the primary ratio...the change in the external ratio is going to make a relatively small difference. It's not going to be like going from a 4.11 to a 3.23...Here's a little info on chains you might find interesting:  http://www.dansmc.com/rearchain.HTM
This calculator will allow you to make final drive ratio changes and see the results with a mouse click.
http://www.gadgetjq.com/drifter_speed_rpm.htm

[greenbarn]

A 17/36 ratio  (just adding a 36 tooth rear, assuming you can find it, with stock front 17 tooth) is almost identical to a 18/38 ratio.

check out http://www.gearingcommander.com/ when you get some time - I'm sure there are others - it calculates gear ratios, and gives you RPMs.

Now, on the other hand, I'm sure there must be some advantage or disadvantage between having the same gear ratio depending on whether the front sprocket is larger or smaller - but I don't know what they are.  Good question for Troll.  Has anybody heard from him lately?

[CDNRatMan]

    you mean a 6th gear correct? I have read all the post here and on the Delphi forum about the Great Sprocket Swap. I cannot remember reading anything about a 36T sprocket and the 40T rear.
Stock is 17/40, I have for a summer ran a 18/40 and found a huge difference in top end and lower rmps.
This winter I will be swapping to a 18/38 which seems to be the one everyone agrees is the best over all swap.
Cost is really cheap and the work can be done by yourself and is really simple.

but I did find these few links after hunting for them....
http://www.vulcanforums.com/forums/showthread.php?t=4265
http://www.vulcanforums.com/forums/showthread.php?t=33249

Ask and I'll give you Santa pictures.....

[Drift1]

Ok guys I know this subject has come up , over and over again and am sorry for beating a dead horse on this subject but here's the deal .
I just come from the shop that I use ( and hang out ) thanks for the tip last year from Pastor Dude . Totally different story so back on track . I asked the mechanic who's been working on these bikes for some time now and brought up this subject . I told him like everyone else here ,I seem to be looking for 5th gear and went on with what others have done . His response was he would go with a 36 rear and leave the front alone . He stated I could run 90 mph with this mod know problem , with out that 5th gear searching problem , we all been through or still are going through , for that matter . Know , he did mention take offs wouldn't be fast off the line , but perfect for highway miles witch I seem to do a lot of . Everyone knows each mechanic has there own opinions , like ourselves , so I am curious if anyone has tried a 36 tooth rear sprocket . I couldn't even find one so far , so not even sure if they exist for our scoots ? I do know this much , I would love to be able to cruise at higher speeds with out constantly searching for another gear . What's my fellow riders thought and findings on this ? I appreciate all the feed back we can get and put this subject to rest for myself and others with the same arising question . Thank you all in advance . And ratman no Santa pictures needed for this subject