hi all , im after a bling pulley , and the one im looking at is a 65 tooth 1.5 inch wide , but on my 99 wideglide im running 70 tooth at the moment. so i gather im gunna have more pull down low and lose a bit of top end - but how much?

 

enough to notice?

 

looking foward to everyones thoughts.....

 

cheers ,

 

wilso

yer mate

going back to the trail bike days we used to fuck with cogs all the time the cheapest option was to change the counter shaft sprocket as it was easy and cheap but you want to change the rear it used to go like this one tooth on the front is equal to four teeth on the rear  before computers and yes you will feel a nice increase in pull and not to much of the top end unless you drag it i think you will be happy.

cheers mate

shit can i rephrase that its the other way less pull more top end maybe you wont be happy try it if you dont like it go one tooth smaller on the front to compensate.

fuck me how much shit am i going to cop for this its a cunt being dslexsic.

cheers 

I'm pretty sure you will lose grunt and gain about 10% top end by reducing the rear pulley.

fuck me i think i was right the first time can some one else confirm it i have said enough sorry mate.

heres my explanation ..... if your make the rear smaller your will increase top end a the expense of torque

                                              if you increase the rear you will loose top speed but launch harder

                                              in both cases you can counteract by changing gearbox output .. but you dont have a lot of room to get big

                                             remember 10 teeth moving at the front is still going to move 10 teeth at the back.... its just what percentage of a wheel rotation  is 10 teeth

                                             you could then fuck with the primary ....... but thats a whole differant story..... then theres tyre profile  ???

Divide the front gear into the rear gear. eg 10 front 70 rear. Front turn 7 times to the rears once. Giving us a final drive ratio of 7:1

I think it is the lower the number the higher the top end and vice versa.

You may find that you have to cruise in 4th instaed of 5th at certain speed etc.

Not sure what it does to the speedo calibration.

We do it all the time Karting, without getting technical larger rear sprocket for shorter tighter tracks where torque is important however its important to keep revs up out of corners. but if there is a long straight you will go through the torque range too quick and run out of steam and you will peak RPM before the end of the track which brings you to long flowing tracks where you drop teeth on the rear, need to stay in torque band longer and get peaks revs just before the end of the straight. So what they said above posts is spot on, more teeth will rev its titties off a lot quicker i.e. you may peek out at say 220k's but get there quicker than less teeth however, having less teeth can get you to say 240 k's, confused? the gear ratio should not (quote should not) effect speedo calibration but changing wheel size, tyre profile will but not by much. eg when I put larger wheels on one of my commodores the speedo was out but by a small percentage which increased percentage as the speed increased, this was easily fixed by changing the PCM values using EFI live. Not sure how configurable the HD PCM's are (going to start studying soon). There used to be different coloured speedo drives that would suit your driveline and wheel size configuration, have the chart somewhere, now I am babbling - the end.

By changing the rear sprocket you have changed the final drive ratio and will put the speedo out of calibration.

When I went from 3.46 : 1 to 3.9 : 1 rear end ratio in my commodore I had to get the PPK code changed with EFI live to calibrate the speedo. Changing rear wheel diametre has done the same as changing the diff ratio.

The speedo is driven by a hall effect sensor on the 4th gear. If you change the rear sprocket the 4th gear shaft will spin either faster or slower dependng on the final drive ratio.

As stated above it may only be a couple of kays but will progressively be more out of calibration the faster you go.

best thing to do is strap on a GPS. If the 70 tooth is standard on the bike all good, make sure the GPS reads the same as the speedo, then throw on the 65 tooth and have another run, it maybe only a couple of % out and that may not show up until you get to 40 + k's.

thanks all, im gunna stick with a 70 to be safe as i like launching harder and dont want to stuff with the speedo,

cheers , wilso.

cheers jack, much appreciated