Adam_Winstone wrote:davla wrote:Cheers again for the replies. I'll stick with the Pacemaker box until I've run it in and then throw in the SX200 box to see how it goes. If it struggles I'll go back to the Pacemaker and change the front sprocket and go somewhere in-between.
This all depends on the specification of the porting and any changes that you might make to your set-up configuration (pipe etc.). Capacity alone is almost impossible to judge gearing requirement from as it all depends on the rev range that the motor and pipe produce power at, which is why a 225's requirement can range from 5.2 (recommendation for a TS1225 with revvy pipe) to 4.4 (same TS1 225 with very torque'y pipe)... and depending on 1-up, 2-up, large 1-up + luggage, flat area, hilly area, riding style, etc.
You could well find that the Pacemaker (15/46) is too short, depending on the above factors, and/or the SX200 15/46 too long (again depending on the above factors). The Pacemaker 16/46 (stretched 80 chain or 81 with pull down tensioner) is the a half way house that should perform pretty well for all of those factors. That said, a pal in my local club had one of the 175 steel lined alloy kits from AF, which he used very reliably for about 6K miles (and it was fast on the standard Pacemaker 15/46, as the AF porting revved well with the extended exhaust period)... but then ran into repeated piston/ring failures as the hard chrome thin rings kept wearing the soft iron liner. My pal went through about 10 pistons and a couple of rebore at 175, then took it to 200 to reduce the % exhaust width to bore ratio, had the same happen, then went back to an iron barrel and used it reliably from then on. Strange that this kit ran so well for 6K, then had so many repeat wear and ring breakage issues (the port was a good oval shape to start with but after a while the rings would wear the port square until it couldn't cope anymore, then...!).
Adam
PS - If Cgt75b or others though that my previous comment was intended to 'take the piss' then I apologise as that was not my intention.
I hadn't noticed anyone taking the piss tbh, just interested in peoples opinions, thx