Any experience with 12T counter sprocket on CRF-450

[Nestrick]

I am looking to gear my 02 CRF-450 down for better control on tight trails ... it originally came with 13/50 sprockets and I installed a Regina ORN O-Ring chain ... only ran this combo for about two months before changing the rear sprocket to a 52 ... this made it better but the bike is still geared way too high for tight trails. This year I needed to replace the chain and both sprockets and opted to get Sidewinder Ti-Moly units ... they offered a 12T counter sprocket which I got, and I kept the same size 52T rear sprocket that I had been running. This combination gives a final ratio of 4.33 which is up from my original 4.00. I am now running a Sidewinder Ti-Moly O-Ring chain as well.

While eminently more 'ridable' ... I am now a bit worried about excessive wear on the 12T counter sprocket and whether or not this will put unnecessary strain on the main shaft exiting the transmission. I have also installed a 15 oz Steahly flywheel weight at the same time I made these latest gearing changes and find it to be a dramatic improvement over stock.

Anyone have any experience with 12T counter sprockets on CRF-450s? Longevity ... chain wear ... motor problems?

Is a RevLok auto clutch a better way to achieve the performance in tight situations than gearing down via sprockets. It seems that the only 'wide ratio transmission' I can find for CRF-450s is the one from Baja Designs and it does not alter the original gearing for 1st and 2nd gears which is where I want most to increase the gearing!

Thanks in advance for any advice ... terry nestrick :bang:

 

[Jaybird]

Terry,
You shouldn't see much difference in the longevity of the CS bearing.
It's fact that you place more stress on the chain when you use a smaller front. Keep a good eye on your chain and keep it from reaching over 1.5% growth from new, and your sprockets will last nicely.
Lube that ring chain the same as you would a standard, just don't use gooey wax or similar product that will attract ring killing dirt and sand.

 

[Nestrick]

Thanks for the advice Jaybird

Figured the chain would suffer some extra abuse ... glad to hear you feel the CS bearing will likely receive no extra stress.

I always take good care of my chains ... they see a steady diet of Digilube Performance Products Ultra-Film after a quick wash with Simple Green and a nylon brush. Got almost three seasons from a Regina ORN ... wonder how long a Sidewinder Ti-Moly will last ... even with a 12T counter sprocket ... guess we'll see!

terry nestrick ;)

 

[Jaybird]

LOL...You da man!
:cool:

 

[Shig]

I'm curious to hear if you've seen accelerated wear on the plastic chain buffer on the top of the swingarm. It's likely that the smaller countershaft would cause more chain friction and a minor power loss.

 

[Nestrick]

Hey Shig

Only have about 12 motor hours operation time on the unit to date ... one weekend ride session in the Upper Peninsula of Michigan ... as yet have not seen any indications of wear but will keep my eyes open and be alert to wear on the upper surface of the chain buffer. I just changed it this year after almost three years use with 13/52 sprockets and a Regina ORN chain ... it really didn't show any significant wear ... but I changed it anyway as I bought the part and had the swing arm apart for bearing maintenance. The new Sidewinder Ti-Moly front sprocket shows a bit of wear on the outside of the teeth [sort of a polishing] but the teeth on either front or back sprocket show absolutely no sign of wear and the same for the rollers on the chain. After the first 6 hours run time, I did tighten the chain from about 38 mm slack to the spec of 30 mm where I set it originally upon installation. After the next 6 hours operation, the chain remained at 30 mm slack.

Will report on this setup as I put time on it ... that is, if I keep it in this format. I may go to an auto clutch setup instead?

terry nestrick

 

[GREENBEAN]

The better mod for me was a 13oz (I think) over stock flywheel weight... I did have a 14/52 and I didnt like it I changed to a 14/50 with the flywheel weight and it is a different bike.. SO much better and I can use more gears... I am hitting 3rd and fourth instead of 2nd all the time... You should try a flywheel weight for sure....