2011 Beta Evo 4T gearing question

[bonito]

I have a 2011 Beta Evo 4T gearing question. 

I find first ok but second and definitely third way to tall. What do people do, drop one tooth to a 10T on the front sprocket?

happy for any input

[lineaway]

 First is good for almost all sections, second is not that bad unless you are doing big walls. My son has a 2015 with all the bells and whistles. He mainly rides first. Second when doing splatters. Do you have an aftermarket pipe? I could see going down a tooth if you are running the stock exhaust.

Edited January 16, 2018 by lineaway

[timdog]

Went down a tooth to 10 on front and works great for me, but i like it to plonk slowly in first( thats why i like 4T)  makes 2nd more useable for me combined with amal 80/200 throttle. Personal taste though

 

[Darcy Sarto]

They all come with a 11T front on the 4t's from the factory. Mainy for riding on the road in Italy. Dropped to a 10T and it was better for UK trials. Now living in OZ where the trials are a little more technical and very dry. On my 2014 300 4t I went down to a 9T after a local guy who rode the pants of everyone recommend it. It worked making 1st good for twisty sections, din't feel to slow mind, 2nd for steeper bits and 3rd worked great for hillclimbs. This was running a 42T on the back. Might have to play with the links on the the chain, its cheap to experiment with the front sprocket. Hope that helps... 

[section swept]

Running with a very small gearbox sprocket can cause issues with the chain. Theres stuff about this somewhere on TC and Google, with a larger rear sprocket there is a better reaction from the chain. Basically with a very small eg 9 tooth gearbox sprocket ( for example only) the chain links are at their maximum with regards to following each other around the gearbox sprockets teeth and either a smaller chain ie going from a 520 to a 428 and associated sprockets would alieviate the problem. In the case of a chain fitting around the smallest gearbox sprocket it tends to want to lift off the teeth rather than neatly follow round the sprocket. The torque reaction in the chain, where the tensioner should be placed to mimick the chains centrifugal whip at the highest point of the whip...if you see what I mean. For this reason it is better to use a larger rear wheel sprocket instead of a smaller gearbox sprocket. I know this may sound b@ll*@s to some of you..no disrespect...but Im sure its shown with a diagram on the back of some of the better quality chains. Many bikes are overchained ( too big ) fitted with a 525 that looks good and strong but heavy, its this weight that causes problems for the sprocket teeth. Swapping down to a 428 means less overall chain weight and less weight in the thinner front and rear sprockets. Hope you understand this, Ive left out the math content as its near to Christmas and we have enough to think about???

[crashmonkey]

nearly all the 125 bikes come from the factory with a 9t on the front and there fine ?‍♂️

 

[jonnyc21]

Yes fine, but they will ware out faster than a 10T and a larger rear sprocket under the same conditions.  Where it isn't explained in detail what section swept is talking about is real and a 10T and larger rear is a better over all option long term.