CRF250 L thread

[garyboy]

just had a thought
(yes, it hurt)

after I had put the 45t rear cog on .. and fitted the larger rear tyre ..
the clutch wore out, to near its limit, (as there was little lever adjustment left) ..
and also the rear tyre slipped a bit, slanting the tube valve ..


.. so I was wondering if the gearing is still too high,
and pulling over-hard on the rear tyre?
(even tho it felt ok)

.. so wondering if a 13t front cog would solve/help this
and also give the rear tyre more room to the swing arm?
(as the chain would be slacker from 1 less tooth)


if previous calcs are right = 12.7% lower gearing

(the bigger tyre cancels out the bigger rear sprocket, in effect,
but the 13t brings the gearing close to 14/45t with oem tyre?

[minkyhead]

your going to fry your brain gary .....

have alook on here change the tyre size sprockets ect

https://www.gearingcommander.com/

[ggp59]

I hope this doesn't sound like a dopey question, but will ask anyway........

I fitted a 13T (AFAM) front sprocket to my 200 mile CRF 250L, which felt like it had a bit of play in it so refitted the original Honda one that feels the same!
Unfortunately didn't check before removing it, but my 250X one with a 'one bolt in the middle' method of fitting is as tight as a drum.
So, is it the two bolts and a collar thing that holds it on (I even torqued the bolts up) thats always like this, or am I missing something really obvious?

Does everyone else's have this less than snug fit??

[steve the grease]

I hope this doesn't sound like a dopey question, but will ask anyway........

I fitted a 13T (AFAM) front sprocket to my 200 mile CRF 250L, which felt like it had a bit of play in it so refitted the original Honda one that feels the same!
Unfortunately didn't check before removing it, but my 250X one with a 'one bolt in the middle' method of fitting is as tight as a drum.
So, is it the two bolts and a collar thing that holds it on (I even torqued the bolts up) thats always like this, or am I missing something really obvious?

Does everyone else's have this less than snug fit??

The plate and 2 bolts method allows the sprocket to move about in a pretty alarming way. When it has a load on it ( riding) it will tend to run 'straight,' to some extent the floating sprocket will compensate if the wheel is a bit misaligned

[garyboy]

I noticed this `sliding on the shaft` movement
what I find more worrying is some reports of the replacement sprocket not being a good fit to the shaft
so causing the shaft to wear?

[johnnyboxer]

I noticed this `sliding on the shaft` movement
what I find more worrying is some reports of the replacement sprocket not being a good fit to the shaft
so causing the shaft to wear?

Only buy a Honda front sprocket as some of them are rubber damped to avoid spline shaft wear

[garyboy]

I noticed this `sliding on the shaft` movement
what I find more worrying is some reports of the replacement sprocket not being a good fit to the shaft
so causing the shaft to wear?

Only buy a Honda front sprocket as some of them are rubber damped to avoid spline shaft wear

I have ordered a 13t front sprocket from manp .. JT sprocket, as I don't think Honda would do a 13t?
for the crf250L
as it is not std?

[ggp59]

Thank you all

Whilst i take the point of using a Honda sprocket, as have always found original stuff lasts way longer than aftermarket, but as it does the same thing when I put the original back on (no rubber strips attached) suspect that's not the problem.
Will go to Bransons tomorrow to have a look at one of thiers - they might frown a bit if I turn up with an 8mm socket to get the cover off for a better look though

It that feels anything like mine will go with theory of it simply being designed that way!

[catcitrus]

The rubber inserts are for chain "dampening"--and JT are a solid japanese manufacturer--used them lots of times--never a problem--and never worn a shaft--they are HARD.

[garyboy]

according to minky's [gearing commander] chart ..

Stock Final Drive Ratio = 14/40
Current Final Drive Ratio = 14/45
Custom Final Drive Ratio = 13/45 …. (for new 13t sprocket)

Difference Current to Stock = 8.5% .. .. for 90 profile tyre v 80

Difference Custom to Current = 7.7%

Difference Custom to Stock = 16.9% .. .. for 90 profile tyre v 80