CRF250 L thread

[garyboy]

Dodgy Renthal sprockets warning:
although unlikely to affect anyone with a brain.........Detail here"https://m.facebook.com/groups/411216699 ... 4606349750"

porton down dun it .. innit

[Simon_100]

Dodgy Renthal sprockets warning:
although unlikely to affect anyone with a brain.........Detail here"https://m.facebook.com/groups/411216699 ... 4606349750"

Interesting, "the link you ... is temporarily unavailable" ... !

[catcitrus]

This is a closed group--hence the difficulty--I've been contributing so here'e the summary. One of the owners bought a Renthal replacement and ran into a problem. Honda sprockets are a loose fit on the shaft and are retained by a plate with two bolt holes (offset). The plate is splined and slips on, rotates in a groove, and then bolts to the sprocket. In this position the splines on the plate are offset from the splines on the shaft so the sprocket can't slide off. The problem with this particular sprocket was that they have drilled and tapped the holes incorrectly so that when bolted up the splines ARE IN LINE--NO RETENTION. The sprocket has been returned to Renthal and they have been a bit non committal--There could be a whole batch out there so the recommendation is to check before you bolt up and ride--or buy JT!!

[garyboy]

I have read, re-read, and pondered over this .. looking at the original post and Cat's.
The only way I can see this system work, in the oem,
is for the groove to be positioned between the front sprocket and the locking plate.
This means that the locking plate forms a (non-fixed) stop-end washer
which stops the sprocket sliding off the shaft
as the splines on the outer (plate) part are offset?
by a thickness of a spline.

The ends of the splines, at the point of change (at the groove area) are all that is holding the front sprocket on.
as the front sprocket is not bolted to a back plate
or bolted to a cental sprocket thread
or interference fitted to the splines
or bolted to the shaft, in any way.

So .. the new 13T front sprocket should be offset, to form 2 systems of non-continuous splines,
locked together by the 2 bolts between plate and sprocket.

surely .. if the renthal 13t sprocket is machined wrong, the 2 fixing holes will not align?
so there is no danger of riding it unfixed
(as it cannot be fixed)
as the 2 spline systems would need to be parallel?

[garyboy]

oem 14t

28577495_10157243045887571_9036612039820318936_n by gary boy, on Flickr

[garyboy]

renthal 13t

28576774_10157243045852571_2344763150458224179_n by gary boy, on Flickr

[garyboy]

28872026_10157251235407571_355397625576280059_n by gary boy, on Flickr

[garyboy]

29313655_10157294068127571_1043784315441250304_n by gary boy, on Flickr

[garyboy]

anyone got a pic/diag of the splined output shaft?

.. showing the groove?

[minkyhead]

a bit of back covering by renthal ...they ballsed that up big time

i dont think they would have much luck defending that ...if it came to it

its highl;y unlikely that two bolts will come loose but the idea is if one drops out the plate holds the sprocket ...oh well mistakes happen