Hillhater wrote:Yes , those pawls have to be tough little critters to do that job !
...were all the pawls still in their correct locations ??.. or was it too scrambled to tell ?
I would guess a pawl came out of location and jammed the mechanism... but no way to know for sure
The pawls and pawl return springs were positioned just as they are supposed to be when I opened it up. What caused the seizure/lockup was the piece of ratchet tooth that sheared off and was subsequently compression welded as it formed a wedge between the inner driver and another ratchet tooth.
Miles wrote:Looks like the pawls are out of alignment.... Was the lock ring unscrewing?
The pawls never seated directly in the centre of the ratchet teeth, but that was not a bi-product of an unscrewing/loose lock ring causing axial misalignment between the inner driver and the outer ring. Just dodgy manufacturing tolerances or unopimized/lazy design by Dicta I guess, but I don't think having them centred would have changed the final result though
. Originally the lockring did unscrew almost immediately (even when torqued significantly). I quickly fixed that with locktite and never had the same problem again (I actually had to cut the lock ring out with a Dremel just to open it up after it failed)
Miles wrote:I seem to remember that you tried one of the Tensile freewheels?
Yes I've still got that 96 click 18T Tensile. I haven't tried it in a freewheel crank setup yet for two reasons.
Firstly, I never liked the look of the design of my Tensile from a torque handling point of view. It actually looks worse than the Dicta! The problem is the ratchet teeth are very shallow in their protrusion (short ridges/valleys) so as a result the pawls contact almost the very tip of the ridge of each ratchet tooth. This design limitation is obviously a bi-product of trying to cram more ratchet teeth than your average freewheel into a set diameter (chasing greater engagement points). However, even if the steel quality is much higher in the Tensile over the Dicta, it just looks mechanically handicapped and therefore unsafe. I don't trust it..... Maybe the 60 click version aint so bad
Secondly, even with 4 of the 6 pawls removed, the freewheeling drag of the Tensile is unacceptable to me (removing two sets of the triple synchronous pairs means you loose engagement points, not torque capability
). The drag is the worst of any freewheel I have hand spun. It's also noisy as hell compared to other freewheels, even when packed with grease to try and quiet it down.
The Dicta and Shimano freewheels i own on the other hand are very quiet.
On another note: I found an ENO can also be made near silent by packing the engagement system with grease without sacrificing engagement reliability (An alternative to weakening the pawl return springs like you did Miles). The factory lubes the ratchets/pawls with light oil only.
Miles wrote:An ENO with an additional outboard bearing, perhaps?
That was my first thought as well. No way I can see to achieve it though seeing as every set of freewheeling crank arms I have ever played with never
has perfectly concentric and true running screw-on freewheeling threads in relation to the BB spindle hole (the only place to mount a secondary bearing). I even emailed trials bike retailers about this issue and was informed that even the most expensive freewheel crank arms have at least some degree of unconformity in these fastening points. There is no great incentive to get these precise as Trials bikes only transfer torque when the freewheel is in a locked state, and low tooth counts (18T) mean chainline wobble is made negligible by small tooth contact radius's.