as Im replacing bits on the rebuild, Im looking at the primary tensioner blade 70-8310 also 68-0244.
the one on the bike and all Ive ever changed have the plastic material along the full length of the blade, the ones advertised on ebay are only covered for half blade length. unless really badly worn, that shouldnt be a problen.
thoughts please?
Hi Chaz,
All I can think is that when the primary chain adjuster is close to its maximum the primary chain engages with almost all of the blade. If the plastic is not full then it is possible for the chain to contact the metal. You probably have examples like this but the photo shows a tensioner blade with full plastic and grooves worn just about along the full length. This chain is new and has not yet been adjusted but even with a new chain the adjuster is screwed in about half way.
Both come up on a search and suppliers are using the same part numbers. Burton Bike Bits have the proper one.
Dave.
yes Dave, its ok when the new pad is full length but my thoughts that the blade is in there for a long while, if its only half length and wears through there is more chance of metal being shaved off into the chain also would end up noisier OR is it just a ploy to make us change it earlier?
I ve only ever replaced one blade in many rebuilds , no real reason to change now but just thought I might. but as they are over £20 now probably wont do this one, as its still full length and has enough wear for a year or two.
the plastic/rubber on the blade will wear quickly until it hits the rollers whether its half or full length, it takes a while before it gets to the metal.
;)
hmmm
ebay have notified me the blade (half covered) I can now get for 50p off, now £9.50 instead of £10 and including free post!!
if I want I can buy two and get second at 50% off second one, so, that makes two for £14.50 compared to Draganflys full length one for £21.84 +vat +p&p so approx a small change from £30.
difference seems to be that the half covered one is poorly moulded looking at the flash on the metal, makes me wonder how long it will last continually covered in hot oil and then subject to the chain rattling over the top.
Hi,
I would go for the full length and as Derek says the rollers eventually run on the support material. At this stage wear must be really slow as the rollers will roll so virtually no friction.
Dave.