The adjustable lockring allows a range of cassette widths depending on the number of sprockets. All journal bearings are rubber sealed to avoid water ingress. A common problem with standard cup and cone bearings typical of older trikes. The freehub body is machined from tough, hardened steel. Promising a very long life.
Though the original clear grease was blackened with use it was still in good (greasy) condition. In the absence of the recommended de-greaser I had to use petrol. This was used to wash all the components in a small glass jar only just large enough for take the special, freehub body. The freehub was carefully brushed through with an old toothbrush to remove any possible metal dust. The rest of the components had a quick bath in the petrol and were set aside to dry in the warm sunshine. All the components were given a final polish with a clean cloth.
The pawls and their springs are self retaining. So there is no danger of things flying away if the Trykit free-hub is dismantled. Everything was thoroughly clean and then well greased before it went back together. Such an apparently simple mechanism but a true work of mechanical genius!
The new 9sp cassette was then fitted to the Trykit freehub. The 9sp is wider than the 8sp so there is not so much visible thread beyond the Trykit locking ring. Though I still used my thick, brass spacer ring. I think it looks smarter with the lock ring almost flush with the end of the freehub. A 10sp would not need the brass spacer ring but my bar-end gear levers are limited to 9 speeds.
Front of Sram 12-26T, cassette showing the high gear, splined locking ring. This holds the 12T top gear in place. The sprockets are sandwiched between this ring and the rear locking ring. I torqued down on both simultaneously to ensure all was tight. The sprockets won't fall off or slip because of the splines but they don't want to be loose or they might cut the splines of the free-hub over time.
The Sram cassette sprockets are well cut away making for a remarkably light assembly. The designer went the extra mile and matched the cutaways to produce an attractive geometric arrangement. The rather "techy" cut-outs have their own character rather than being simple radiused arcs. I haven't had to do it yet but it looks much easier to clean than a Shimano cassette.
I deliberately made the chain one link longer than the last time to see if it affected anything. Removing another link (if necessary) is very easy with a modern link extractor. As usual I allowed enough chain to use the largest sprocket and the largest chainwheel at the same time. Not a normal occurrence out on the road but it offers complete safety and confidence in a hurried gear change when I suddenly need a low gear.
(Note: the overlong chain proved to be complete waste of time and caused all sorts of problems! Make the chain the correct length every time! Wrap the chain around the largest sprocket and largest chain-wheel and bring the ends together so they overlap. Use one free end as your marker at the overlap then add one link. Break the chain at that point. Use a modern link extractor with an adjustable stop screw or you will damage such a narrow chain! I used a cheap, chain link extractor designed for normal 1/8" chains. The chain broke a couple of times while I was a long way from home! It was my own fault! I have now invested in a modern, Spectra chain link extractor)
It reached 74F this afternoon. A bit warm for me standing out there in the sunshine.
One link less: Better, but still not enough tension.
And yet another link but still skipping. I should have been more ruthless at the start. Setting the chain length to match the largest sprocket and biggest chain-wheel plus one link. Just allowing the chain to pass safely through the changer rollers without the chain going completely tight.
See important note about correct chain length above!
Also remember to tighten the wheel nuts properly after any maintenance work!
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