11 Mar 2017

10th March 2017 Spring cleaning, by any other name..


Friday 10th 43F, 6C, heavy overcast, mild but rather windy from the NW. We were promised some sunshine. More fake news! Where do I queue for my compensation for hurt feelings?  Walked to the village to find two pairs of Coots today. Each on their respective pond. I doubt they'd tolerate others by sharing such small areas of water. It's amazing how they can ignore the roaring traffic only a few feet away from the bank!  Still no images to share.

The image shows the Trykit 2WD body sitting on top of the Sram cassette sprockets. The Trykit hollow axles are to the right beside the slide hammer used for easy dismantling. This screws into the wheel retaining bolt's threads.

Cruised with a tailwind at a steady 19mph for several miles. A cross headwind coming home brought me back to reality and 10-12mph. 17 miles.

Spent the afternoon stripping and cleaning the Trykit ready for a replacement chain. Ever the optimist, it doesn't look like we'll have any more frosts requiring road salting. A spray of engine cleaner and an old toothbrush helps to start the cleaning process of the sprockets and chain rings. Followed by several rags discarded as they become dirty. Surgical gloves are amazingly tough for working on this sort of job. A wipe over the gloves with a cleaner rag stops them re-contaminating shiny components. Thin enough to handle the tiniest and slipperiest components. Highly recommended!

The cassette is very easy to rebuild by matching the only narrow slot on each sprocket with the only narrow spline on the body/freehub. I start with the lock ring and a spare spacer ring on the Trykit 2WD body and fit the largest sprockets first. Each sprocket has a spacer ring added before the next sprocket is slipped onto the body. The last sprockets have their own built-in spacers followed by the locking ferrule screwed almost fully home.

I use a chain whip to hold the cassette still while I thoroughly tighten the [bottom bracket style] lock ring at the rear with a C-spanner. Then the front ferrule can be fully tightened without the risk of it bottoming early without sufficient torque having been applied.

This is an eleven speed 11-36 MTB cassette by Sram with the 11T sprocket removed. This was to allow chain clearance in the reinforcing loops of the Trykit axle for the oversized bottom gear. The sprocket plating is excellent and has protected the sprockets from corrosion. The cassette was horribly black before I started cleaning as I was trying to put off chain replacement until warmer and drier weather. Despite being narrow, these eleven speed components have lasted really well. The quality must have been increased to match the expense.

This large cassette seems very light thanks to all the perforations, the cutaway centers and the aluminium alloy carrier for the largest three sprockets. It's quite a work of engineering art when you think back to the heavy, solid sprockets on a five speed, freewheel block of the past. 11 speeds and all those clever holes would have seemed like alien technology in my youth. Imagine what it would have cost to make such a thing back then! If it was even possible. Each sprocket is ramped and the tooth profile varies around each 'cog.'
Click on any image for an enlargement.


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