40 is the new 34

Bike with Cassette fitted

Front wheel setup

On the largest cassette cog

Sunrace 11-40 cassette

Hi

I've always been a fan of fairly simple things and my latest purchase makes a bicycle simple.  For a while now, mountain bikes have been available with wide range gear systems which rely on a single cassette for their gear range and the current king of the heap is the Sram Eagle 10-50T cassette and gear system, and this is reviewed here .  Its good to have simple controls on mountain bikes too!  The primary focus in mountain biking is not smashing into a tree, and thinking about what front cog you want to select can be a bit difficult at times!


The Eagle is an expensive 12 speed system, it needs lots of fancy pants parts and a narrow chain.  But there has been a trickle down effect, and now wide range cassettes are available as standard parts.  The one I bought is an 8 speed 11-40t cassette from Sunrace, and this comes from the range of Sunrace cassettes listed on their website.  (If you go up to 11 speed, you can get a 46t largest chainring in the same product range, and the largest 10 speed is 42T) A google search on the Sunrace CSM680 part number came up with a few suppliers, and Alibaba looked the best one for me .  Cost was $US 15 plus postage of US 20 or so - quite cheap I thought.  There are now ebay suppliers as well.

Anyway, I fitted the cassette without the 13T, 2nd smallest cog because there was not enough space for it on the spline. A few teething problems involving the chain derailing from the chainring were fixed by replacing the chainring for a sturdier model with aluminium trouser guards / chainplates.  It now runs well on my FWD recumbent leaning trike.  This trike has a custom, large derailleur hanger, which might be part of the reason it actually works. This page details a derailleur extender which might make the equivalent on other bikes.  I am keen to take the trike with the new setup on a few long distance Audax rides involving moderate hills.  Here is the video I made of the trike with the new drivetrain.

The previous "solution" I had for low gears on this trike was a Schlumpf mountain drive.  This is expensive, but on this particular trike (for demo see here) it didn't work that well. It allowed for very low gears, but those gears were too low and produced too high a cadence on steep hills.  And slightly higher gears produced ok cadences but also a stressful pedal steer affect which made it hard to balance.



Regards

Steve Nurse