Upgrading chainring and bottom bracket. My experience.


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I just wanted to tell my experience after changing the old crankset from this piece of crap

and the standard Turbo chainring and crankset and pedals.

JESUS! what a difference! I do not understand why I didn't do that before. I guess is because I was not sure about the components that I had to buy and if they were to fit my Turbo. After doing some extensive research, everything worked fine, and I'm proud to say that I was able to select the proper components at once, at the only order.

I think even the battery life improved a little bit after this more-efficient pedaling =)

Total cost of the upgrade: +/- 200 dollars in components (excluding tools, I did the job myself).

If you are interested, these are the components selected:

Bottom bracket:

Shimano Dura Ace BB-R9100 (buy the original in the box, the one that comes with the adapter, there's a cheaper version without the adapter but you will need it to tight it properly in the screw).

Chain ring: New BB also implies changing the chainring, right? not only because it has to be compatible with the new BB, but also because the old one I had, was too worn, due to delaying chaning the chain. Rookie mistake. If you don't change your chain after it has lost it's "rigidness", it will wear off the chainring and the casette very quickly. Have that in mind. Chains are much cheaper than Chainrings and casettes to change. You can easily check if your chain is worn using this cheap tool

Shimano FC-R460

I chose this particular model because it was the only one I could find of 48T at a decent price. I don't mind that it has a smaller chainring, it might even be useful in the future. This model also has special teeth that makes the chain harder to fall.

The chain: Shimano CN-E6090 specially designed for e-bikes and for the new chainring (the chain ring manual says "use only with HG-X shimano chain which I did).

And to complete the upgrade, for the pedals I chose this model: Shimano PD-MT50

I also want to change the cassette and the rear derailleur for a newer model (the ones that have a small lever where you can make the chain stiffer), but I haven't received those yet, so that will be for another entry.

Have fun!
Hi, I replaced my derailer on my St2 , $52 well spent on the bike. What a difference in shifting that made. So easy to bump and move out of proper allignment with cassette. Visually checking from rear looked out, which was correct on new replacement. Nice job on your turbo. St2 is awesome. Thanks on tip for checking chain wear, put that on my bucket list I have been neglecting.
I need to replace my bottom bracket. It is very rough. When you were ordering parts did you get the 68mm or the 70mm? I can't find any literature on this.

I am thinking of getting a SRAM and a new SRAM Rival 1 crankset and chainring.
I changed my BB and chainring with a Praxis Zayante M30 direct-mount 42T. I wish I'd changed to a 42T a long time ago! Now I can actually use my 11T sprocket that was never needed with the 48T.


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I was suffering chain drops very frequently with my previous chainring from above, so I decided to buy a new one with less theeths and with a chain drop protector as this Alfine FC-S501 (around 65 dollars).

I can't be happier with the purchase. Chain drops are a thing of the past. This model is 45T and I feel it more comforable, specially on the higher speed cog, than the previous 48T I had.

I went with a fairly affordable Race Face Ride crankset and threw out the 34T chainring. I used the same 48T 104BCD chainring I had before and ordered another (similar) 50T narrow-wide chainring made by Deckas (you can buy them through eBay or AliExpress). It did make a big difference to the ride, as my old one was worn without me really noticing.
I haven't installed the new chain ring yet as the old one was still OK. I did replace the chain, which I do every 6000km or so.

Another thing to replace is the rear freehub assembly. Mine was making weird noises. Replace at about 10-15,000km. I had done 19500km.
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