Replacing Shimano cranks with carbon

Started by crazyravr, October 07, 2025, 08:54:55 AM

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crazyravr

Is this a simple swap or are there things to look out for? Is the Q factor the only thing to consider?
Currently I am using 105 cranks with shimano chainrings on one of my bikes. I would like to replace the cranks with carbon BUT keep the same rings and not do too much tinkering after. Is the below a good option or would you recommend something else (better or cheaper)? The below "should" have the same Q-factor as a Shimano 105 crankset.

https://www.aliexpress.com/item/1005009175039163.html

jonathanf2

If you run into issues I highly recommend this 3 bolt spacer for that Bigrock crankset you linked. This allows you to move the crankset further out without altering your chain line too much if you do run into problems like your FD hitting the crank arm. Using this, you can either use a thin spacer or no spacer at all on the axle to get a good chain line with Shimano chainrings.

https://www.aliexpress.us/item/3256808692988907.html

crazyravr

#2
Quote from: Serge_K on October 07, 2025, 09:16:23 AM
i've never paid attention to Q factor because road cranks should be road cranks, and a few shims / spacers usually solve problems.
Spindle (axe de pedalier) is to consider, but your link is 24mm, which is the Shimano standard.
For cheaper, but in 170mm only, there are Riro and Racework options, and i think both have adaptors to run shimano chainrings. Bearing in mind their chainrings cost 25 eur shipped, we together have probably put 30,000km on these chainrings, they work, they just need replacing more often than Shimano ones.

I assume this is what you are talking about? https://www.aliexpress.com/item/1005007344893638.html
This has Q-Factor:153MM so 7mm wider than stock. Pretty sure there will be quite a bit of tinkering with the chainline here.

toxin

No, that's a 24mm aluminium axle, nobody should ever buy that.

vermit25

I am also looking for something similar.
What do you guys think about this: https://www.aliexpress.com/item/1005009549219633.html?

Da11as

Quote from: vermit25 on October 07, 2025, 03:08:00 PM
I am also looking for something similar.
What do you guys think about this: https://www.aliexpress.com/item/1005009549219633.html?
Another Cybrei clone. As always, should be fine

toxin

Well it's not really a clone if it all comes from the same factory

vermit25

Quote from: toxin on October 08, 2025, 03:02:20 PM
Well it's not really a clone if it all comes from the same factory
Quote from: Da11as on October 08, 2025, 02:21:43 PM
Another Cybrei clone. As always, should be fine

If these Leese cranks are the same as the Cybrei's, how come the Leese ones are so much cheaper?
Note that I was not able to find the Cybrei's on Ali.

toxin


crazyravr

Pretty sure I have decided to go with this one... the titanium alloy sold it for longevity and durability.
https://www.aliexpress.com/item/1005009549219633.html

vermit25

Yeah it seems like a good choice with the titanium axle and a pretty good price.
Let me know how it goes as I am looking to get one towards the end of the year.

Da11as

Quote from: vermit25 on October 09, 2025, 07:59:07 AM
If these Leese cranks are the same as the Cybrei's, how come the Leese ones are so much cheaper?
Note that I was not able to find the Cybrei's on Ali.
Quote from: toxin on October 08, 2025, 03:02:20 PM
Well it's not really a clone if it all comes from the same factory
Indeed, I mean it is the same design with slightly bigger weight/worse finish/possible inconsistencies

hubba

Those titanium axles that were tapered in the middle were known to have some stiffness issues. Most moved away from them so it's an older design.

toxin

I wouldn't say "most" moved away from it. That was certainly the reason Elilee moved away from it, but it's still quite common, it's even what Cybrei use. It's easier and therefore cheaper to make, which is why I'd say it's still pretty common.

bichler.bua

Quote from: crazyravr on October 07, 2025, 11:53:50 AM
This has Q-Factor:153MM so 7mm wider than stock. Pretty sure there will be quite a bit of tinkering with the chainline here.

Small note: Q-factor and chainline are not the same, even if it is likely that a larger Q-factor might impact the chainline it does not have to be the case