Author Topic: Riro 24mm axle carbon crankset  (Read 3094 times)

Sebastian

Re: Riro 24mm axle carbon crankset
« Reply #15 on: December 02, 2024, 11:22:38 PM »
There's a reason that Shimano 24mm axles are made of steel.  They are just not strong enough.  Dub axles at 29mm can be aluminum but of course they are much bigger and therefore stronger.

Hambini did a video on this and argued that it can be done if the wall
Thickness is thick enough and the aluminium grain structure is consistent enough. However you still have the problem of steel bearings wearing on the axle as it happens with all aluminium crank spindles over time. And then I wonder just how much of a weight advantage there’s left if you built an aluminium crank spindle sturdy enough in 24mm. I think there’s also a reason why until now every aluminium spindle was oversized, BB30 or DUB. Same reason why aluminium bike frames are oversized when compared to steel. Stiffness to weight qualities of aluminium just work better that way.

jonathanf2

Re: Riro 24mm axle carbon crankset
« Reply #16 on: December 13, 2024, 02:24:44 PM »
Hambini did a video on this and argued that it can be done if the wall
Thickness is thick enough and the aluminium grain structure is consistent enough. However you still have the problem of steel bearings wearing on the axle as it happens with all aluminium crank spindles over time. And then I wonder just how much of a weight advantage there’s left if you built an aluminium crank spindle sturdy enough in 24mm. I think there’s also a reason why until now every aluminium spindle was oversized, BB30 or DUB. Same reason why aluminium bike frames are oversized when compared to steel. Stiffness to weight qualities of aluminium just work better that way.

The Riro/Racework 24mm carbon crankset is about 388g (ver. 1 was about 377g) and the Goldix hollowed out alloy crankset is about 477g. I also have the Racework/ZRace 24mm steel axle crankset and that one is about 560 +/-. I keep that one around just in case one of my alloy axle spindles has a failure, but no problems so far. All are 3 bolt cranksets. Carbon crank arms save about 100g and going with a 24mm alloy axle saves another 80-100g. I guess the Chinese crankset makers could make a carbon crankset with steel axle, but they probably figure the weight savings wouldn't be worth the hassle. Though that would probably silence all the alloy axle naysayers!
« Last Edit: December 13, 2024, 02:26:35 PM by jonathanf2 »

pavlo.k

Re: Riro 24mm axle carbon crankset
« Reply #17 on: December 15, 2024, 09:54:05 AM »
I had to return the crankset. The problem metioned earlier about the cranks seizing up the bb was happening on 3 different bikes with 3 different bbs. ztto threaded pressfit and token ninja would seize up completely even without the preload ring installed. On shimano bb92 pressfit bb the crank was still moving but was very tight, definitely overloading the bearing.
I think it's either the axle that's too short or the actual material of the axle is too soft so when it's toruqed correctly, the driveside crankarm sits deeper on the splines that it should.

TidyDinosaur

Re: Riro 24mm axle carbon crankset
« Reply #18 on: December 16, 2024, 07:27:28 AM »
I had to return the crankset. The problem metioned earlier about the cranks seizing up the bb was happening on 3 different bikes with 3 different bbs. ztto threaded pressfit and token ninja would seize up completely even without the preload ring installed. On shimano bb92 pressfit bb the crank was still moving but was very tight, definitely overloading the bearing.
I think it's either the axle that's too short or the actual material of the axle is too soft so when it's toruqed correctly, the driveside crankarm sits deeper on the splines that it should.
Looks like a Shimano BSA BB is your best bet to get this working. I use 3 of these cranks on this type of BB and no problems.

jonathanf2

Re: Riro 24mm axle carbon crankset
« Reply #19 on: December 16, 2024, 10:42:03 AM »
I'm curious how Trace Velo got his Riro 24mm crankset to work with a BB86 threaded PF on his OG-Evkin frameset? It seized up when I tried using it on BB86 frame and the Mangoe Cycling store who seems to be the biggest seller of the crankset, told me to stick with threaded BSA.

volan

Re: Riro 24mm axle carbon crankset
« Reply #20 on: December 18, 2024, 11:11:59 AM »
I had to return the crankset. The problem metioned earlier about the cranks seizing up the bb was happening on 3 different bikes with 3 different bbs. ztto threaded pressfit and token ninja would seize up completely even without the preload ring installed. On shimano bb92 pressfit bb the crank was still moving but was very tight, definitely overloading the bearing.
I think it's either the axle that's too short or the actual material of the axle is too soft so when it's toruqed correctly, the driveside crankarm sits deeper on the splines that it should.

Here's my experience: shimano bb was too tight on my 268 bb shell. Or probably, and most likely, vb 268 bb shell was a bit too tight for plastic bb, so the bearings got squeezed more then they should. I then installed ztto threaded bb and when I torqued the riro cranks, they would seeze and not spin well. I then noticed that I could tighten the bb cups a bit more. They were pretty close to the frame shell, but still had just tiny bit of room left to sit really fluish to the frame. So I tightened them just a bit more...

then, I could tighten the cranks pretty tight without seezing. So they really need to be on the point with the bb width in order to be tightened to the specd torque. I've been rinding them, now about 500kms, they work pretty darn well.

However, I have one question. The bolt that's on the drive side, one that had the torque specs written on it, I would like to buy one spare cause I think I saw trace velo said on one of his videos that it failed on him, but I don't know what video was that... Is it same as ordinary DUB crank bolt?
« Last Edit: December 18, 2024, 11:13:42 AM by volan »

KopytoNieBladzi

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Re: Riro 24mm axle carbon crankset
« Reply #21 on: December 18, 2024, 01:13:20 PM »
Hope it's gonna last more than I think  :-X
DH-Devinci Wilson carbon 2013 RC,
Enduro-Santa Cruz Nomad CC v4,
XC-Cannondale Scalpel Carbon 2023
and now tourist-Carbon GR201(some may call it a gravel even)

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