Bottom Bracket/Magene P505 Compatibility

[reckonair]

Hi All,

New here, looking to build up a bike using an Elves Vanyar, I want it to be on the lighter side of things but also want to record my power output, I’m at a loss on the compatibility side of things as I’m new to building - the elves Frameset comes with a “either a BB386 -24R Shimano compatible, BB386-29R SRAM DUB or BB386-30R Rotor bottom bracket.”, I want to pair carbon chainrings (looking at the riro GXP ones) with a magene PES p505, would this be possible?

Thanks!

[TidyDinosaur]

The Riro Carbon crank will fit a shimano compatible BB. I have 2 and on one I have the P505 PM.
BUT: the spindle on the crank is too short to be able to fit all bottom brackets. I consider this a fault in the design. I could not get the bolt of the crank tight enough with an Aliexpress BB without the bearings seizing (and I am not the only one). When I changed it to a Shimano branded BB it was OK. It seems the generic BBs usually use 7mm wide bearings and shimano uses 6mm.
Since you don't really have much choice of bottom brackets with that frame (I presume), this might become a problem.

[reckonair]

Can the supplied BB be discarded and a fresh Shimano branded one be used (as long as it’s to BB386 spec?) if so are threaded/press fit BBs interchangeable? Sorry for the stupid questions I’m new to building bikes.

Thanks!

[TidyDinosaur]

Can the supplied BB be discarded and a fresh Shimano branded one be used (as long as it’s to BB386 spec?) if so are threaded/press fit BBs interchangeable? Sorry for the stupid questions I’m new to building bikes.

Thanks!

I have a BSA bb and there the riro crankset works with the shimano BB. No guarantee it will work with other Standards...

[coffeebreak]

Can the supplied BB be discarded and a fresh Shimano branded one be used (as long as it’s to BB386 spec?) if so are threaded/press fit BBs interchangeable? Sorry for the stupid questions I’m new to building bikes.

Thanks!

Supplied BB can be discarded and other one can be installed - yes. Also press fit and threaded BBs are not interchangeable that is why people pay special attention to what sort of bottom bracket shell is on the frame they are considering. The press fit bb shell will not have threads to install traditional threaded bottom bracket like the good old BSA 68MM or T47. The BB386/30/92/86 etc shells don't have threads at all and they all rely on "pressing" the cups into frame rather than threading hence the name.

Having said that, to add to confusion there are certain "thread together" bottom brackets that you can install in the press fit type shell. The important distinction here is the bottom bracket cups don't thread into frame (like BSA) but rather into each other as in both cups tighten into a metal tube that attaches both cups. Look up Token Ninja BB386 thread together bottom bracket or Wheels Manufacturing thread together bottom bracket. These type of bottom brackets take care of creaking issues that lot of people face on press fit type shell.

Also it's easy to adapt already installed bottom bracket to different types of cranksets. You just need correct sized bearing adapters for your bottom bracket. That's exactly what Elves is doing when they give you option of different bottom brackets. E.g.You can install Shimano crankset in a BB30 frame with help of 30mm to 24mm reducer cups
Same applies to BB386. You can get 30mm to 29mm reducers to install SRAM cranksets.

Check what sized crankset you are eyeing and get the reducer adapters on your own or ask Elves to do it.

[jonathanf2]

The Riro Carbon crank will fit a shimano compatible BB. I have 2 and on one I have the P505 PM.
BUT: the spindle on the crank is too short to be able to fit all bottom brackets. I consider this a fault in the design. I could not get the bolt of the crank tight enough with an Aliexpress BB without the bearings seizing (and I am not the only one). When I changed it to a Shimano branded BB it was OK. It seems the generic BBs usually use 7mm wide bearings and shimano uses 6mm.
Since you don't really have much choice of bottom brackets with that frame (I presume), this might become a problem.

I was only able to fit the Riro carbon crankset on my Shimano BB equipped bikes (regular PF and threaded BSA). My BB86 threaded PF bike would seize with the Riro crank. I'm surprised I haven't heard issues from other owners of this crankset. It seems quite popular.

[reckonair]

Not sure where do go with this now - looking at using an LTWoo Erx but wanting to track power and prioritise weight (pick one I guess) as it’s a climbing build. Does anyone know of a crankset that would fit the case? Or just a light crankset? I can look into pedal based PMs if easier

[toxin]

How much you ready to spend?

[reckonair]

Not really sure tbh! Just been window shopping and pricing things up, probably about 2k on a build but can go upwards from there

[toxin]

Well if you want to lose any meaningful weight on the cranks you need to go with carbon cranks.

Riro and Racework carbon cranks are the cheapest options that this forum likes but I personally really don't because of the wide q-factors and aluminium 24 mm spindles.

Next step up are Lexon carbon cranks which appear to mostly be a slightly aesthetically modified version of cybrei cranks for 65% of the price.

Then there's Elilee, Skypivot, Cybrei and a few "cybrei-esque" cranks for around 400€ all somewhere in the 320 g vicinity.

Perhaps your best option is if you can find a retailer selling discounted carbon sram red cranks. They're cheaper now to get rid of old stock as the new models will be coming in soon.

As for power meters, Favero Assioma (the only reasonable pedal pm option) and spider based power meters all come with a pretty similar weight penalty

[TidyDinosaur]

Not sure where do go with this now - looking at using an LTWoo Erx but wanting to track power and prioritise weight (pick one I guess) as it’s a climbing build. Does anyone know of a crankset that would fit the case? Or just a light crankset? I can look into pedal based PMs if easier

You could just look for a BSA-based frame and make life easier for yourself.

[reckonair]

Any recommendations for a decent lightweight frame?

[jonathanf2]

Any recommendations for a decent lightweight frame?

Onirii One is an Aethos clone which takes a threaded BSA bottom bracket and you should have no problem using a Riro crankset. For more money you could go the Panda Podium route and get a Big Rock (another Aethos type clone) either in regular (730G) or lightweight Team edition (603G), but it'll cost more money for sure.