Quarq Exogram DZero GXP and new frameset. Compatibility question

[parajba]

I have a Quarq DZero Exogram GXP with Praxis chainrings.

I am thinking about buying one of these frames: S Works Venge 2019, new Canyon Aeroad (when released) or Cervelo S5 Disc (when released).

Can I use my existing Quarq, do I need an adapter?
Thanks a lot

[jlok]

With the right bottom brackets DZero Exogram GXP are compatible with both the Venge 2019 and Aeroad.

[parajba]

With the right bottom brackets DZero Exogram GXP are compatible with both the Venge 2019 and Aeroad.

Thanks, did you mean with a BB adapter or really a BB? The Venge comes with a CeramicSpeed BB if I am not mistaken.

[TobinHatesYou]

Thanks, did you mean with a BB adapter or really a BB? The Venge comes with a CeramicSpeed BB if I am not mistaken.

Either.

You can take your existing BB with CeramicSpeed 6806 cartridge bearings and install a kit like this one from Wheels Mfg. It’s basically a pair of Delrin cups that plug into the ID of the existing bearings and assorted spacers to take up any slack. In the case of GXP, the nature of the stepped spindle design means the NDS cup is sandwiched between the crankarm and spindle...that means any spacers added on that side need to be 30mm ID and go in between the cup and 6806 bearing. The DS spacers are 24mm ID and go between crankarm / cup. The Wheels Mfg instructions don’t mention a wave washer, but I would probably replace the outermost 24mm spacer with a wave washer.

Alternatively you can bang out the CeramicSpeed 6806 bearings and installed a GXP conversion BB.

Since CeramicSpeed bearing sets are exorbitantly priced...what are they like $500, maybe do the former until the bearings wear out, then get a proper conversion BB.

Another option is to just sell your GXP DZero for a BB30 one if you buy a Venge or S5.

This is one reason why I just go with pedal based power meters. Not only are there zero crank/frame compatibility issues, but they are the lightest non-left-only option overall.

[Stendhal]

Thanks, did you mean with a BB adapter or really a BB? The Venge comes with a CeramicSpeed BB if I am not mistaken.

Either.

You can take your existing BB with CeramicSpeed 6806 cartridge bearings and install a kit like this one from Wheels Mfg. It’s basically a pair of Delrin cups that plug into the ID of the existing bearings and assorted spacers to take up any slack. In the case of GXP, the nature of the stepped spindle design means the NDS cup is sandwiched between the crankarm and spindle...that means any spacers added on that side need to be 30mm ID and go in between the cup and 6806 bearing. The DS spacers are 24mm ID and go between crankarm / cup. The Wheels Mfg instructions don’t mention a wave washer, but I would probably replace the outermost 24mm spacer with a wave washer.

Alternatively you can bang out the CeramicSpeed 6806 bearings and installed a GXP conversion BB.

Since CeramicSpeed bearing sets are exorbitantly priced...what are they like $500, maybe do the former until the bearings wear out, then get a proper conversion BB.

Another option is to just sell your GXP DZero for a BB30 one if you buy a Venge or S5.

This is one reason why I just go with pedal based power meters. Not only are there zero crank/frame compatibility issues, but they are the lightest non-left-only option overall.

Hi Tobin. I think this answers a similar question of mine, but am soliciting input to makew sure I am not missing your point.

I just bought a Tarmac SL6 frame (see ad nauseum account in the S-Works SL6 thread ). I also have a GXP crankset, which I prefer to use. At the last minute in the build, the LBS mechanic recommended and installed an all-in-one Praxis BB30 to GXP converter \ BB system, rather than using an outboard mounted adapter. He removed the installed Ceramic Speed bearings, and I have them.

After 50 miles of riding, the new bottom bracket system feels rock solid, but heavier than my prior bike (GXP was on a SRAM GXP \ Italian threaded bottom bracket, about 57g per SRAM; best as I could discern, the Praxis BB system is 155g). Also, perhaps I am imagining things, but I seem to miss the ceramic bearings; this particular Praxis system only comes with metal bearings. (My other bike is also threaded bottom bracket + ceramic bearings, using a cbear BB).

It appears from what you write, and what I heard initially from the mechanic, that if one uses the $30 Wheels Mfg adapter (on sale 20% at Competitive Cyclist too with an online coupon), and puts the Ceramic Speed bearings back in, one do not need a separate BB insert or whatever it is called (I'm terrible at terminology). The result, for only $24 and installation costs, would be:

[*] ceramic rather than metal bearings
[*] replacing a 155g Praxis BB with 48g Wheels adapters = weight savings of (107g - Ceramic Speed bearings weight) = 107g-49g (just weighed the bearings) = 58g

The downside would be not having whatever money I could get for selling the Ceramic Speed bearings on-line, plus, well, a question for all: will the performance of the all-in-one Praxis BB system be so much better, dramatically reducing the risk of creaking as compared to Wheels, that it would be folly to swap out the Praxis?

Am I crazy or missing something, or should I reverse the BB \ crank system decision on the new bike?

[TobinHatesYou]

You pedal at a cadence of probably 90rpm +/-10rpm...perhaps reaching 120-130rpm in sprints. Ceramic BB bearings are largely snake oil. The reduced friction is from using non-contact seals and lighter grease/oil. Even with heavily packed grease, you're losing a fraction of a fraction of a watt going from a good ceramic BB to a good steel bearing BB.

[Stendhal]

You pedal at a cadence of probably 90rpm +/-10rpm...perhaps reaching 120-130rpm in sprints. Ceramic BB bearings are largely snake oil. The reduced friction is from using non-contact seals and lighter grease/oil. Even with heavily packed grease, you're a fraction of a fraction of a watt going from a good ceramic BB to a good steel bearing BB.

I respect this opinion; an Internet check shows that many others concur, and with well reasoned positions.
It appears that the quality of the bearing (roundness, tolerance to spec) matters more than the material, although there may be micro-connections between the two.
Also, Praxis Works products (including BBs) get good reviews, and with a brand reputation for quality to uphold I would think the company would not risk using substandard bearings,
I will evaluate with more riding data, and almost certainly sell the Ceramic Speed bearings in the interim. Tobin, given your position on this, I'm sure you'd pay top dollar for them

[Jugi]

Also, Praxis Works products (including BBs) get good reviews, and with a brand reputation for quality to uphold I would think the company would not risk using substandard bearings,

The Praxis BB is technically considerably better than two "stand-alone" bearings pressed into the frame. Most important features of a long lasting BB are the alingment of the bearings in relation to each other and to the crank axle, adequate weather sealing and general mechanical durability of the BB. A screw-together BB which replaces the typical pressfit solution achieves all that.

[Stendhal]

Also, Praxis Works products (including BBs) get good reviews, and with a brand reputation for quality to uphold I would think the company would not risk using substandard bearings,

The Praxis BB is technically considerably better than two "stand-alone" bearings pressed into the frame. Most important features of a long lasting BB are the alingment of the bearings in relation to each other and to the crank axle, adequate weather sealing and general mechanical durability of the BB. A screw-together BB which replaces the typical pressfit solution achieves all that.

Again, logical.
In the immortal words of Colombo, just one more question for the experts (I do not mean that to be sarcastic or ironic, it's genuine). Will I get similar or better performance (including a lower risk of creaking or mis-alignment), all things being equal, simply by using a BB30 crankset and bottom bracket on the BB30-like Specialized "OSBB" shell, rather than using a GXP crankset with a Praxis adapter? It's an additional expense, but, I think, a 150g weight savings.

[Visus]

With praxis adapter (assuming it has been installed correctly and is of good quality): heavier, will never creak, won't wear out the BB Shells, same performance as BB30
With pressfit BB30 Bearings: depending on frame tolerance might develop creaking and thus wear out the BB shells, lighter, same performance

you decide