I need to replace the spindle in my Velo Orange Grand Cru bottom bracket. I marred the female threads of the spindle. I contacted Velo Orange and they do not have spare spindles.

I can't seem to find replacement spindles for cartridge bottom brackets. Any advice?

As the whole selling point for cartridge BBs is that you toss them when they are gone instead of rebuilding, I would think replacement spindles for them would not be something commonly available. Perhaps steal one out of another BB?

Are you sure that's the selling point of a cartridge BB? I agree they do not require the maintenance of a cup/cone BB, but replacement cartridge bearings are widely available. I don't have any other spindles that will work. I need one in the 107-109mm range.

Phil Wood specifies a tight tolerance press fit between the axle and bearing ID,
so they can be pressed out and changed, ..

have you an arbor press to remove that axle?

some designs put a shoulder on the axle, some don't?
I have no Idea about the way VO's source contractors put their BB assemblies together
never owning one.. ,
You may be able to rethread the axle oversize,
if you have the right tap and a replacement bolt.
OTOH,

You may be stuck with just buying another whole unit.
As there is no universal common cartridge bearing BB spindle.

do they offer a cut away diagram as to how they were made..
and a link for the curious

Have you taken it apart? I did not know they could be serviced at all. I assumed the term "cartridge" referred to the whole assembly, not the bearings. I could be wrong......

No. I do have a deep freezer, wood blocks and a hammer.

I'm not aware of a diagram of VO's BB. I do not know the manufacturer.

I believe you are incorrect. Think about it. I'm supposed to throw away my $50-200 cartridge bottom brackets after 10-15k miles?

well its apparently toast as it is , bang away on it and see how its made..

Loc tite Corp has some interesting compounds for threaded machine parts ,
perhaps some will build up your damaged threads and still let you take it apart again.

I found this Ritchey replacement spindle. The auction states that it is compatible with Tange and other manufacturer's BBs. It's the best thing I've found so far (and likely the best I will find). Thoughts?

It's a shame too. Zero miles; hasn't even had a non-drive side arm mounted.

Mixing spindles and cups from different BBs is usually a hit and miss operation even when the BBs utilize standardized bearings. Otherwise, separate spindles tend to be available only for high end BBs - Phil Wood and Action Tec.

I support the bike parts industry the same way Colonel Lloyd does. FUBARed many parts before their natural mortality. Just buy a new cartridge BB and think of it as a lesson in bike mechanics and helping out your parts supplier.

NB: over-tightening square taper crankarms on the tapered BB axle ends,
can damage the crank arm also, by over stretching the aluminum..

moderation in all things , use of spanners included.

Fair enough.

The spindles are not meant to be replaced. The BB functions as a whole (as most cartridge BBs do). I also seriously doubt it would wear out after 10k miles unless these were really hard miles. Even if that was the case, you could ride ~15 miles everyday for ~three years. Sorry you ruined the threads, but unless you can re-thread it somehow, it will need replacing.

Just thought I would share this with everyone. I had emailed Velo Orange asking to buy a replacement spindle, but as they aren't a part that normally wears out, they do not stock them and had none around. But today, I get an email from a VO employee saying the following:

Thumbs up, VO!

Both you and the person at VO are named 'XXXX?' Weird!

I'm Justin. He's Alec. I didn't really think names were necessary, but there you go.