The Mavic K10's I had on my bike are toast due to an unfortunate meeting with an SUV. Thankfully, my brother is selling me his old custom built wheels. I know nothing about these and was hoping BF could educate me on how these compare to the K10s. What do I gain/lose out on?

Kinlin XR200
Sapim CX Ray Spokes
Alchemy ELF front hub
White Industries rear hub
20/28 Build
https://www.flickr.com/photos/quality...57622907949859

At ~1290 grams, they seem to be a much better $/gram value than the K10s.

Sound like very nice wheels. Hubs are great. What's your weight. If you're on the heavier side, go a little easy on the front wheel i.e. don't use it for hopping curbs etc. The Kinlins are pretty stiff, durable and light, but the XR200's do sacrifice some durability and stiffness for weight, esp. w/ a 20 spoke count, but that shouldn't really matter as long as you're not 250 and slamming into potholes.

As eippo1 said, that's a very nice set of wheels built for a relatively light person. I'm on the same rims with 28 spokes front and rear, and at 180 lb had no problems. I personally wouldn't recommend 20 spokes up front on those rims for anyone over 140 lb, mainly from a spoke tension standpoint. If you like climbing, this super light set should gain you 2 mph in placebo effect alone.

I'm just shy of 160lbs.

If these wheels are lighter than my Mavic K10's, and about half as expensive, what advantages do the K10's have over them? Durability?

durability? probably
stiffness? most likely

So then despite being lighter, these wheels are not as durable and not as stiff? Would K10's generally be preferred over these? Just curious as to whether this would be a downgrade/upgrade/equal to what I had. Mostly for the placebo effect, of course!

They probably have a beefier rim, but that's about it. If the Kinlins were handbuilt by a competent builder who took care with the spoke tension, they will last quite a while. At 160, just be wary of potholes and the like, and try to lose 10 or 20 pounds (if you have any extra fat to lose).

Personally, I think just about every wheel and rim Mavic sells today is overpriced and underperforms. They got too big of a name and are now greedy from it.

I can probably drop to 150 if I stopped lifting weights for my upper body, but that's not a sacrifice I'm willing to make right now.

Would it be possible/worth it for me to have the fronts rebuilt with 24 spokes instead?

Hubs and rims have specific hole counts. So not possible to have yours rebuilt with the existing parts AND get a higher spoke count. You'd have to buy both with 24 holes and have them built. Possibly worth it, but probably not.

Advantage of factory wheels is debatable, and I imagine arguments cite both fact and opinion. You definitely get more bling, and bling is good. It just won't win a practicality argument.

Somebody who knows something about wheels built those, I'm quite sure. That's a very boutique wheelset. They're very nice, and would be great to own.

But then, I'm an "anything-but-Ksyrium" kind of guy.

Sounds like you have a great set of climbing wheels in the Kinlins, with that spoke count, over a good pair of all rounders which is what the mavics are. If you do have problems with the front you could try a beefier spoke since you have a bit of scope to make the wheels heavier without ending up with an anchor for a wheel, or changing lacing pattern, but I have to admit I've never ridden with cx rays and don't know what is stronger in terms of spokes. The flange spacing of the elf front hub is pretty wide also so chances are you've got a plenty stiff front wheel already, with potential to build it into a really stiff one.

I wouldn't bother. You'd have to buy new rims and hubs, and it's not a good idea to reuse spokes or nipples. So, that's buying a whole new wheel. As mentioned above, they were probably built by a knowledgeable person, and as long as you don't run over big objects in the road or hammer through potholes, they will be fine.

Reminds me of the farmer who loved to tell everyone about his favorite axe. He'd proudly say it's an heirloom, that it's been in his family for several generations, and that the handle has been replaced three times, and the head twice.

I have a similar build;

XR200s
Extralite SX Hubs
Sapim Xrays 24-28.

They come in at 1160 grams.

I am 138 pounds and love these wheels. They were so much better and cheaper than an equivilent mass build. They accelerate so quickly and love the weight.

Wow that's light! This does have me concerned with my set of 20/28 since I'm quite a bit heavier at 160lbs. and you're already running a beefier combo of 24/28.

So do you guys say these are climbing wheels because of the weight/savings from less spokes? What characteristics would wheels for flat-ground/straight line speed have? Or is it simply a trade-off in durability (climbing = lighter, but less durable; regular = heavier, but beefier)?

Wheels for flat roads would be more aerodynamic and would be less concerned with weight. They also might be stiffer because racers are more likely to be in a sprint on flat ground.

My builder said that for an extra 4 spokes plus nipples it was worth getting the stronger front wheels. Plus my hubs are where the weight savings are.

Light, low profile rimmed wheels are climbing wheels because the weight reduction gives some advantage during slow speed and accelerations. For flat ground and at higher speeds weight takes a big back seat to aerodynamics. Good flat ground wheels will have deeper rims and possibly reduced and/or bladed spokes.

What kind of riding do you do? Any racing? Hills in your area? Good or bad roads? What is your budget? These things are all pertinent to your wheelset choice and you will get better advice if people know how you will use your wheels.

If you are only going to have one set of wheels my choice would be for more of an all purpose set with deeper rims and maybe a few more spokes in front. If you like the idea of handbuilts I would recommend Kinlin XR270-28/24 DT Comp Spokes-White Industry hubs a good starting point for an all around set. Probably cost $500-600 depending on who builds them. For factory wheels the Easton EA50-70-90 series offers some good choices depending on your budget.

how would you compare the durability of those rims to a Velocity a23?

Close. Some people get hung up on Velocity's rim joints but durability wise there's not much in it. Rim width would be the main difference, are the Kinlins 23mm wide rims?

No, the kinlins are 19mm wide. Typical for an aluminum clincher.

I'm interested in the a23's because of the 23mm rim for the apparent tubular like ride quality, but I don't want to sacrifice durability if I'm going to get a custom wheelset built. I'm trying to find the most durable, yet still reasonably lightweight training wheel for around 500-600$. I saw the Velocity a23's laced to White Industries on Wheelbuilder.com and was wondering about the durability for a 180lb sprinter but still able to handle a lot of climbing.

Sounds like a nice set if they meet your needs. Similiar to a build I'm waiting to get shipped.

Kinlin XR270 Rims:
Alchemy ELF/ORC Hubset:
Sapim CXray Spokes (20/28):

I weigh in at 166 lbs right now.

Xr-200's are not a daily riding rim for the majority of people who swing a leg over a top tube. They are a climbing specific rim. Make it do anything else and it will fail before other rims would.