Xiamen Carbon Speed rims/wheels

[CycOps]

@PeterXu
Do you laminate your rims in-house?
Do you drill drain holes as standart and what are your thoughts about drain holes?
What's recommended tire size for your 26mm inner width rims?
Lots of questions ;-)
I've built wheels with timetec, carbonal and carbonbeam rims so far.
Might try yours next.
Thanks for answering.
Oh and if possible, implement prices in EUR on your web site ;-)

[PeterXu]

@PeterXu
Do you laminate your rims in-house?
Do you drill drain holes as standart and what are your thoughts about drain holes?
What's recommended tire size for your 26mm inner width rims?
Lots of questions ;-)
I've built wheels with timetec, carbonal and carbonbeam rims so far.
Might try yours next.
Thanks for answering.
Oh and if possible, implement prices in EUR on your web site ;-)

Yes, our rims are made in our own factory.
Our rims are drilled with drain holes/ pressure relief holes as standard.
Minimum tire size on our 26mm internal hooked rim is 28C, 30/32C are perfect fitting.

[glepore]

The idea that 100g off a set of wheels is significant enough to affect their handling seems implausible. More likely, the shape of these rims or the geometry of your bike is the reason why riding deep wheels in crosswinds is hard for you.

Crosswind instability arises from a sudden pressure difference between the wheel's two sides as the wheel enters a stall. Once in motion, a heavier wheel would have more torque-induced precision, not less. Looking at the wheel in isolation, a wobble induced by a stall would be worse with a heavier wheel and better with a lighter one. Meanwhile, if the effect is one of system inertia, the mass of the wheel is inconsequential in relation to the mass of the system.

I would love to understand where the Nero guys, Joe, or whoever started talking about light wheels being less crosswind-stable just because they were lighter got the idea from. It doesn't make sense to me that it would be significant.

100% agree. I also find that running a deeper rear than front helps, whether its from different stall points or simply that the aero center of pressure in a crosswind is moved rearward away from the steering axis.

[CycOps]

Yes, our rims are made in our own factory.
Our rims are drilled with drain holes/ pressure relief holes as standard.
Minimum tire size on our 26mm internal hooked rim is 28C, 30/32C are perfect fitting.

Thank you for your answer @PeterXu
As there are manufacturers who offer drain holes as standart and others who offer no drain holes as default, I would be very interested in your opinion about drain holes in general, their size and their exact location in regards to the rim bed. Peter, are you willing to share?

[Ludo]

At this point the need for drain hole (well vent hole really) has been well documented and the only reason not to do it is to save money by cutting a manufacturing step i think

[CycOps]

@Ludo I disagree. If it was just for venting, you wouldn'd need drain holes in tubular rims and real tubless rims, the ones without nipple access holes. IMHO drain holes have the main function to drain any moisture out of the rim. A fellow cyclist in a local group here just asked around how to drill drain holes in a wheel set without, as he gets water inside his rims when gravel riding in the wet. I told him to take a sharp drill and just do it, as I've done it before.
Now I just got a set of chinese carbon rims where the manufacurer doesn't drill drain holes as standart but did it on my request, and I think they shoud be closer to the rim bed for beeing more drain effective useing the centrifugal force without letting water left in the rim.
If there's a full discussion on this topic somewhere I'm happy to konw where to read.

[patliean1]

Funny Story Time

A company sent me out a set of wheels to review. Upon delivery of the wheels not only are they HOOKLESS, a detail they failed to mention anywhere on their website, but the rims have no drain holes. Double whammy.

I immediately and respectfully emailed the company asking about their thought process. Telling them to update their website to include hookless in the description but also the decision not to use drain holes. I offered a couple of valid reasons why almost all wheel brands include drainage IE pressure relief and water ingress drainage.

Here was their response:
"This comes down to a design choice rather than a flaw. Some brands incorporate drainage holes, others intentionally do not. In fact, in the mountain biking space many riders prefer rims without them. While drainage holes can serve a purpose, their absence isn’t considered a defect and ultimately falls into a preference-based design decision."

To be fair, the wheels are ultra budget entry-level. But I took their response as some sort of corporate deflection tactic.

[Sakizashi]

I think the role of drain holes in rims for venting is sort of overblown because the visual of exploding rims evokes such strong reactions. I don't think they are truly needed as a requirement, but I like to see them because I prefer that my rims can dry out if water gets in there.

I don't think any of my MTB rims have drain holes.

100% agree. I also find that running a deeper rear than front helps, whether its from different stall points or simply that the aero center of pressure in a crosswind is moved rearward away from the steering axis.

The rear doesn't need to be deeper, just more aero at shallow yaws to get this effect. See the new Rovals for an example of this.

[gribs]

I'm not sure I understand the holes for venting at all. It could only really be a problem if you're running tubeless, but then you'd have sealant that would literally seal the hole.

[CycOps]

The venting through holes on the rim - normally 2 in total, one one each side, is seen to be necessary when you run a tubless set-up in a rim with nipple access holes ans theirfore tubless tape, and the tape let's pressured air from the tire I to the profile (chamber) of the rim.

[Uberflo]

I ordered two wheelsets from Peter. One new 78 mm road wheelset with the ultralight hubs and one gravel wheelset.

[dolph]

The venting through holes on the rim - normally 2 in total, one one each side, is seen to be necessary when you run a tubless set-up in a rim with nipple access holes ans theirfore tubless tape, and the tape let's pressured air from the tire I to the profile (chamber) of the rim.

My elitewheels 5 spoke wheelset has no rim holes but its got 2 drain holes, air can leak to the rim cavity because any bike rim will always have a valve hole.

[mtm]

Do we have any profile drawing of the new 78mm rim yet? Haven't seen it at least, but maybe I missed it?

[Ludo]

@Ludo I disagree. If it was just for venting, you wouldn'd need drain holes in tubular rims and real tubless rims, the ones without nipple access holes. IMHO drain holes have the main function to drain any moisture out of the rim. A fellow cyclist in a local group here just asked around how to drill drain holes in a wheel set without, as he gets water inside his rims when gravel riding in the wet. I told him to take a sharp drill and just do it, as I've done it before.
Now I just got a set of chinese carbon rims where the manufacurer doesn't drill drain holes as standart but did it on my request, and I think they shoud be closer to the rim bed for beeing more drain effective useing the centrifugal force without letting water left in the rim.
If there's a full discussion on this topic somewhere I'm happy to konw where to read.

You can still leak though the valve seat on tubeless set up

[Ludo]

I'm not sure I understand the holes for venting at all. It could only really be a problem if you're running tubeless, but then you'd have sealant that would literally seal the hole.

Most of the rim explosion/delamination seem to happen when applying quick pressure to seat the tire in, before you put sealant. I delaminated a rim exactly like that, due to leak at valve stem seat.