Author Topic: Xiamen Carbon Speed rims/wheels  (Read 651964 times)

toxin

Re: Xiamen Carbon Speed 10 years anniversary special promotion
« Reply #195 on: December 12, 2024, 08:58:41 AM »
On all hubs, but since mtb hubs see much higher and frequent impact loads, bigger bearings are more beneficial on them than road hubs. I think if dt swiss use 6802 on dt180 hubs, then they should be fine for most road riders.

Bigger bearings would theoretically have more drag as they have more balls, but that means the loads are distributed over a larger contact area, meaning the loads on individual balls are lower, meaning they will wear slower. But the larger contact area means there will be marginally more drag, virtually irrelevant amounts for bike applications though. Seals make magnitudes more impact on bearing drag.

The tradeoffs with bearing sizes in hubs are usually size and weight vs durability:
• smaller bearings means lower weight and smaller, fractionally more aero hub
• bigger bearings means better durability against wear and dirt ingress.

Sakizashi

Re: Xiamen Carbon Speed 10 years anniversary special promotion
« Reply #196 on: December 12, 2024, 01:41:00 PM »
On all hubs, but since mtb hubs see much higher and frequent impact loads, bigger bearings are more beneficial on them than road hubs. I think if dt swiss use 6802 on dt180 hubs, then they should be fine for most road riders.

Bigger bearings would theoretically have more drag as they have more balls, but that means the loads are distributed over a larger contact area, meaning the loads on individual balls are lower, meaning they will wear slower. But the larger contact area means there will be marginally more drag, virtually irrelevant amounts for bike applications though. Seals make magnitudes more impact on bearing drag.

The tradeoffs with bearing sizes in hubs are usually size and weight vs durability:
• smaller bearings means lower weight and smaller, fractionally more aero hub
• bigger bearings means better durability against wear and dirt ingress.

I don't know enough about bearings to make a definitive statement on size and choice of bearing regarding size, drag, and durability. I do know enough to know that it's more complex than this, and a first principles approach like this can be really misleading (same as saying X shape is aerodynamically faster based cross-section without taking into account other factors like varying yaw angles)

For example:
  • Not all bearings of the same size have the same number of balls. In addition to corrosion issues, this is why i tend to avoid cheap ceramic bearings.
  • Material choice and coatings can also matter.
  • Preloads can be a huge factor. For example, if you are worried about the load on a smaller area but can manage preload well with the design, a smaller ACB might be a better choice than fitting a larger radial bearing in a design where preload cannot be as well controlled.

Nkearb

  • Guest
Re: Xiamen Carbon Speed 10 years anniversary special promotion
« Reply #197 on: December 12, 2024, 02:20:55 PM »
Thanks for the clarification, peter. I wasn`t aware the rims are basically made to order.

Had to change to narrower rims, because winspace is very stingy on clarifiying their tyre clearance on the slc 3.0...They can`t deliver the measurment of the chainstay gap at the wheel.
Be it as it may, i`m looking forward to the wheelset.

I have a SLC 3.0 in size L. Othersizes may have difference clearances.

The D65-33 fits with plenty of clearance.

Im actually considering buying the D50-36 for my SLC 3. The front would fit easy, the rear most likely fit fine, wouldnt want to go any bigger though

KaiDeus

Re: Xiamen Carbon Speed 10 years anniversary special promotion
« Reply #198 on: December 12, 2024, 02:57:00 PM »
I have a SLC 3.0 in size L. Othersizes may have difference clearances.

The D65-33 fits with plenty of clearance.

Im actually considering buying the D50-36 for my SLC 3. The front would fit easy, the rear most likely fit fine, wouldnt want to go any bigger though

Peter would kill me, if i change the rim again :)

I don`t understand some chinese frame manufacturers and their tyre clearance claims. Winspace told me that the chainstay clearance would be already tight with a 32mm tyre...
How many mm on either side of the tyre to the chainstay with your setup?

Nkearb

  • Guest
Re: Xiamen Carbon Speed 10 years anniversary special promotion
« Reply #199 on: December 12, 2024, 03:29:05 PM »
On the SLC3 L, the tightest fit is between the widest point of the tire and chainstays. Bit over 38mm measured, so a tire measuring 34-35mm (a 32c gp5000 on a 28iw rim) would be a tight fit. The rim is wider than the tire at 36.6mm but the chainstays spread out enough that they clear this more

ry

Re: Xiamen Carbon Speed 10 years anniversary special promotion
« Reply #200 on: December 14, 2024, 02:42:45 PM »
How do we think the vertical & lateral stiffness/compliance between a 20 carbon spoke wheel and a 24 steel spoke wheel would compare? Data would be better than hypotheses but I understand if it's not available.

I hear of harsher ride being reported on carbon spokes with less perfect road surfaces (ofc also with better aero & weight) but have to expect that 20% fewer spokes may offset that if the baseline was with 24 carbon spokes instead. 

toxin

Re: Xiamen Carbon Speed 10 years anniversary special promotion
« Reply #201 on: December 14, 2024, 08:28:50 PM »
Depends who you ask for the subjective, but usually carbon spoke wheels would still be stiffer. Actual measured data on vertical and rotational stiffness is basically non-existent all we have are lateral stiffness tests. Also, fact is, most carbon spoke wheels are simply overbuilt. We were fine with 20 and 21 steel spokes on the front, why do we need to have just as many carbon spokes? It doesn't make sense.

ry

Re: Xiamen Carbon Speed 10 years anniversary special promotion
« Reply #202 on: December 16, 2024, 09:57:42 PM »
Thanks, Toxin.  That's consistent with the rabbit hole of research I've done over the last couple days.  Appreciate the thoughtful discussion here from people more knowledgeable than I.

I want to get my order in but I'm having trouble picking between 3.8mm carbon, 5mm carbon, or steel CX-Ray spokes for my T1100 D50CU-33.  I'm 60kg fwiw and assuming cross winds won't be an issue. 

The extra cost of carbon spokes is significant but if it makes my bike more fun but not noticeably less comfortable on 32c tires or significantly less safe then it's probably worth it for me. 
« Last Edit: December 16, 2024, 10:15:35 PM by ry »

PoulB88

Re: Xiamen Carbon Speed 10 years anniversary special promotion
« Reply #203 on: December 17, 2024, 12:56:53 AM »
I would think that with 32mm tires at an appropriate pressure for your bodyweight, the type of spokes in the wheel make no discernible difference to the feeling of comfort.

toxin

Re: Xiamen Carbon Speed 10 years anniversary special promotion
« Reply #204 on: December 17, 2024, 07:11:05 AM »
The stress deformation plots of carbon and steel spokes aren't that different. Carbon spokes just fail at a higher load. No point going 3.8mm over 5mm

PeterXu

Re: Xiamen Carbon Speed 10 years anniversary special promotion
« Reply #205 on: December 18, 2024, 04:16:38 AM »
Promotion would still last one week through Dec 24. In future, we will list new products onto our website and shopping mall site: www.xmcarbonspeed.cc

Even after promotion closed, please feel free to contact if you had any question or requirement.

Since Chinese lunar new year is coming soon, we have arranged these T1100 rims for stock through the new year holiday (about 20 days): D45CU-28, D50CU-28, D40CU-33, D50CU-33, D65CU-33 rims.
Carbon rims, wheels, frames and components manufacturer
peter@xmcarbonspeed.com  petercycles@foxmail.com
WhatsApp: +86 18250808148
www.xmcarbonspeed.cc

gajowy

Re: Xiamen Carbon Speed 10 years anniversary special promotion
« Reply #206 on: December 19, 2024, 10:08:29 AM »
Guys, did you order those wide wheels for the road bike?
Is 34.18 too much for a road bike.
I'm thinking about this wide option but I'm worried about the frame (winspace t1550 2gen). Will it fit the frame. I haven't frame yet so I can not measure it.

Nkearb

  • Guest
Re: Xiamen Carbon Speed 10 years anniversary special promotion
« Reply #207 on: December 19, 2024, 02:46:53 PM »
Guys, did you order those wide wheels for the road bike?
Is 34.18 too much for a road bike.
I'm thinking about this wide option but I'm worried about the frame (winspace t1550 2gen). Will it fit the frame. I haven't frame yet so I can not measure it.

I wouldn't be concerned. I think winspace took notes from the western brands, and they understates their tire clearance. I am confident my SLC 3 could clear the D50-36, since I have D65-33 installed and have plenty of clearance.

I would be concerned with some of budget chiner brands, since their sales person likely copied the entire spec sheet from somewhere else, and did no confirmation

gajowy

Re: Xiamen Carbon Speed 10 years anniversary special promotion
« Reply #208 on: December 19, 2024, 04:12:15 PM »
I asked because I am also afraid about ETRTO Standard.
Also watched https://youtu.be/FNKtEhH5KtA?si=kx-Ck3WFdht86ToD screen in attachment. Nobody uses 26 iw for road wheels.

ry

Re: Xiamen Carbon Speed 10 years anniversary special promotion
« Reply #209 on: December 19, 2024, 09:34:08 PM »
I asked because I am also afraid about ETRTO Standard.
Also watched https://youtu.be/FNKtEhH5KtA?si=kx-Ck3WFdht86ToD screen in attachment. Nobody uses 26 iw for road wheels.

The ENVE is pretty close... what's 1mm...