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Tandem Cycling A bicycle built for two. Want to find out more about this wonderful world of tandems? Check out this forum to talk with other tandem enthusiasts. Captains and stokers welcome!

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Old 07-07-12, 04:28 AM   #1
PMK
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All the rage / Chinese Carbon Wheels

So I'm in a shop the other day and all the rage seems to be about the low cost decent quality Chinese carbon rims and wheels.

For grins I clicked on a link that was flashing the low price here on BF and was taken to this site.

http://www.shop-yishunbike.com/

So I find the next page which is about the carbon rims.

http://www.shop-yishunbike.com/rims/...-clincher-rims

I take a moment and look. Let's see, no higher spoke counts than 24. But they do offer a 20 spoke count.

http://www.shop-yishunbike.com/rims/...road-bike-rims

253 pounds max rated, tandem is more but the weight bias should not exceed that 253 pound limit.
20 holes x 2 = 40 holes, so why not redrill on my own with ptoper drills for carbon, which I own, and make 40 hole rear rim. Locating the holes is easy, and one $2 drill bushing and tooling material can make a drill bushing fixture to provide exactly the same hole size and alignment for each hole. Also, if the rims oem drilled the spoke beds slightly canted this could be corrected with the drill bushing fixture.

It seems they are probably using quality fibres from Torray, and no doubt learned the engineering.

Any thoughts other than I am crazy to consider this.

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Old 07-07-12, 01:40 PM   #2
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I wouldn't want to use caliper brakes with them for rim heating issues.
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Old 07-07-12, 01:45 PM   #3
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Your plan to drill holes sounds reasonable but I wouldn't want to experience a tandem with rim brakes and carbon rims. If you have discs I easy go for it.
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Old 07-07-12, 03:44 PM   #4
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There was this guy in another thread whose opinion you may want to weigh in your decision :

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I'll get flamed for this, but when the Chinese composite materials problems begin...well, let's see how the manufacturers start handling or better yet surviving warranty claims.
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Old 07-07-12, 03:59 PM   #5
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455g on the 38mm, vs. Deep V at 30mm and 520g. I don't see much advantage, considering the drawbacks.
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Old 07-08-12, 01:36 AM   #6
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They might even be strong enough with the standard spoke count.
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Old 07-08-12, 04:58 AM   #7
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I wouldn't want to use caliper brakes with them for rim heating issues.
It will be disc brake.

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Old 07-08-12, 05:02 AM   #8
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455g on the 38mm, vs. Deep V at 30mm and 520g. I don't see much advantage, considering the drawbacks.
If I do try this, it will be for the 88mm rim. Rear only. It would be to help smooth some airflow.

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Old 07-08-12, 05:04 AM   #9
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They might even be strong enough with the standard spoke count.
Problem is I don't have a low spoke count hub in 145mm. I do have a spare 145mm tandem hub in 40 hole, basically making the rim match the hub.

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Old 07-08-12, 05:19 AM   #10
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Quote:
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There was this guy in another thread whose opinion you may want to weigh in your decision :



I have no good defense...

As for a warranty, well I doubt they would work with me if I added 20 holes to their rim and had a failure.

I was being cheap, like others that buy this stuff direct.

You are correct, I should listen to my inner self, not only about the carbon, but also the concept of "it ain't the arrow, it's the indian(s)".

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Old 07-11-12, 10:03 AM   #11
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There is so much turbulence at the back of the bike, I wound't worry about airflow too much. IT is the front where it is important. That is one reason why Conti's race set is 22mm front and 24mm rear. Front is for aero, rear is for lower rolling resistance of the wider tire.

Wheel failure on a tandem is a catestrophic. I would rather have a solid "Deep V" rim than something fragile, unless I was racing.

(what comes to mind is a video of a track tandem that had the carbon wheel slowly disintegrate
speed (front tire blew out) - it was pretty ugly)

Here is the link:
http://www.youtube.com/watch?v=Ngv7Iu3y1o0


Quote:
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If I do try this, it will be for the 88mm rim. Rear only. It would be to help smooth some airflow.

PK
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Old 07-16-12, 11:21 AM   #12
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I wouldn't bother. Instead get yourself a light-ish aluminium rear rim and a disc cover. That will be more aero, and unless you're going uphill at <10mph the weight makes less difference than the aero. Plus down any hill you will ride much faster because you will be confident that the brakes work properly.

If you really want to go faster, either invest in some proven technology (much cheaper than a crash) or do some stretching, pilates and so on until you can get a few cm lower. Then you really will go significantly faster than bolt-on upgrades permit.
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