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BORG50C Wheels

Anyone got these wheels?

https://thecycleclinic.co.uk/collections/road-rim-brake-wheelsets/produc...

Interested in full carbon wheels and these look amazing and hand built but concerned about this too hot to handle comment

"Rule of thumb if the braking load would get alloy rims to hot to handle then don't do that decent on any carbon clincher rim"

I don't think I have ever touched my alloy rim following a decent so no idea. I suspect they would be roasting

If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.

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10 comments

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maviczap | 4 years ago
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I've always used alloy clinchers in the mountains, I don't see any real advantage in using carbon rims for going uphill, I'm not that good. But going downhill I'm happy to descend as fast as conditions allow. Carbon makes no difference to this and I have no concerns apart from usual punctures. If I were to use carbon, I'd run them tubeless

Avatar
jaysa | 4 years ago
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I'm torn about using carbon wheels in the Alps.

For sure, less weight and faster descending (less braking and not dragging) will reduce heat buildup.

Mike Cotty, brand ambassador for Mavic says:

“But now there’s resin that’s very resistant to high temperatures. Mavic may not have been first to market with a carbon clincher but from being involved in their product testing I know they don’t want to put something out there if it’s not up to the job.

“They use Mont Ventoux a lot and have had a 100kg-plus rider with a fully laden rucksack on his back going all the way from the top to the bottom dragging the brakes to prove the thermal resistance of their resins."

Yet a quick search on the net shows overheated carbon wheels with discoloured braking surfaces that now grab during braking.

I recall crawling down the Col de Péguère (18% in places and twisty) trying to stop the rear wheel lifting, and burning my finger on the brake track at the bottom. Given the stakes, I'm sticking with alloy rims for now ...

Am I just being a wimp?

Avatar
srchar replied to jaysa | 4 years ago
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jaysa wrote:

I'm torn about using carbon wheels in the Alps.

Am I just being a wimp?

I used Boras with tubular tyres on the Marmotte last year, when the temperature was 26C at the TOP of Galibier. I would have weighed somewhere around 83kg and usually max out at 90km/h on a long, steep descent.  I had absolutely no problems with the brakes, using Campag red pads.

A friend who used Zipp clinchers had two blowouts.  I also know a guy who had a Reynolds carbon rim fold on him at the top of the Glandon a couple of years ago. There's nothing wimpish about wanting to avoid such incidents.

Personally, I don't trust carbon clinchers at all, but I happily ride carbon tubulars down steep roads.

Avatar
peted76 | 4 years ago
2 likes

I think the trick is not to 'drag' on brakes down a mountain, but to feather them.

I'm not sure I'm clever enough to know why a seemingly equal amount of power used dragging or feathering is cooler than the other, but I suspect it's something about maybe letting the air get to the brake block.

 

 

Avatar
Pub bike replied to peted76 | 4 years ago
0 likes

peted76 wrote:

I think the trick is not to 'drag' on brakes down a mountain, but to feather them.

I don't what the difference is between feathering and dragging.  I find that the way to avoid brake fade is to brake less frequently.  Maybe this is what you meant by feathering.  The problem (if you wish to call it that) is that you have to descend faster and only brake when really necessary i.e. before hairpins.   When I have to start braking, I sit bolt upright to get maximum air resistance and then brake hard on both brakes on the drops until I have reached my max allowable speed for the kind of hairpin.  I find inside hairpin 14mph, outside 21 mph, inside racing line to outside or vice versa 18 mph, but that will depend on you and the particularly bike, load and tyres.  It is possible to alternate pressure on front and rear levers to give the rims a break, but not sure whether this helps.

In rainy conditions or when the road is wet this doesn't apply but then the water will cool the rims better anyway.

Avatar
Pub bike replied to peted76 | 4 years ago
0 likes

peted76 wrote:

I think the trick is not to 'drag' on brakes down a mountain, but to feather them.

I don't what the difference is between feathering and dragging.  I find that the way to avoid brake fade is to brake less frequently.  Maybe this is what you meant by feathering.  The problem (if you wish to call it that) is that you have to descend faster and only brake when really necessary i.e. before hairpins.   When I have to start braking, I sit bolt upright to get maximum air resistance and then brake hard on both brakes on the drops until I have reached my max allowable speed for the kind of hairpin.  I find inside hairpin 14mph, outside 21 mph, inside racing line to outside or vice versa 18 mph, but that will depend on you and the particularly bike, load and tyres.  It is possible to alternate pressure on front and rear levers to give the rims a break, but not sure whether this helps.

In rainy conditions or when the road is wet this doesn't apply but then the water will cool the rims better anyway.

Avatar
Pub bike replied to peted76 | 4 years ago
0 likes

peted76 wrote:

I think the trick is not to 'drag' on brakes down a mountain, but to feather them.

I don't what the difference is between feathering and dragging.  I find that the way to avoid brake fade is to brake less frequently.  Maybe this is what you meant by feathering.  The problem (if you wish to call it that) is that you have to descend faster and only brake when really necessary i.e. before hairpins.   When I have to start braking, I sit bolt upright to get maximum air resistance and then brake hard on both brakes on the drops until I have reached my max allowable speed for the kind of hairpin.  I find inside hairpin 14mph, outside 21 mph, inside racing line to outside or vice versa 18 mph, but that will depend on you and the particularly bike, load and tyres.  It is possible to alternate pressure on front and rear levers to give the rims a break, but not sure whether this helps.

In rainy conditions or when the road is wet this doesn't apply but then the water will cool the rims better anyway.

Avatar
AfterPeak | 4 years ago
1 like

Cheers. Yes he seems totally honest and I suspect his words can be used for all full carbon rims I just dont want to buy carbon rims then knacker them in 5mins.

 

I guess I could actually go out and see how hot my alloys get. I am pretty terrible at decending and drag the brakes a lot.

 

 

Avatar
vonhelmet | 4 years ago
2 likes

I've got wheels from Malcolm and I'd definitely buy again. As said, he'll be honest about what's what.

For what it's worth, I understand his Borg rims are rebranded Kinlin rims so you can look up reviews of those rims if it helps.

Avatar
kil0ran | 4 years ago
3 likes

Malcom stands by his wheels and is dead honest about what they will and won't do. If you're worried about heat stick with an alloy track or switch to discs - as he says heat buildup is a fact of life with any carbon rim.

There aren't many builders out there who will rebuild a wheel for just the cost of the rim, given how time-consuming that is.

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