19 posts • Page 1 of 1
Tried to search for this but didn't find the info I was after.
I've got a set of 24mm aluminium wheelset! - do plenty of climbs with it. I'm also thinking of getting a 50mm carbon wheelset for the flats. I've heard carbon wheels are not the best for descents especially in the wet and some may fail, so I'm a bit worried. So I've heard people do wheelset swaps/pads etc depending on terrain - climbing/flats.
In terms of doing the swap for climbing, I was wondering if I had my carbon wheelset on and just change the carbon front to my the aluminium front wheel and pads (basically rear carbon and front aluminium), are there any issues with it? It just allows me to have aluminium braking(and I think the front brake does more of the braking than the rear) for safety if the carbon does fail. Plus my aluminium is entry level shimano wheelset hence i want to keep the carbon rear wheel because its lighter. Oh and I'm lazy, so minimal work with the swap will be good
Anyone that has done this, would love to hear your feedback. Thanks in advance guys!
You won't have any physical problems if you swap the pads over, obviously some reduced braking...
How do you brake with the current wheelset? if you are applying force to both wheels, then you could delaminate the carbon wheel even if you have the alu front. It's not like a motorbike, a large chunk of the weight is going to be on the rear wheel still.
If you are concerned with delamination, get yourself some alu/carbon wheels like the Aura 5 Bontragers or Giant SLR-0 (???) or something like that. Weight isn't that different to pure carbon in a clincher, and it's the aero benefit you want more than the weight at 50mm.
Why buy an aero wheelset and not use the front wheel? The front is where most of the aero benefit derives as the rear wheel is shielded behind the seat tube. I think Xplora's suggestion is sensible, if you want aero wheels and good braking then a carbon fairing with aluminium brake track is the way to go. However, these won't be light.
Hi Pretend3r, I have CF 50mm and 38mm alloy wheelsets and I much prefer the alloy wheelset for descending. The alloy wheelset has more road feel and the CF wheelset is noisy and creaks alot.
So, a 50mm CF rear and 24mm alloy front sounds like a reasonable idea. The rear wheel is what drives you on the flats so having a 50mm rear is not a bad idea. The 24mm front wheel should feel light and nibble while the CF 50mm rear should feel solid. The combination should be quite interesting ... I might try it myself with a 50mm CF rear and a 27 or 38mm alloy front ... and have good front wheel braking :=)
thanks KL :=)
^^^ KL, the research shows that the rear wheel does very little for the aero profile of the bike compared to other savings from aero bars, a better position but especially the front wheel. My concern is that he's trying to cruise the brakes down the hill the whole way (no crime, that's what I do!) but this is a recipe for delamination.
End of the day, you are prepared to risk delaminating, or you aren't. There isn't much point trying to mitigate the risks because no one here (unless they know your routes and weigh the same as you) can give you a fair idea of what to expect. Me? I'm not prepared to risk it; I'd rather use the alu/carbon 50s all the time and break out the shallow wheels on windy race days - after all, if the wind is so bad that you don't want to use the 50s, you probably don't want to be riding in close quarters with other people unless you HAVE to.
How is it reduced braking? if I swap the carbon front with an alum front? I thought the alum front will improve the braking overall. Changing to alum wheel is more a safely precaution just in case the carbon rear delaminate in which I assume its a very low chance if I brake correctly (heard alot of riders still descent with full carbon wheelset with no problems), now if it fails the alum will allow me to brake to a stop or coast down to the bottom... this is purely my assumption, given I haven't ridden carbons before.
The alum/carbon wheels I've checked are quite heavy though, the carbon wheelset I'm planning to get is about 1350g so they light for 50mm. Now I can easily change rear carbon to my alum wheel and there are no issues, but I want the aero profile and the lightness of the 50mm compare to my alum 24 rear - plus its one wheel, I dont have to change the pads and swap the wheel haha
Aero wheelset is to attack the flats, like beach road (in melb), but I also do plenty of climbs, so I thought an easy front swap with two pads will take be a few minutes instead of doing a full wheel swap, plus i get the aero rear wheel benefit and lightness since majority of my steep climbs also has 30-40% flats. It's an odd combo, just wondering if anyone has tried it thats all.
Hi KL - you seem to get my logics, definitely let me know how you go? very curious
I'll go through my logic process here, based on the info you've given.
Aero > Weight
Carbon aero > alu aero
alu weight > carbon weight
Let's not get too confused about this - you cannot delaminate an alu brake track.
I also cannot predict how this future set of carbon wheels is going to cope with on descents.
We are assuming that your braking is going to be sufficient through the front wheel alone, in the case of the rear delaminating.
We are also assuming that the braking performance of the different wheels will be safe under "extreme loads" aka emergency braking down 10%.
Your carbon wheelset is going to be tubular at 1350gms. Inconvenient! Why do they need to be that light if you are not going to climb with them as well? You need aero more than light. If you are struggling with an extra 500 grams over the bike, look at the handlebars and how much water is on board to reduce the weight. But the reason to shed weight is to climb and you're giving up the lightest part of the carbon wheelset to the alu front wheel (I vaguely recall many carbon wheelsets save weight on the front wheel, rather than the back... you might have 600 front, 750 back while the heavier 1500 carbon clincher that I suggested would be 700 front, 800 back. The gains are on the front wheel).
I really can't stress the significance of delamination as a risk factor for any carbon wheel on a big descent - it's hard to say how risky it is. Tons of guys have been fine. But many have had issues. We can avoid this by picking up an alu/carbon wheel. They can be built as light as 1600 for your spec as a clincher. Most brand name carbon clinchers at 50mm are 1500gms. I don't think you're appreciating the risk here, from a cost to benefit ratio - possibly 250 grams and sacrifice the security of alloy? If you aren't racing A grade and doing some time in the wind, your aero wheels may not need to be good to get an aero benefit.
If you are comfortable with descending on carbon, just do it. Don't waste your time going with an alu front wheel, when your rear wheel will still endure a lot of punishment and if your brake track delam's at 50kmh, you're going to have a bad time. Thing is, some people don't trust carbon, and if you don't trust it then you aren't forced to use it to get that aero benefit.
End of the day - lighter wheels are more expensive, and giving up the weight advantage for any reason is a bad move unless you have crazy amounts of cash to burn. All in, or fold on the flip as they say. A better alternative is to give up 300 grams (I wish I was joking), have 100% confidence in the braking track, and dump the 24s unless it's tornado time and you're racing. If you go out in the wind and descend at 50+ you're braver than me, because I've done it recently and it's brownknicks time. Most of your customisable weight is hubs and spokes, not the rims, so reconsider your purchase options.
I totally dig where you are coming from, and having the same things to consider, bought Aura 5s.
Last edited by Xplora on Sun Nov 24, 2013 9:05 pm, edited 1 time in total.
Mixing is fine, pain to change over the pads but if you feel safer descending on alloy rims then do it.
Personally not a fan of carbon clinchers on long descents or any carbon in the wet. I expect it depends where you live. Not that many long descents close to where most people live in Oz. Also depends on your riding style.
This year I have seen 3 sets of Zipps destroyed on descents... but then last year I saw someone carted away after descending on alloy clinchers.
Horses for courses.
Personally I am happy racing my carbon clinchers in hilly terrain, because the worse descent I get is 5km at 60kph then I need to stop. Never an issue in the 3 races or recon rides down that descent.
The issue with descending on carbon rims, is if you are constantly on the brakes on a big descent, ie descending a famous TdF col with a bunch of people you don't know or trust and constantly on the brakes like the 3 zipps in TLL experience.
Go read November Bikes blog wrong tool for the job or their terms and conditions if you buy their carbon wheels. Good clear honest advice from a supplier.
Not a big fan of carbon braking in real heavy rain, but most the time here (Perth WA) the rain is light, I have always used my carbon clinchers for racing, never my alloy "training" wheels. Have turned up to two races with alloys on my race bike. One because it was forecast 60kph crosswinds + rain, race got cancelled. Left home one day in pouring rain and howling wind, got to the course 30 minutes away, all calm and dry, so I raced my untested crit bike with carbon clinchers rather than regular road bike with alloys. Aero and weight matter to me (got 2nd in that race).
My advices, get the carbon clinchers, try them in the hills (provided you understand their limitations) and rain and see if you prefer alloy and in what circumstances.
And I do not see anything wrong with alloy front & carbon rear, if that is your informed decision.
Hopefully nick and TLL have made it clear that it would probably be ok, but we cannot guarantee it will be ok even with trusted brands. I personally think that having an alloy front as a backup is stupid, because you are sacrificing too many benefits to make it worthwhile to keep the carbon rear - after all any safety benefit will be stronger with both wheels Alu and you would only lose 250gms to do so. A lot of these benefits from the sexy wheels are for racing where every gram counts. Skull hit the nail on the head. If you really can afford to muck around like this, get carbons for the flat, Alu carbon for descending and the 24s for windy days. This isn't excessive if 2k on carbon clinchers isn't excessive lol
Went up for a training camp in Bright a week or two back, and was considering similar options to the OP. Ended up taking a spare aluminium front wheel/pads. I weight in at about 72kgs and would classify myself as an average descender (I don't do many technical descents), so approached the weekend with some caution. New bike, complete with carbon clinchers.
Didn't have a problem descending Buffalo on the carbon rims, so left them on for Hotham also without drama. Found the braking to be on par with what I'd expect from an aluminium rim, of course the weekend was dry. Did ride them in the wet the other day however, there was some performance degradation but nothing too sketchy.
Crit season means I'm riding to 3 races a week (if it ever stops raining), and probably commuting and training on the same wheelset. I'm too lazy to switch wheelsets so at the moment I'm pretty happy with the carbon clinchers; light, fast, and not tubulars. I say ride the carbon rims unless you find they really aren't working for you.
After Wednesdays cancelled crit I was chatting to another guy running the same rims (Roval CLXs). Probably 10kgs lighter than myself, also liked the wheels very much, but found descending Baw Baw on them was somewhat out of their comfort zone. Rims didn't warp, but braking was noticeably affected.
I have a set of carbon / aluminium wheels that I use in races with heaps of long / steep climbs or if the cross winds are brutal.
I run a 58 mm carbon FFWD in the back and a Mavic Kysrium in the front. Both tubulars. I run standard shimano brake pads in the front and swiss tops in the rear.
This is a very nice wheelset. Extremely light and with that little more power in the front brake when I need it.
I am a bit 'old school' with my dislike of a deep front in the wind but I don't care. The Kysrium is fast and I can still navigate my way in and out of the gutter with precision and predictability when it is blowing a gale.
I like these wheels a lot.
Giant Trinity Composite 1
I didn't buy full carbon clinchers for exactly this reason. The idea of fast mountain decents at 80+kph combined with my 90 odd kilo self, meant I wasn't confident with the stopping power or heat dissipation capacity I'd read about carbon clinchers.
If you take the descents relatively easy and aren't over ~70kg, then I'd probably just use the full carbon wheels! Same goes for 'smaller' hills - is anything less than 15-20mins of descending really going to be a factor?
Personally, I figured that for the sake of a few hundred grams that it was better to just get the deep wheels with an Al brake track and never have to worry. Most of us have a few hundred grams we could shed ourselves anyway!
Interesting thought to swap the front wheel out when going on this type of ride - but to change the pads as well (with any sort of regularity), i'd be running into a massive CBF'd factor after only a few changes. Sell the full carbon clinchers, buy some alloy track carbon wheels and pocket the change I reckon!
Having delamed a set of 60mm full carbon clinchers at 50+ kph descending falls creek in the 3peaks day,then reversing the course and putting on a RS30 front there is no problem mixing(i used swiss stops on both)....i then descended using just the front brake all day....Ps i got a full warranty set replacement
What brand were they?
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