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Discussion: Hard Tail vs Dual Suspension

in: Adventure Racing; General;

May 2, 2016 10:01 PM # 
Forgive me if this topic has been discussed to bits already and point me to the thread if that's the case thanks.

How many of you use DS in AR? My trusty starter mtb is destined to become my commuter/heavy trainer

My head is saying HT for racing. Lighter, stiffer, higher spec and fewer components plus technical riding is usually a smaller proportion of the overall bike volume in AR. But isn't a DS a natural progression? A real mtb? A more comfortable ride?
May 2, 2016 11:53 PM # 
Lambo Shih Tzu:
Cookies or Cake? YES!
May 3, 2016 10:21 AM # 
Ok I walked into that! And I found a couple of old threads.

Does FS become the better choice over longer races? Does the rear lock out give as stiff a power transfer as a hardtail on flat terrain?

Context: My current bike is a 2010 Trek 6500 and it has been like a faithful golden retriever. Attractive, reliable and fun. I've risked life and limb on DH, hoisted it over countless hike a bikes, road, single track etc.. Its done it all and bounced back from all kinds of trouble.

Alas its in need of some upgrades now so I believe that the frame is the important bit. I got a TT frame years ago and build my own TT rig for Ironmans.

I've always thought about FS as I bump over my local trails and upgrading was inevitable. My budget is €3k ish and I'm currently looking at a Giant Trance Advanced 27.5 2. Its a pretty black on black but also SRAM. I've had Shimano on all of my bikes so thats an unknown.

I'm leaning towards the FS but lingering there is the climbing and the hike a bikes (I'm the carry the bike vs walk it over rocks type) and my budget just doesn't stretch to make the FS lighter.
May 3, 2016 11:26 AM # 
I don't race AR, so my thoughts might not be especially useful. I have a rigid, a hard tail and a FS. For unpredictable terrain, I would by far rather depend on the FS. Lock outs are pretty good these days and I don't think you get much riding with it locked any more.
I mostly only carry my bikes up and down the stairs at the house, but I don't think the extra weight of the rear suspension would bother me for short carries - it might if I was carrying it a km or more at a time.
May 3, 2016 11:36 AM # 
Just to add a bit of 'triathlete' to the conversation ;)

Like Mike I too am on the Trek 6000 and its a beast of a yoke! Like a cockroach never dies, through hell, out the far side laughing it off!

Looking around and chatting to a few bikers I know who are (trying to) convince me that a fatbike is "needed", chatting wheel size for AR 29/27.5/26 etc and it was thrown out that a gravel bike would be more suitable for the sort of racing I've been doing.

Gravel bike being like a cyclo-cross (or maybe a fancy name to add €1k to a cyclo-cross).

Kinda makes sense in one way
- faster on roads, most of our racing have been on roads, poor roads, but road all the same.
- much lighter than a MTB nice for long carries in hike-a-bike
- will handle some rough stuff

The balance being between time lost by not being able to throw yourself down every trail and time gained by being much quicker on hard surfaces. Also worth thinking about energy svfed and possible quicker trekking off-road.

I'm on the fence. Also easily tempted too! :D
May 3, 2016 11:41 AM # 
Yes faster on road and lighter to carry but the risk of sheer death on a trail descent at night with sleep monsters rules that one out for me! Plus on flat terrain you can still only move at team speed. They are not going to sit in your 35-40kph for very long and bungeeing (is that a word?!) the lot of them to your seat post only drops the team speed to fat bike anyway.. :-)
May 3, 2016 12:19 PM # 

I was thinking more of a full team set up rather than one greyhound ;)
May 3, 2016 12:44 PM # 
I'm not the fastest rider in this forum but I've had pretty good AR results for years with FS. Being able to ride technical trails and read a map is more important than whether my bike would be the best choice for the local MTB race on groomed trails. It's so much easier on the body over the long haul! I've had to do hike-a-bikes through the forest and it's not great but that's never great with any bike. The difference of a few pounds is similar to the difference in my pack weight before and after drinking my water and eating my food, i.e. noticeable but not super important. I have semi-slick tires to improve speed on roads while still being able to handle mucky, rocky snowmobile trails.
May 3, 2016 1:08 PM # 
Good points Bash.

I wondered similar about tyres and you just answered it for me. Running knobbly trail tyres on my MTB and my feet go numb after a few hours. I came across a Continental X-King which was 'road type' on the centre and trail on the sides so smoother on flat surfaces yet grippy in mud or cornering on trails.

That in itself could allow better speed / less friction on roads and still allow the downhill nutter his freedom ;)
May 3, 2016 1:08 PM # 
I went through the same dilemma a few years ago.

My chosen setup for AR and MTBO is a 29" HT with tubeless tyres and a suspension seatpost (only added in 2015 for Swaziland Exped Africa and NZ GODZOne rutted roads).

The tubeless tyres allows lower pressures and therefore more comfort. The suspension seatpost takes the sting out of long rides.

However others prefer FS particularly if you can afford a light bike. You also need to consider water bottle storage as some only have one bottle carrier.
May 3, 2016 1:10 PM # 
My preferred tyres are tubeless Schwalbe Racing Ralphs which are a good compromise between low rolling resistance on roads and grip on mud/grass/gravel/rock.
May 3, 2016 1:38 PM # 
Most AR races specify no cyclocross bikes. With a narrow tire on my FS I'm just as fast on a gravel/paved road as I am on my cross bike and it has a better gear selection for climbing.
May 3, 2016 2:00 PM # 
It's probably worth mentioning my Tierra Viva teammate who had to give up AR (after DNFing late in that race) due to a severe neck problem after many hours of rattling over corduroy-gravel roads.
May 3, 2016 2:19 PM # 
My vote: HT 29er. Switched over years ago from a FS 26 inch bike and haven't missed it at all. Even in XPDs (up to 7 days) I haven't longed for a FS bike. The 29er makes up for some of the FS comfort in a 26 inch bike in my opinion. I don't run tubeless like GD44, but still am comfortable enough (nor do I have a suspension post). I prefer less cost and weight and fewer moving parts. I'm also not very big though, so there's that...
May 3, 2016 2:39 PM # 
Hmmm .. what is not very big?!

I'm 85kg but 78kg @ race weight with a FTP of 300w+. But hills still bloody hurt!

It seems to be HT 29er lighter, simpler vs FS more comfortable. Or less effort climbing vs less effort reading the map on gravel etc..

Another Q? 29er vs 27.5? I get that 26 is a thing of the past but why are 27.5 (650b) now getting more popular?
May 3, 2016 3:20 PM # 
Not to pile on what already seems to be the prevailing opinion, but HT 29'er is my vote. You'll even find more and more folks racing fully rigid depending on the anticipated terrain for riding during a race.

My first 29'er was Moots YBB with a Rohloff internal gear hub. Damn near indestructible, but also damned heavy! (29 lbs with cages and no saddle bag). Plus, there is some power loss through the Rohloff that although small, surely adds up over time.

Last year I converted to a carbon HT carbon 29'er Cannondale Lefty 1x11. (19 lbs with cages an no saddle bag) Holy freaking cow did it feel like I was cheating and or doping the first couple of races. The greatly reduced weight and the more efficient drive train were a HUGE difference. I don't think I would consider anything else for shorter races (less than 30 hours).

It's tubeless and I've not yet had a comfort issue, but then again I've not done anything longer than a 30 hour with it.

The only concern of course is the durability of carbon. For a 5-7 day race, especially with more brutal terrain, having a virtually indestructible titanium frame and drive train has its appeal...

Depending on who you talk to, 27.5 is everything from a revelation to a marketing ploy. For AR with miles and miles and miles (and miles) of gravel/dirt road slogging I think 29 is the answer (unless you're super small).
May 3, 2016 5:02 PM # 
Well, since we're sharing, 65 kg give or take. But several teammates of mine who are considerably bigger have also gone with the HT 29er set up and have sworn by it for the same reasons: 29er absorbs much of what would add up on a 26 inch. Can't say much about 27.5!
May 3, 2016 8:15 PM # 
29er full suspension. I have a 100 mm front/80 mm rear FS at ~25 pounds with non-XC tires. But I covet the current crop of light-ish 120 mm expensive bikes, as they can weight 26 pounds and less, and can do everything a typical AR bike rider wants to do and you can also take it to a "real" mtb trail and rock it better. If you don't ride rough at all, then just upgrade your HT. And if you have the money....cookies and cake!
May 4, 2016 12:03 AM # 
wheel size...pick the same as yer teammates. prefer 29.

suspension...don't need it. more weight to carry and more parts to break. i don't lose *that* much time being careful on the downhills and DANG i appreciate the rigid fork on the uphills.
May 4, 2016 12:47 AM # 
Where you are racing matters. I am not an expert rider by an stretch of the imagination. However, I did a lot of homework last year on a bike investment and landed with a Salsa Ti XTR. The ti takes some bumps out, I think I coud get seat post, and it makes my luddite heart happy. Oh, and I am mostly bumping around Michigan's glacial goodness.

UPDATE: If my food log could afford the calories...COOKIES AND CAKE.
May 4, 2016 1:08 AM # 
Cookies and cake kinda gal.
May 4, 2016 1:55 AM # 
Mr Wonderful:
Me: I never go over 30 hours, and am not strong on the bike.

Were I buying another today, I'd get a rigid carbon 29er and put on skinny tires. As close as I get could get to cx without being sent home. My last USARA experience was soo....much....road. Largely echoing Sean's position.

Other than Wilderness Traverse, where ridable trails are an afterthought and I missed my old full suspension.

Last I paid attention I thought Kyle was running full susp. with a three stage single lever locking setup, which also sounded interesting. (Locked, medium, soft)
May 4, 2016 4:45 PM # 
I race AR with my hardtail carbon 29 - 1x11 but could use a FS of some sort just for riding the local rocky terrain. which one is cookies and which one is cake?
May 4, 2016 4:56 PM # 
Is the fully rigid more of a graham cracker?
May 4, 2016 6:32 PM # 
Lambo Shih Tzu:
Cookies or Cake? BOTH!

Here are some very unofficial stats based upon FB pics:

100% of racers on the top 5 ARWS teams use FS (full suspension) for expedition races.
75% of racers on the top 10 ARWS teams use FS for expedition races.

Team HT FS
Seagate 0 4
Columbia Vidaraid 0 4
Adventure Medical Kits 0 4
Haglofs Silva 0 4
Swedish Armed Forces Adventure Team 0 4
Raidlight-Naturex 4 0
Merrell Adventure Addicts 1 3
GODZone Adventure Team Expedicion Guarani 1 3
Peak Performance 0 4
YogaSlackers 4 0
Total 10 30
Percent 25% 75%

Here is how I would decide on eating cake of cookies at my next race if I were you to get an end result of a faster overall race time (not just on the bike stages)... It's all about getting to the finish line more efficiently (aka faster) whether you are aiming to win or complete a race.

PS by FS i mean a CX racing bike with ~100mm in both the front and rear.

1) I am strong on the climbs, but I struggle to maintain DH pace with my teammates = FS

2) I always am waiting for teammates on technical descents, but get my ass towed up the hills my Mari = HT

3) Going to race in a 2+ day race in big mountains that have ST trails = FS

4) Going to race in a 2+ day race in Central / South America = FS

5) Going to race Cowboy Tough = HT

6) I live in the midwest of the USA (or similarly mountainous lacking place) and race mainly local 24 hour and shorter races = HT

7) I live in the Rockies (or similarly mountainous place) and race mainly local 24 hour and shorter races = FS

8) I'm going to push my bike through swamps for 8 days in the Pantanal = HT

9) I'm going to do 3+ day races and will try to catch power naps on MTB descents = FS

10) What other scenarios am I missing? (I am going to get this up in a blog post soon)

XC bikes are no bueno for multi-day races. I once did a 15 hour road ride with a backpack, and it crippled me!

29ers are really the only size wheel for AR in my opinion.

A rigid fork just seems like pure fun-hating, but Silky likes it. Curious how that affects her paddling in a multi-day race?

I ride a Scott Spark 900 RC that weights 23 lbs (10.43 kgs) (w/o AR gizmos). 29 inch wheels. It has 100m of travel in both the front and rear and as Mr. W mentioned has a TwinLoc remote that allows for 3 travel settings. The remote controls both the fork and rear suspension. So i can choose to have the bike fully open in Descent Mode (100mm), Trail Mode (70mm) for cruising on ST or rough roads, and Climb Mode (fully locked out front and rear) for road riding / climbing. My bike probably has an MSRP of $10,000US (carbon wheel set, custom build), but one can find the TwinLoc on a Scott Spark 960 for under $2,000US and will weigh around 30 lbs (13.61 kgs). The more budget you have the lighter you can get, but that is the high and low end range [$10,000 & 23 lbs - $2,000 & 30 lbs]
May 4, 2016 8:20 PM # 
KP...who stayed in the boat at the end of CT 2014?

nice recap!
May 4, 2016 8:39 PM # 
Be fair silkychrome, the world was not yet aware of the efficacy of your "ohmygodimgoingtofalloutoftheboat" ninja front kick...
May 5, 2016 1:02 AM # 
Awesome analysis!
May 5, 2016 1:35 AM # 
Kyle, I remember seeing Paul Romero doing multi-day Gold Rush, that year of the fire, on a rigid. But I think he likes punishment.
Great feedback and analysis. I'll still add that for a rider who lives in/around technical trails with downhill (Santa Cruz, BC/Canada, Sierras, CO Rockies, Boggs/Mendo) and can't afford two good bikes, the modern light-ish 120 mm bikes are a better choice for overall fun plus high performance.
May 5, 2016 2:52 AM # 
The silkychrome/KyleRPeter debate.
May 5, 2016 8:09 AM # 
^^ Ditto what Bash said! Good insight/knowledge Kyle.
May 5, 2016 8:56 AM # 
Thanks Kyle, class breakdown!

So to recap what you are saying is we all need a minimum of x10 bikes to cover all options ;)
May 5, 2016 1:23 PM # 
You mean everyone doesn't already have 10 bikes??? Don't tell my wife.
May 5, 2016 2:58 PM # 
Thanks JayXC, I'm suddenly feeling very inadequate with my 3 :(

May 5, 2016 7:05 PM # 
Carbon's Offset:
Big ditto to what Kyle said. Thanks for all that, and saving me a lot of typing to contribute similar thoughts. Some of it is the "depends" answer based on where you are racing and how long (as Kyle explained).
29er definitely, get all of that efficiency advantage. No need to go 27.5. I use my one mountain bike also for technical downhill riding, and I'm a small guy (5foot6, 167 cm). I don't need 27.5 wheels and didn't feel any advantage of them when I test rode both back-to-back, I just felt that the 29er was noticeably more efficient.
Tubeless tires, definitely, for many reasons.
Use tire sealant in your tubeless. Stan's has worked best for me.
FS usually.
Weight savings comes down to how much money you are able to spend. Put the emphasis on light wheels, moreso than fancy components or lighter frame - your work goes into making the wheels rotate, so make them light.

Another tidbit: there is a study paper done by Schwalbe that suggests that wider tires roll with less resistance (due to how a wider tire can flex across its breadth rather than its length) and this more than compensates for increased weight, even on fairly smooth dirt, grass, gravel, and even going up hills. The only time a skinnier tire was better was on pure pavement. Schwalbe has another paper with similar findings re: wanting lower tire pressure for better rolling efficiency over anything but pure pavement (I doubted this at first but have tried it and am a believer now; and the improved handling is fantastic). At Wilderness Traverse 2015, I was on 2.4 inch tires at low pressure and never regretted them, even with a fair but of pavement in the mix. I also ran low tire pressure at BC Bike Race and never felt I was giving anything up. In one AR long ago, I punctured a tubeless tire, the Stan's sealant sealed the leak, I continued on about 25 psi instead of the 40 psi I used to mistakenly run, and I could feel that it was easier/faster at the lower tire pressure.
Sorry I don't have a link to the papers right now, I'm busy travelling. I can look for them in a couple of days, or someone may beat me to it.
May 5, 2016 7:32 PM # 
Mr Wonderful:
I know I'm supposed to like tubeless, but my anecdotal and admittedly miniscule sample is that my tubeless teammates flat twice as often tubed teammates, so it's been hard to convince myself to switch yet.
May 5, 2016 9:21 PM # 
Lambo Shih Tzu:
I won't race with teammates that have tubes in their tires. Mr. W, we can no longer race together and possibly can't be friends anymore either.
May 5, 2016 9:52 PM # 
Schwalbe Rolling Resistance Study

Why do wider tires roll better?

Because of the longer flattened area of the narrow tire, the wheel loses more of its "roundness" and produces more deformation during rotation. However, in the wide tire, the radial length of the flattened area is shorter, making the tire "rounder" and so it rolls better.

The image in the link shows this principle, makes sense the second time I read it.
May 5, 2016 11:30 PM # 
Interesting that the wider ground contact is faster than the longer contact at higher psi. But is there a limit to how wide? XC racers use a 2.1 not 2.2+

Also on tubeless. Some of my tri mates used tubeless on their very fancy tt rigs. Getting 200psi adding to the rolling resistance etc...

But why tubeless for AR? Is it just weight? Is the risk of puncture really worth it?

Unfortunately I don't have 10 bikes or even in a position for cookies and cake. Im still between HT and FS. To KP's analogy I'd usually be waiting for my teamies is at the bottom of a technical descent but I can out climb them too and my local mtb playground is 75km of single track. While HT probably reduces my effort on hills surely a FS would mean slightly less time looking at the map on the move?
May 6, 2016 7:41 AM # 
OOOOHHHH you're on for a race to the bottom next time at Ballyhoura!!! :D

I need to stop taking photographs on the trails ;)
May 6, 2016 7:50 AM # 
Carbon's Offset:
Thanks for digging up the Schwalbe study. It didn't fit my conventional thinking at first, but I have tried it myself and am a believer.
I've had several flats on tubes, and those problems disappeared when I switched to tubeless. I did run over a nail or something that gave me a 5mm hole in one race, and the Stan's sealed it up while the wheel was still spinning (was rolling quickly on a downhill at the time, this probably helped).
Being able to run lower pressures with tubeless (thanks to not worrying about pinching the tube) is an advantage in multiple ways: better handling and grip, nicer ride, lower rolling resistance (as per the Schwalbe study).
As for puncture resistance, I did a week of riding in Moab where I must have gone off the trail and hit a lot of cactus thorns. When I got home, I saw about 25 quills sticking out of my tire, but hadn't flatted. If I were running tubes, I probably would have flatted repeatedly.
As for FS versus HT, when I first did this comparison in 2001 while bike shopping, I rode several bikes head-to-head on the same loop of mixed terrain, while wearing a heart rate monitor to try to keep the comparison fair (and re-rode each bike so that no bike got the advantage or disadvantage of me being fresh or tired). The FSs were all quicker even though the HTs often felt peppier. Contrary to what I would have thought at first, the biggest advantages of the FSs came on the climbs and flat sections, not the downhills. The FSs simply enabled you to stay in the saddle and keep pedalling while the HTs bounced you around more and interfered with your pedaling.
May 7, 2016 2:14 AM # 
Carbon's Offset:
Re: the durability of a carbon frame:

My aluminum frame broke once in the rear triangle and then once in the front triangle over about 5-6 years of adventure racing. My next bike was fully carbon FS (Scott Spark) that I used for everything: multi-day AR, intense Moab trips (it went down Porcupine Rim aggressively about 5-8 times), the 7-day BC Bike Race (quite hard on bikes), 24 Hours of Adrenalin, several good crashes, lots of training and fun rides on technical terrain, etc etc for about 8 years. Didn't break.
This has given me *more* confidence in carbon frames than aluminum, but that's just based on my own experience.
May 10, 2016 3:56 AM # 
Cake n cookie combo are the best! Just to toss in my 2 cents, I would echo KP, and add that when riding bike for the long haul, the FS reduces cumulative fatigue (increasing efficiency) as well vs the HT vs rigid. This year I went with a nice FS and noted increased quickness, and smoothness (obviously)as a whole; not so critical in shorter events.There are many events that I wished I had a FS. Well, now I have one and my back and body are already calling my brain an idiot for not doing it sooner! I am also concerned with carbon frame durability, and am hoping carbon offset is right. Time will tell.
May 11, 2016 1:07 AM # 
And if you want all kinds of sage mixed with silly advice, there is this rabbit hole:
May 12, 2016 8:42 PM # 
I had the same problem described here, depending on the race/terrain a hard tail (Florida) or full suspension (Virginia/NC/PA mountains) is preferred. I invested in a Scott Spark that has the capability to simulate a rigid, HT and FS. After a few rides switching between modes has become automatic. As the trail goes up hill or I'm on pavement, I lock out both shocks. Big downhills or really rough terrain I switch to FS. Most of the time I'm on trails or fire roads I ride in the HT mode. While the lock-out is not 100%, it's more than enough to conserve energy when climbing in rigid or hammering on HT modes. The selector is on the handle bars, no hand movement required just a thumb flick. After about a year of owning the bike I'm very satisfied. Here is the description from the Scott website:
Our patented Twin Loc technology now offers simultaneous control of rear shock travel and fork lockout. The open position allows full travel, front and rear. One click switches the rear shock to Traction mode, while the fork remains fully active. Click again and rear shock and fork lock at the same time. No other bike in the world offers this user friendly system.
May 13, 2016 1:19 PM # 
Pretty much deceided to go with a HT 29er at this stage.

Another Q: Do any of you use a 1x drive train?
May 13, 2016 3:31 PM # 
May 13, 2016 3:45 PM # 
Carbon's Offset:
I just switched to a bike with a 1x11 drivetrain last summer and was worried about whether it would give enough range for Wilderness Traverse. It was fine. I went down by one ring size on the front, for my general recreational use with all the climbing I do in the Rocky Mountains in Canada, and was worried that I might have sacrificed too much top end speed if I was on a lot of fast pavement in an adventure race. Wilderness Traverse had plenty of fast pavement but it wasn't a problem. There were about 4 brief moments where I was spinning fast in my top gear but I didn't feel like my gearing held me back; by the time I was topped out, I was coasting on downhills anyway.
I didn't expect the gearing to work out this well for AR. The change to a lower front ring was a good move if you are in an area with a lot of climbing or steep pitches.
May 13, 2016 3:49 PM # 
Carbon's Offset:
Really liking the 1x drivetrain
May 13, 2016 4:20 PM # 
When you say you switched to lower crank what was your drop? On a 1x11 speed I don't forsee problems really climbing on 32/42 but spinning out on 32/11 on flatter terrain?
May 13, 2016 4:42 PM # 
Carbon's Offset:
The next smaller front ring (versus the original) on my 29er had two less teeth. I think that was a drop from 30 teeth to 28 teeth. I could still climb everything around here on the original 30 tooth ring but it was a bit of effort, not a relaxed spin that I could sustain for a long time without paying the price in energy drain (e.g. A long fire road climb in an adventure race and trying to stay efficient).
I think my rear cassette is 10-42. I will check.

Similarly, I think a lot of the 27.5 bikes come with a 32 tooth front ring, stepping down to a 30 tooth on a 27.5 would be a similar comparison.

Edit: confirmed, my 29er came with a 30-tooth front ring and I changed this to a 28-tooth. More relaxed on steeper climbs, a more sustainable light spin, and still seemed to give just enough top end almost all of the time on fast paved sections. Rear cassette is 10-42T.
May 13, 2016 8:19 PM # 
42 is a pretty huge ring on the cassette. 36 is the granny rung on my triple. Albeit paired with a 24 so similar to 28/42 I guess. Thanks for the posts. While I have no issue with a double, the absence of a front derailleur and some cable plus less complexity is appealing.
May 13, 2016 10:18 PM # 
Carbon's Offset:
The 10-42 cassette is simply what came on my 29er (but yes, it looks large). I think that is a fairly typical design which balances out with the bigger wheels and the lack of multiple small rings on the front.

Interestingly, when I googled a comparison of gear ratios for 1x, 2x and 3x, my small change of front ring (30T to 28T) gave me the same bottom end as a stock 2x10. Also, the comparison table I found made it really obvious that the multiple front rings of 2x and 3x gave a lot of overlap and not many additional unique gear ratios. I'll try to find it again and share the link.
May 13, 2016 10:45 PM # 
Carbon's Offset:
Here's the gear ratio comparison table

If you look at the table on the left, you see the ratios for a 2x10. I briefly owned a 2x10 29er. The bottom end of the gearing seemed good; I wasn't sure if I ever used the highest gear(s), and it felt like I only got a couple more gears when I shifted into the big ring (which this table somewhat confirms). This made me open-minded toward trying a 1x.
When I got my 1x 29er, I did notice that the bottom end gear ratio wasn't quite as easy as the 2x10. The 1x11 gives up two gears versus the 2x10, and is usually geared so that it splits the difference a little between giving up a little top and a little bottom end. Maybe just right if you don't deal with a lot of steep, long climbs. The table on the right showed me that if I changed my 30T front ring to a 28T ring, I would get the same bottom end ratio but my top end ratio would drop to 2.800, thus giving up almost two top gears versus the 2x10's top ratio. I figured this was fine for recreational riding,there would rarely be situations where I would top out, or would need to keep pedalling faster if I was already going that fast. But when I was taking this bike to an adventure race, I wasn't sure. As it turned out, it was fine. Our team did some pretty fast pacelines on pavement, with plenty of fast downhill sections, and I rarely felt limited even though I did spin at max cadence for a few brief moments.

Anyway, I've talked a lot. This is just my 2 cents, based on my preferences, but is it based on the same concerns that you are wrestling with, then having tried it out and seeing how it worked for me, rather than just marketing that might say "1x11 is the cool new thing, so you need to switch to it". My presumption going in was that the range of speeds in AR would require a 2x drivetrain for more range.
May 13, 2016 11:26 PM # 
Cheers. Seen that table before and its a good help. Although it only goes to 3.600. 2.800 seem pretty low as your biggest gearing. I guess team speed pace lines in AR are still moderate by comparison to daily commute's etc.

Plus I'm used to the pain of TT's on 4-4.500 ratio from triathlon days

I did presume a 2x for the range would be needed for AR. But we are not doing the Alp D'Huez. Plus having the 11 speed 42t with say a 32 crank is practically a granny. I prefer lower cadence on pace line so 2.800 would not be enough. I should be good with a 32.

I'm considering the 1x11 more for simplicity and weight reduction than anything else.

The only real advantage of the double IMO is that the derailleur also acts as a chain guard. Plus when the chain pops off you can just shift it back on the smaller ring on the move straight away.

Great to get some knowledgeable insight from an AR perspective though thanks!
May 13, 2016 11:54 PM # 
And then there's this.
May 14, 2016 5:15 AM # 
Carbon's Offset:
Looking at the numbers, I too thought that a ratio of 2.8 was giving up too much top potential versus the top end numbers of 2x and 3x, but it didn't really turn out that way when I raced it. I also tested it on the road when I still had my 2x bike and forced myself to not use the gear ratios that wouldn't be available to me on the 1x. It seemed like I could still get the speed that I wanted on pavement, so I took the chance on the 1x and the smaller front ring.

I guess a TT/Tri bike would want higher ratios because of other factors like better aerodynamics, lighter weight, less rolling resistence, etc. The mountain bike doesn't hold the same top speeds.

Yes, there is some good weight savings by ditching a front ring, front spider, front derailler, mount, shifter, and cable. And the simplicity is great. At first it will seem odd to have to downshift about 4 or five gears before a sudden steep uphill rather than just dumping the front ring, but soon it becomes so much nicer to not have to think of "down one ring on the front, and a few harder on the rear".... All you have to think of is whether you want a harder or easier gear, not how to make the perfect combination of shifts on the front and rear. I already love it and wish I could do a similar set up on my road bike. Now that they are coming out with 12 speed soon (and probably 13 after that) it's a realistic possibility ...

I also don't bust chainring teeth on rocks now because the chain is always on that ring and acts as a bit of a guard (whereas the big ring used to unintentionally serve as the guard for my smaller rings when I would hit rocks). I guess the chain must take some of that abuse now, but I always change the chain every season anyway because that brought my record of chain breaks to zero and also reduced the wear on the rings and cassette. Chains are relatively inexpensive if you search online ( Even for us Canadians) and replace them yourself (easy to do).
And because the chain is not shifting to other rings, they know how the links will line up, and can make rings with alternating wide and narrow teeth to exactly fit the alternating wide and narrow gaps in the chain links. This holds the chain on the ring much more securely and means you are very unlikely to drop the chain... A nice little bonus, less need for a chain guide on really bumpy terrain.
Jun 13, 2016 4:19 PM # 
Cookies & cream ??

One thing about riding a 29" with big tyres is the road drag. May be a perception but I definitely felt the bike runs a bit sluggish on the downhills, especially on road.

But a beauty to ride a FS bike.
Jun 14, 2016 11:13 AM # 
What size tyres are recommended for AR with lots of road travel and maybe 30% single track, technical rocky muddy etc..?

2.0, 2.1,2.2, 2.25?
Jun 14, 2016 4:52 PM # 
Lambo Shih Tzu:
I have been really happy with Maxxis Ardent Race. It's a 2.2. Seems to be designed for AR with a combo of XC racing and trail riding. I opt for the heavier EXO style to get extra sidewall protection for expedition races.

If things get crazier, I swap out the front for an Ardent. If they get more mellow, I swap out the rear for something leaner. But I am pretty lazy and show up to 99% of races with the Ardent Races on both wheels.
Jun 15, 2016 11:48 AM # 
Schwalbe Racing Ralphs are popular too. I use the 29 x 2.1 Tubeless with Snakeskin.

Size:ETRTO 54-622 (29 x 2.10 Inch)
Execution:SnakeSkin, TL Easy
Weight:585 g (21 oz)
Pressure:2.00 - 4.00 Bar (30 - 55 psi)

I ride these for the majority of races but I did put on some "Tough Tom" tyres for local MBO races last winter.
Jun 15, 2016 4:24 PM # 
Currently have the Schwalbe Hans Dampf 29 x 2.35 tubeless. While durable and great grip. Defenitely drag on tarmac roads. I was thinking the 2.1 Rcaing Ralphs would be ideal so I'll suss them out thanks

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