Feeling Faster isnt Faster hardtail vs FS rant number 1 in a series.

I just hate to see the misinfo that gets spread around on the web. Mountian Biking is one of the most counter intuvative sports to explain the physics of and most people go by feel, and not by what is actually faster.

 

You hear it all the time. hardtails are faster more efficient and lighter than thier FS counterparts. People also claim that they 'feel' faster.

 

lets take a look at each word used to described hardtails vs FS.

 

Lighter - I am not going to argue this one at all. Hardtail frames are much lighter. The thing I am going argue that alot of weight weenies dont underrstand is lighter doesnt always equal faster.

 

More effficient - hardtails are more effcient at a less efficient pedaling style. Let me explain. They will pedal better standing for sure, and also people who tend to pedal like they are sawing logs will beneifit from the fact a hardtail doesnt bob. This is all assuming smooth surfaces, make it a trail, especailly a trail that has tons of rocks,roots or logs and the FS bike is simply more efficient up the climb. Especailly bikes that have pedal platform built into how the suspension pivots and not just the rear shock.

 

Faster - well faster isnt subjective. You can simple take a bike out and ride it hard around a set loop, then take another bike out and ride the same loop and find out whats faster. Most people will never do this though. I have to be fair my wasnt truly apples to apples as the hardtail was a SS but even on the easiest trails in the area the FS bike is faster. The SS 'feels" faster for sure though. I have never heard others say this but let me try to explain alot of people will feel 'bouncing' or 'roughness" as faster it quite often is not the case though. hardtails will feel faster because well they are bouncing in less control and actually going slower.

 

ride what ever you want but dont justify anything with actually seeing for yourself what is really faster. Now if you justifing it for fun or being different then no harm. I still like my hardtails especailly my SS hardtail. well because its fun and mixes up the local trails.

 

 

A-HA!   The MeaTBall version of roadie "float".

 

http://www.bikethink.com/Frameflex.htm

 

http://www.kirkframeworks.com/Flex.htm

 

For my money, Jan Heine came up with a decent enough rule of thumb:  the fastest bike is the one that makes you want to shift -least- when climbing.

 

great links BTW but I disagree with Heine quote.

 

If the race was all climbing then he would be right but besides hill climbs that isnt the case. alot of time can be made up on flats and decents in a MTB race

 

 

What he said doesn't go against that:

the bike you want to shift least will be the one that flexes right for your pedaling style, force, and cadence.   The idea being that any given *human* doesn't really _vary_ how  they go about high-effort pedaling very much at all during any one given ride.    If you jackhammer on the climbs, you'll probably jackhammer on the flats.

Velonews did a test of HT vs. FS this year. They had two bikes with SRMs on them, and a timed loop. With the same power going into the pedals, the FS was faster on every single lap. IIRC the bike FS was faster in every sector uphill, flat or downhill. I wish I could link you guys to this, but Velonews doesn't put their print edition stories on the web anymore (glad they don't since my subscription was starting to feel like a waste of money). 

Same rider, or different?

 

 

I believe it was the same. but whats the difference between 300 watts from my legs or 300 watts from Eatoughs legs? there is none the bike wouldnt know.

 

I still think they should just let people go out and ride as fast as possiable and see whats faster not just base it on the power meter.

I thought I remembered it being more than one rider, but alas, I think I've thrown that issue away.

 

BW - I think that without using the powermeter, the test isn't really a test anymore. 

 

 

Your first post explicitly states that the bike *does* know.   

 

300Watts is the scalar *power* = it doesn't tell you how the force is distributed over time or distance, spikes or smooth.

 

touche but the velo test does state the FS was moving down the trail on the same amount of power. That is more efficient.

 

Totally agreed.   

 

IMO, a power meter is necessary to prove the assertion, but not sufficient.

 

Isn't watts how much power is going in at that instant? There must be some smoothing so tat it can display a reasonable number instead of being all over the place. It would be interesting if the computer also added up all of the power into Watt-Hours or whatever and you knew how much energy the rider used on the entire lap.

 

A hundred watt bulb lights up on both DC and AC.   Just by seeing it lit, you don't know whether the power supply is DC or AC.   You'd need a voltage measurement to know DC from AC or what frequency AC (50Hz Euro?  60Hz US? 400Hz airplane?) and the resonant circuit you'd design for each case would be different.

 

 Similarly, you'd need a force graph from the crank to really determine  force cycles (sorry). 

 

And that ^ (power*time tracking) is how the calorie counters work on the *better*exercise machines ( the Concept2 rower comes to mind instantly here, the power is computed from the back-EMF of the fan motor) .

This is an interesting discussion that plays right into an issue I have been facing.  I am about to replace my FS (4" front/back) mountain bike with a 29er.  A huge portion of the good riders in Durango are going to 29ers, and it seems like the majority of those are abandoning their rear suspension and going with hardtails.  The rational is definitely based on weight, but also that 29" wheels give a smoother ride so that suspension is not as essential.  I have heard things like a 29er hardtail is like having 1" of suspension on the rear.  The common "wisdom"  remains that hard tails are more responsive and efficent.

 

I was very glad to read the articles posted because I decided a long time ago that my hardtail days are over.  FWIT I have decided to go with a Niner FS with just 3" of travel rather than the heavier 4.5" frame, which also requires a heavier fork.  My "wisdom" is that the 29" wheels do smooth things out some and, although I ride alot of rough trails, I don't catch big air or do big drops, so the travel/weight compromise seems about right for me.  We've got a lot of vertical around here, so weight and climbing efficency are a bigger consideration than in many other locals.

 

The one important factor that I think is missing in real life application of the hard tail vs FS test is the fact that the a huge percentage of FS riders do not have their suspension tuned correctly from an maximun efficency standpoint, so it is actually inhibitiing their riding to some extent.

 

 

How many 1" travel fulls do you see anymore. Remember DeKerf and of course the YBB?

 

I think a lot of it will depend on where you ride and how you ride. Sounds like if you have to have a 29er the Jet9 may be just the bike for you. Around here the RIP 9 seems to be more popular.

 

What bike are you on now anyway?

 

Also, I think there is a difference between suspension that is efficient and suspension that feels efficient.

 

I am 6' 5" and currently on an 8 year old custom 3D Racing Cush-E.  It was actually the proto-type for their current full suspension design. The owner, designer, builder is a friend of mine, and my bike was kind of an experimental model built for me and then modified several times after I started riding it.  I may have the only  bike in the world with the rear shock on top of the top tube (my idea).  His rear suspension linkage design was copied (although he uses a different word) by Rocky Mountain Cycles.

 

Regardless of the feel the rider experiences, I am often suprised when I see how some people have their bikes set up.  The suspension adjustments are getting so complicated that many people seem to just go with how the shop sets it up initually, or mess with it without really understanding it because the manuals are getting so obtuse.

 

 

You pay a pretty big weight penalty for the bigger hoops and of course a big penalty in moment of inertia too. Obviously for the trails you ride a lot of riders seem to feel that the benefits outweigh that though.

 

You're right about suspension setup too. Shocks have so many settings now, it is easy to get them all wrong (and then some people never even try).

http://www.v2racing.com/3dracing/cushe.html

 

Looks like Chris hasn't updated the site in quite a while. What's his take on FS these days? He ought to have a pretty good feel for what works in Durango. 

 

Herting has never been a real fan of full suspension for his personal bikes.   He is currently riding nothing but a 29er single speed.  When he wants suspension he goes for his motorcycle.  He has come up with a cool new SS frame design with intertnal cable routing that should be appearing in the bike mags pretty soon.  Those are air cartridges mounted between the twin top/seat tubes.  He's got a sub 20 lb. newer belt drive one he is riding now.  He is still building some of the nicest custom frames for the money in the business, but you usually have to wait to get one. 

I've seen that bike only with a Hammerschmidt, so a 2-speed. I did notice that it had he breakaway dropout for a belt drive. 

Yeah, he has been running it with a two speed some times, and then switchs to a regular bb if he races it as a single speed. He told me that from a practical standpoint he does not end up actually shifting it very much with the two speed.  It sounds like its real advantage is for the road to get to and from rides, but you'd have to talk to him about that. I know that, like most of the good riders in town, he is currently in a love afffair with SS and rides nothing but.   I have chased him on my FS on a few rides and the SS guys definitely can rip.  Unfortunately, because of my size and age I don't see a SS in my future.  It would be a fun toy for limited situations, but not a substitute for my regular bike.

pretty cool stuff mudfoot.

I don't have a lot to add but I'm really intrigued with that SS. 

Treckchick:  The new belt drive for single speeds seems to be finally catching on. It is super quiet and works in the mud because the teeth are on the belt and they push the mud right out of the "chain ring" holes.  If you want a frame like that you can check out the link in Epic's post and call up Chris at 3D.  Custom frames are great because you can get the geometry specific to your body and a combination of materials and tubes tailored to your needs.  There is nothing like the feel of a bike made just for you.

Did you see this thread?

http://www.epicski.com/forum/thread/78871/trek-district

 

 

My observation:

 

My 24lb HT feels and is faster than my 26.5lb FS-esp going uphill. But........
 

 

 

.......on any ride over 20 miles I am noticably less tired on my FS.

 

Don't take this as me being confrontational (it's easy to do that on the web). How do you know? What are these hills like? Of course all of us need to recognize that riding in VT is not the same as PA, which is not the same as UT, or CA. Obviously, there is a point where the smoothness or the grade of the trail will render suspension superfluous.

yes most people think 'stiffer' rear suspension equals better climbing/pedaling performance. this is not the case. suspension with platform built into how it pivots and not the shock will out climb all other and yet still feel plush on flats/DH. the problem is the only suspension that pedals well while being plush and maintains tractions with the ground is limited to a very few amount of bike makers.

 

'

The dw-link design is engineered to balance the effects of acceleration and braking forces in order to improve traction and efficiency. It uses a kinematic suspension force called "position sensitive anti-squat". When a vehicle accelerates the suspension reacts (typically in the form of suspension compression) to a phenomenon called load transfer.^[7][8] The position-sensitive anti-squat of dw-link offsets the rearward load transfer that happens during vehicle acceleration. This unique attribute is mathematically proven to reduce efficiency losses, while improving traction, and bump sensitivity, and if properly engineered, eliminating perceptible pedal feedback, when compared to other methods of achieving a similar offset of load transfer.^{[citation needed]}

Inventor Dave Weagle's US patent 7128329 was the world's first and remains to be the only published account on the method of mathematically and geometrically characterizing linkage chain/ belt-driven, and shaft-driven motorcycle and bicycle suspensions. The 7128329 introduced several new concepts and measurements to the suspension world, specifically the concept of characterizing anti-squat as a curve or area when graphed as a function of anti-squat versus compressive travel. The portfolio also proposed the same basic measurement for braking squat versus compressive travel distance. These measurements are now accepted as "anti-squat curves" and "braking squat curves" for some professionals in the field of vehicle suspension dynamics.^[8]

The dw-link suspension design was used to win six Elite level UCI downhill World Championships from 2005 to 2007, the highest contested level of the sport. This winning streak made the dw-link the winningest linkage suspension platform in the history of the sport of downhill."

 

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7128329.PN.&OS=PN/7128329&RS=PN/7128329

 

 

have you actaully timed this? plus if the hardtail is 5 seconds faster uphill then the the FS is 10 second faster all around the FS bike is still faster.

 

 

At 6'5" I'd recommend a 29er hands down.

 

I was a hold out on the 29er thing for quite a while. For a taller, heavier rider, I think the 29er makes sense. If you are in the small medium or small frame size cat, I would make an argument for a 26 inch ride.

 

As far as full suspension, or hardtail, the distinction is less clear. I bought a Ventana El Padrino hardtail. My reasoning was that I bought the bike for endurance riding, and racing. The endurance courses tend to be a little smoother, with sections of fireroad, and even pavement. With the larger tires, it tends to soak up some of the smaller bumps. Not to mention it is lighter weight.

 

My next ride? I do want full suspension. I have a hard time giving up my 26 inch Hi Fi Pro. I really like this bike. I have trouble thinking of getting rid of it. Keeping the Ventana 29er. I am considering either a Niner Jet 9, or something like the 26 inch Intense with an adjustable 5.5 to 6 inch travel. I like the maneuverablity of the 26 inch wheels, the traction and rollover anything ability of the 29er wheel.

 

I am still doing some fairly long semi rough trail rides.  With my hardtail there was always that sore crotch and back feeling after about 3 hrs. where all I could think of was when can I get off this bike, but since I got full suspension I can ride comfortably as long as my legs will last.  If I was only doing 1.5 hr. rides I think I would go with a hardtail, but now that the FS bobbing issue has been resolved I'm a convert to FS for riding in the mountains

There are two rides that are my basic "out my back door" types. One is 16 miles, the other is 20. They both start and end with three miles of easy singletrack. Both have a mile of pavement mid ride and the rest is jeep trail or dirt road.

I notice two things on these two rides.On the HT I am in higher gears (on the flats and climbs) and can keep up-better- with my main riding buddy (he is faster than me). I have never timed myself, FS v HT, but the above obsevation is good enough for me.

But like I said, above 20 miles I am noticably less tired on my FS. Less tired means I can ride faster. The FS bike is faster by virtue of the engine's energy level. On rides under 20 miles my energy level is such that the HT is faster. YMMV.

Truth be told while I enjoy both of my bikes, I ride my FS 75% of the time,