The Trek 7.2 FX isn't slow, you are...and myself for now :)
 

Eight weeks ago I purchased my 2009 7.2 FX an 18-20 mile round trip commute and weekend fitness riding, based on forum research and my LBS's recommendation. This is my first bike since adolescence. I am 26 now, and although not in "shape", I am athletic. While riding almost daily, it has taken the entire eight weeks of persistent research to convince myself that my bike will not hold me back on my commute and as I develop as a cyclist.

I am happy now, but for a while I was frustrated. Do I need drop bars?!? Is my bike too heavy?!? Will the entry-grade drivetrain/wheels slow me down?!? Oh noes my folk is hi-tensile steel!!!

This forum has been instrumental in learning all I have thus far, and it is full of knowledgeable and helpful people, for which I am very appreciative. It's good to live in the internet age! However, it seems that, innocently, much of the advice given is tailored towards what is optimal...often without explaining that easier/cheaper/different/suboptimal alternatives aren't that bad (at least for the new cyclist). The 80% solution explanations are out there, but are less abundant.

I was finally able to convince myself that my 7.2 is ok, after hours and hours of forum searching, by doing some cycling physics learnin' to cap it off. It appears that speed (velocity) is primarily affected by wind resistance, followed to a lesser degree by rolling resistance, and distantly followed by other minor attributes. Weight only impacts acceleration and climbing, essentially...which are not primary considerations for me. Even if they were, at 155 pounds a 10 pound decrease of the bike (going from my 30 lb'er to an expensive 20 lb'er) is only an approximate 5% reduction in total weight. Does it really make that much of a difference when riding only 30-120 mins? On the other hand, does weight matter much at all for someone significantly heavier?

My bike is "heavy" and the flat bars keep me too upright it is said. So what! Put some 700x28's on, lower the stem (the 7.2 has 3 spacers), put some bar ends on angled aggressively, and go clipless (or at least clips). I can cruise on flats in the 18-22 mph range, have hit up to 27 mph on the flats, and have TONS of gear left. My bike isn't holding me back, my body is. I begin my daily peddling commute in the next 2-4 weeks, and expect to be a much different rider in a year or so.

Is the 7.2 the perfect bike for me for the next 10 years? Of course not. Would my wife have allowed me to spend $1000-$1500 on a more ideal one without prior knowledge that I would become obsessed with the sport? Of course not (neither would I). Could I have gotten more bang for the buck with a used gem? Sure. Are those easy and timely to find, in the right size? Nope. In a year or two, I am sure I will sell this or upgrade the snot out of it. I have already extensively researched that future procurement and can't wait :)

My aim with this post is not to incite any flat bars vs drops debates, to tell anyone they're wrong, or the like. I also do not expect that I am 100% right, and there are of course different strokes for different folks. I just wanted to relay the experience of my first couple months of cycling, researching, upgrading, and performance for those in a similar boat. Now if I have mis-characterized anything or you disagree with any of my points, by all means have at it! I still have much to learn :thumb: In the meantime, I can't wait to start commuting!

Your bike rocks because you do. You make many good points. The 80% solution, if I understand it correctly explains why I've been a hybrid rider for the last twenty plus years.

Re: 80% solution. I was referring to the 80/20 principle...a general rule thrown around in an engineering curriculum. 80% of the benefit comes from 20% of the effort. The remaining 20 percent of the benefit requires 80% of the total effort. It's just jargon for diminishing returns. In this case, the benefit is velocity provided by the bicycle and effort is cost.

Oops, sorry, I have no idea what you are talking about, but it still might explain why I ride hybrids.

Not to put words in your mouth TRI...

He means that if he got anything beyond a 7.2 FX or a road bike, it would be diminishing returns relative to where he is at in his cycle "journey" and what the bike needs to do for him.

trinamuous:
Are you an engineer ? You sound like one since you have apparently agonized over your initial purchase. I did the same thing. I found this forum AFTER buying my bike. After going thru a lot of post, I began to realize that I should have gotten a road bike. However, gradually I saw the light and figured the hybrid was right for me all along. It was affirmed when JETJOCK posted that there is very little difference in avg speed between his road bike and hybrid and at the end of the day, he is a lot more comfortable overall on the hybrid.

Morgan:
Thanks, that's what I was trying to say (in a lot more words)! I am an engineer. Everything I buy goes through this agonizing/fun research process before buying.

Eventually, I may want more of a commuting capable road/touring bike, such as the Trek Pilot or a LHT. But then again, I may opt to convert the 7.2 to drops and upgrade the drivetrain. Either way, it will be another agonizing/fun decision process :)

I think its slow. Its cranks are just awful. I have 2 Trek 7.2 FX bikes and a Fuji Absolute 2.0. My Fuji is a lot faster and I don't think its just due to 28c tires vs 35c. Better wheelset, better crankset (only $10 difference methinks). Others may not agree with me but that's my take. Of course, "slow" is a relative term.

"A lot" is relative too :) Is there a quantifiable speed increase on flats? If not, are you just accelerating more quickly? You have reinforced my original point, regardless. If I were still shopping, there is no way to take your experience and perspective, as stated, and make an educated decision based on cost an performance. Which is unfortunate, given that you have two bikes of the same type with different component sets. That being said...my cranks are the first component in line on the chopping block :)

This is *almost* right. Rolling resistance is (tyre coefficient) * (bike + rider mass) * (speed). So weight does affect flat road speed - but only slightly, because aero drag dominates.


That's wrong. Rolling resistance isn't the same as friction so narrower tyres aren't faster. The most important factors are the rubber compound used and the tyre wall thickness. Major manufacturers have tyre application charts and tech docs to guide you through tyre choice - speedy rubber either costs more or requires you tolerate reduced puncture resistance.


You'd be better off sawing the bar down to shoulder width. Of course you can do both, although I like my hands on the brakes at speed - bar extensions are really for kicking on the gas in a climb. Stem changes are easy if you want to go longer. Be wary of used stems - metal fatigue can cause nasty accidents.

BMX pedals work 99% as well clipless and better than conventional clipped pedals. It's pull through at the bottom of the stroke that matters - power from pulling up in normal riding is a myth.

Wheels and cranks don't really affect speed - the angular kinetic energy stored in a wheel is tiny compared to that the overall kinetic energy of a bike and rider, and all bicycle powertrains are very efficient if kept clean and used in a suitable gear.

Tyres aside, a good racer will have two advantages over a typical hybrid -

- Reduced air resistance

- A rider position that lets the rider generate more power

Air resistance is the big enemy. If you cut it by, say, 30% and you can kick out 10% more power, your bike's performance will really perk up. Unfortunately it won't go 40% faster, because air resistance rises drastically with speed.

You got me on the tires meanwhile. I should have been more specific. The stock tires of the 7.2 FX are treaded and have a max PSI of 85 (or close). So, the new tires, narrow or not, improve performance by effect of the smoothness and increased pressure. Right, no, kinda?

I suppose I should look into cutting the bars at some point. The grips are pushed in by 2-3 cm due to the bar ends, so if my arms are spread it is not by much at all.

Do the fancy expensive cranks do anything besides reduce weight?

Probably, but not *quite* certainly. Some moderately treaded tyres are faster than some slicks, because tyre compound is such an important factor. Eg Schwalbe rate their new treaded Marathon Extreme as being faster than the slick/semi-slick Marathon Plus, but the Extreme is very expensive and uses an exceptional compound.

If you really want fast tyres I'd suggest Sport Contacts or Marathon Supremes. (The later are fast and exceptionally puncture resistant and high mileage - but pricey. They have more wet grip than the Contacts too.)

The best way to cut bars is with a plumber's pipe cutter - very cheap off ebay.

No. But some people are willing to spend crazy money to save weight. You'd be surprised how many people buy carbon frame racers without first achieving your understanding of what they're buying. To be honest, I think most of them don't understand the basics - if you read the bike physics page on wikipedia and understand air resistance a little better (ie that it's a speed cubed thing) you'll be ahead of 99% of them.

The other thing that will help with bike speed is frequent powertrain cleaning.

If you want a bike to go faster start with the wheels and tyres as reducing rotational weight (and the bike weight) and the rolling resistance will give you the greatest gains.

A lighter (and stiffer) crank will also increase performance as it too rotates and it is easier to spin up a lighter crank and a stiffer unit will not be subject to as much flex / power loss during transfer. There is a good reason why a top of the line racing crank can cost upwards of $500.00.

On an upright hybrid you are always going to be limited by wind resistance and this will manifest itself when you try and hit higher speeds as it increases exponentially to your speed.

I have hit 55 kmh on flat ground on my roadified hybrid and that was more a result of reducing wind resistance than any reductions in bike weight... the skinnier 700:28 Marathons cut through the wind so much better than the 700:40 Marathons it came with and at the same psi roll much faster.

I never changed the gearing but went with a stiffer and lighter crank than it came with.

My old '99 Trek 7500 also has a more roadish frame and lacks the steeper top tube angles of it's younger siblings and other comfort oriented hybrids so I can get more aero.

Being able to get low in the drops is something you notice immediately when you are trying to go faster or have to battle stiff headwinds.

I am not a weight weenie... my road bike is a vintage Ron Cooper that curbs out at 21 pounds and I can't get that bike to go any faster on the flats than I can my hybrid (the gearing is pretty close)... but I can ride it at higher speeds longer, it accelerates like a rocket, and climbs like a goat on speed.

And here is a wrench in the works...

My 1955 Raleigh Lenton is a fixed gear road and touring bike and is all steel with nary a speck of aluminium and hits the curb at 32 pounds which would have made it a lightweight in it's day.

It is a full oiler in that aside from the headset, all the bearings are oil lubricated.

This bike is so incredibly smooth to ride and I have done a sub hour 40 on it... that's 40 km in just under an hour... it's vintage Dunlop Gold Seal tyres are 26 by 1 1/4, are rated for 65 psi, and still roll out incredibly fast.

I was going to take my Trek on an 180 km out and back tomorrow but am thinking I will take the Lenton as it does rides like this so very well.

The bike in touring mode...

http://www.ravingbikefiend.com/bikepics/regnew1.jpg

It is a myth that you can make significant gains this way. Wheels are already very light and they're one of the hardest parts of the bike to reduce weight on because they need to be strong, rigid and tough, which aren't easy things to combine.

The physics is very simple. You can crudely think of weight lost at the rim as the wheel as counting double - the "times ten" figure some people claim is pure lunacy. (I'll go through proof for this is anyone cares.) But that doubled-up figure works for energy stored in wheels and the bike, but not for energy lost to resistive forces, which is what matters for maximum speed - for this purpose, weight is weight wherever it is on the bike. Working from this:

- If you lose a total of 500g on both wheels and you weigh 80kg and your bike 12kg for a total of 92kg, you've lost 0.5% of total system weight.

- This will cut your rolling resistance by 0.5%, but not reduce air resistance at all

- RR is probably about 30% of total resistance at top speed, so total resistance is cut by 0.15% - ie the bike behaves as if you have gained 0.15% more pedaling power

- Resistance is mostly from air drag, which is speed cubed, so your speed increases roughly - this is a slight over-estimate - by the cube root of 1.0015, ie 1.0005. In a 100km race that's a lead of 50m and worth paying for - but in any other circumstance you'd have to be insane to give a damn.

The special benefit of lighter wheels, as opposed to a lighter frame, will be a small increase in acceleration. A loss in frame mass means that only linear kinetic energy for a given speed is reduced, but a loss in wheel mass means that both linear AND angular kinetic energy are reduced.

Anyway, the optimizations worth making to a reasonable quality wheel are:

1. A better tyre! Go for one with low RR. Even among racing tyres RR can vary by about 40%, for a whopping c. 12% reduction in overall power needed to maintain a given speed. You'll get low weight as a side effect. Don't neglect grip and puncture protection. Any bike can benefit from premium tyres.

2. Keeping the wheel true so that it rolls optimally.

3. High quality inner tubes - they contribute to RR too.

4. Checking and topping up air pressure regularly.

There is a good reason why high end cranks cost this much - it's human psychology. You've never seen a test of crank showing the above but you still believe it - because if a crank costs more and everyone buys it there must be a reason!

There is no way that you can exert enough pedaling force to bend a standard crank enough to cause an energy loss of even 1%! (And if you did lose 1% of energy, the difference in maximum speed would be 0.3%, because of the cube law for air resistance.) By comparison a dirty power train can cost around 10% of pedaling energy.

Really - grab a crank and try to bend it! It won't. Those things are solid - energy is not being lost.

However, again, lightness is worth paying for in a pro team racing bike, because even a few metres advantage won on a climb can be decisive.

You won't turn an FX7.2 into an Allez using the suggestions I've made, but I'd bet on a bottom of the range Allez with these wheel tweaks and a clean chain against a top of the range Allez - riders being equally matched and motivated twins, etc. Regular maintenance and some research and willingness to spend on unglamorous rubber can add the equivalent of several thousand dollars of performance to a bike...

Finally, for the OP -

- A longer stem won't just give you more aero, it may also balance you better for turning. Obviously, be judicious in deciding how long a stem! I'd much rather see you riding a bike with a longer stem (cheap, easy to fit) than trying to use bar ends for aero, with your hands away from the brakes...

- Performance isn't just about speed but turning and stopping power. So add fast but *grippy* tyres, Kool Stop Salmon brake pads, and regular brake maintenance.

(Long post - I've adapted something I was writing for a blog.)

People neglect rider position and how it affects power output. This is because it is a hard sell for manufacturers - it requires a complex fit between rider and bike, so a bigger range of frames and better LBS staff. So ad money and PR time doesn't get spent on it, bike journalists don't write about it, and it doesn't enter the collective consciousness. Otoh, energy loss to "frame flex" - which is nonsense - is a great selling tool, so it gets pushed.

The Treks are that of my siblings whom don't take the best care of them. To be fair, the bike is durable and its frame is not any reason for slowness (besides hybrid geometry vs road). It is possible that I didn't have the Treks on the same gear equivalent as my Fuji. I just had both bikes at the middle gear on both sides but this still does not mean that different gear systems correspond perfectly. I am in a hilly area so its possible that the Trek 7.2 was on a gear or two higher (and for a lazy guy like me that makes a difference) and so it was tougher to pedal on than it is on my Fuji. Also, the Trek has a more upright set up (as I did not set it up) whereas my Fuji has a little more optimal 45 degree back angle set up...FOR ME. So I guess you are right.

I have gone pretty fast on the Treks before. They are durable and look nice. I just wish it had better components...shift better...cranks not slightly bend up the hill and waste energy...etc (but I'll stop whining about that). I don't ride anything with less than Deore components. The next bike I get for myself (I like having several bikes) will be (1) Trek 7.5 FX nickel color (2) Specialized Rockhopper Pro Disc in mango color (3) and then several years down the road if I am conditioned for the flat back posture...a Trek 2.3 road bike in its awesome white color + patterns.

I do agree that the 7.2 is a good first bike although I personally find the Absolute 2.0 to be best bang for the buck in the same exact price range (especially for 2009 models when Trek's prices were raised and before they had Alpha Black Al for the 7.2 FX).

I own a 7.2 FX, and I think it's a great bike! Fast enough.

And since it's cheap, learning how to do mechanical maintanence on a 7.2 is no big deal. If you **** up a part, you're not out a lot of money.

I like the bike so much that I'm considering getting a second one.

Your story sound like mine. I had not riden a bike since being a kid. I recently graduated from a dept. store bike which I used once a year on vacation. I settled on the Giant Sedona based upon the recommendation of the LBS. It is not the most serious hybrid out there but it is obvious that riding a decent bike vs. riding a Huffy is more enjoyable and I ride more often with the better bike. When I reach a more reasonable weight (right now I'm at 275 lbs.) I will upgrade to something like a flat bar roadie maybe. Right now the entry level bike suits me fine. These forums provide the best free education out there for us.

This thread in particular has a lot of good info in it. Bike riding is great for burning calories. Enjoy the ride and the resulting weight loss. For most of us speed isn't really important. It's how much you ride and how much effort you put in when you ride. Heart rate monitor probably more useful than a bike computer, though I don't use either.

I have a $320 'cheap' hybrid with probably 'cheap' components, it's steel and I've only been riding since May (hadn't been on a bike in years and years) and I so far can get to 32 km/h on a flat road and almost 50 km/h downhill and I live *IN* Vancouver, BC which has tons of hills, I used to think I had to get a road bike but now I think differently. I'm getting bar ends (thanks Les) to make climbing hills even easier. I ride in Critical Mass and ride for over 3 hrs and could probably keep on going.

i wish to retract my naive posts. the trek 7.2 fx was slower for me than the fuji because the two bikes have different gearing systems and i wrongly corresponded one with the other. yes, the trek 7.2 is a very good first bike that will not limit your speed until you reach the point where you are ready (and want) for a straight back road bike posture. with the new alpha black aluminum, the 7.2 fx is an even better bargain.

Getting up to speed and reaching your potential is a multi year process... some would say three years of continuous and well thought out riding is what the average person needs.

After the engine is optimized you may find yourself looking for a better tool to optimize the output of the engine... overcoming wind resistance is critical.

We had a 1979 Raleigh Sports (men's) bike at the co-op and it's previous owner had done a drop bar conversion on the bike leaving the three speed and lovely fenders and chain guard intact.

That little change made this the fastest Raleigh Sports I have ever ridden except for my 1954 model which came as a 3 speed drop bar version that will soon be a 9 speed with a dual and true hybrid drive.

My Specialized Sirrus is a lot slower than the Allez I used to own. About 3mph slower over 10-15 miles. But, guess what? I am way more comfortable and enjoy the Sirrus much more. Could I make it faster? probably. Do I want to? nope. All I plan on changing is the rear derailleur to a Deore or LX, and the chain to an SRAM. Maybe some lock on ergo grips as well, these tend to move while riding, but are so comfy.

IF you really wanna go faster, you gotta buy a race-oriented road bike.
I will stick with my comfortable hybrid. I may go for shorter rides, but I ride more often, which is more miles in the end!

Encouragement for the 7.2 fx
 

I am 50 years old, typically rode about 500 miles a year on a road bike. This year I bought a 7.2 fx with the goal to increase my riding. After 6 months I've rode about 2200 miles and just road my first century in about 6.5 hours. Changes to the bike included upgrading to Conti Ultra Gator 28s, clipless pedas and bar ends. My biggest 'ahha' was making sure that my motor was properly fueled before riding. I endorse the 7.2 fx.

^^^

since you're doing long distance riding, don't the flat bars bother your wrists?