agarose2000

I'm currently rocking on a used, purchased for $100 steel Gary Fisher Mamba hardtail, complete with commuter bike rack, kickstand, and pump. Looks kind of funny when I take it on the mountain climbs around my area, but it works great, as I'm not a big downhill rider, and avoid big drops or really nasty technical terrain.

This bike is 35+ lbs with all the stuff on it. Right now, I don't mind the extra weight, since I'm not racing at all on it, and using it for hard training, so it has been ok. However, I've recently gotten more into road cycling, and am enjoying covering larger distances faster, and started looking at lightweight mtn bikes, such as the BikesDirect FLY, which they claim weighs in at close to 20 lbs, or a 15 lb differential betweeen it and my steel bike.

Have any of you riders done a similar upgrade to a much lighter bike? If so, did it help a lot, a little, or did you not really notice at all? And is such a light framed bike risky on the downhills?

SunFlower

I dropped 8 minutes off my 4 hill climb time when I switched from a 31.5 lb mountain bike to a 21.4 lb mountain bike.

Dheorl

I've recently bought a bike that is half the weight of my previous one, and climbing has become soooo much easier it's unbeliviable.

junkyard

Approximately 56.7465%

kenhill3

At least there's SOMEBODY here with the knowledge to provide hard numbers.

zlr101

If you want to got a bit lighter remove the kick stand and get slightly lighter wheels and tires. I did that with my old bike made a world of difference.

My bad it was a long day

agarose2000

I could definitely shave weight by removing my commuter gear, but that's unfortunately my commuter bike. I'm thinking of a more significant weight drop anyway, such as 5-7 pounds for performance on a separate dedicated mtn bike. Any other comments on how much easier it would be?

Metzinger

Some of those old Fisher steel frames were pretty good. With the right tires and wheelset, it could feel roughly the same and climb almost identically to a fancy new rig.
But we like new bikes here, don't we?

Just remember, proper interval training beats a fancy new bike almost every time.

Jordan300

but a fancy new bike just looks so cool!!

junkyard

I sense sarcasm in that statement. I did the math, you wanna check it for me?

agarose2000

As mentioned previously, my current steel Gary Fisher bike is primarily my COMMUTER bike, and only occasionally a mtn bike. I'm thus unwilling to put upgraded lightweight parts on it - makes it a target for theft. The way it looks right now, it's a fairly unremarkable beige bike that attracts little attention. Still, I can outclimb basically all of my nonracing friends on some steep mtn climbs with it; I train fairly hard as a runner and now triguy, so my aerobic engine is pretty solid. (Yup, I do intervals.)

An upgraded mtn bike would be a mtn-dedicated bike for me. Hence the question about the lightweight stuff. I admit though, even if I had the chance to make my beige GF steel an upgraded "lite" one, I'd likely upgrade the frame/fork anyway with a new bike altogether. Beige is definitely unsexy.

dminor 

20 lbs @ 3500 watts over 60 minutes ÷ 35± lbs @ 3750 watts over 60 minutes X the Q-factor of .56497 for a mountain bike on a 20% grade at 68° F with no wind X √π = 56.7185%

You're off.

telebianchi

If your GF is a COMMUTER bike, then it's not a mountain bike.

Go spend your money and help the world economy!

But, slightly more seriously, have you test ridden any other bikes? A new(er) bike, besides being lighter, may give you improvements in geometry, components, brakes, wheels, etc. Or it might not. But until you do some riding you won't know. I ride a '97 Specialized Ground Control FS -- it's an old pogo-stick of a bike but it's the only one I've ever owned. Last fall I had chances to ride 2008 Specialized Epic and a Giant Trance. Both were better bikes than my old ride - lighter, stiffer, better brakes, less unwanted bounce in both the rear shock and fork. But, neither made me want to get out the credit card.

I understand you're looking at the BD bike that is mail order, but go into a shop or two and test some similar bikes. I suspect you would answer your own question fairly quickly.

ed 

I can outvomit basically all off of my nonracing friends on some steep mtn climbs with mine; I train fairly hard in the bathroom so my trajectory is pretty solid.

agarose2000

My GF is a true steel mtn bike which I have converted to a commuter bike. I was primarily a marathon runner in the past 2.5 yrs, and only did biking to ride with friends. As they weren't racers, I didn't mind adding extra weight as a "handicap" so I wouldn't outpace them all too quickly. (As you might imagine, serious marathon running at 70+ miles per week makes you a pretty decent bike climber even with limited experience. Not so good on gnarly downhill though!)

I'm finally about to "take the plunge" to a real mtn bike setup. I should probably try some bikes like you recommended - although I'm finding it really, really hard to top the BD pricing. At those prices, I would even be willing to "gamble" and just hope it fits right. After all, mtn bike sizing seems a lot more forgiving than road bike cycling.

As for adding to the economy, I've done more than my fair share of bike purchases this year! In moving from marathon to triathlon, I spent $2700 at my LBS on my fitted Cervelo P2C tribike, and then added $500 in accessories instantly. And I don't make much money - my car is worth $4000 tops!

I don't see how BD bikes are so problematic for LBS's, anyway. I don't want to re-hash the BD flamewars, but in my opinion, if you get a new potential cyclist to buy a quality bike (by offering great value at great prices), you'll have a greater chance at turning them on to the sport, and thus make a LOT more LBS purchases/maintenance. I've ridden bikes casually for 20 years, but as they were all only slightly better than "Huffy-grade", I never had any inclination to ride more. Things changed a LOT with my Cervelo - all of a sudden, with this road MACHINE, I wanted to buy EVERYTHING for my bike! My LBS benefited BIG-time from ownership of a bike with higher end-parts. Even if I had gone BD and got a high-component end bike there, LBS's would be the direct beneficiary of all my additional upgrades, tuneups, and accessory purchases - all of which must be at LBS quality stores to match the hi-end componentry of the BD bike. Ok, that's it about BD - I'm going to go put my flameproof suit on now before everyone jumps all over me just because it's my opinion!

dminor 

The nerve: having an opinion on a public forum!

Seriously, and in answer to one of your original questions: YES, you will notice the difference when you get on a lighter bike, And it doesn't even have to be silly-light to appreciate the difference. It will accelerate instantly when you push on the pedal - - to where it'll feel like it could squirt out from under you. My first bike was in the 35 lb range; and, even though I habitually ride even heavier stuff now, it is a pleasant experience when I get on a light bike and ride trails.

Metzinger

When I reread the title question I realized the purpose of the thread.
Was it,"How much would I improve on climbing by using a marginally lighter bike? " The new bike has essentially already been bought.

The title should have been, "Hooray, I'm getting a new bike! Is it going to be super-awesome or just awesome? Comments?"

agarose2000

I must be misunderstanding "marginal" then.

My bike: 35 lbs, probably closer to 36-37,actually
Motobecane Fly: 21 lbs per website, probably closer to 24-25 per reviews

Is 10lbs marginal nowadays? I certainly haven't absolutely ruled in the new bike; other excellent options include accepting the 30+lb bike weight and going dual suspension for a more fun downhill and a minimal weight advantage on the uphill. Of course, if 10lbs makes it a LOT easier to climb, that may tilt me enough toward the flyweight bike.

rydaddy

You'll feel and enjoy the difference even with a 28 lb hardtail. Don't get too obsessed with weight alone though.

ed 

Open Season

junkyard

I assumed 67.6° F

cyclezen

climbing? anything, anytime, weight makes a huge diff. and with better wheels and Drivetrain, all that much easier. any amount of weight, anytime
10 lbs? do a test in 'reverse' -get a 5 lb bag of Idahos and a 5 lb Bag of Reds, hang one off the stem and one off the seat rails on your current ride, then go climb a hill. report back...
(reds cook up moe betta as raste-potatoes, Idaho are, of couse, defacto - baked...)
the big sack of potato on the saddle, well, its always cooked... no hope for that

whatz worth spending the dosh, is always up for discussion

Zephyr11

Keep in mind there's more that goes into it besides total weight of the bike. For example, rotating mass counts for more than non-rotating mass (wheels count for more than frame, rims count for more than hubs, etc). Geometry will also play a role, since some bikes will put you in a more aggressive position that might enable you to generate more power. Finally, as silly as this sounds, there's the mental aspect. You said you're a marathon runner...you know how you run faster in flats than trainers, even though the weight difference is really small and should only account for a few seconds per mile? Yet the difference is significant just because you *feel* faster? I ride better on my squishy than my hardtail, with more of a difference than rear suspension should be accounting for, just because I *feel* like I'm more capable a rider on it. Buy a bike that feels fast, and you'll be faster.

DirtPedalerB

I dropped 15 minutes from my 17 mile usual loop from switching from a 30lb hardtail to a 31lb full suspension. (lots of roots and rocks) I say ride what inspires confidence.

evul9

i dont know. i have a trek 1995 820 like 38lb and i bought a mtb trek 4300.honestly i think the trek 820 is better on road but its a no suspention bike