General Cycling Discussion - Is there a way to make a bike faster?

My girlfriend has a trek 7.5 FX and I have a redline 510. Her bike is really quick and I have to peddle a good amount more then her to keep up with her. Any suggestions or am I out of luck?

I'm not sure what the Redline 510 is. If it's a mountain bike, you might try slicks rather than knobby tires on it. Otherwise, work out more, get a new bike, or ask her to slow down a bit.

It may be her that's quick, and not her bike.

Also, check your air pressure, make sure you're okay there. Make sure everything's spinning freely- pick the bike up and give the wheels a whirl, should be obvious if something's binding up or a brake is rubbing.

Switch bikes on a ride. Does the quickness shift over to you, or does she still kick your butt? There's your answer.

Is this it?
http://www.joebikeler.com/store/product/redline_r_510/

I would guess that most of the problem is how heavy it is and how huge the tires are (700 x 55?)
The gearing looks fine to me (28/38/48, 11-34). I had a hybrid geared like that and it was pretty quick. Besides, I figure the Trek has similar if not the same gearing.

If the tires are knobby, you can start there and swap them for smooth/slick tires.
Make sure they're inflated fully. Check if the brakes are rubbing. Assuming none of the bearings or wheel hubs are worn out, that's probably all there is to it.

My girlfriend has a trek 7.5 FX and I have a redline 510. Her bike is really quick and I have to peddle a good amount more then her to keep up with her. Any suggestions or am I out of luck?
You're out of luck. :o
The Redline 510 is a true hybrid. The Trek 7.5 FX is a flat bar road bike.
Hybrids are inherently slow. Flat bar road bikes are designed to be faster than a hybrid but not as fast as a traditional road bike.

I have to peddle a good amount What are you selling, and how does selling something make a bike go faster?

I would say the Trek 7.5 FX is a hybrid - but the pendulum swings closer to road-bike than mountain-bike. All hybrids go a bit one way or another in this way. But the Trek 7.5 FX is a very quick bike. No match for a actual road-bike - a good one - but for a hybrid, it trucks quick.

The Redline is also a much more upright bike, so she is almost certainly in a more aerodynamic position than you are, with her torso probably tilted forward at 45 degrees.

Hope she waits for you at the top of the hills, and meantimes, enjoy the view.

Try using a narrower tire, down to 28mm width, with the tire pressures all the way to the max. Check bearing preload at the hub cones to make sure the cones aren't too tight.
The 7.5 has higher gearing as well.

Ride more ... outside.

You're out of luck. :o
The Redline 510 is a true hybrid. The Trek 7.5 FX is a flat bar road bike.
Hybrids are inherently slow. Flat bar road bikes are designed to be faster than a hybrid but not as fast as a traditional road bike.

What's "flat bar" mean?

Straight handlebar instead of the curved-under style used on a road bike.

Straight handlebar instead of the curved-under style used on a road bike.

Gotcha! That curved-under style bar is a "drop bar"? Bare with me guys... I'm getting it slowly but surely :p


While I've derailed the thread maybe I could ask another question about something I've seen discussed in this thread. What exactly makes one bike style so much faster than another bike style, especially when they seem so similar? I could understand tires making a big difference, but it seems as if subtle changes in the frame and handlebars (like the difference between a hybrid, cyclocross, and road bike) make a large difference in speed. I'm just curious how.

The main differences why some bikes are faster are in the frame geometry. Subtle changes in frame geometry can alter performance in huge amounts.

For instance: I have a Trek 1100 which I used to ride a lot. It's a 60 cm frame with a 57 top tube. The seat tube angle is 73.5 degrees. I now have a carbon framed Orbea Orca that I ride. It's also a 60 cm frame size but has a 59 cm top tube. The seat tube angle is 74 degrees.

The difference between the 2 bikes is astounding. On the Trek I averaged around 13-14mph on just about any ride over 20 miles. On flats I could maintain 23mph for around 2-3 miles before I would blow up and couldn't push the gears anymore.

The Orbea is a joy to ride. I can AVERAGE 19 mph over 25 miles on it over the same roads and I never get winded doing it.

Same frame size, different geometry.

That is amazing Rob, a half of a degree of difference in seat tube angle making the bike that much faster.

Gotcha! That curved-under style bar is a "drop bar"? Bare with me guys... I'm getting it slowly but surely :p


While I've derailed the thread maybe I could ask another question about something I've seen discussed in this thread. What exactly makes one bike style so much faster than another bike style, especially when they seem so similar? I could understand tires making a big difference, but it seems as if subtle changes in the frame and handlebars (like the difference between a hybrid, cyclocross, and road bike) make a large difference in speed. I'm just curious how.
A big difference is aerodynamics. Recumbents are fast because much of the rider's body is horizontal. Time Trial bikes are fast because the rider leans forward on the front jutting aero bars to make the torso almost horizontal and keep the arms in a streamlined position. Racing bikes are fast because the handlebars are set lower than the seat to get the torso tilted far forward. Comfort bikes are slow in part because you sit upright in the wind.

Another issue is optimizing leg power. If you are leaning forward over the pedals you can push down harder using your body weight, and thus accelerate and sprint faster than if you are sitting upright. On a recumbent, that same effect is accomplished by having a brace behind your back.

A lighter bike is slightly faster to accelerate, and faster uphill, but a little slower downhill, and not much different from a heavy bike cruising on the flats.

High pressure tires (which are usually skinny) are a bit faster than low pressure tires (which are usually fat), but wide tires pumped up to high pressure are faster than skinny tires at the same pressure.

Slick tires are faster than knobby ones.

Small wheels accelerate faster than big ones, but don't have any weight advantage once your speed levels off. However, they are also slightly more aerodynamic than large wheels.

Aerodynamics and leg power (the first two) are the most important, and bike weight is somewhat important in really hilly conditions.

Optimize your aero. Slide the stem down as far as it'll go, then drop the angle on it (it's adjustable, right?) so it's parallel with the ground. Then flip the riser bars upside down so they drop down then pull back. Get 100psi road tires, no more than 32mm wide (1 1/4").

You reach the point of diminishing returns after that. So, if that's not enough to let you keep up, you'll need a new bike. WARNING!!! If you one-up her, she will one-up you and the arms race will be on! Which is to say, if you're gonna do it, you might as well go all the way now. Buying a $5K bike now will be cheaper than buying a series of $1K bikes.

What are you selling, and how does selling something make a bike go faster?


LOL! That was funny! :roflmao2:

A lighter bike is slightly faster to accelerate, and faster uphill, a little slower downhill, and not much different from a heavy bike cruising on the flats.


I haven't thought about this in terms of bikes, but doesn't gravity accelerate all objects at the same rate, regardless of mass? Maybe it's a question of inertia or momentum?

That is amazing Rob, a half of a degree of difference in seat tube angle making the bike that much faster.It's also the longer top tube, which stretches him out a bit, and thus puts his head lower, and there may be differences in tires, gearing and handlebar height that he didn't mention.

I haven't thought about this in terms of bikes, but doesn't gravity accelerate all objects at the same rate, regardless of mass?
If it were only gravity acting on it, then yes. But there is more to it, such as road friction and wind resistance, which I assume heavier weight will help power thru. Think of a bowling ball and a beach ball of the same size falling from high in the sky. I'm willing to bet the bowling ball hits the ground first.

Disclaimer: I'm not a scientist and the pay per hour motel I slept in last night was definitely not a Holiday Inn.

I haven't thought about this in terms of bikes, but doesn't gravity accelerate all objects at the same rate, regardless of mass? Maybe it's a question of inertia or momentum?

When falling yes, but bikes roll down a hill, so rolling resistence comes into play along with weight. For example, a heavy Hot Wheels car or a Pine Wood Derby car is faster on a steep decent track. The lighter car is normally faster on a track with a long level run at the bottom where it passes the heavier car. This illustrates the coasting effect with gravity and weight.

Many other factors are involved which someone in physics can describe.

rolling resistance would be slightly higher for a heavier bike (frictional force = mu*normal force). So that isn't it.

yes, something like a feather and a book fall at different rates, but that's due to air resistance. put the feather on top of the book and drop: they fall at the same rate.

the forces acting on two cyclists are the same: gravity, rolling resistance, and air resistance (ignoring internal mechanical inefficiencies). there is no difference in air resistance between two bikes, assuming they are of the same geometry. one could weigh 14 lbs, the other 30, and it's inconsequential to air resistance. as i said before, rolling resistance rises with weight. and gravity accelerates all objects at about 9.8 (m/s)/s.

even looking at in terms of kinetic energy, mass is irrelevant.
ke = 0.5*m*v^2
this rearranges to v = (0.5 ke/m)^0.5
which, assuming you are coasting from the top of a hill, is
v = (0.5 *m*g*h/m)^0.5 = (0.5*g*h)^0.5, ignoring energy lost from resistance.

where mass will come into play is just after the hill. the bike/rider combo with more mass has more kinetic energy (and momentum, if you choose to look at it that way), as they both are moving the same speed, but one has more mass. This means more work is required to stop the heavier bike. If both bikes continue coasting, the lighter one will stop first. This is also important if you want to brake very quickly. the lighter guy stops first.

You say that you have to pedal a good deal more than her in order to keep up with her, so you may want to look at your gearing. A larger chainring (up front) or a smaller cog (in back) will give you a higher top-end speed.

As the others have said, check your wind resistance and your rolling resistance. Are you wearing a big floppy shirt? Does your wheel rub against your brake?

Also, do you maintain your drive train? Is it noisy? Remember, every "squeak" out of your chain and gears is a little bit of lost energy.

rolling resistance would be slightly higher for a heavier bike (frictional force = mu*normal force). So that isn't it.

yes, something like a feather and a book fall at different rates, but that's due to air resistance. put the feather on top of the book and drop: they fall at the same rate.

the forces acting on two cyclists are the same: gravity, rolling resistance, and air resistance (ignoring internal mechanical inefficiencies). there is no difference in air resistance between two bikes, assuming they are of the same geometry. one could weigh 14 lbs, the other 30, and it's inconsequential to air resistance. as i said before, rolling resistance rises with weight. and gravity accelerates all objects at about 9.8 (m/s)/s.

even looking at in terms of kinetic energy, mass is irrelevant.
ke = 0.5*m*v^2
this rearranges to v = (0.5 ke/m)^0.5
which, assuming you are coasting from the top of a hill, is
v = (0.5 *m*g*h/m)^0.5 = (0.5*g*h)^0.5, ignoring energy lost from resistance.

where mass will come into play is just after the hill. the bike/rider combo with more mass has more kinetic energy (and momentum, if you choose to look at it that way), as they both are moving the same speed, but one has more mass. This means more work is required to stop the heavier bike. If both bikes continue coasting, the lighter one will stop first. This is also important if you want to brake very quickly. the lighter guy stops first.There is a big diference in the effect of air resistance as they roll down the hill just like in the feather and book example. Any experienced group rider knows heavier people and/or people on heavier bikes generally coast downhill faster. The gravitational acceleration (or the vector that parallels the slope of the road) is the same for all riders, but what overcomes air resistance is the gravitational force, which is stronger on the heavier rider.

ah, think I've got it. It has to do with your terminal velocity, which does depend on mass. silly me. on descents at less than terminal velocity, the weight shouldn't matter. I've seen this discussed elsewhere and not clarified.

sorry for the hijack.

The gravitational acceleration (or the vector that parallels the slope of the road) is the same for all riders, but what overcomes air resistance is the gravitational force, which is stronger on the heavier rider.

This is the first time I think someone actually gave an answer to this question that makes it clear to me.

It is the same reason a light rider can climb faster. Gravity is applying the same acceleration to each, but there is a greater force to overcome for the heavier rider.

I always have been hung up an the constant acceleration... and knew there must be more, since I know I have to feather my brakes on some hills while other people are pedaling to maintain the same speed.

Do you simply want to go faster than her? A small brake adjust should do the trick. Slow her right down to your speed.

The main differences why some bikes are faster are in the frame geometry. Subtle changes in frame geometry can alter performance in huge amounts.

For instance: I have a Trek 1100 which I used to ride a lot. It's a 60 cm frame with a 57 top tube. The seat tube angle is 73.5 degrees. I now have a carbon framed Orbea Orca that I ride. It's also a 60 cm frame size but has a 59 cm top tube. The seat tube angle is 74 degrees.

The difference between the 2 bikes is astounding. On the Trek I averaged around 13-14mph on just about any ride over 20 miles. On flats I could maintain 23mph for around 2-3 miles before I would blow up and couldn't push the gears anymore.

The Orbea is a joy to ride. I can AVERAGE 19 mph over 25 miles on it over the same roads and I never get winded doing it.

Same frame size, different geometry.

You are also comparing a Alu Frame/Carbon fork ( 20ish lbs) $1k bike to a complete carbon frame/fork ( 15ish lbs) $3k+ bike. You have to compare apples to apples to give an accurate comparison.

You are also comparing a Alu Frame/Carbon fork ( 20ish lbs) $1k bike to a complete carbon frame/fork ( 15ish lbs) $3k+ bike. You have to compare apples to apples to give an accurate comparison.

This is true and there is a HUGE difference in weight between the 2 frames as well as the frame materials. However, the point is, the geometry of the Trek is "touring" oriented and the Orbea is more race/speed oriented. The guys I ride with have commented on how much faster I am with the new bike because I'm not working as hard. This is because my body position is more forward on the frame (ie the "power position"). Which translates directly into "staying power" and "sustained speed." Some of this may be placebo effect as well but if so, there isn't much of it IMO.

The wheels/tires are the same. I just switched them from one bike to the other so that didn't change anything. The "fit" is almost the same as well. The seat/pedal distance is the same. The reach is the same too. The only difference is the seat/bar drop. On the Orbea it's a bit lower because the stem had already been cut and I couldn't add another 5mm spacer.

15 lbs? I wish. At 60 cm I'm lucky to be at 18-19 lbs without bottles. The Trek weighs in at a whopping 27 lbs dry.

What is comes down to is that the Orbea is much more aggressive as well as being a whole lot lighter. I could have weight weenied the Trek down to around 20-22 lbs if I'd really tried but even then it would not have compared to the Orbea in performance. After all the thousands of miles I put on that bike I KNOW what its limits are and it could not compete because it was not designed for that use. So what it really boils down to is frame geometry is what makes a bike faster (given the same power output and other variables).

Gotcha! That curved-under style bar is a "drop bar"? Bare with me guys... I'm getting it slowly but surely :p


While I've derailed the thread maybe I could ask another question about something I've seen discussed in this thread. What exactly makes one bike style so much faster than another bike style, especially when they seem so similar? I could understand tires making a big difference, but it seems as if subtle changes in the frame and handlebars (like the difference between a hybrid, cyclocross, and road bike) make a large difference in speed. I'm just curious how.

Usually I let the grammar issues slide, but in this case the meaning changes a bit between bear and bare.

ah, think I've got it. It has to do with your terminal velocity, which does depend on mass. silly me. on descents at less than terminal velocity, the weight shouldn't matter. I've seen this discussed elsewhere and not clarified.

sorry for the hijack.

Nope. Heavier riders have an advantage going downhill period. Larger riders start pulling away from the very start on a downhill. The effect becomes more noticable as speeds increase.

Usually I let the grammar issues slide, but in this case the meaning changes a bit between bear and bare.

So what? Not a single person had a problem understanding what I was saying.

So what? Not a single person had a problem understanding what I was saying.A little harmless razzing - I wouldn't worry about it.

A little harmless razzing - I wouldn't worry about it.

I'm a ball breaker by nature (Italian construction worker from New Jersey) so I could take some ribbing. But I think his corrections go deeper than "razzing".

Bare with me guys.

You first.

I'm a ball breaker by nature (Italian construction worker from New Jersey) so I could take some ribbing. But I think his corrections go deeper than "razzing".

My, pretty thin skinned. Guess I should not point out I made only one correction.

I think I'll just get get stronger in my leg muscles. lol

My, pretty thin skinned. Guess I should not point out I made only one correction.

Knowing your kind, I'm sure it's killing you inside.

Weight vs downhill speed has been discussed on various forums ad nauseum. Think of it this way. A heavier weight sitting on the top of a hill represents *more* potential energy than a lighter object. It took more energy to get it up the hill, right? If we're talking about 2 bikes with riders, the heavier one will have more energy to liberate while rolling down the hill. Acceleration due to gravity is the same for both: 9.8 m/sec/sec, but on the Earth we also have to worry about air resistance; and if we're on bikes, there are mechanical losses to consider, too. Both theoretical cyclists have approximately the same losses: similar frontal areas and coefficient of drag, same losses due to bearing and rolling resistances, etc, and the wattage must be used up by the bottom of the hill; so the one with the most energy to start with will go the fastest. If you accept that heavier riders have a tougher time going up the hills, then for the same reasons you must accept that they get more payback going down.

If you accept that heavier riders have a tougher time going up the hills, then for the same reasons you must accept that they get more payback going down. It's not for the same reasons. Even if there was no air resistance, it would still be more difficult to get the heavier rider up the hill, even though both riders would roll down the hill with the same speed.

the heavier one will have more energy to liberate while rolling down the hill. But rolling at the same speed as the lighter rider would actually liberate more energy, so that does not explain the advantage.


Acceleration due to gravity is the same for both: 9.8 m/sec/sec, but on the Earth we also have to worry about air resistance; and if we're on bikes, there are mechanical losses to consider, too. Both theoretical cyclists have approximately the same losses: Yes, the have a similar frontal area and coefficient of drag, therefore will encounter similar air resistance. But if you apply the same force to the object of different masses, it will have more effect on the lighter one. That's why air resistance will slow similar down the lighter rider more than the heavier rider.

The gravitational acceleration (or the vector that parallels the slope of the road) is the same for all riders, but what overcomes air resistance is the gravitational force, which is stronger on the heavier rider. Yes, the force gravitation force is stronger on the heavier rider, but that's because a stronger force is required to affect a heavier object in the same way as a lighter object. So that gives you no advantage. The gravitational forces acting on two riders are proportionately matched and would produce the same results wrt speed and acceleration.

What matters is that the air resistance is not proportionately matched, since it depends on the surface area and not on mass. It is roughly the same for both riders. That's why it has less effect on the heavier rider, hence the heavier rider comes out a winner.

I would say the Trek 7.5 FX is a hybrid - but the pendulum swings closer to road-bike than mountain-bike. All hybrids go a bit one way or another in this way. But the Trek 7.5 FX is a very quick bike. No match for a actual road-bike - a good one - but for a hybrid, it trucks quick.

I'll agree. the 7.5fx is a rocket for a hybrid.