power surge!
 

What does "thrust" or pick up in a bike depend on?I recently purchased a 1993 Speciallized Allez Comp and its noticeably faster or has more thrust when I want to take off than otherbikes I've owned including my 1987 Pinarello Montello a true racing bike.I think this phenomenon of power response is called energy transfer to the wheels or something like that.I also had a real noticeable power response with my 2000 Litespeed Classic which I have since sold. Is it dependent on the wheels?The specialized has Mavic Open Pros,and the Litespeed had Mavic Heliums while My Pinarello has Open Sports a cheaper wheel.Surely its not just one thing but perhaps people could enlighten me on the subject a little.Thanks!

Is this something that is measurable, for example doing a 100 yard standing start Strava segment?

A couple of options.

• Just a feeling of a new bike moving and reacting differently.
• Gearing. For example, starting in a little lower gear will help with acceleration.

boy... this must have been discussed to death in other subforums... maybe check the road cycling discussions?

regarding the physics, the main factors of the bike that influence how fast you increase speed are inertia and friction. Bike weight is a primary factor affecting inertia. Friction and other losses are dominated by aerodynamics, tire flexing, chain and bearing lubrication, etc.

Bike fit can be a factor in how well the rider can develop force and effectively apply it to forward motion.

Psychological factors can be important too, both in the perception of acceleration and in the ability to focus and generate power.

This is a huge subject, so don't expect a quick comprehensive answer.


Steve in Peoria

btw, for a good review of college physics, I like this series of lectures on youtube...
https://www.youtube.com/channel/UCiE...9%A5%20Physics.
It ought to provide some insight into acceleration and what affects it.

Newness. I believe shorter chainstays and stiffer BB area attribute to faster acceleration, but wheels have some input too.

Shorter chainstays of course mean less distance for your power to travel through the chain.

A stiffer BB shell area, like Bianchis SuperSet and SuperSet 2 frames, mean less side to side flex in the frame thereby reducing energy loss and transferring more power to the drivetrain.

lighter wheel accelerate faster than heavier wheels.

You could try swapping the wheels and seeing what that feels like to you. Some people say it's about stiffness of the frame/components, for others it is the wheels, for others it's the geometry, for others...

I have the same experience with my 2008 Trek 7.2 FX Hybrid. It out accelerates every other bike I have ever owned. It's also measurable.

When riding around town, I would occasionally get met at traffic lights by a group of road bikes. We would say "hi" and all that. Then my standard old hybrid with a rack and panniers with the older guy (me) in normal clothes would blow their doors off to the next stoplight. I would stick with them (at the front) until there was about a km stretch of non-traffic-controlled road. Then they would leave me in the dust, until the next stoplight.

BTW - I'm almost 60.

Coffee.

Brent

:thumb:

Meth!

I think a lot of that is gearing. I'm not great off the blocks... but once I get rolling, I can blow by most hybrids... if I feel like it.

The Allez is red, right? It's been scientifically proven that red is the fastest color. Don't get a beige bike...slow, slow, slow.

That's true.

The gearing on this hybrid is designed to go from 0 to 16 mph in the same gear very quickly, and that's about 75% of the top speed. I live in about two gears most of the time.

If you race people who aren't racing you, it's easy to leave them behind! :thumb:

Otherwise, the weight of the wheels is a big factor. Also: having your weight placed just right over the pedals, for maximum pedaling efficiency (I'm not sure whether you'd call this bike fit or setup). Being in the right gear, and staying in the right gear as you accelerate, helps a lot as well.
Some cyclists spend a little extra time clicking in to their pedals before really accelerating; this gives the guy with platform pedals a momentary advantage.

I can dig what our OP is saying. I went from a steel Trek 460 racer to a Cannondale Criterium Series. Night and day difference. The Cdale is a notorious sprint/climb bike and it pays back in instant response. Every pedal stroke is a surge forward. If I couldnt feel the difference it would not be my absolute favorite bike and probably not in my fleet.

I appreciate the feedback from all!Gearing and wheels seem the most probable influences.

Wheels... my Roubaix OEM Mavic Open Sports developed cracks around the nipple holes on the rear after about 10 years. I got a deal on a set of Reynolds Stratus Elites, and it transformed the bike. It was a sluggish, but comfortable cruiser, now a comfortable but way more fun and responsive ride. It also handles better on turns. I used to hear the speedo spoke magnet ticking the fork sensor on curves with the old Mavic. I set the magnet very close to the sensor on the new Reynolds, and never hear any contact, telling me that the old wheels were flexing more than the new ones. I don't have any numerical data, not even wheel weights, but the difference is noticable and much welcome. I don't feel any change in ride quality (comfort), to speak of. Win win.

You really do live in rural Washington!