Question about speed.

[RedBullet]

This maybe a silly question but when im riding down hill or get up to speed on the flat i feel that i my gears spin out to soon and i cant increase my speed.What is the best thing i can do on my bike. Do i need more teeth on my big crank on the front (54) or am i missing something?????

 

[User33236]

More teeth on the front or less teeth on the smallest cog on the rear. What do you have at present?

 

[RedBullet]

50/34 on front, 12/25 on back

 

[uclown2002]

I've got the same compact setup and I spin out just under 40mph; I can't say I reach that speed too often on my routes. That's impressive if you're spinning out on the flat!

 

[User33236]

You would get marginally more gain from dropping to an 11 at the small end on your cassette than going to 54 on the front.

 

[RedBullet]

thanks scottish geek, i will have change to an 11 then.

uclown2002. it has something that has been bugging me for a while so i tend to notice it very easily but living in the hills its probably after a downhill and it levels off, thats when im still spinning and its driving me mad!

 

[Herzog]

If you're spinning out downhill (which I'm assuming to be over 110 rpm), then you're likely to be going around 36 mph (50:12). At this point, it probably makes more sense getting into aerotuck than attempting to keep a high cadence. If you got an 11 tooth rear, you could do 39 mph for 110 rpm.

http://www.machars.net/bikecalc.htm

If you're doing this on the flat, I've the number for Sky if you want it...

 

[green1]

If you're spinning out downhill (which I'm assuming to be over 110 rpm), then you're likely to be going around 36 mph (50:12). At this point, it probably makes more sense getting into aerotuck than attempting to keep a high cadence. If you got an 11 tooth rear, you could do 39 mph for 110 rpm.

http://www.machars.net/bikecalc.htm

If you're doing this on the flat, I've the number for Sky if you want it...

That or he's watched too much of Guy Martin behind that truck.

 

[ColinJ]

The top gear on my Basso is only 52/14 but I have done 55 mph on it downhill. I just pedal to about 35 mph then get into an aero tuck and freewheel.

I stay in the tucked position at the bottom of hills until I slow to about 35 mph and then start pedalling again. Let's face it - it isn't long before most people's speed drops back down to a maximum of low 20s in mph anyway!

 

[Fab Foodie]

52x12 and spun her up to 50 mph on ventoux .....




..... And then I descended

 

[ColinJ]

52x12 and spun her up to 50 mph on ventoux .....




..... And then I descended

After which, you woke up!

 

[Doyleyburger]

I asked the very same question on my first thread. I also live in a very hilly area. Was convinced I needed that extra gear but it's all about tucking in. Makes a hell of a difference going downhill.

 

[HLaB]

^^^^^ This^^^^^^ The fastest for last year for me was on a borrowed cyclocross with a 48t big ring, as said its all about tucking in and learning to spin

 

[Rob3rt]

The gears you have are more than adequate for the average cyclist! I very much doubt you are spinning out on the flat!

 

[Chris1983]

I have got a 50F and 12R and a maximum cadence of 140RPM going by the RPM counter on the spin bike at the gym...

I have never span out on the road in the real world....that would give a top speed of 45MPH+...my legs don't have the power to over come the real world factors like wind resistance but above all my head won't let me go that fast on the push bike...as 40MPH approaches i'm not pedaling and covering the brakes

This might be interesting to calculate the differences between the ratios

http://focushacks.com/kc-bike/topspeed/

Chris