How much more performance can i expect from a Road bike?

[Munkii]

Hi,

I currently ride a fairly light, Giant CRSA Hybrid. I am taking part in the London Duathlon in sptmeber and am thinking of getting a road bike. Are they really that much faster?

I appreciate that I am the engine and I am not suddenly going to be breaking records but will a road bike help and how much would i need to spend to see a speed benefit over a £700 hybrid?

Thanks

Pat

 

[marinyork]

I went from a 700x35C hybrid with flat bars to a 700x23 roadbike with drops. The speed difference is in the 1-7mph range. It really depends on what you put in, the course and how you're feeling. If you have an off day, windy something inexplicable it might only be a slight speed increase. Most of the time it's about 3mph faster, there are a few freak rides that are a much bigger difference. When I redid a century ride on the roadbike I chopped about 3hrs off - it was a more challenging course too.

The surprise for me was how much quicker it is up hills, always being slow on the flat.

 

[HLaB]

On my hybrid I usually average around 13.5mph comfortably over distance and can work harder do around 15mph. With my flat bar road bike I was averaging around 14.5 comfortably, 16ish when I really worked. I converted it to drops and now it comfortably manages 15.5mph and with work I getting around 17mph. With my summer road bike I'm comfortably getting around 16.5 miles on a long hilly solo ride around the 18sh working.
A road bike will make it so much easier to maintain a comfortable speed that you'd need to work for on flat bar and hope its not windy (that's when I especially see the advantage of drops)

 

[accountantpete]

A stiff top-end road bike will make an enormous difference- but make sure it is top-end as regards the frame and wheels/tyres-you can go a little lower with the rest of the kit (105/Chorus).

Second hand a decent aluminium frame/carbon forks will set you back £250,wheels £200 and the rest say £400 inc pedals and tyres etc.

It won't be the most comfy bike ever assembled but it will get the job done.

 

[peanut]

one of the keys to extra speed is to get down lower and become more aerodynamic which you can do more efficiently on a road bike.
When you get above 18mph every additional 1 mph takes an ever increasing amount of energy to achieve due to increased wind resistence .

 

[MacB]

well I have a Giant CRS Alliance which began as my commuter and has become my weekend bike. It has butterfly bars so I tend to ride on the sides, only using flats to brake or change gear. Originally it had rack, guards and 35mm M+ tyres. Now it has no rack, no guards and 23mm Schwalbe Blizzard road tyres. When I first made the changes I tested against my own 20 mile time trial route, I had an immediate 2mph, from 14.5 to 16.5, improvement.

I don't know what it would do now as I haven't had a chance to put it through its paces recently. Closest I've come was the first 25 miles of the return leg from Bognor last Saturday. Having been up riding all night and also having only been back on bike for 1 week since 3 weeks off due to knee injury. Those 25 miles were done at about 15.5-16mph, but I had already done 77 miles prior to this.

Most of my miles are commuting at present, 40 mile round trip, on my hub gear bike that weighs in at 36lbs unladen, approx 42lbs with luggage. My speed varies from about 13.6 to 15mph, depending on wind and legs. The Giant weighs in at 24lbs so I would guess that it would give me about 16.6-18mph for the same amount of effort.

So I surmise that, if not already done so, stripping Giant down and adding road tyres could give you 2-3mph. I would be surprised if you could up this by more than another 2mph via roadbike. Though I would say the headwind aspect can be a major factor.

 

[MacB]

just to add the stripping down option could be done for no more than £50. Touring/butterfly bars, or bar ends, will offer more hand positions and allow you to get lower.

I've been thinking on getting a new weekend road bike and have looked at everything from entry level to high end £8k titanium. To get a significant improvement over the Giant I reckon I'd need to spend £1200 upwards. I also looked at converting Giant to road bars but the parts are so pricey compared to buying a complete bike. The Giant alliance frame(carbon/alu mix) is actually quite a high level frame. But the parts, ie trigger shifters etc, are relatively cheap low/end.

 

[Munkii]

MacBludgeon,

I can't really strip the Giant down as I want to keep it as my daily commute bike. Thanks for the input good to hear that the bike I have is a good one

Pat

 

[Munkii]

A stiff top-end road bike will make an enormous difference- but make sure it is top-end as regards the frame and wheels/tyres-quote]

How would I know it was top-end? Simply by the price?

I was looking at buying either the Trek 1.2 Triple or Univega Via Laser

Pat

 

[jimboalee]

one of the keys to extra speed is to get down lower and become more aerodynamic which you can do more efficiently on a road bike.
When you get above 18mph every additional 1 mph takes an ever increasing amount of energy to achieve due to increased wind resistence .

Here's the formula for that....

Pf = ( Crr x (W/375) x V ) + ( CdA x (V^2/391) * (V/375) )

Crr is coeff of rolling resistance, W is weight, V is speed and CdA is Coeff of drag x X section area.

Reduce A and you will ride faster.

 

[I am Spartacus]

I love the formula.
Indurain would still leave you ( and everyone else on here probably) for dust if he ever did get his leg over an Apollo.
If you do have to have the desire to be really competitive, that means investing money into something that all the other participants are using.... equal levels of fitness.
If you dont have enough fitness, a shiny sub 7kg bike still isnt going to suddenly switch itself to the magic button and pedal harder.
Alternatively,
run faster
(don't bother with the swimming)

 

[accountantpete]

How would I know it was top-end? Simply by the price?

I was looking at buying either the Trek 1.2 Triple or Univega Via Laser

Pat

Very basically -yes. If you go down the second-hand route then £200 will probably get you a 3+ year old aluminium frame that originally cost £500+(just the frame & forks) which would be an entry level frame from one of the top manufacturers.

If you want to be competitive then those two bikes are a dead loss

 

[beanzontoast]

I love the formula.
Indurain would still leave you ( and everyone else on here probably) for dust if he ever did get his leg over an Apollo.
If you do have to have the desire to be really competitive, that means investing money into something that all the other participants are using.... equal levels of fitness.
If you dont have enough fitness, a shiny sub 7kg bike still isnt going to suddenly switch itself to the magic button and pedal harder.
Alternatively,
run faster
(don't bother with the swimming)

 

[Garz]

I appreciate that I am the engine and I am not suddenly going to be breaking records but will a road bike help and how much would i need to spend to see a speed benefit over a £700 hybrid?

Pat you have to improve yourself first before any mechanical improvements begin to help. It is far cheaper to streamline yourself and get to peak fitness before embarking on some expensive gear that may shave a few seconds off your time.

Not every athlete uses a road bike, they just tend to fit in better by looking the part. Invest in one when you can afford to in a few months time and you may be able to get a more worthy purchase at £700+ which will be considerably better!

 

[jimboalee]

I love the formula.
Indurain would still leave you ( and everyone else on here probably) for dust if he ever did get his leg over an Apollo.
If you do have to have the desire to be really competitive, that means investing money into something that all the other participants are using.... equal levels of fitness.
If you dont have enough fitness, a shiny sub 7kg bike still isnt going to suddenly switch itself to the magic button and pedal harder.
Alternatively,
run faster
(don't bother with the swimming)

They didn't call him 'Big Mig' for nothing. He was over six foot and weighed 81 kg when he won the tour several times.

With a clear 10kg of bodyweight more than his rivals, he had to produce the difference in power to keep up and then go ahead.

The bikes were the same weight ( on the legal limit ) so it was down to Power/weight ratio.

I have mentioned before on this forum that the pros aim for 7 Watts per kg.

Going up the Ventoux needs about 4.5 W/kg.

When you do get somewhere like 4.5 W/kg, you will notice the flat road riding gets faster.