How much faster would "x" make me?

[Tin Pot]

Well, a TT bike is fairly specialist piece of kit, and the return on your investment in terms of speed will not be linear. The main issue is that the position is different to a road bike, and as such your power delivery is compromised. The extent to which that is the case varies from individual to individual, and depends on a number of factors, such as time spent in new position, suitability of position to athlete, aero gains vs. power loss trade off etc.

But in even in a best case scenario hoping for 30 minutes over 82 miles is over-optimistic.

I suspect so myself, and partly hence choosing that particular stat for feedback

 

[young Ed]

I like it - it's a bit of fun. There's a few things it doesn't account for, such as adopting multiple hand positions while out riding, like most probably do. Also, if you have a category for 'under-inflated' tyres, you should also have one for 'over-inflated' as well.

that one is called bang go to wiggle!
Cheers Ed

 

[Machin]

I'm surprised that the gains are so significant for a cyclist of my poor calibre

The "good news" is that the slower you are as a rider the more absolute gain you will see from something like a TT bike; because you are out on the course longer than a faster rider: this effect is greater than the fact that aero is more significant at the higher speeds of the faster rider! So that is good news for us non-professionals!

Re. TT bikes/Aerobars and power output; I do have the caveat on the respective "info" page that I have assumed that your power is unaffected, but that this might not be true for some people... scientific studies into this dual affect are hard to come by (most studies of riding positions are wind tunnel tests, rather than "on the road" tests: which would be affected by variable climate conditions). Whilst a 30 minute gain over 82 miles does sound a lot, it is only about 7 minutes in every hour or a gain of just 2.5mph for the same power output. I've done tests myself and find that 2.5mph (compared to an upright position) is about right for me (although as before everyone is different).

I suppose the other caveat is regarding anything that has a physiological impact on the rider is VERY individual dependant... for example scientific studies into the effects of training show huge differences between individuals; two people doing the same training regime may find that one improves their power by 5% whilst the other may show no gain (known to sports scientists as a "non-responder"). My program presents the average result of a group of people as presented in the results of the original scientific study.

I'm shortly going to add the links/references in to the original scientific studies so people who want to read more, can.

 

[Machin]

Another couple of notes on the TT bike performance gain: the 30 minutes would've been relative to an upright position on a "standard" roadbike? if you change your starting configuration to riding in the drops (for the whole ride) the gain drops to about 20 minutes... this change is effectively "free" since most road bike have drop handlebars. if you chnage your starting configuration to Aerobars (available for about £40) the gain for the TT bike drops to about 10 minutes in 82 miles... so the cost of a TT bike starts to look quite expensive.....

 

[400bhp]

Another couple of notes on the TT bike performance gain: the 30 minutes would've been relative to an upright position on a "standard" roadbike? if you change your starting configuration to riding in the drops (for the whole ride) the gain drops to about 20 minutes... this change is effectively "free" since most road bike have drop handlebars. if you chnage your starting configuration to Aerobars (available for about £40) the gain for the TT bike drops to about 10 minutes in 82 miles... so the cost of a TT bike starts to look quite expensive.....

I have heard "save 1 minute over a 10 mile" as a rule of thumb with a TT bike, so sounds about right I guess.

 

[Tin Pot]

Thanks, and yes I noticed the TT bike was a cumulative effect -
I was getting tri bars anyway (for tris) so this supports my buying ways
Cheers.

 

[Jon George]

A fascinating calculator - I'll be addressing some of the possible major improvements on a 20 mile BP course in the next few weeks. It certainly looks like I'll have to reattach those aero bars I bought when I was skirting with being a GATGNI.

 

[MikeG]

I tell you what would be nice............I don't know if it is possible, though: if the list of gains would organise itself into ranks. In other words, the biggest potential gains would be at the top of the list, with the smaller gains ranked below them.

I'd also like plenty of additional clothing options. What do I tick when wearing a waterproof jacket and longs?

Anyway, this is a wonderful effort, and very useful. Thanks for sharing it.

Mike

 

[G3CWI]

Anything that gets me to the pub quicker is a bonus.

 

[oldroadman]

All this discussion seems to be about equipment, and assumes that the output of the rider remains the same. Use the right kit and increase the output. The increased output will show some real gains. Here's the bad news - going properly fast is about the ability to sustain pain. Go back to the Lemond quote - never easier, just faster. Enjoy...in a perverse sort of way. I always hated TTs, no chance to have a chat with friends in the peloton in the quieter moments!

 

[RecordAceFromNew]

Although a few years old, this is a pretty good road vs tt ballpark comparison by Spesh.

The interesting thing, is while Spesh says Aero is Everything, those Taiwanese appear to be saying Spesh and McLaren have been pissing in the wind...

 

[oldroadman]

Although a few years old, this is a pretty good road vs tt ballpark comparison by Spesh.

The interesting thing, is while Spesh says Aero is Everything, those Taiwanese appear to be saying Spesh and McLaren have been ****ing in the wind...

Depends what bikes are in your range and who you want to sell to. Some people will believe anything producers feed them. Cynical, me? Nah...

 

[Machin]

I tell you what would be nice............I don't know if it is possible, though: if the list of gains would organise itself into ranks. In other words, the biggest potential gains would be at the top of the list, with the smaller gains ranked below them.

I'd also like plenty of additional clothing options. What do I tick when wearing a waterproof jacket and longs?

Anyway, this is a wonderful effort, and very useful. Thanks for sharing it.

Thanks for the feedback. I'm sure it would be fairly simple to re-order the results... although at the moment I'm not sure how (my html programming skills are fairly basic!). I'll have a look into it.

Re. the clothing options, I have some wind tunnel data for wet weather jackets so I'll add this shorlty. But what I will say is that because the results are relative you should find that the effect of other (non-clothes related) items will be largely unaffected by what you are wearing... (it will make a difference, but not that much)... e.g. if you were wearing a skin suit on an 18 mile 1 hour ride and changed from an upright position to riding on aerobars you would save 4 mins 5 seconds. But if you were wearing a wool jersey and long tights and cycled 18 miles in 1 hour the effect on the position would only change to 4 mins 8 seconds. (Of course, if you were doing the same 18 miles in 1 hour in both clothing configurations it would mean your average power in the skinsuit scenario would've been less because it has less drag.

 

[Machin]

A fascinating calculator - I'll be addressing some of the possible major improvements on a 20 mile BP course in the next few weeks. It certainly looks like I'll have to reattach those aero bars I bought when I was skirting with being a GATGNI.

Cool, have fun, and let us all know how your testing goes!