Fast hybrid opinions ?
- Thread starter widowmaker
- Start date
- Feedback
- View
Re: Re:
No worries
One option is for me to build a bike to my own spec
scottyp":324mo1go said:will try and get some tonight - just bedding it in having finsihed the oily work yesterday
No worries
One option is for me to build a bike to my own spec
- Feedback
- View
This was a karma frame that I built up for winter road use before the jake.
Osella
Senior Retro Guru
mattr":353w6phf said:
I don't believe the words 'road bike' were mentioned.. Simply that in response to the point, certainly in my opinion; I wouldn't base a short->mid-distance, plus gravel path/towpath bike on a Racing Bike, and I find it extremely odd and ill-considered that so many people choose to base their choice of commuter cycle on a bike designed for racing, where they often seem to base their choice of motor vehicle on the closest match to a tractor or military scout vehicle!... (I believe you are correct, possibly on all counts where my brother is concerned!)
Back on topic; I do personally think that an MTB frame - self build with handpicked components serves well as a base for a commuter and will provide greater flexibility for 'off-road' use even than a CX machine - particularly if panniers, racks or mudguards might be a consideration for the commuting side, as I'm (genuinely) not sure if there quite as many options with CX frames.
highlandsflyer
Retro Wizard
- Feedback
- View
Osella":1md8ckfw said:
Why the need for discs?
Osella
Senior Retro Guru
If you want to go fast, you want to stop fast.
I'd rather err on the side of caution and have them on a commuter to account for all the stupid things people do in towns/traffic, than not have them and break my wheel slamming into the back/side of the next car to pull out in front of me.
The practices of 'road' cycling don't really apply when it comes to commuting in traffic. Open roads fine, no problem, but towns and traffic (or pedestrians on pathways!) provide by their very nature shorter stopping distances, less anticipation time and more awareness required - hence my suggestions/inflated opinion that commuting bikes should provide plenty of visibility for the rider, a reasonable deal of comfort, enough gears to start/stop/start/stop, and climb hills, hopefully light weight to allow for quick acceleration up to a steady 25-30mph and at least two brakes, preferably powered by hydraulics and ideally disc.
I'd rather err on the side of caution and have them on a commuter to account for all the stupid things people do in towns/traffic, than not have them and break my wheel slamming into the back/side of the next car to pull out in front of me.
The practices of 'road' cycling don't really apply when it comes to commuting in traffic. Open roads fine, no problem, but towns and traffic (or pedestrians on pathways!) provide by their very nature shorter stopping distances, less anticipation time and more awareness required - hence my suggestions/inflated opinion that commuting bikes should provide plenty of visibility for the rider, a reasonable deal of comfort, enough gears to start/stop/start/stop, and climb hills, hopefully light weight to allow for quick acceleration up to a steady 25-30mph and at least two brakes, preferably powered by hydraulics and ideally disc.
I'd agree with the idea of discs for reliability / durability over thousands of miles of commuting, however it's rare on the road not to be able to lock up wheels even with cantis. V's are definitely sufficient on power, and I have no problems on my road bike to lock the rear wheel with dual pull callipers. Hydraulics are nice in that there are no cables to gum up though.
secret_squirrel
Senior Retro Guru
- Feedback
- View
I think hydraulics of any type give you a tiny bit more edge and that edge is important in serious commuting. In serious traffic you are probably the fastest acceleratibg thing next to a motorbike and due to that and a tiny front cross section tour can be constantly under estimated.
YMMV but for me every tiny bit of braking power counts - just in case.
YMMV but for me every tiny bit of braking power counts - just in case.
PurpleFrog
Kona Fan
Re:
For a once a subject I actually know something about - fast flat bar bikes on the road! (Qualifications: ex-San Fransisco bike messenger, physics degree and a fair number of bike performance papers/studies read.)
The people who said "mtb with slicks" have the winning answer. Why? Sports hybrids aren't built to go fast but to look as if they do to Joe Know Nothing Public while keeping flat bars - if necessary at the expense of features that will make them fast (and handle well.) The result is a marketing dept driven abomination of a machine.
Why? Well speed on the flat is about two things:
- Air resistance
- Rolling resistance
Hybrids are no better than MTBs for AR; the rider's position is set by stem length and height and bar width and that's it. (Which is a losing game to play against drops for physiological reasons - especially alignment of the carpals as go into a low and narrow position.) So all you can play with is rolling resistance....
People assume (see "Silence Of The Lambs"..) that narrow tyres roll faster. But, in fact, the opposite is fundamentally true. Emphasis on "fundamental" because most wide tyres are made to wear well an be puncture proof and cheap, while most racing tyres - which are made to go fast at the expense of all these properties - are 25mm are less. But the best possible 40mm tyre will have lower RR than the best possible 25mm - and corner better, be more comfortable, and safer over potholes.
And that's on good roads. On bad roads, the advantage gets even larger because vibration transmitted the rider's body weight causes big energy losses - much larger than the figures in the standard calculators (like the one at Analytic Cycling) assume because those figures came from riderless rolling drum tests.
So, old Konas and GTs that can take fast but wide tyres (like Grand Bois and Almotions) are faster than silly marketing driven bikes like the Sirrus that are restricted to maybe 32mm.
At this point someone normally asks why TDF bikes have narrow tyres. This is, in fact, because AR matters relative more at VERY fast bike speeds and the slight AR reduction counts more for the guy at the front of a peloton (sp?) than the fairly hefty increase in RR. But these are elite riders who are moving at speeds that even they can't sustain for long riding solo.
People also often claim that the ability of narrow tyres to take higher pressures reduces RR compared to narrow tyres. All I can say here is that testing shows otherwise - in fact it drives vibration losses up. Bicycle Quarterly has done a lot of testing here:
http://janheine.wordpress.com/2012/06/1 ... -of-tires/
- and see the links near the bottom.
Re. discs on the road: I'm doubtful they're any advantage. Tour magazine (it's German and OCD) did a test of stopping distances in the wet and with dual Koolstops there was barely any increase in stopping distance. Overall braking power is limited by 1. toppling, which is derived from centre of gravity and 0.7g for most performance bikes, and by 2. front brake skidding, where a large contact patch is an advantage - and vees or cantis can already push a bike to this braking limit.
As for weight, including wheel weight: it makes a minute difference on the flat and not much more (because it is swamped out by rider weight) on climbs. If you 3lbs off a 20lb bike that often feels really different, because the sensory information to your hands has changed, but with a 180lb on top of it then vehicle weight has gone from 200lb to 197lb, so you'll climb about 1.5% faster. Worth paying $1000 a lb for in the TDF, but probably not while commuting.
For a once a subject I actually know something about - fast flat bar bikes on the road! (Qualifications: ex-San Fransisco bike messenger, physics degree and a fair number of bike performance papers/studies read.)
The people who said "mtb with slicks" have the winning answer. Why? Sports hybrids aren't built to go fast but to look as if they do to Joe Know Nothing Public while keeping flat bars - if necessary at the expense of features that will make them fast (and handle well.) The result is a marketing dept driven abomination of a machine.
Why? Well speed on the flat is about two things:
- Air resistance
- Rolling resistance
Hybrids are no better than MTBs for AR; the rider's position is set by stem length and height and bar width and that's it. (Which is a losing game to play against drops for physiological reasons - especially alignment of the carpals as go into a low and narrow position.) So all you can play with is rolling resistance....
People assume (see "Silence Of The Lambs"..) that narrow tyres roll faster. But, in fact, the opposite is fundamentally true. Emphasis on "fundamental" because most wide tyres are made to wear well an be puncture proof and cheap, while most racing tyres - which are made to go fast at the expense of all these properties - are 25mm are less. But the best possible 40mm tyre will have lower RR than the best possible 25mm - and corner better, be more comfortable, and safer over potholes.
And that's on good roads. On bad roads, the advantage gets even larger because vibration transmitted the rider's body weight causes big energy losses - much larger than the figures in the standard calculators (like the one at Analytic Cycling) assume because those figures came from riderless rolling drum tests.
So, old Konas and GTs that can take fast but wide tyres (like Grand Bois and Almotions) are faster than silly marketing driven bikes like the Sirrus that are restricted to maybe 32mm.
At this point someone normally asks why TDF bikes have narrow tyres. This is, in fact, because AR matters relative more at VERY fast bike speeds and the slight AR reduction counts more for the guy at the front of a peloton (sp?) than the fairly hefty increase in RR. But these are elite riders who are moving at speeds that even they can't sustain for long riding solo.
People also often claim that the ability of narrow tyres to take higher pressures reduces RR compared to narrow tyres. All I can say here is that testing shows otherwise - in fact it drives vibration losses up. Bicycle Quarterly has done a lot of testing here:
http://janheine.wordpress.com/2012/06/1 ... -of-tires/
- and see the links near the bottom.
Re. discs on the road: I'm doubtful they're any advantage. Tour magazine (it's German and OCD) did a test of stopping distances in the wet and with dual Koolstops there was barely any increase in stopping distance. Overall braking power is limited by 1. toppling, which is derived from centre of gravity and 0.7g for most performance bikes, and by 2. front brake skidding, where a large contact patch is an advantage - and vees or cantis can already push a bike to this braking limit.
As for weight, including wheel weight: it makes a minute difference on the flat and not much more (because it is swamped out by rider weight) on climbs. If you 3lbs off a 20lb bike that often feels really different, because the sensory information to your hands has changed, but with a 180lb on top of it then vehicle weight has gone from 200lb to 197lb, so you'll climb about 1.5% faster. Worth paying $1000 a lb for in the TDF, but probably not while commuting.
pimpdriver
Old School Hero
- Feedback
- View
audax bike (700x25c) or touring bike 700x35c
Nuff said
Nuff said
Similar threads
Latest posts
-
-
-
-
For Sale Raleigh Lightweight & SBDU Collection
- Latest: Mark south wales
