Bravura bikes

General cycling advice ( NOT technical ! )
gloomyandy
Posts: 1088
Joined: 16 Mar 2012, 10:46pm

Re: Bravura bikes

Postby gloomyandy » 20 Feb 2016, 9:44pm

Colin, what bike is that? Looks very nice.

User avatar
531colin
Posts: 13197
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Bravura bikes

Postby 531colin » 20 Feb 2016, 10:40pm

Vantage wrote:That's interesting in that I'm forever hearing about compromises having to be made in smaller frames if 700c wheels are to be used. I never could see what these compromises would be or understand why if Dawes and Raleigh can do it, then what's Surlys excuse.
Is there an actual reason why 26 inch wheels are easier to design a small frame around?

Vantage wrote:I made a note of the Vantages angles when I bought it. The 48cm geo hasn't changed a bit since then.
Coincidently, I was never able to set it up so I could ride comfortably resting my fingertips on the bars and sore wrists were something I sort of got used to.
The steering was definitely lively. Riding no hands was scary to say the least........


I think thats "asked and answered" isn't it? Dawes have done such a good job of your Vantage that it doesn't steer properly and in order to reach the bars your saddle is so far forward that it throws your weight onto your hands.
The difficulty with small frames is that if you put the bars where the rider can comfortably reach them, they are likely to be kicking the front wheel. There are 2 ways round this....smaller wheels ( not always acceptable to customers)....or a slack head angle and long-offset fork, which gives good neutral steering and a shorter top tube for the same foot clearance.

User avatar
531colin
Posts: 13197
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Bravura bikes

Postby 531colin » 20 Feb 2016, 10:45pm

gloomyandy wrote:Colin, what bike is that? Looks very nice.


Prototype tourer, in steel, cable disc brakes, 9 speed triple. (currently "Wayfarer")

User avatar
CREPELLO
Posts: 5558
Joined: 29 Nov 2008, 12:55am

Re: Bravura bikes

Postby CREPELLO » 20 Feb 2016, 11:14pm

531colin wrote:
gloomyandy wrote:Colin, what bike is that? Looks very nice.


Prototype tourer, in steel, cable disc brakes, 9 speed triple. (currently "Wayfarer")
It looks excellent to my eyes. Head tube is nice and high, even on the small size. The name is a nice choice too. I might have to consider swapping my main tourer (I hope the tyre clearance is good :wink: )

User avatar
531colin
Posts: 13197
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Bravura bikes

Postby 531colin » 21 Feb 2016, 11:33am

I don't like fag-paper clearances either....35mm Marathons on the prototypes, clearance more than 10mm everywhere, and you can still use road STIs and RX6 mini vees.
The little bike is just as my 5 foot test rider had it set, there will be a bit coming off the extended head tube so the bars will go level with the saddle....couple of other tweaks, too.

gloomyandy
Posts: 1088
Joined: 16 Mar 2012, 10:46pm

Re: Bravura bikes

Postby gloomyandy » 21 Feb 2016, 2:11pm

Looks very, very nice Colin. Can you say when it is likely to be available? I'm looking for a new touring bike and that one looks like it ticks many of the boxes for me.

User avatar
531colin
Posts: 13197
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Bravura bikes

Postby 531colin » 21 Feb 2016, 10:33pm

Summer, if not too much goes wrong......

Crusty Loaf
Posts: 89
Joined: 5 Jun 2015, 9:20pm

Re: Bravura bikes

Postby Crusty Loaf » 7 Apr 2016, 7:49am

I am what you would term "vertically challenged" so have always had to ride a small frame and it is truly a difficult feat for frame designers to come up with a geometry that "works" with 700c tyres.
I have quite a few pro level race framed bikes in my stable (Look/Isaac/Cervelo etc) and to get the Geometry right for purpose, there is inevitably quite a degree of "Toe overlap" with the front wheel. 650C rims can help this as can 26, but then you lose out in the rolling resistance stakes and would get dropped on the flats.
Most experienced riders just accept this and learn to ride accordingly. Even mid sized race frames can have some toe overlap, but is never an issue when you are used to it.
As previously stated, to overcome this, the top tube would have to be overly long and too much of a stretch, even with a short stem and inline pin, or the fork rake would be too great and steering would be awful.
Many smaller riders also use cranks far too long for their height and a five foot rider should reall only be using 150/155mm cranks, which would help overlap somewhat. Close clearances, enable a bike to handle vastly better, particularly on big climbs and on twisty fast descents, they also yield better aerodynamics, which on long rides, equates to a less tired pilot, towards the end of the day.

User avatar
531colin
Posts: 13197
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Bravura bikes

Postby 531colin » 8 Apr 2016, 6:54pm

Crusty Loaf wrote:....... Close clearances, enable a bike to handle vastly better, particularly on big climbs and on twisty fast descents, ..............


Low-trail, short-wheelbase designs turn quickly and require little rider input to initiate a turn. If you are an elite athlete with lightning reflexes and perfect coordination racing in a tight bunch, that can be an advantage. However, such designs respond with equal enthusiasm to accidental steering inputs, from sidewinds, road surface/camber, and tired riders who wobble when they look round or change gear.

Crusty Loaf wrote:I am what you would term "vertically challenged" so have always had to ride a small frame and it is truly a difficult feat for frame designers to come up with a geometry that "works" with 700c tyres.
I have quite a few pro level race framed bikes in my stable (Look/Isaac/Cervelo etc) and to get the Geometry right for purpose, there is inevitably quite a degree of "Toe overlap" with the front wheel. 650C rims can help this as can 26, but then you lose out in the rolling resistance stakes and would get dropped on the flats.
Most experienced riders just accept this and learn to ride accordingly. Even mid sized race frames can have some toe overlap, but is never an issue when you are used to it.
As previously stated, to overcome this, the top tube would have to be overly long and too much of a stretch, even with a short stem and inline pin, or the fork rake would be too great and steering would be awful.
Many smaller riders also use cranks far too long for their height and a five foot rider should reall only be using 150/155mm cranks, which would help overlap somewhat. ..........


Where can we buy these cranks?

If you vary either head angle or fork offset independently, the steering soon becomes "awful". If you match a long fork offset with a shallow head angle you get not only a short top tube for a given front centre, but decent steering as well. Few people make bikes like this, which means that many short riders have never known anything but overlap. Although I can tolerate a bit of overlap, I prefer not to have it; some riders find overlap really challenging.
Moving the saddle forward (with an in-line seatpost) is a poor compensation for too long top tube, as it throws weight onto your hands and spoils the spatial relationship between hip joint and pedals.

A trivial question.....I had a bit of a look and I couldn't find an RSP bike that matched these "Bravura/RSP" bikes. I see you were selling one http://forum.cyclinguk.org/viewtopic.php?t=104639, were you ever able to find a match?

lowrider
Posts: 135
Joined: 21 Mar 2009, 2:25pm

Re: Bravura bikes

Postby lowrider » 24 Apr 2016, 12:25pm