Singlespeed & Fixed Gear - Tire and frame/fork clearance

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View Full Version : Tire and frame/fork clearance


chevy42083
05-08-07, 08:39 AM
I see lots of bikes in this section with very minimal clearance between tires and frame/fork. I was wondering if that's frame design, or if a larger than stock tire/rim is being used. I mean, I've seen one pic where the poster said if they over-inflated, the tire would rub the fork. :eek:
I had wondered if it was a 27 tire on a 700c frame/fork. Out of curiousity, I stuck a 27 wheel on my Bianchi roadie (700c)... and it still had PLENTY of clearance, no where near as close as some of the bikes I've seen on here.

Really just curious.

What's the point of the minimal clearance? Looks? Aero (taken from track bikes)? Greater BB clearance?


Pfutz
05-08-07, 08:44 AM
track bikes have closer forks because they do not need to turn as agressivly, it is more aerodynamic.

But you will be able to do barspins.

oldsprinter
05-08-07, 08:45 AM
A true track frame is built to be used with 19-22mm tyres, but a lot of road tyres are bigger.


oldsprinter
05-08-07, 08:47 AM
track bikes have less rake on their forks because they do not need to turn as agressivly, it is more aerodynamic. Riding a bike with less rake leads to poorer handling.

But you will be able to do barspins.

Less rake is more aerodynamic?? :lol:

Pfutz
05-08-07, 08:49 AM
Less rake is more aerodynamic?? :lol:

ok so I am not the best at wording things, feel free to correct me.

chevy42083
05-08-07, 09:42 AM
Sorry, I don't mean rake, or tire width. I mean diameter clearance.

Like this bike....
http://www.fyxomatosis.com/images/news/slickrick_sorenson.jpg

http://farm1.static.flickr.com/198/483132025_f942b85ed9_o.jpg

Versus this, which is what I normally see...
http://farm1.static.flickr.com/188/429816454_321181d92c.jpg

piwonka
05-08-07, 10:04 AM
lol, i don't think it has anything to do with aerodynamics...although the lack of clearance is a product of the way the bikes are designed.

babychris
05-08-07, 10:05 AM
because it looks really good.

baxtefer
05-08-07, 10:19 AM
well that Soren Son looks to be running 28c Vittoria Randonneurs.

chase.
05-08-07, 01:59 PM
IIRC it's just a characteristic that many track frames have. 110 or 120 rear (versus 126 or 130), coupled with steeper HT and ST angles, and a higher BB. In concert with the above fact about skinnier tires on tracks, designers can make everything tighter.

Shiznaz
05-08-07, 02:07 PM
http://velospace.org/files/cyclops3.jpg
I am running 23s when the bike is really only designed for 19s or 21s.

lyledriver
05-08-07, 02:09 PM
^same here.

Edit: Here's what Randy Cunningham, the maker of my frame, had to say about clearances:


Any good/real track bike should have tight clearances as you are generally
going for ultimate strength and it all adds up. There is an incredible
amount of junk being fobbed off as 'track' frames these days. Like so much
else in our society, things are getting more and more diluted.

metallo pesante
05-08-07, 03:00 PM
http://i4.photobucket.com/albums/y131/givexmeoxygen/Bike%20stuff/fggphotos005.jpg

cause it's sexy....RIP big buddy.

Shiznaz
05-08-07, 03:01 PM
I want to see a bike with crank overlap