# Colnago Steering Geometry?



## fallzboater (Feb 16, 2003)

I keep hearing about how stable Colnagos are, with perfect "stage race" steering geometry. For some reason they don't list the front end specs anywhere, from what I've been able to find. 

I'm especially interested in the largest frame sizes; anyone know what the typical HA and either rake or trail numbers are?


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## Clevor (Sep 8, 2005)

fallzboater said:


> I keep hearing about how stable Colnagos are, with perfect "stage race" steering geometry. For some reason they don't list the front end specs anywhere, from what I've been able to find.
> 
> I'm especially interested in the largest frame sizes; anyone know what the typical HA and either rake or trail numbers are?


Colnago used to post the head tube angles and other data, not sure why they discontinued this. I don't recall off hand, but I believe the head tube angle of a Colnago is around 71.2 degrees, whereas on a Giant monocoque, it's 73.1 (the higher the number the more squirrely). Most frames are between 72 and 73.

The rake on a Colnago fork is 43 mm (as are most OEM forks), whereas on a Giant it's 45 mm (the higher the number, the more squirrely). Giant is the only manufacturer that specs a 45 rake fork as stock; normally you'd have to go aftermarket for a fork with this kind of rake. The reason for this is Giant frames have long top tubes and short chainstays to put your weight behind the rear wheel, to optimize climbing. The geometry was tailored to help Jan Ullrich on his climbs against LA. If you got a long top tube, you need a steep head tube angle and fork rake to compensate and quicken up the steering.

Now you know why I am high on my Giant beater bike as being a good training bike. It ain't as easy as the Colnago to ride 'no hands'. When I climb in the hoods on my Giant, the front end is quite a bit skittish. But bombing down steep descents and handling on tight switchbacks is a dream. In actuality, it's a good climbing and descending frame.

And you are correct in that the head tube angles do change depending on size. I believe the larger the frame, the steeper the head tube angle. The specs I gave above are for a 53 cm Colnago frame. But you can get the idea about how relaxed the geometry is on Colnagos. 

I always joke about Rabobank going from Colnagos to Giants. See Oscar Friere win a stage and do his no-hands celebration - and hit the pavement! Who knows, maybe this had something to do with that horrible crash last year of the Rabobank rider named Horrifo (?), who went down a ravine 180 ft and was lucky to survive. I think it was at the TDF on a descent. Yeah go laugh at Giant bikes, but not an easy bike to ride.


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## fallzboater (Feb 16, 2003)

Real small frames may need a slack HA to reduce the likelihood of toe overlap. Most mfg's make the largest frames quite steep, probably to keep the wheelbase down and handling fairly quick, and keep a reasonable amount of weight on the front wheel. It seems to lead to problems if the frame and fork isn't stiff enough, though. 

I wonder if a rider can tell the difference between a 2-3mm change of rake? I should be able to find out soon, since I'm getting a used bike with a 73.2deg HA and 41mm rake fork, and I already have the identical fork (Alpha Q Z Pro) with a 44mm rake. I'll try and ride the same loop twice, swapping forks at my car.


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