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I am going nuts...(13 posts)

I am going nuts...Psychler
Sep 1, 2003 7:27 AM
I thought I was unhappy with my old frame. 56/56. It felt too long, I was always "reaching" for the hoods. The frame was about 3.25 lbs. Bike was stable, smooth and efficient (Dean, El Diente). Called Dean, they would make a custom at minimal cost due to repeat business...Went to the local Serrota fit center, fitter said, "let's get you on a 55 top tube, 57 seat tube"...The fit cycle felt great. (I am 5'10").
New frame came in, I explained the toe overlap in a previous post...about 3/4"... The bike feels "twitchy" at speed. Like, if you move the bars the slightest, you are making a huge adjustment...Like a Formula 1 car vs. an old Caddy. No room to play... Called Dean...they said that we are talking about 3/8" difference between old frame top tube and new...BB to front skewer about the same... New frame, 2.3 lbs...same fork- Ouza Pro 45 degree rake.
QUESTION: could this small amount bring such a large change? Is this OK? Is this "sports car" feel OK... I want to change my 100 stem to a 110 to compensate...Would a pic of me on the frame help? Should I shut up and enjoy, cuz any changes to the frame will cost me $$$$.
Did the headtube angle change? nmFatManLittleBike
Sep 1, 2003 9:41 AM
Nope...73 both HA and STA.Psychler
Sep 1, 2003 9:46 AM
The geometry is standard for Dean
should not be twitchy...C-40
Sep 1, 2003 7:12 PM
I've got both a 54cm Colnago whihc has a lot of trail and a quicker steering Fondriest. The Fondriest front-center is 2cm shorter than the Colnago. The Fondriest is quicker, but scarcely noticeable, except on a high speed mountain descents, where the quicker steering requires a lighter touch than the Colnago (which seems to steer itself).

A 73 HTA is very standard. If you wanted fairly slow steering, you should not have used a 45mm rake. I would agree with the others who suggest a change to a 40mm rake. This will increase the trail from 55.7mm to 60.9mm.

For comparison, a Colnago with a 55cm TT would have a trail of 65.2mm.
BUY A COLNAGO...merckx56
Sep 1, 2003 10:27 AM
short top tubes and laid back geos.
Laid back geometry?? really....nmRusty Coggs
Sep 1, 2003 11:45 AM
nm
BUY A COLNAGO...AFrizzledFry
Sep 1, 2003 11:52 AM
short top tubes? you sure? i think it just seems that way because Colnago measures seat tubes C-T instead of C-C like most companies do...

for instance, Colnago's 55cm frame has a 55cm seat tube center to top (but that's only 53 center to center, which is how most companies measure it), and a TT length of 54cm. so, really, they are no better than any other frame as far as a longer TT goes...
TTsRusty Coggs
Sep 1, 2003 4:03 PM
MOST others don't necessarily measure C_C. But, my 58 colnago has a 56.3TT. and the 58 c-t cdale had a 57.5 and my 58 Trek 5200 is 57cm...Bottom line , it doesn't pay to generalze.
More trail?Al1943
Sep 1, 2003 12:08 PM
You could increase the trail by reducing the rake, this should take the twitchy feel out of the steering. But that would mean a new fork.
~Al
Please explain...Psychler
Sep 1, 2003 12:14 PM
I know that the current rake is 45...Ouzo offers 43,45,50...Is this what you mean?
Rake and TrailAl1943
Sep 1, 2003 3:06 PM
Rake is the offset expressed in mm, not degrees. Reynolds Ouzo Pro is also made in a 40mm rake, I'm riding one. Here is a reference that explains rake and trail better than I can:
www.dclxvi.org/chunk/tech/trail/
~Al
And more...Al1943
Sep 1, 2003 3:37 PM
http://www.cyclingforums.com/showthread/t-11217.html

http://traylorfwd.home.mindspring.com/geometry_def.html

~Al
Get the 'nago....Mariowannabe
Sep 1, 2003 4:54 PM
I've had two friends go through the Serotta fit thing this year and both ended up with "twitchy" handling. Sure, the fit feels great on the machine but on the road I think they lack someting. I don't think its TT or overlap. I'd look at stem heigth/angle and fork rake. Unfortunately, I think a lot has to do with stearer tube angle. That's why I love the Colnago ride. 55 mph and I'm relaxed (unless there's a strong side wind!!)

Listening to you, I'd say get out over the front wheel more - with a longer stem. I hope you don't have a lot of spacers and a rise on the stem. (I'm an old, stiff 5'10" guy and use a 120). I'm sure you're aware that the longer the stem the more relaxed the handling. So, it they fit you on a shorter TT, then get that longer stem. See it the shop will loan you a few different stems to try on a Saturday. Make sure each test ride has some real speed.

IMHO....