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De Rosa Primato geometry

Old 04-06-11, 08:01 PM
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jimmm18
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De Rosa Primato geometry

Hi all

Does anyone have a geometry chart for a mid-nineties Primato? Is it the same as a Neo? I am trying to determine if a 50cm will work for me. I need seat angle and top tube length.

Thanks for any insight.
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Old 04-06-11, 08:46 PM
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I'd love to see a geometry chart as well.
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Old 04-06-11, 09:01 PM
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Originally Posted by Old Fat Guy View Post
Google is your friend:
http://tinyurl.com/3mrqoj9
O.F.G., even DeRosa can't get around the real world of geometry, UCI and 700c wheels.
Note in that chart, for a 50cm frame ctc, the front center is 58 cm, top tube is reasonable only because the seat tube angle is steep, over 75°. As every DeRosa fork I have measured is near 50 mm of rake... the head angle is probably slack.

If one wants "big bike" handling at 50 cm then overlap is needed, with a 58 cm front center, 165 cranks (not easy to find today) short clips (read size 39 shoes) careful tire measure will bring the shoe and front tire to just kiss. Pretty sure the head angle is too slack for the fork rake to keep the trail in check.
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Old 04-06-11, 09:03 PM
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So damn mean

I've seen the Neo Primato charts... part of me is hoping the original Primato's weren't quite so square

If the day comes, I guess I'll have to get a 57 or 58 and a deal with the drop.
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Old 04-06-11, 09:34 PM
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Originally Posted by Old Fat Guy View Post
The geometry on the Primato is slightly different. I have this chart, courtesy of gomango, that lists the geometry of a 56 cm Primato:


Note the rake is 40mm.
Did not match mine.
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Old 04-06-11, 10:14 PM
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Thanks all. I ride small bikes and let me tell you they can really mess up the geometry on them trying to avoid that stupid "dreaded toe clip overlap" Ridiculously slack head angles with fork rake out to here....

I can deal with the 50cm neo primato--I would need to use a 9cm stem and 75 degree seat angle is doable. My other 75 degree bike, my lovely Masi Nuovo Strada, has a 515 mm top tube so 525 would be do able. The bike would be tall for me but I can handle that. The ad for the primato in Boise (nice catch OFG) says 530mm. I think that would put it just out of reach for me.

By the way with my size 7.5 feet I have no toe clip overlap with my masi which is running a 73 head angle with a 50mm fork rake. It is my favorite geometry as it makes for a tight bike like you would find on a 56cm frame. I am finding I love the long rake/short trail on my bikes. My Bianchi and my RB1 both use the 50mm rake. Just can't let the head angle get slacker than 72 or the front end has to be set before the back will come around.

I have asked the seller to review the top tube length for me. Also that seat angle maybe a little slacker than the Neo from the look of it which would be perfect.

I like the older primato over the newer one--not sure why. However in the States the smallest size they advertised was a 50 ctc. So I know it maybe a compromise.

Please don't ask me why I want a De Rosa. It has no basis in rational thought.

Last edited by jimmm18; 04-06-11 at 10:15 PM. Reason: gramer
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Old 04-06-11, 10:28 PM
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Tugrul

Have you seen this:

http://bhovey.com/Masi/Scans/RoadBik..._08DeRosa2.htm

Review on the Primato from 1993 for a 57cm bike. They list the seat angle, top tube, chainstay length and BB height. In inches unfortunately.
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Old 04-06-11, 10:34 PM
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Originally Posted by jimmm18 View Post
Review on the Primato from 1993 for a 57cm bike. They list the seat angle, top tube, chainstay length and BB height. In inches unfortunately.
No, but it seems to match what OFG posted. Neo Primato's seem to have 0.5cm longer top tubes. (Neo 56 has 56 TT vs 55.5, Neo 57 has 56.5 TT vs 56).

The Neo 57 seat tube angle hasn't changed since that article at 73, but the Neo 56 is more than a degree steeper than the 72 cited above.
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Old 04-06-11, 10:51 PM
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Originally Posted by tugrul View Post
No, but it seems to match what OFG posted. Neo Primato's seem to have 0.5cm longer top tubes. (Neo 56 has 56 TT vs 55.5, Neo 57 has 56.5 TT vs 56).

The Neo 57 seat tube angle hasn't changed since that article at 73, but the Neo 56 is more than a degree steeper than the 72 cited above.
Well if that held true for the 50 then it would be close to perfect.
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Old 04-07-11, 09:29 PM
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OK I bought it. Pics when I get it setup for me.

Jim
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Old 04-07-11, 09:32 PM
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Originally Posted by jimmm18 View Post
OK I bought it. Pics when I get it setup for me.

Jim

Outstanding!!!

Congratulations.
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Old 04-17-11, 09:38 AM
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Ok here it is!!

First ride yesterday. Still sorting it but so far I like it!!

First off it is beautiful. The pics on the auction, nor the one below, do it justice. And the Shamal wheels it came with are Stunning!!!!!! I have never seen Campy hubs or any hubs so shiny!!! I will need to sell them as they are sew-ups

The sizing is a little different from the auction. I measured the top tube as 530mm as he stated but the seat tube is not 50cm c2c by my measurements. closer to 49.5 but it really isn't exact. Seat tube to the tip of the lug is 51. Either way stand-over isn't a problem.

For you geometry guys out there the seat tube angle is between 74-75. I can only guess any better than on my angle finder but I put it 74.5 for now. Head tube around 72, typical for a small bike. Not sure on the fork rake as I have no way of measuring it but from riding I think it might be a 45.

I had a 9cm stem to put on it (showed up a craigslist last week for $10 for a 3T and a nice one at that) but I didn't like the way it looked. So I put the 10 on and decided to be a bit stretched out and run a little closer to the pedal axles ( I normally ride a quite a bit behind.)

It is built up with mixture of Centaur, Athena and Record. The levers are 1998/9 Athena's I that had rebuilt to 10 speed. Luv campy don't you? Wheels are Nucleon's that I bought cause of the silver spokes. The tire are Corsa CX's but I think I will replace them with some Torelli gumwall Torino's.

The bike is fairly stiff feeling. As you can tell from sig I have a few italian bikes. It most reminds of the Pegoretti but somehow firmer riding. The front end feels very planted and reassuring going downhill. It did not feel all that great climbing but the ride I did yesterday was not a ride I have done lately. And I am just getting back into riding again after the winter so I am not at my best. And at my best I grind up hills very slowly.

I paid more than I would like but every time I try to get a De Rosa in my size it seems to be always more than I want to spend so I bit the bullet. I will have the pieces I took off the bike, basically a 8 speed built kit with wheels, for sale so I can recoup some of it that way. Can't wait to ride it again!!

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Old 04-17-11, 09:49 AM
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Beautiful Bike!!!!
Get us some detail shots!

Thanks for the detailed report.

Jake
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Old 04-17-11, 09:58 AM
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Very pretty bike you've got there.

Love the chrome lugs and fork.

As long as you ride the bike, and get some frequent enjoyment from her, you did not overpay.

Price a new Neo Primato frameset, along with a new Chorus or better gruppo.

Puts things in perspective quickly, doesn't it?

.....and btw, that's quite a substantial stable you've got there.
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Old 04-18-11, 10:21 AM
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Thanks!! I will get some detail shots up in the next few weeks.
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