Which size Colnago?

[phcollard]

Hey folks!

Long time no see :)

I'm looking to get a Colnago C-RS, my first carbon bike ever.

I'm 5' 8.5". My current bikes are a Merckx Corsa Extra and a Merckx Gara. Both have a 55cm top tube, 10cm stem and a 72.5cm saddle height. I'm 48 and have a fragile back so I'm definitely looking for a relaxed position. I run a more or less 5cm drop from top of saddle to top of bars.

I'm not sure if I should get a 52s or a 50s C-RS. Geometry here (https://www.colnago.com/wp-content/uploads/2018/06/CRS-SLOPING.pdf).

50s : 145mm HT, ETT 54cm, STA 74
52s : 163mm HT, ETT 55cm, STA 73.6

So on paper both sizes are very close. I have the choice to run either the 50s with a lot of spacers and a 11cm stem, or the 52s with fewer spacers and a 10cm stem.

Thoughts?

Here is a recent pic of my Merckx alloy for reference...

https://i.imgur.com/Z6OVWlb.png

Cheers!

[bigbill]

Unless you're hard and fast on buying a Colnago, you could get an Allied with a taller head tube to get the reach you want without a bunch of spacers. Made in Murica.

[phcollard]

Unless you're hard and fast on buying a Colnago, you could get an Allied with a taller head tube to get the reach you want without a bunch of spacers. Made in Murica.

Thanks. I had never heard of the brand so I took a brief look. They look great and made in USA is definitely an advantage. But frameset at $3k vs complete Colnago at $1.2k is a no brainer.

[bigbill]

Thanks. I had never heard of the brand so I took a brief look. They look great and made in USA is definitely an advantage. But frameset at $3k vs complete Colnago at $1.2k is a no brainer.

Allied was partially formed from Guru when they closed. Then the Colnago needs to have the right tt length with a 110 stem. I've had some back surgeries, my bikes have long head tubes.

[oldpotatoe]

Hey folks!

Long time no see :)

I'm looking to get a Colnago C-RS, my first carbon bike ever.

I'm 5' 8.5". My current bikes are a Merckx Corsa Extra and a Merckx Gara. Both have a 55cm top tube, 10cm stem and a 72.5cm saddle height. I'm 48 and have a fragile back so I'm definitely looking for a relaxed position. I run a more or less 5cm drop from top of saddle to top of bars.

I'm not sure if I should get a 52s or a 50s C-RS. Geometry here (https://www.colnago.com/wp-content/uploads/2018/06/CRS-SLOPING.pdf).

50s : 145mm HT, ETT 54cm, STA 74
52s : 163mm HT, ETT 55cm, STA 73.6

So on paper both sizes are very close. I have the choice to run either the 50s with a lot of spacers and a 11cm stem, or the 52s with fewer spacers and a 10cm stem.

Thoughts?


Cheers!

52 with longer headtube..

[phcollard]

52 with longer headtube..

Thanks very much OP. That what I'm leaning towards...

[Dave]

Don't overlook the difference in the STA. With the steeper STA on the 52, you're likely to need a 90mm stem, once the saddle is moved to the same position, relative to the bottom bracket.

Oops, I now realize that the 72.5 was saddle height, not STA, but without the STA to compare, you can't know what stem length is needed.

[oldpotatoe]

Don't overlook the difference in the STA. With the steeper STA on the 52, you're likely to need a 90mm stem, once the saddle is moved to the same position, relative to the bottom bracket.

But Merckx's he has probably has STA of 73.5..so very close to the 52cm Colnago.

[phcollard]

But Merckx's he has probably has STA of 73.5..so very close to the 52cm Colnago.

That's correct. Merckx has an STA of 73.5

That blue Merckx of mine has a HT length of about 160mm.

I found this geo comparator. 50s and 52s have the same reach apparently. Not sure what it means!

https://i.imgur.com/JqAlFRC.png

[wallymann]

as others have suggested, focus on STA + TT length to pick your comparable size.

[Dave]

Reach is the horizontal distance between the center of the BB and the center of the head tube. If the reach is the same on two frames, the stem length needed should be the same.

https://rideonmagazine.com.au/how-to-measure-stack-and-reach/

LOOK gets it. The 785 reach increases by 10mm for each size.

[m4rk540]

Unless you're hard and fast on buying a Colnago, you could get an Allied with a taller head tube to get the reach you want without a bunch of spacers. Made in Murica.

If a Colnago head tube isn't tall enough, one should rent a time machine, go back to 2005 and order a Serotta.

[weisan]

Or a Giant (https://www.giant-bicycles.com/us/defy-advanced-2).

[paredown]

I don't have an opinion on your sizing, but I have been watching the clearance on the CR-S, so I will be curious to see what you think.

FWIW--as a general comment, what I read made me think these are a little bit less a cheaper version of an all out race bike, and a little more of a comfort fit, whereas the last time around with the ACR, it was more the former.

[oldpotatoe]

Or a Giant (https://www.giant-bicycles.com/us/defy-advanced-2).

A Giant rather than a Colnago for $1200?..righto..in yer dreams, pal..

[Davist]

A Giant rather than a Colnago for $1200?..righto..in yer dreams, pal..

Uh, doesn't Giant make the carbon Colnagos? I thought so..

[phcollard]

... If the reach is the same on two frames, the stem length needed should be the same.

Hmmm. You're right!

So choosing between the 50s and the 52s is just a matter of how comfortable I am with head tube length right?

Right?

:)

[Black Dog]

Hmmm. You're right!

So choosing between the 50s and the 52s is just a matter of how comfortable I am with head tube length right?

Right?

:)

Yes. The choice is going to be about the head tube length.

[dddd]

After looking at the geometry chart, and reading of your fit parameters, I believe the 52s with the shorter stem will have better steering response.

I have a 52s CX-Zero with slightly steeper headtube angle than the CR-S, and although I (at 5'9") got a marginally better fit with a 110mm stem, the bike definitely had a better (lighter, quicker) cornering feel with the original 100mm stem.

Here's a picture with the original stem:
https://c1.staticflickr.com/5/4430/35548774213_e3f321f070_z.jpg

[wallymann]

the non-C lines, yes.

Uh, doesn't Giant make the carbon Colnagos? I thought so..

[oldpotatoe]

Uh, doesn't Giant make the carbon Colnagos? I thought so..

Don't think the C-RS is made anywhere but Italia..:rolleyes:

[Dave]

I need to post a correction to my comments about the reach comparison between two frames of different sizes. Reach can only be compared properly between frames with the same stack height. If the stacks are different, then a correction of 3mm for each 10mm of additional stack height is needed. With the C-RS, the reach of the 52 is 1mm longer, but the stack is 18mm taller, so the real difference in reach is in the 6-7mm range. That means that one size shorter stem might be required.

Another way to think of this is the smaller frame would mostly likely be built with 20mm of additional steering tube spacer and that moves the stem back about 6mm. That 6mm should be subtrated from the reach of the smaller frame.

You can tell that I've been away from biking for 8 years. Fortunately, I have word documents where I've kept a lot of my old writings.

[phcollard]

I need to post a correction to my comments about the reach comparison between two frames of different sizes. Reach can only be compared properly between frames with the same stack height. If the stacks are different, then a correction of 3mm for each 10mm of additional stack height is needed. With the C-RS, the reach of the 52 is 1mm longer, but the stack is 18mm taller, so the real difference in reach is in the 6-7mm range. That means that one size shorter stem might be required.

Another way to think of this is the smaller frame would mostly likely be built with 20mm of additional steering tube spacer and that moves the stem back about 6mm. That 6mm should be subtrated from the reach of the smaller frame.

You can tell that I've been away from biking for 8 years. Fortunately, I have word documents where I've kept a lot of my old writings.

Thanks for the detailed explanation Dave, much appreciated! I understand (a bit) better now.

I did some Photoshop since I don't have access to a C-RS in real life. Saddle is at the correct height for me in the pictures below, and all the other contact points that I measured with PS fall right in place.

I found another contender to the Colnago, about the the same price. Decisions :)

https://i.imgur.com/TlqoPfH.png

https://i.imgur.com/x67nD8x.png

[phcollard]

Hey folks. An update.

I was able to briefly try a 50s CR-S! The fit was great with 3cm of spacers under the stem :eek: The bike was quite nervous with a 10cm stem as far as I could tell but the shop owner said a 11cm stem would be better, which is good because the reach was a bit short, I felt.

The 50s at $1200 went out of stock right this morning :crap:

They still have a 52s at $1200. What do you guys think? Safe buy?

[oldpotatoe]

Hey folks. An update.

I was able to briefly try a 50s CR-S! The fit was great with 3cm of spacers under the stem :eek: The bike was quite nervous with a 10cm stem as far as I could tell but the shop owner said a 11cm stem would be better, which is good because the reach was a bit short, I felt.

The 50s at $1200 went out of stock right this morning :crap:

They still have a 52s at $1200. What do you guys think? Safe buy?

I still think, when compared to your Merckx(STA, top tube length) and longer head tube(yer back issues)..the 52 would be the one..100mm stem..go ride.

[Dave]

Anyone know of a better price than than $1700 for the C-RS frame? My searches haven't brought up much. Wrench Science has them, but Colorado Cyclist must have run out and now only has them to order.

[ultraman6970]

THis

I still think, when compared to your Merckx(STA, top tube length) and longer head tube(yer back issues)..the 52 would be the one..100mm stem..go ride.

[paredown]

Anyone know of a better price than than $1700 for the C-RS frame? My searches haven't brought up much. Wrench Science has them, but Colorado Cyclist must have run out and now only has them to order.

Velomine has some complete bikes listed on eBay @ $1399--and only $1199 directly from their web site:
http://www.velomine.com/index.php?main_page=index&cPath=597

[Keith A]

Velomine has some complete bikes listed on eBay @ $1399--and only $1199 directly from their web site:
http://www.velomine.com/index.php?main_page=index&cPath=597That seems like good price for a new Colnago with 105.

[paredown]

That seems like good price for a new Colnago with 105.

Word. I've been talking myself down for a week or so....:banana:

[Dave]

Velomine has some complete bikes listed on eBay @ $1399--and only $1199 directly from their web site:
http://www.velomine.com/index.php?main_page=index&cPath=597

I can't pass that up, the order has been placed! Thanks for the info!

I'll be passing along a really good deal on the components.

[Dave]

I received my bright red C-RS on Tuesday morning and just now got it completely finished, with a Campy Chorus group and Zonda wheels. The paint is just what you'd expect from Colnago - very well done. The size was perfect. I had no problem duplicating the fit of my 51cm LOOK KG461, using the same stem length and the same model of seat post. I've got the stem slammed as low as possible on the 48cm frame, but left 10mm of spacer on top of the stem, if some adjustment is needed. The steering tube was already cut fairly short, with 30mm of spacer, from the factory. Colnago supplie a 3 inch long compression plug to support the steering tube, but I opted to replace it with an FSA model.

Th internal cable routing was a bit of a challenge. If I ever need to replace a rear brake cable, I'll tape some string to the end of the cable, before I remove the cable. There is no internal guide tube to make the job easy. I also needed access around the bottom bracket, to get the shift cables in place. The Campy cups weren't in the way, but the original 105 BB would have been.

This is my first bike with a press-fit BB86 bottom bracket. I borrowed the needed tools from a neighbor. Removing the 105 bottom bracket was easy and so was pressing in the new Campy cups. The press-fit bores in the frame are CF, not aluminum bonded to the CF frame. I'm glad that I read up on the use of loctite 609 before installing the cups. I used grease and won't resort to the loctite unless I have a cup problem. Since the Campy cups are aluminum, it's possible to bond the cups in so well that they can't be removed. If you have delrin or other plastic around the BB bearings, the loctite won't stick to the plastic and will only serve as a gap filler.

[phcollard]

Hey Dave I'm happy you like the bike and the unbuild/build went fine.

So how does it ride?

And what? No pics? :)

As far as I am concerned I missed the boat. I agonized for too long over geometry and when I was finally ready the last 52s in black was gone. Boohoo.

[Dave]

I plan to give the bike it's first full ride on Saturday. Since I'm now 65, I've been off the bike for 8 years and only logged 400 miles in the last month, I have to rest about 2 days between hard climbing rides. I'm still in the process of gaining some strength and endurance. I've worrked my way up to a 32 mile ride, which doesn't sound like much, but I ride from my house to Horsetooth Reservoir and partially around the lake, where the climbs are steeper than I ever did in the mountains.

The frame sure has a big downtube and some beefy chainstays. It looks a lot stouter than my old KG 461 and it's quite a bit lighter.

[paredown]

I plan to give the bike it's first full ride on Saturday. Since I'm now 65, I've been off the bike for 8 years and only logged 400 miles in the last month, I have to rest about 2 days between hard climbing rides. I'm still in the process of gaining some strength and endurance. I've worrked my way up to a 32 mile ride, which doesn't sound like much, but I ride from my house to Horsetooth Reservoir and partially around the lake, where the climbs are steeper than I ever did in the mountains.

The frame sure has a big downtube and some beefy chainstays. It looks a lot stouter than my old KG 461 and it's quite a bit lighter.

Can't wait for the ride report. I still admire the one that's left that's my size.:)

[Dave]

I decided to take the C-RS out for a 20 miler today because tomorrow's weather report looks questionable. I'm pleased with the bike. It's very stable, as you would expect with Colnago's usually large trail. The bottom bracket and new Chorus crank make for a stiff combination that works well for climbing out of the saddle. I rode as slowly a 6 mph up one hill and had no problems holding a straight line. I didn't go to the big hills where I often descend up to 45 mph, but I've got no doubt that the bike wil be stable at those speeds. I'm anxious for more, but my old body isn't.

I've got all new parts on the bike, but used a lot of the same parts that I did 10 years ago. I have three leftover Fizik Gobi saddles that I picked up, probably 10 years ago, right after a redesign ruined the new model for me.

The stem is a Ritchey 4-axis, 110mm with a -6 degree angle. I had been using a -17, but decided that my old body needed a little higher bar.

The post is an FSA with 25mm of setback and the 2-bolt rocker style clamp that allow very fine angle adjustment.

Bars are Easton EC-70 carbon, that are quite a bit cheaper than the EC-90.

The bar tape is my favorite Deda that really is about 10 years old. I had two rolls of red and two rolls of black that I bought sometime before 2010.

https://forums.thepaceline.net/picture.php?albumid=93&pictureid=389

[paredown]

I decided to take the C-RS out for a 20 miler today because tomorrow's weather report looks questionable. I'm pleased with the bike. It's very stable, as you would expect with Colnago's usually large trail. The bottom bracket and new Chorus crank make for a stiff combination that works well for climbing out of the saddle. I rode as slowly a 6 mph up one hill and had no problems holding a straight line. I didn't go to the big hills where I often descend up to 45 mph, but I've got no doubt that the bike wil be stable at those speeds. I'm anxious for more, but my old body isn't.

I've got all new parts on the bike, but used a lot of the same parts that I did 10 years ago. I have three leftover Fizik Gobi saddles that I picked up, probably 10 years ago, right after a redesign ruined the new model for me.

The stem is a Ritchey 4-axis, 110mm with a -6 degree angle. I had been using a -17, but decided that my old body needed a little higher bar.

The post is an FSA with 25mm of setback and the 2-bolt rocker style clamp that allow very fine angle adjustment.

Bars are Easton EC-70 carbon, that are quite a bit cheaper than the EC-90.

The bar tape is my favorite Deda that really is about 10 years old. I had two rolls of red and two rolls of black that I bought sometime before 2010.


Looks great--and sounds like it's a nice ride without dropping a whole lot of cash.

[Dave]

I notice that Colorado Cyclist has a good deal on the C-RS with Ultegra group in sizes up to 54cm.

The only complaint I have with mine is the location of the cable stop for internally routing the rear brake cable. It's on the right side of the head tube, rather than the left which makes for a short and abrupt route from the bars. Changing stem lengths without a change to the rear brake cable and housing is unlikely. My old LOOK KG461 has a stop on the left side of the top tube, that works a lot better.

[soulspinner]

I decided to take the C-RS out for a 20 miler today because tomorrow's weather report looks questionable. I'm pleased with the bike. It's very stable, as you would expect with Colnago's usually large trail. The bottom bracket and new Chorus crank make for a stiff combination that works well for climbing out of the saddle. I rode as slowly a 6 mph up one hill and had no problems holding a straight line. I didn't go to the big hills where I often descend up to 45 mph, but I've got no doubt that the bike wil be stable at those speeds. I'm anxious for more, but my old body isn't.

I've got all new parts on the bike, but used a lot of the same parts that I did 10 years ago. I have three leftover Fizik Gobi saddles that I picked up, probably 10 years ago, right after a redesign ruined the new model for me.

The stem is a Ritchey 4-axis, 110mm with a -6 degree angle. I had been using a -17, but decided that my old body needed a little higher bar.

The post is an FSA with 25mm of setback and the 2-bolt rocker style clamp that allow very fine angle adjustment.

Bars are Easton EC-70 carbon, that are quite a bit cheaper than the EC-90.

The bar tape is my favorite Deda that really is about 10 years old. I had two rolls of red and two rolls of black that I bought sometime before 2010.

https://forums.thepaceline.net/picture.php?albumid=93&pictureid=389

Glad you are back in the saddle and here on Paceline. I valued your posts and learned a lot from you.

[oldpotatoe]

I notice that Colorado Cyclist has a good deal on the C-RS with Ultegra group in sizes up to 54cm.

The only complaint I have with mine is the location of the cable stop for internally routing the rear brake cable. It's on the right side of the head tube, rather than the left which makes for a short and abrupt route from the bars. Changing stem lengths without a change to the rear brake cable and housing is unlikely. My old LOOK KG461 has a stop on the left side of the top tube, that works a lot better.

Probably on the right because it's not 'tubed' in the top tube but 2 holes and if it were on the left side of the top tube, it would rattle against the tube. Same for Spec-ed...same gig...

[Black Dog]

Probably on the right because it's not 'tubed' in the top tube but 2 holes and if it were on the left side of the top tube, it would rattle against the tube. Same for Spec-ed...same gig...

And trek and Canondale and.....:mad:

[Dave]

I watched a video review on the C-RS recently. The owner noted a problem with the seat post clamp, where the clamp bolt was damaging the clamp. I checked mine out more closely. The slotted hole where the clamp bolt goes through is wider than necessary and the machined recess for the allen head bolt is too narrow for a decent sized washer. The provided washer on mine was no larger than the M5 bolt head.

To prevent eventual damage to the clamp, I made new washers to spread out the load on the clamp. Number 8 stainless steel washers from home depot have a hole that's just big enough for an M5 bolt. I filed parallel flats on both sides of a washer to make an oval shape that barely fits into the bolt head recess and and used two of these modified washers, since one is not thick enough to avoid cupping.

Here's a link to the review, skip to about 2:40 to see the clamp problem.

https://www.youtube.com/watch?v=e8Qzz2iC6hE

[phcollard]

Hey!

Sorry to bump that old thread but I just noticed Merlin has 2019 CRS frames in most sizes for about CA$ 1300.

That's $ 995 in real money :)

https://www.merlincycles.com/colnago-crs-road-frameset-2019-168970.html

[Dave]

Bike Exchange has more C-RS options at only $700, plus $45 shipping. Seems like a steal.

https://www.bikeexchange.com/a/road-frames/colnago/c-rs-frame-hs/116164254