# Add a cm to the stem length to compensate for the fork rake?



## Clevor (Sep 8, 2005)

This post was prompted by a similar thread on the current page:

On my TCR Comp 1, it has a 55 cm TT and I use a 110 mm stem. The fit appears to be perfect, e.g., when I sight down the bar it obscures the front hub exactly. It has a 73 degree head tube angle. The bike also feels about right: no toe rubbing on the front wheel, etc.

My C50 has a 54 cm TT so you'd think I would use a 120 mm stem for the exact same fit. But if the fork is raked at that slack angle (71.3?), would I need to add another cm to the stem to compensate? So I should get a 130 mm stem???

I am planning to use a Cinelli RAM bar/stem so getting the stem length wrong will be an expensive mistake. I know I should install an actual bar and stem to mock everything up and be sure, but I don't have a spare bar and stem to throw on the bike right now.

I'm thinking 120 mm stem can't be that far off and heck, it would be more comfortable to ride even if it comes up a tad short. Might be aesthetically nicer too.


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## fabsroman (Jul 14, 2006)

I just bought a 50 sloping Cristallo that has a 54cm top tube and I bought a Cinelli Ram bar in 110/40. The 110 stem length gives me the same reach as my current bike which happens to be exactly what all the websites that provide fitting information have been giving me (i.e., 65cm total reach). Like you, it will probably be better for me if the stem is 1cm short versus 1cm too long. The frame is in the stand, the headset has been ordered, and the bars arrive on Monday, so I'll know pretty soon.


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## Fignon's Barber (Mar 2, 2004)

I've had a couple colnagos for a few years and have logged probably 20,000 miles on them. I normally use 120mm stem. I did an experiment, placing a 130mm stem on one to see what the difference would be. I alternated weekly between the 2 for about 2 months. My conclusion: the 130mm stem gave the steering a quicker feel, somewhat squirrelly in nature. I think the human body adapts pretty well, as your arms,legs, back, etc. are not rigid structures, so both were comfortable for me. You have to remember,also, that the longer the stem, the less stiff it becomes. Personally, and this is from my own experience, if your colnago is fitted properly to your proportions, 120mm stem is the best starting point and move the seat back if you need more length. I've also noticed that with my colnagos, they really respond to keeping your weight back in a standing sprint. Its hard to describe, as I've not had this with other frames. They also seem more stable at faster speeds than at slower speeds. That's my own clinical experience.
So if you had to go with one stem: I'd go 120mm. Another idea would be to go to the LBS, as most have loads of discarded stems lying around that they've taken off purchased complete bikes. You could borrow a120 and 130 and experiment.


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## em3 (Dec 25, 2005)

Guys, using a longer/shorter stem will not compensate for the effects of your fork rake! You may provide a bit more weight out front with a longer stem but that will not change the handling of your bike in the same way that rake does.

Also, if I were to walk into a shop and they tried to fit me on a bike using the archaic site over hub method, I would quickly leave. This is a very old school and ineffective method for fitting bikes with the geometry found in most bikes sold over the last 20 years (i.e. steeper head and seat angles).
EM


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## Zampano (Aug 7, 2005)

em3 said:


> Guys, using a longer/shorter stem will not compensate for the effects of your fork rake!* You may provide a bit more weight out front* with a longer stem but that will not change the handling of your bike in the same way that rake does....
> EM


I believe the OP is asking about the Colnago's slightly longer front-center that is a result of its slack frontend geometry.


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## T-shirt (Aug 15, 2004)

Clevor,

As well, factor in seat tube angle (maybe you are already doing this?). STA affects the length of the reach. When comparing two frames with identical top tube lengths and different STA's, one frame's reach will be longer than the other's. Of course if the STA's are the same, then there is nothing to worry about. I hope this helps.

Thanks,
Tshirt


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## Fignon's Barber (Mar 2, 2004)

em3 said:


> Guys, using a longer/shorter stem will not compensate for the effects of your fork rake!
> 
> Also, if I were to walk into a shop and they tried to fit me on a bike using the archaic site over hub method, I would quickly leave....
> EM


 I don't believe this to be the OP's question. He was interseted in cockpit room as effected by HT angle in combination with SA. He also never mentioned that his shop fitted him in that method.


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## Clevor (Sep 8, 2005)

I have short legs and a long torso so I may find some surprises on a Colnago. Even though I am 5'8", I ride a MED compact on the Giant with a 55.5 cm TT. The biggest C50 I can ride is a 53 cm with a 53.5 TT. Due to the conventional geometry, anything bigger will have no standover height and little exposed seatpost above the frame.

So to be safe I'm gonna have to mock up the C50 with a bar and stem. I think I'll need a 130 mm stem minimum (the math bears this out). The slack HTA drops the bar back towards the saddle and down. I don't want to put on a 120 mm RAM and find out my knees hit my elbows with my hands in the drops :mad2:. Figure I also have to run pretty much little to no spacers on the stem to get my saddle higher than the bar, because of my short legs. 

I know you're thinking just get a sloping C50, but I already got a compact in the Giant and definitely want that classic look on the C50.


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## gun2head (Sep 3, 2006)

Have you thought about going to an even smaller frame with a 14 stem?


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## merckxman (Jan 23, 2002)

*In that he already owns the C50...*

...isn't the process?: a) establish correct position over pedals, b) since his TCR is perfect in fit, take the TCR saddle tip to handlebar measurement and replicate the same distance on the C50, and that will determine the stem length for the C50.


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## Clevor (Sep 8, 2005)

Remember my original question was whether I might have to add an extra cm to the stem length for the slack head tube angle of the C50. I suppose I can do the math as it's a simple triangle, but I think the difference here (71.3 versus 73 for the Giant), probably won't make that much difference since I'll be using little to no spacers.

I also have a Douglas Precision Ti frame same specs as the C50: 53 cm c-to-t with conventional geometry; STA at 74 is also the same. I calculated a 125 mm stem and the 110 could indeed use an additional 20 mm. But the Douglas has a steep 74 (!) head tube angle which is similar to the Giant.

The longest Cinelli RAM in my bar width is 130 mm anyway. If anybody knows where I can get a RAM2 (2nd generation) bar special ordered in the El Toro scheme let me know. Nobody in the U.S. sells Cinelli. I even tried the place in England where I bought my C50 with no luck. I e-mailed Cinelli twice but no reply so far.


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## fabsroman (Jul 14, 2006)

Try this website for the Cinelli bars. I don't think they have the El Toro scheme, but they do have some of the bars.

http://www.universalcycles.com/shopping/index.php?category=2786

I have seen the El Toro for sale somewhere else, but cannot remember the name of the place.


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## lpdjshaw (Aug 8, 2004)

*Are you running Shimano or Campy?*

This makes almost a cm of difference. Campy shifters can't be mounted completly horizontal on the Ram bar due to the internal cable routing holes. This positions the shirfters at a very slight downward angle which in effect moves them forward about a cm. I bought a 120 length Ram bar after running a 120 3ttt stem and it made for a slighlty more
stretched out position. I would say that you could get away with a 1cm shorter stem length for a Cinelli Ram if you are running Campy.


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## Clevor (Sep 8, 2005)

lpdjshaw said:


> This makes almost a cm of difference. Campy shifters can't be mounted completly horizontal on the Ram bar due to the internal cable routing holes. This positions the shirfters at a very slight downward angle which in effect moves them forward about a cm. I bought a 120 length Ram bar after running a 120 3ttt stem and it made for a slighlty more
> stretched out position. I would say that you could get away with a 1cm shorter stem length for a Cinelli Ram if you are running Campy.


That really throws a wrench into the works! I mean most shops don't have a RAM (much less RAM2) bar lying around you can mock up on a frame. One of the LBSs I talked to has only seen a RAM once - on a bike. 

On this rig, I'll be running Campy Record. However what you say is enlightening considering the 2nd generation RAM2 bar has a revised location of the internal cable routing holes, probably due to the fact you mentioned. From the Cinelli web site:

"The second generation integrated handlebar. Fully renewed in the structure and in the positioning of the layers of Carbon fibre. The position of the entrance holes for the brake cables has been lifted so that the hand position is higher and more comfortable. The variable radius drop (Variable Radius Concept) is unique and innovative, development studies have been carried out on the athletes: the hands follows the arc of the drop smoothly, without feeling any gaps, and reach the brake levers easy and safely."

This is probably another good reason to go with the RAM2 bar. The RAM2 has also been beefed up with high modulus carbon fiber.

So assuming the RAM2 bar gets me back to square one, I'm pretty sure a 130 mm will be what I need (fingers crossed). It's a good thing I got a good deal on the frame and saved a bundle, as it will make up for the cost of this Cinelli part. This is a special order as the RAM2 bar doesn't normally come with the El Toro paint scheme.


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