# Seat tube length on a new Madone (54cm)?



## ping771 (Apr 10, 2006)

What is the seat tube length of new Madones (54cm) from center of bb to tippy top of seatmast clamp? I'm thinking its 56cm or 57cm but not sure. The bike shops where I Iive don't stock 54cm in their stores. I would imagine that a Pro Fit or a Performance Fit 54cm have the same seat tube length, so owners of either, please chime in. Thanks!


----------



## zac (Aug 5, 2005)

ping771 said:


> What is the seat tube length of new Madones (54cm) from center of bb to tippy top of seatmast clamp? I'm thinking its 56cm or 57cm but not sure. The bike shops where I Iive don't stock 54cm in their stores. I would imagine that a Pro Fit or a Performance Fit 54cm have the same seat tube length, so owners of either, please chime in. Thanks!



The effective size from center of BB to the dot on the seat mast is the size of the frame...So for a 54cm frame it is 54cm. And that is true whether or not it is Pro or Performance. The clamp moves with the seat cap, so what specifically you are asking doesn't make a lot of sense.

However a better measurement is Frame Stack and Effective Top Tube and would have more meaningful information when comparing frame size to frame size and frames across manufacturers.

Trek Madone geometries are available on their website under the specs sections for the individual frames you are looking at. 

HTH
zac


----------



## ping771 (Apr 10, 2006)

zac said:


> The effective size from center of BB to the dot on the seat mast is the size of the frame...So for a 54cm frame it is 54cm. And that is true whether or not it is Pro or Performance. The clamp moves with the seat cap, so what specifically you are asking doesn't make a lot of sense.
> 
> However a better measurement is Frame Stack and Effective Top Tube and would have more meaningful information when comparing frame size to frame size and frames across manufacturers.
> 
> ...


Sorry so let me rephrase. If you took off the seat post and clamp you have an extended seat tube that rises above the top tube for some distance--right? What is the center of the bb to the top of the seat tube (that is where the carbon tubing of the seat tube meets the seat clamp at the lowest position possible). In other words, the distance from center to bb to lowest possible position of seat clamp on a 54cm is xcm?

If I remember correctly, the dot is some number of cm below the lowest position ot the top of the seat clamp--what is that distance? Thanks.


----------



## zac (Aug 5, 2005)

ping771 said:


> Sorry so let me rephrase. If you took off the seat post and clamp you have an extended seat tube that rises above the top tube for some distance--right? What is the center of the bb to the top of the seat tube (that is where the carbon tubing of the seat tube meets the seat clamp at the lowest position possible). In other words, the distance from center to bb to lowest possible position of seat clamp on a 54cm is xcm?
> 
> If I remember correctly, the dot is some number of cm below the lowest position ot the top of the seat clamp--what is that distance? Thanks.


I am still not understanding what you are trying to describe.

But the "V" dot is almost exactly the frame size. So measuring along the Seat Tube, from center BB to dot: a 54cm frame will be 54cm. 

The minimum seatmast cap set line for a 54cm frame would be about 27-30mm below the dot, or 51 to 51.3cm up from the center BB.
This would be the lowest measurement from the center BB to the BOTTOM of the seat cap clamp. You could probably set the cap ~1cm lower, but you are going to eat into paint. And I am not sure if the mast at that point is designed to hold the clamp, probably, but I don't know.

HTH
zac


EDIT so we don't all get confused: Are you asking about the OCLV Madones (5.x and 6.x) or the TCT Madones (4.x)? Because these are different.
Also you seem to have a bit of a misunderstanding as to how the OCLV Madones seat mast and cap work. The seat mast is part of the frame. It is a no-cut mast and it does not have a clamp associated with it. The seat cap, which attaches the saddle to the mast/frame, comes in two main sizes (120mm and 160mm) and slides over the seat mast. The clamp is integrated onto the cap and is part of it, and as such slides up and down the mast with the cap.
TCT Madones (4.x series), on the other hand, have a traditional seat post and clamp system.

EDIT II: really trying here...are you just trying to get the measurement from the center of the BB to the bottom of the seat cap clamp at it lowest possible setting for a 54cm Madone?


----------



## ping771 (Apr 10, 2006)

zac said:


> I am still not understanding what you are trying to describe.
> 
> But the "V" dot is almost exactly the frame size. So measuring along the Seat Tube, from center BB to dot: a 54cm frame will be 54cm.
> 
> ...


Zac,

Ok, now I see how I am not making sense. Below are 2 photos from Trek's website. 1)What is length of seat tube from center of bb to top of that if it was a 54cm (looking at the bottom photo from the set of 3photos depicting an exposed seat tube)? 

If I use the short cap (120mm)(right one in photo 2), and slam it (figuratively) down as far down the seatmast, will it be too high once I put my saddle in. I ride a 69ish cm saddle height with a low profile (Selle Italia SLR). I may in the future use a thicker saddle which would mean I would have to lower my saddle and I don't know if I could lower it anymore using a short cap. The 52cm frame has too short of a head tube for me (and I prefer the Pro Fit frame).

When they say 120mm, what does that length represent, just the carbon part, or the bottom of the carbon post to the where the "seat" clamp meets the saddle rails? I am sorry for being so precise about my questions.


----------



## zac (Aug 5, 2005)

Ping give me till tomorrow and I will give you all the measurements. I ride an SLR so I can give you those too!

zac


----------



## PJ352 (Dec 5, 2007)

ping771 said:


> Zac,
> 
> Ok, now I see how I am not making sense. Below are 2 photos from Trek's website. 1)What is length of seat tube from center of bb to top of that if it was a 54cm (looking at the bottom photo from the set of 3photos depicting an exposed seat tube)?
> 
> ...


Although I can't answer your specific question re: the length of the seat tube, I think I understand why you're asking. My saddle height is about 682 +/- and when I was checking out the new Madones, I test rode a 5.2 Pro in a 54 CM and the seat mast was positioned very close to bottom to accomodate my saddle height. At that point I decided that the 52 CM was the better choice, because of possible future changes to saddles/ pedals/ shoes. It sounds like you're in a similar situation, and you're right that going to a 52 will shorten the HT and lower frame stack.

Below is a chart that you may find helpful. It basically gives a range of saddle heights for a given frame and cap. Hope this helps.

https://trekroad.typepad.com/photos/uncategorized/2007/06/05/2008_trek_new_mdaone_seat_height__2.gif


----------



## zac (Aug 5, 2005)

ping771 said:


> Zac,
> 
> Ok, now I see how I am not making sense. Below are 2 photos from Trek's website. 1)What is length of seat tube from center of bb to top of that if it was a 54cm (looking at the bottom photo from the set of 3photos depicting an exposed seat tube)?
> 
> ...


Ok, getting there.

Unfortunately I didn't measure to the top of the seat mast with the cap removed.

Cap measurements: 120/160mm cap measures from the Center Line of the saddle rail to the Center Line of the clamp bolts, measured inline through the saddle pivot bolt, assuming the saddle is set level and no lateral tilting either.

But that doesn't help much so I measured from the very bottom of the seat cap to the bottom of the saddle rail for the 120mm cap. That measurement is 125mm.

Next since you are going to be using an SLR, that measruement from the very bottom of the seat cap on the 120mm cap to the top of the saddle is 167mm.

[NOTE all these measurement are inline like you would measure from center of BB to top of saddle along the seat tube.]

So from yesterday, You are looking at a 510mm minimum lowest possible set for the seat cap (along the frame) from the Center of the BB. then add another 167mm to the top of an SI SLR saddle and that will give you 677m well within your desired 690mm setting. So it sounds like you should be good to go. And yes a 120mm cap will go this low.

Now I mentioned that you could possibly set the cap another 10mm lower, however, I am not sure the 120mm cap will go that low.

I would estimate the distance from the "V" dot to the very top of the naked mast to be ~60mm.

Please take a look at the chart that PJ linked to. This is very much inline with what I just posted above from actual measurements, however it is much more comprehensive.

CAVEAT: ALL the measurements relating to the seat cap are assuming you are using the new style black clamp cap, and not the older style silver clamp cap (the one you pictured).
good luck
zac


----------



## ping771 (Apr 10, 2006)

*Thanks Zac and PJ532!*

I really apprecieate you guys for taking the time/effort to answer my questions (and understanding what I am asking).

To PJ: I looked at the chart before and to me it seemed a little misleading. The stated minimum saddle height on a 54cm with a short cap is 67.5cm but one has to wonder what saddle they are accounting for, surely not the old Bontrager saddles (which look have a Concor profile) nor the new Bontrager R and RL saddles, which appear to have a high profile too. With either of those saddles it looks like on a 54cm the minimum saddle height is at least 70cm. Thanks for the chart btw.

To Zac: Thanks for the personal measurements. When you measure at the 51cm mark is that the distance from the center of bb to the lowest "hashline" on the seat mast? I seem to recall if you go below the lowest hashline, the seat tube begins to bend toward the top tube, and putting it that low would definitely scratch or damage the tubes/paint, as you said. 

If I was able to test ride a 54cm, none of this would have to be asked, but the bike shops I go to either have a 50cm or 56cm or greater. Thanks again. I'm saving my pennies in these hard times for a 5.2 Madone Pro Fit. That black paint with white is amazing. But I equally like Zac's red scheme and of course, PJ's black Madone is awesome. The slight logo change in Trek for 09 is cool too, and I like the color schemes slightly better this year.


----------



## zac (Aug 5, 2005)

ping771 said:


> I really apprecieate you guys for taking the time/effort to answer my questions (and understanding what I am asking).
> 
> To PJ: I looked at the chart before and to me it seemed a little misleading. The stated minimum saddle height on a 54cm with a short cap is 67.5cm but one has to wonder what saddle they are accounting for, surely not the old Bontrager saddles (which look have a Concor profile) nor the new Bontrager R and RL saddles, which appear to have a high profile too. With either of those saddles it looks like on a 54cm the minimum saddle height is at least 70cm. Thanks for the chart btw.
> 
> ...


Yes it is.


----------



## ping771 (Apr 10, 2006)

zac said:


> Yes it is.


Zac,

Thanks again. I looked at your Madone from the post your carbon treks thread---your bike is sick looking! (I mean that in a good way!)

Btw, what is your saddle height? It looks like 75cm or thereabouts. Decent saddle to bar drop....

I don't know much about Reynolds wheels (btw clinchers or tubs?) but they make your bike pop even more.


----------



## zac (Aug 5, 2005)

Thanks, and you're welcome. 

Good eye: 755mm, with a ~4" drop. I can be a bit flexible in my measurements. More a range than precise absolutes.

Clinchers: Those are the new Assaults. Not totally sold on them. Bit to flexy for me, especially the rear.


----------



## ping771 (Apr 10, 2006)

zac said:


> Thanks, and you're welcome.
> 
> Good eye: 755mm, with a ~4" drop. I can be a bit flexible in my measurements. More a range than precise absolutes.
> 
> Clinchers: Those are the new Assaults. Not totally sold on them. Bit to flexy for me, especially the rear.


Thanks. I appear to have a gift for perceiving things (when it comes to bikes that is). 4in=10cm. I posted elsewhere a long time ago that I thought that Levi's bike was not a 54cm even though it was listed like that on cyclingnews, since Contador's 54cm bike is larger (and it's not just that his saddle is higher). People thought I was crazy. You ride a 54cm right? Your frame looks larger than Levi's. His bike doesn't even look like a 52cm, since I've seen 52cm in person, and they don't have that kind of upwards slope on the top tube. The angles on his bike look slightly off. But I'm flogging a dead horse, so I'll leave it at that.

I did some looking around, and it appears that there are mixed consumer reviews on rbr on the Reynolds Assault, with similiar comments as yours. Then again, I don't know any full carbon clincher high profile wheel at that price point. Cyclingnews also gave it 4.5 stars. If you want rigid though, go with Mavic R-SYS--way super stiff.


----------



## zac (Aug 5, 2005)

It's a 56cm but the measurements for a 54 are easy to interpolate, as the "v" dot is exactly at that dimension.

I don't know about LL's bikes, from the few pictures I have seen and from his size, if I had to guess I'd say 50-52cm.

As to the Assaults, I like to try new equipment, so I thought I would give them a try...
The Reynolds hoops are first rate (indeed they are their prior top end DV46s), but the hubs (generic) are just serviceable, and I don't have enough miles on them yet to see how well the hubs hold up. What I was least impressed with is I had to rebuild the rear due to it just being too flexy. I think a company the size of Reynolds could do a much better job on this wheelset's build, especially seeing that it is most likely a gateway wheel to their higher end products. 
Since the rebuild though, they have been fine. The front has been dead on true, as well as the rear, and I do ride on pavé and other nasty new england road conditions. 
Don't get me wrong I like them, but they don't have that solid, silky smooth, almost invisible feel of a Mavic Cosmic Carbone. But then again the Carbones are almost a pound heavier too.
I'll probably ride the year with them and then replace the rear hub with a DT 240 which should pretty much be a snap in replacement.

Good luck with your intended acquisition.
zac


----------

