Do slammed stems mean bike fits have gone out the window

Discuss light weight issues concerning road bikes & parts.
bilwit
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by bilwit

length of head tube
head cone stack/headset dust cover
spacers
angle of stem
length of stem

You can get the same fit from a "slammed" setup versus the a stem with some spacers if you change one or more other factors listed. Whatever your ideal position is is completely personal and yours alone. And yes, your body does adjust accordingly if you spend enough time in a different position (same as going from road bike to TT), but there's also a difference between discomfort and not being able to put out the most power in a given position due to it being untrained.

Some "bike fits" get you setup to the most comfortable position, others get you in the position where you can put out the most power, others will get you in the most aero position, and others will give you a combination of any one of these.

by Weenie


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Calnago
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by Calnago

Exactly, there’s many ways to arrive at the same fit, through the use of spacers, different stem rises, etc. and what about frames tha come with say, a short top cover and a tall cover. Is it not “slammed” if you opt for the tall cover, or does your frame not fit you because the stem isn’t sitting on top of the headtube. Cannondale has had some super tall 3cm volcano top covers. Is that any different than a 1cm headset cover plus 2cm of spacers. I actually think a lot of slammed setups are less aesthetically pleasing than a spacer or two, it just depends on the situation, the fit and the frame geometry. A “rule” that the stem must be slammed is just ridiculous.
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corky
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by corky

Some people don’t ride their bikes much....just lean them up against a wall and take pictures of them.

Hexsense
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by Hexsense

AJS914 wrote:
Fri Aug 10, 2018 3:21 pm
I see people on the forum buying a frame that is one size too large so they get more stack height and can slam their stem but that is sort of the exact oppposite of pro positioning. The people buying a larger frame are just doing that so they can slam their stem. It's aesthetics over function. In reality they would be better off on a smaller frame with a couple of spacers and a longer stem.
There are exceptions, ofcourse. And one of a few exceptions to go a larger frame is when you are short.
Using the correct size frameset may allow the use of slammed -7 degree stem or -10 not slammed at 100mm to 120mm stem length. But most bike companies do make many compromises in handling geometry (slacken head tube without lengthen fork offset, resulting in long trail and sluggish handling etc.) just to shrink a bike with limitation of 700c wheel size.

Therefore, trying to fit on a bike that is atleast size 49+ eventhough it may be a bit big that you need to use 90-110mm stem at -17degree slammed may yield a better handling characteristic than a size 44-46 bike with compromised handling geometry.

Toby
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by Toby

onemanpeloton wrote:
Fri Aug 10, 2018 3:50 pm
so you'd sacrifice every other characteristic of a frame and it's geometry just so you can slam your stem?
Seriously? That's not what I said. There are lots of bikes out there. Why would it be impossible to find the right characteristics and geometry, especially since part of having the right geometry is that I'm not stacking a bunch of spacers to make it fit right? If I need an inch of spacers on a bike, I'm going to go looking for one with another inch of head tube instead.

To flip it around, I could ask "so you'd stack two inches of spacers under your stem to make up for buying a bike that doesn't fit you right?", but that would be stupid and inflammatory.

AJS914
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by AJS914

Hunting for a frame with a taller head tube is not always a realistic option.
especially since part of having the right geometry is that I'm not stacking a bunch of spacers to make it fit right?
No, I don't think that is "right". There is no such rule that is carved in stone. That is purely an aesthetic choice. This idea would put many riders on an endurance frame instead of a race bike. I'd rather have my properly fitting race bike with a couple of centimeters of spacers rather than an endurance frame or the next size up frame so I could get rid of the spacers.

I would agree though that if you have 2 inches of spacers then you may want to look at fit.

Toby
Posts: 64
Joined: Thu Sep 06, 2012 4:30 am

by Toby

AJS914 wrote:
Fri Aug 10, 2018 7:27 pm
Hunting for a frame with a taller head tube is not always a realistic option.
especially since part of having the right geometry is that I'm not stacking a bunch of spacers to make it fit right?
No, I don't think that is "right". There is no such rule that is carved in stone. That is purely an aesthetic choice. This idea would put many riders on an endurance frame instead of a race bike. I'd rather have my properly fitting race bike with a couple of centimeters of spacers rather than an endurance frame or the next size up frame so I could get rid of the spacers.

I would agree though that if you have 2 inches of spacers then you may want to look at fit.
I'd rather be on an endurance bike with fewer spacers than a "race bike" with more. However, that's sort of a moot point for me, since I'm on the old Cervelo geometry with a -17 stem anyway, so usually what I'm doing is making sure a given frame doesn't have an extra inch of stack over what I have already.

And so how many spacers is "reasonable"? I'm not talking about half an inch; I'm thinking of the ones I see with a huge pile. "Slammed" is perhaps the wrong word, but I'd rather get there by using a cm of spacers and a rising stem than 3cm of spacers and a flat stem. If I needed a bunch of spacers and the upturned stem... yeah I'm thinking I'm on the wrong bike, even if that means switching to an "endurance bike".

markdjr
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by markdjr

Is there something to be said for sizing down in hopes of more agility? I ride a 58cm tarmac with a couple spacers and a +6 stem. I could have gone with a 61 and slammed the stem but felt like the larger frame was a bit more cumbersome. Is this just me?

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ergott
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by ergott

themidge wrote:
Fri Aug 10, 2018 4:28 pm
I have to disagree with you there, there's a good fit for the person, and then there's fitting that fit onto the right frame. When there are spacers on a bike, for me it usually indicates that that second step has been done badly or sometimes even dispensed with entirely, in favour of aesthetics or brand loyalty.
You don't ride enough with really fast riders because that statement is simply fashion. Slammed stem is nice if if it's convenient, but not essential. If you were correct then no pro (who's entire career is bike riding) would ride with spacers and that's flat out false. Don't go blaming sponsors either. Pros aren't riding endurance versions of their sponsor's lineup and many of them have spacers. They don't have stacks and stacks, but they have spacers.

spdntrxi
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by spdntrxi

I've got two choices... a few spacers or not very much seatpost showing, both not great in the looks dept. I'm gonna chose a couple spacers on my next bike.

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Calnago
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by Calnago

markdjr wrote:Is there something to be said for sizing down in hopes of more agility? I ride a 58cm tarmac with a couple spacers and a +6 stem. I could have gone with a 61 and slammed the stem but felt like the larger frame was a bit more cumbersome. Is this just me?
You’re probably just fine with your 58. I would ride a 58 in a tarmac as well. Also with a couple spacers. In your case (comparing the two Tarmacs) I think the 58 would feel quite different than the 61 but only you could decide which one is better, for you. There’s some rather big jumps in certain aspects of the geometry between the 58 and the 61 Tarmac that would certainly make me (speaking for myself now, and knowing my fit and preferences) lean towards the 58 with spacers versus the 61 with no spacers. The 61 almost seems like a “catchall” size intended for all riders over a certain height. The Effective top tube for example is almost 2cm longer between the sizes. That’s a big jump. Compare that to a 59 Traditional Colnago with a top tube of 577mm (same as the 58 Tarmac) versus a 61 Traditional with a top tube difference of only 9mm between the two. I can ride either just fine. The 61 certainly looks good, with only a 3mm red spacer (for a little bling) above the 15mm top cap, but the incrementally smaller 59 is indeed a little snappier handling. What you have to be careful of is confusing a little bit quicker handling just because the bike is a bit smaller (but still fits just fine) versus very quick handling because the bike is simply too small. There’s a difference and tradeoffs either way. Sometimes the frame choice is very clear (you “know” one size works and the other won’t just like trying on shoes). Other times it’s not so easy to decide and you make choices. And sometimes you just need to move onto a different brand of frame if you want to be sure to check ALL the boxes as to handling, fit and how it builds up aesthetically to your specs.
Last edited by Calnago on Sat Aug 11, 2018 1:46 am, edited 2 times in total.
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alcatraz
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by alcatraz

The more you ride the easier it is for your body to adapt to that position. Lets say you are healthy and used to your fit already for a long time. Dropping a 5mm spacer will just make you faster, not lose significant power. When you reach an extreme angle and if you are a bit older naturally you need to do some stretching before riding.

It's amazing how the body can adapt and put out power in positions that initially were impossible, as long as the changes were done in small increments over a longer time. I'm not talking about huge changes but still significant considering marginal gains.
Last edited by alcatraz on Sat Aug 11, 2018 2:28 am, edited 1 time in total.

AJS914
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by AJS914

Hinault would have had a couple of inches of spacers with his very stretched out fit had he been riding a modern bike:

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ergott
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by ergott

alcatraz wrote:
Sat Aug 11, 2018 2:26 am
The more you ride the easier it is for your body to adapt to that position. Lets say you are healthy and used to your fit already for a long time. Dropping a 5mm spacer will just make you faster, not lose significant power. When you reach an extreme angle and if you are a bit older naturally you need to do some stretching before riding.

It's amazing how the body can adapt and put out power in positions that initially were impossible, as long as the changes were done in small increments over a longer time. I'm not talking about huge changes but still significant considering marginal gains.

Seriously, stop. There's a limit to the hip angle. You can't just keep dropping the bars until they are even with the front axle. If your thighs hit your ribs as you get up and over the crank no amount of flexibility will make that better. The legs have to move freely withouth the upper body getting in the way. This is especially true with small to medium riders as the cranks don't change length proportionally with the height/size of rider.

Again, you guys don't know more than pros like Mark Cavendish, Greg Van Avermaet, Dan Martin, Sylvain Chavanel, Julien Vermote, Jesus Herrada, Larry Warbasse, Jakob Fuglsang, Miguel Angel Lopez (I stopped looking at this point). They have spacers under their stems. These are pros that put out more power than 99% of the users here or anywhere else for that matter. They have the legs to support the most extreme positions on the bike. People with half the FTP/kg (still not bad) don't have to always emulate the same position because you need the power in the legs to sustain it. There's an efficient/powerful position for each rider and the frame's stack and reach doesn't dictate that nor should anyone think they need to find a frame that will with no spacers.

It's preposterous to comment on a rider's fit on a bike or their relative fitness based on the spacers they have under their stem.


by Weenie


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