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-   -   stem slamming and power output (https://www.bikeforums.net/road-cycling/833948-stem-slamming-power-output.html)

jsutkeepspining 07-23-12 07:59 AM

It's partially a joke to just post slam your stem, but as mentioned before in this thread somepeople are more comfortable with lots of drop vs. little to no drop.

Bacciagalupe 07-23-12 08:08 AM

I for one don't think it's a good idea to mess around with your bike fit unless you know what you're doing. That goes double for people with unusual dimensions.

I'd recommend you talk to the best fitter you can find in your area, and check to make sure they have experience with tall riders. The fitter can get you into the right spot, reduce repetitive injuries, and can explain to you why doing X results in Y.

On a side note, lactic acid is fuel, not a caustic waste product. You can't feel it, and the only way you know how much lactic acid is in your system/muscles is with a blood test.

Campag4life 07-23-12 08:17 AM


Originally Posted by elcruxio (Post 14516244)
so now what? Seat back? Longer stem? A new bike is obviously not an
option. Unslam? This stuff is seriously way too complicated


Thing is...you don't know if your setback is right or wrong for you. I can tell by your picture however your reach isn't conventional...and I showed you a couple of examples...Hincapie is 6'3".

I asked you for a saddle tip to handlebar center dimension and you didn't post it.
If you do, I can make a suggestion as to how much you need to increase your stem length.
I will provide another suggestion. Drop a weighted string from the nose of your saddle with your bike upright on level ground. Measure the lateral distance from saddle nose plum to BB aka crank center. This is called setback. Let me know that dimension.

PS: Stack and Reach your 61 Crux cross bike is almost identical to my 58 Roubaix SL3. You are almost 5" taller than me. My personal opinion is...your fit is mostly off because you are slamming the stem on a bike that is too small for you. If I order a Crux...a bike I would consider owning for general riding...it would be a 61. FYI.

Campag4life 07-23-12 08:31 AM


Originally Posted by DaveWC (Post 14516331)
It seems odd to me that very often on bicycle forums people recommend bike fits from the LBS but then they also seemingly randomly shout "slam that stem". Wouldn't it make sense that during your bike fit the stem would be sitting at the appropriate level for your body & the bike? I understand that not everyone gets a bike fit and those that do don't necessarily slam their stem afterwards. But the "slam the stem" mantra seems to completely ignore fit issues.

False premise. Probably 80% of fits I see coming out of bike shops are poor anyway.

Campag4life 07-23-12 08:35 AM


Originally Posted by Bacciagalupe (Post 14516408)
I for one don't think it's a good idea to mess around with your bike fit unless you know what you're doing. That goes double for people with unusual dimensions.

I'd recommend you talk to the best fitter you can find in your area, and check to make sure they have experience with tall riders. The fitter can get you into the right spot, reduce repetitive injuries, and can explain to you why doing X results in Y.

On a side note, lactic acid is fuel, not a caustic waste product. You can't feel it, and the only way you know how much lactic acid is in your system/muscles is with a blood test.

The counterdiction then is...you never understand unless you mess with your fit. Most good riders I know understand fit pretty well. Deferring to people about best fit reminds me of a golfing parable...that goes like this:
Lee Trevino was asked...Mr. Trevino, with your unorthodox swing...why is you never took lessons? Why that's simple sonny boy. I never met a teacher I couldn't beat.

MrTuner1970 07-23-12 09:04 AM

It's necessary to know the length of the saddle when we're talking saddle setback. Setback will be different when he's on a Toupe than when he's on an Arione. The fit could be made identical with these two saddles.

But yeah, bike looks too small to me also.


Originally Posted by Campag4life (Post 14516464)
Thing is...you don't know if your setback is right or wrong for you. I can tell by your picture however your reach isn't conventional...and I showed you a couple of examples...Hincapie is 6'3".

I asked you for a saddle tip to handlebar center dimension and you didn't post it.
If you do, I can make a suggestion as to how much you need to increase your stem length.
I will provide another suggestion. Drop a weighted string from the nose of your saddle with your bike upright on level ground. Measure the lateral distance from saddle nose plum to BB aka crank center. This is called setback. Let me know that dimension.

PS: Stack and Reach your 61 Crux cross bike is almost identical to my 58 Roubaix SL3. You are almost 5" taller than me. My personal opinion is...your fit is mostly off because you are slamming the stem on a bike that is too small for you. If I order a Crux...a bike I would consider owning for general riding...it would be a 61. FYI.


wphamilton 07-23-12 09:18 AM


Originally Posted by roadwarrior (Post 14516282)
It's not if you know what you are doing. Do not move the seat back. This changes your pedal stroke, assuming that you are in the best position for that part of the fit. Putting a longer stem with the correct rise might sort out the rest of your issue.

You can't set up a bike from a pros picture or try why they try.

The question is, how can you know this, that you are in the best saddle setback position? You can't determine it by any immediate difference in power or comfort. In my limited experience I can move it an inch either way (and of course that also means up and down). At first it will feel weak and odd but after a few hundred miles I'll be about back to where I started. Muscles and pedal stroke adapt. So it seems to depend a lot on training to a position.

DaveWC 07-23-12 09:40 AM


Originally Posted by Campag4life (Post 14516537)
False premise. Probably 80% of fits I see coming out of bike shops are poor anyway.

It's not my false premise. I assume the false premise is that of suggesting that people get a bike fit at a LBS.

Brian Ratliff 07-23-12 11:50 AM


Originally Posted by elcruxio (Post 14515744)
http://farm9.staticflickr.com/8006/7...86807a97_z.jpg
posture by El-Carpaso, on Flickr

Ok, thanks for the input so far. It has given me lots to think about.
Here is a quick picture of my cycling posture on the hoods. Now you might notice that the bike looks really small. This is because I am a fairly big guy and at my size 700c wheels start looking very small on a frame. Secondly there is a bit of angle distortion. The picture should have been taken from the same level where my bum is, but since it was raining we didn't have time to adjust angles. So it's taken from head level which makes the bike look tiny.

But even though the bike looks small, it really is not. I'm not too far ahead since the handlebar covers the front hub when I look down, I don't feel cramped and in my opinion all the angles look kinda right. Ok, of course the top tube could be a lot longer but I don't feel comfy on a longer bike. Believe me, I've tried.

One of the reasons why I felt a loss of power is that I noticed my saddle was way back and nowhere near the KOPS. So I moved the saddle forward and up (2cm forward and 1cm up). Moving the saddle really gave me a lot of power back. But I imagine that I could get rid of the spacers at some point to get even lower. I know I can manage it with time since I'm still quite young and adaptable.

The reason for this really was to find the optimal position between aero and power output to maximize speed. It would seem it will be a long journey...

If you've got your power back, and you handle the position fine, then ride it like that for a while. You really aren't in that low of a position; you could go lower. But ride it like that for a while and see where it takes you. I don't think the bike is too small, FWIW. Eventually you'll probably find yourself with no spacers at all and a -17, 130mm stem (sort of hard to find, but doable). But don't jump to that right away. It took me four years to get into the racing position I'm in currently from the rec rider position I was in formerly.

It's really not as complicated as it seems listening to a rash of advice from riders who've all gone through the long fit process. If I described all the stuff I've tried, I'd fill pages; but what matters is the process of trying stuff and experimenting, and that is a lot simpler. The basic jist is, if you want to try something, try something. You are young; you ain't going to hurt yourself if you just listen to your body. There should be no sharp pains anywhere. Muscle tension, say in the neck or shoulders, is a sign of lack of adaptation; take some time to adapt and see where you are. Joint pain is a no-no and a sign of incompatibility; if a joint hurts, change something immediately to make it not hurt. Keep this in mind as you try stuff, listen to your body, and you'll be fine.

jerrycan42 07-23-12 11:56 AM

On a lighter note, did you get nailed with the squid ink in Mario Kart?

Banzai 07-23-12 12:44 PM

Didn't Nick Legan write about this stem slamming nonsense on Velonews a short while ago?

Pendergast 07-23-12 12:57 PM

Steve Hogg provides about the most sensible fitting guidance that I've seen on the web. Quite a bit of info to absorb, and while someone might not end up with the absolute perfect fit by following it, I'd be very surprised if someone ended up with a bad fit.

http://www.stevehoggbikefitting.com/faq/

elcruxio 07-23-12 01:05 PM


Originally Posted by Campag4life (Post 14516464)
Thing is...you don't know if your setback is right or wrong for you. I can tell by your picture however your reach isn't conventional...and I showed you a couple of examples...Hincapie is 6'3".

I asked you for a saddle tip to handlebar center dimension and you didn't post it.
If you do, I can make a suggestion as to how much you need to increase your stem length.
I will provide another suggestion. Drop a weighted string from the nose of your saddle with your bike upright on level ground. Measure the lateral distance from saddle nose plum to BB aka crank center. This is called setback. Let me know that dimension.

Right. I'll get those measurements in the morning. Bear with me.

And thank you all again for the valuable input. I'll need to tweak a few things and take a few pictures and hopefully I can solve this without needing to buy a new bike (since I can't afford one for at least a year)

Campag4life 07-23-12 03:41 PM


Originally Posted by elcruxio (Post 14517853)
Right. I'll get those measurements in the morning. Bear with me.

And thank you all again for the valuable input. I'll need to tweak a few things and take a few pictures and hopefully I can solve this without needing to buy a new bike (since I can't afford one for at least a year)

I want to give you some words of encouragement. If you are earnest about becoming a good cyclist, which you might me...fit is critical really.
And fit isn't that difficult all said. Yes you can obsess but you can get in the ballpark pretty easily. So post some metrics and will give you some guidance. There really is a high correlation between rider size and cockpit on the pro tour. Basically these metrics can be applied to average cyclists as well. If you want corroboration...run your body metrics through the Competitive Cyclist Fit Calculator. I find the output to be very reliable and correlates pretty close to my fit.

Campag4life 07-23-12 03:46 PM


Originally Posted by Brian Ratliff (Post 14517457)
If you've got your power back, and you handle the position fine, then ride it like that for a while. You really aren't in that low of a position; you could go lower. But ride it like that for a while and see where it takes you. I don't think the bike is too small, FWIW. Eventually you'll probably find yourself with no spacers at all and a -17, 130mm stem (sort of hard to find, but doable). But don't jump to that right away. It took me four years to get into the racing position I'm in currently from the rec rider position I was in formerly.

It's really not as complicated as it seems listening to a rash of advice from riders who've all gone through the long fit process. If I described all the stuff I've tried, I'd fill pages; but what matters is the process of trying stuff and experimenting, and that is a lot simpler. The basic jist is, if you want to try something, try something. You are young; you ain't going to hurt yourself if you just listen to your body. There should be no sharp pains anywhere. Muscle tension, say in the neck or shoulders, is a sign of lack of adaptation; take some time to adapt and see where you are. Joint pain is a no-no and a sign of incompatibility; if a joint hurts, change something immediately to make it not hurt. Keep this in mind as you try stuff, listen to your body, and you'll be fine.

Overall good advice. I may philosophically disagree with your credo of adaptation which you have pretty consistently espoused...but yes, given enough time and dedication, we can adapt...to a point. And that investment can regress each year as well. We all, no matter how much training we do however...each of us reach a threshold of how aggressive a position we can ride. Flexibility is a bell curve from time of birth for each person. Some incremental improvement can be made but nature dicatates a fair amount of it including other aspects of cycling physiology that separate riders. One of the greatest TdF riders of our era rode with almost a recreational riding position in terms of drop in particular.

elcruxio 07-23-12 04:00 PM

Ok, so I did to measurements
Saddle tip to handlebar 60cm / 23.6 in
setback (from saddle tip) 10.5cm / 4.1 in
handlebar drop 14cm / 5.5 in

I now realize I might need a 140mm stem... Or not. This is weird because the bike was completely fine before all this hassle. I am completely over thinking this but the good thing is that in the end my posture might be very "racy" (as in months or years)

mazdaspeed 07-23-12 04:01 PM

Your reach is way too short

Campag4life 07-23-12 04:18 PM

1 Attachment(s)

Originally Posted by elcruxio (Post 14518659)
Ok, so I did to measurements
Saddle tip to handlebar 60cm / 23.6 in
setback (from saddle tip) 10.5cm / 4.1 in
handlebar drop 14cm / 5.5 in

I now realize I might need a 140mm stem... Or not. This is weird because the bike was completely fine before all this hassle. I am completely over thinking this but the good thing is that in the end my posture might be very "racy" (as in months or years)

Mazda is right and your reach is too short. One of the complications of fit for example is...depends where you want to go with it. For example I would suggest less drop as I don't like a lot of drop. I do like reach however. Below is Tom Boonen's specs. Check out his saddle tip to handlebar dimension...almost a full 2 inches more of reach and he is still an inch shorter than you. :) Now he is world class rider and you don't need to ride as stretched out as big Tom but maybe in the 620-630mm range would be a good starting point. So even if you go 140mm stem length, you will need to increase your setback which I recommend as well to elongate your reach to the handlebar. See if you can push your saddle back to 12cm of setback or so and put a 140mm stem on the bike. Believe you will have an 'aaahhh' moment. You may not be done but you will be closer.
PS: not sure your background but keep in mind when you move your saddle fore/aft, you change the distance from top of saddle to BB. So if you push your saddle back, you need to lower it by about 1/3 of how much you push it back to derive the same height.

zandoval 07-23-12 04:40 PM

Great thread - I did not know that lowering your stem was called slamming - Just try to remember that this may not be a good thing for us older guys with bad backs - THANKS -

DaveSSS 07-23-12 04:40 PM


Originally Posted by elcruxio (Post 14516244)
so now what? Seat back? Longer stem? A new bike is obviously not an
option. Unslam? This stuff is seriously way too complicated

Moving the saddle forward 2cm was a mistake. It takes time to adapt to a new position. Don't expect to make a change and get instant results - it doesn't work that way. You're upright and cramped, despite the "slammed" stem. What's your actual saddle to bar drop? Measure the height of the bars and saddle from the floor and take the difference.

mazdaspeed 07-23-12 04:43 PM

Just slam the saddle all the way back and be done with it IMO (when you're that tall on a smallish frame)

elcruxio 07-23-12 04:44 PM

Mmkay.
So if I were to go really specific with this I should probably measure all the inseams and stuff again... I did it a year back but of course I don't have the info anywhere. The funny thing is that the competetive cyclist calculator recommended a 58-60cm TT back then and I just accepted it.

Well, it's stem shopping tomorrow then
Thanks for all the info. I want to learn to do this stuff myself. Doing bicycle related activities (be it maintenance etc) independently has become a kind of a passion and I think this is one of the most important things to know.

Banzai 07-23-12 05:15 PM


Originally Posted by Campag4life (Post 14516537)
False premise. Probably 80% of fits I see coming out of bike shops are poor anyway.

+1.
Generally, unless you're dealing with a highly knowledgeable owner, unless he's been very lucky with finding employees you'll be "fit" by someone with very little practical knowledge, no academic training, and perhaps a marketing tool/device at his disposal.

Honestly, how many "fitters" are exercise physiologists, or even a trainer of any kind?

I'll agree with Campag's later post that the Competitive Cyclist fit calculator is probably the best online tool around. Of course, a shop can foul that one up. Had a buddy use the fit calculator, went into a shop and rode a bike that matched the output, and the shop eventually persuaded him that it "looked too big". They put him on a bike that was one size smaller, which he rides now and has issues related to a cramped cockpit.

Campag4life 07-24-12 04:28 AM


Originally Posted by elcruxio (Post 14518839)
Mmkay.
So if I were to go really specific with this I should probably measure all the inseams and stuff again... I did it a year back but of course I don't have the info anywhere. The funny thing is that the competetive cyclist calculator recommended a 58-60cm TT back then and I just accepted it.

Well, it's stem shopping tomorrow then
Thanks for all the info. I want to learn to do this stuff myself. Doing bicycle related activities (be it maintenance etc) independently has become a kind of a passion and I think this is one of the most important things to know.

Pretty easy to mess up the body measurement process. You need a girl friend or wife to help...and do it twice.
You need at least a 60cm top tube. Per the Competitive Cyclist fit calculator...I need a 590mm top tube and I am almost 5' inches shorter at just over 6' feet.
My personal view is you should be on 63-64cm center to top bike since you are 98% in height...what the largest frame is designed for...guys your size. If you scrounge enough you can find a 150mm stem as well. I ride a 150mm stem on my size Large 29er.

Bacciagalupe 07-24-12 06:13 AM


Originally Posted by Campag4life (Post 14516554)
The counterdiction then is...you never understand unless you mess with your fit.

Or, you learn by getting a good fit, and talking to the fitter about what he or she is doing for you.

Changing your fit when you don't know what you're doing can be counter-productive. For example, the fitter may recommend a change that feels wrong at first, but is actually a better fit, and takes a week or more for you to adapt to it. If you're fitting yourself and it doesn't feel good right away, you're almost certainly not going to stick with it.

You can't really observe yourself well when you're in the saddle. And if you don't know what you're doing, how will you know what to look for?

A good fitter is also a little less likely to advocate lowering a stem because it "looks good" or is more macho.

And of course, you could do the cheapskate mode of getting people to do a fit for you over the Internets. In which case good luck, because you're going to get a lot of conflicting advice from people who have no idea how you actually move on the bike.

That's not quite as bad as getting a medical diagnosis via Web forum, but it's close. ;)

Campag4life 07-24-12 08:00 AM


Originally Posted by Bacciagalupe (Post 14520663)
Or, you learn by getting a good fit, and talking to the fitter about what he or she is doing for you.

Changing your fit when you don't know what you're doing can be counter-productive. For example, the fitter may recommend a change that feels wrong at first, but is actually a better fit, and takes a week or more for you to adapt to it. If you're fitting yourself and it doesn't feel good right away, you're almost certainly not going to stick with it.

You can't really observe yourself well when you're in the saddle. And if you don't know what you're doing, how will you know what to look for?

A good fitter is also a little less likely to advocate lowering a stem because it "looks good" or is more macho.

And of course, you could do the cheapskate mode of getting people to do a fit for you over the Internets. In which case good luck, because you're going to get a lot of conflicting advice from people who have no idea how you actually move on the bike.

That's not quite as bad as getting a medical diagnosis via Web forum, but it's close. ;)

I think we each need to go our own way. To use your medical diagnosis analogy. A patient can go to five doctors and get five different diagnoses.
A car owner can go to five different repair shops and get five different repair suggestions.
A bike owner can go to five different fitters and get five different suggestions for setback, reach and drop...common btw.

In the end, the consumer has to determine his best course. The irony of decision making is...it takes talent to recognize good advice...what I believe in large measure separates people at all levels...even among better amateurs.

Nick Bain 07-24-12 08:06 AM


Originally Posted by elcruxio (Post 14516244)
so now what? Seat back? Longer stem? A new bike is obviously not an
option. Unslam? This stuff is seriously way too complicated

FYI you can't depend 100% on what people here say, I only use it for insight/ ideas. Even if they do know what there talking about they are not along side you watching you pedal like a fitter would do.

elcruxio 08-11-12 12:37 PM

I'm confused. I did the competetive cyclist fit calculator. Here's the results.
[TABLE]
[TR]
[TH] [/TH]
[TH][h=4]The Competitive Fit[/h][/TH]
[TH][h=4]The Eddy Fit[/h][/TH]
[TH][h=4]The French Fit[/h][/TH]
[/TR]
[TR]
[TD="class: left"]Seat tube range c-c[/TD]
[TD]58.9 - 59.4[/TD]
[TD]60.1 - 60.6[/TD]
[TD]61.8 - 62.3[/TD]
[/TR]
[TR="class: alt"]
[TD="class: left"]Seat tube range c-t[/TD]
[TD]60.8 - 61.3[/TD]
[TD]62.0 - 62.5[/TD]
[TD]63.7 - 64.2[/TD]
[/TR]
[TR]
[TD="class: left"]Top tube length[/TD]
[TD]58.3 - 58.7 [/TD]
[TD]58.3 - 58.7[/TD]
[TD]59.5 - 59.9[/TD]
[/TR]
[TR="class: alt"]
[TD="class: left"]Stem Length[/TD]
[TD]12.2 - 12.8[/TD]
[TD]11.1 - 11.7[/TD]
[TD]11.3 - 11.9[/TD]
[/TR]
[TR]
[TD="class: left"]BB-Saddle Position[/TD]
[TD]82.6 - 84.6[/TD]
[TD]81.8 - 83.8[/TD]
[TD]80.1 - 82.1[/TD]
[/TR]
[TR="class: alt"]
[TD="class: left"]Saddle-Handlebar[/TD]
[TD]58.5 - 59.1[/TD]
[TD]59.3 - 59.9[/TD]
[TD]61.0 - 61.6[/TD]
[/TR]
[TR]
[TD="class: left"]Saddle Setback[/TD]
[TD]6.8 - 7.2[/TD]
[TD]8.0 - 8.4[/TD]
[TD]7.5 - 7.9[/TD]
[/TR]
[/TABLE]

According to this the crux is absolutely perfect (competetive fit, which is where I'm aiming at). I've ordered a 130mm stem to try out. With that I can get my saddle handlebar to 63cm which again allows me to move my saddle a bit forward. The saddle position is the one thing I'm seriously struggling with right now. I can't feel the difference in the saddle positions if the chances are not major. I might go with a setback of 8cm. it's 10cm now and it's affecting my spinning speed. Mashing on the other hand is now easier.

Now it seems to me, there are at least two schools in bike fitting. The one that favours the the smallest frame possible and the one that favours a much longer fit. I don't know which I'm going to go with yet. It'll become apparent when I buy a new bike in few years. Looking at pro's today it seems that they are riding very small frames. But then again they are professional athletes who can manage it.

rruff 08-11-12 01:32 PM


Originally Posted by jsutkeepspining (Post 14510825)
^thats why i have tons of drop on my bike. It's more comfortable!

Me too!

No power loss for me. You just need to reorient your posture and pedaling stroke a little.

rruff 08-11-12 01:37 PM


Originally Posted by zandoval (Post 14518820)
Just try to remember that this may not be a good thing for us older guys with bad backs - THANKS -

Maybe not. I'm an old guy with a bad back and it's the best solution. 6' with 13cm from mid-saddle to bar tops.


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