Stem angle

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Marcus Aurelius
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Joined: 1 Feb 2018, 10:20am

Re: Stem angle

Postby Marcus Aurelius » 11 Feb 2020, 4:06pm

The two most critical, and easily adjusted geometry parameters for comfort and handling / aero and efficiency are the stack and reach measurements. A lot of pro riders actually spec bikes that would be too small for them ordinarily, then put super long stems ( 150 and 160 mm stems aren’t unusual in the pro peloton) and no spacers, and cut steerer tubes, to get suitable stack / reach for them. For most mere mortals the slammed stacks and super long stems they use to get the requisite stack and reach to make their positions as aero and efficient as possible, would really hurt. Unless you want to go extreme, and your bike is pretty much the right size to start off with, a few degrees / mm length, and a couple of mm of spacers, really won’t make a noticeable difference.

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RickH
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Location: Horwich, Lancs.

Re: Stem angle

Postby RickH » 11 Feb 2020, 10:34pm

RH20 wrote:A good starting point is, top of the seat level with the top of the handlebars and then with your elbow touching the nose of the saddle, hand in line with forearm, if your finger is touching the centre of the handlebars you should not be too far from a reasonable position for general cycling. If you fingers are short of the bar centre then consider a shorter stem, or longer if the fingers are beyond the bar centre.

That seems way out, for me at least. With my elbow against the saddle nose, my fingers come to just beyond the stem cap (I can get my other hand palm flat sideways between my fingertips & the bars). My elbow to fingertips is roughly 45.5cm & saddle nose to near edge of the bars is about 52.5cm.

One change I almost always end up making with any bike is to fit a longer stem.

Bear in mind the shape of the bars makes a difference - on one bike I fitted shorter reach bars (12.5cm from 15cm) & a 1cm longer stem. The tops were then further away (which I wanted) but the hoods closer (which I also wanted).

thatsnotmyname
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Joined: 23 Jan 2020, 10:23am

Re: Stem angle

Postby thatsnotmyname » 12 Feb 2020, 8:59am

Marcus Aurelius wrote:The two most critical, and easily adjusted geometry parameters for comfort and handling / aero and efficiency are the stack and reach measurements. A lot of pro riders actually spec bikes that would be too small for them ordinarily, then put super long stems ( 150 and 160 mm stems aren’t unusual in the pro peloton) and no spacers, and cut steerer tubes, to get suitable stack / reach for them. For most mere mortals the slammed stacks and super long stems they use to get the requisite stack and reach to make their positions as aero and efficient as possible, would really hurt. Unless you want to go extreme, and your bike is pretty much the right size to start off with, a few degrees / mm length, and a couple of mm of spacers, really won’t make a noticeable difference.


I would disregard the above, as it completely misunderstands and confuses what ‘stack and reach’ actually are in geometry terms. They are fixed measurements on a frame, so cannot be adjusted.

Marcus Aurelius
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Joined: 1 Feb 2018, 10:20am

Re: Stem angle

Postby Marcus Aurelius » 12 Feb 2020, 10:24am

thatsnotmyname wrote:
Marcus Aurelius wrote:The two most critical, and easily adjusted geometry parameters for comfort and handling / aero and efficiency are the stack and reach measurements. A lot of pro riders actually spec bikes that would be too small for them ordinarily, then put super long stems ( 150 and 160 mm stems aren’t unusual in the pro peloton) and no spacers, and cut steerer tubes, to get suitable stack / reach for them. For most mere mortals the slammed stacks and super long stems they use to get the requisite stack and reach to make their positions as aero and efficient as possible, would really hurt. Unless you want to go extreme, and your bike is pretty much the right size to start off with, a few degrees / mm length, and a couple of mm of spacers, really won’t make a noticeable difference.


I would disregard the above, as it completely misunderstands and confuses what ‘stack and reach’ actually are in geometry terms. They are fixed measurements on a frame, so cannot be adjusted.


They effectively can, and are.

thatsnotmyname
Posts: 114
Joined: 23 Jan 2020, 10:23am

Re: Stem angle

Postby thatsnotmyname » 12 Feb 2020, 10:30am

Marcus Aurelius wrote:
thatsnotmyname wrote:
Marcus Aurelius wrote:The two most critical, and easily adjusted geometry parameters for comfort and handling / aero and efficiency are the stack and reach measurements. A lot of pro riders actually spec bikes that would be too small for them ordinarily, then put super long stems ( 150 and 160 mm stems aren’t unusual in the pro peloton) and no spacers, and cut steerer tubes, to get suitable stack / reach for them. For most mere mortals the slammed stacks and super long stems they use to get the requisite stack and reach to make their positions as aero and efficient as possible, would really hurt. Unless you want to go extreme, and your bike is pretty much the right size to start off with, a few degrees / mm length, and a couple of mm of spacers, really won’t make a noticeable difference.


I would disregard the above, as it completely misunderstands and confuses what ‘stack and reach’ actually are in geometry terms. They are fixed measurements on a frame, so cannot be adjusted.


They effectively can, and are. You really don’t have a clue about anything do you?


Stack and reach are not adjustable. Stack is the measurement vertically from the centre of the BB. Reach is the measurement horizontally from the top of the head tube. The stack/reach distance is where they intersect. All you have to do is google it. It would be far easier to accept the correction than it would be to argue it.

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andrew_s
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Location: Gloucestershire

Re: Stem angle

Postby andrew_s » 12 Feb 2020, 11:49am

Raylike1969 wrote:
Mick F wrote:You can buy adjustable stems of course.
This one for instance.
https://www.tredz.co.uk/.System-EX-Adju ... _24665.htm
24665-47730_1_Supersize.jpgWhen you're happy with the angle, buy a fixed one to suit.


Morning Mick
Thank you , thats a brillant idea.

If you can find someone who's got one of these
Image
you get a pretty full range of adjustment, rather than just angles for a fixed length stem.
As the link notes, it's the sort of thing that makes for a good club loaner.

Whereabouts are you?

mcshroom
Posts: 46
Joined: 30 Aug 2011, 12:00am

Re: Stem angle

Postby mcshroom » 12 Feb 2020, 3:12pm

pwa wrote:In the past when I have had a stem that felt no quite right for me I would ride the bike and as I did so try to work out where I would like the brake hoods to move to. Maybe, for example, 10mm closer to me and 5mm higher. Then back at base I would try to work out what sort of stem and spacer arrangement would give me that change.


This is the approach I'd take. Bar angle and position of the hoods on the bar can make changes as well. Your bike fit hopefully has you pretty close to where you need to be, but I'd treat it as a starting point, and then adjust slowly to where you feel your contact points are where you want them.

Marcus Aurelius
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Joined: 1 Feb 2018, 10:20am

Re: Stem angle

Postby Marcus Aurelius » 12 Feb 2020, 3:58pm

andrew_s wrote:
Raylike1969 wrote:
Mick F wrote:You can buy adjustable stems of course.
This one for instance.
https://www.tredz.co.uk/.System-EX-Adju ... _24665.htm
24665-47730_1_Supersize.jpgWhen you're happy with the angle, buy a fixed one to suit.


Morning Mick
Thank you , thats a brillant idea.

If you can find someone who's got one of these
Image
you get a pretty full range of adjustment, rather than just angles for a fixed length stem.
As the link notes, it's the sort of thing that makes for a good club loaner.

Whereabouts are you?


Those are great, but the hinges tend to creak and wobble like a good’un under hard efforts.

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willcee
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Location: castleroe,co.derryUlster

Re: Stem angle

Postby willcee » 12 Feb 2020, 4:40pm

THE real question is with one of those fitted and adjusted would you really be honking that hard that its all over the shop..i wouldn't.. but then i don't race on the open road nor am i a sunday warrior just someone perhaps like the other person who likes to be well seated and comfy when riding within my abilities.. no diss intended.. just common sense.. will