Fit question stretched out on the hoods

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breakwellmz
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Re: Fit question stretched out on the hoods

Postby breakwellmz » 17 Mar 2013, 8:53am

531colin wrote:From an old thread http://forum.ctc.org.uk/viewtopic.php?f=5&t=53020&hilit=overlap&start=105
This is the 51cm tourer, 610mm front centres, 32mm tyre, 165mm crank....22mm clearance.

Image

My roughstuff bike has 640mm front centres....no overlap in boots.


Where`s the mudguard gone? :P

I nearly came cropper the other day whilst doing a`U`turn an old Sun tandem.I suddenly found it had about 2" of toe overlap,compared to the bike i normally ride that has about 2"of clearance :oops:

Mark1978
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Re: Fit question stretched out on the hoods

Postby Mark1978 » 17 Mar 2013, 9:04am

btw my stem is 90mm. I might order a 60mm stem. Then decide if I want to tackle fitting it myself! Although looking at some videos it doesn't look too hard and getting the same part just shorter should simplify matters I guess.
Last edited by Mark1978 on 17 Mar 2013, 10:20am, edited 2 times in total.

The Mechanic
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Re: Fit question stretched out on the hoods

Postby The Mechanic » 17 Mar 2013, 9:44am

JohnW wrote:
531colin wrote:Rules of thumb for riding position....thats all they are, just rules of thumb....but they do provide a place to start.
These rules of thumb result from the "herd experience" of generations of cyclists....they aren't science, they aren't fact, don't waste time arguing the toss over wether they are right, wrong, or halfway between, dont try to explain them.....just use them to get started, then play around from there.
Set the saddle up first to be comfortable to pedal, then set the bars....you can't move the BB!!

1) foot position on the pedal....ball of the foot over pedal spindle, or a bit forward of pedal spindle.
2) saddle height so there is a bit of bend in your knee when the bottom foot is level

Image

3) saddle setback....lots of people are comfortable when set up "knee over pedal spindle" ....thats all..no science...just works for lots of people.....compare with your bike you are used to....don't feel an outcast if it doesn't work for you!

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4)handlebar height....I'm 65, I have my bars level with the saddle....good place to start if you aren't used to drops. You may well find your stem can be flipped up the other way to get more height.

Image

5) angle of bars and brake lever position...I like the forward pointing flat bit of the top of the bars level, and the levers quite high on the bends, so the hoods are a continuation of that flat bit of bar, or even angle upwards....I find this the most comfortable position for riding on the hoods, incidentally it also reduces the effective reach compared to having the levers set lower.

Image

6)Reach....the hardest bit for rules of thumb, and the last bit to work on anyway. Rule of thumb one....elbow on saddle nose, index finger brushes the back of the bar.....maybe!!.
Rule of thumb 2....when riding, the bars hide the front hub....maybe!!
You should be comfortable and relaxed, with a bit of give in your elbows. If the reach is too long, I find my hands come back to behind the hoods....too short, and I drop my neck down between my shoulders.

It will take time to get used to drops!


Colin - it's easy to see that you're a professional among professionals. This post of yours should be published as a text book, and posted on the forum every time someone asks the same, or similar, question.

I'm going to have a go at printing this off - so often we get new cyclists in our section who don't even know about position.

A big thank-you Colin. This explains it all in a simple and easy to understand way.

Even if one follows the rules, there's always a milimeter or two adjustment to get it perfect, but the rules get one near enough - and some people never need to go further than that.

But you illustrate it so well.

And - nice bike!!!


I would question item 6. I have always used the rule that you put your elbow on the saddle nose and your hand at right angles to your fingers. The edge of the hand then approximates where the bars should be - maybe. There is a missing hand width in Colin's explanation. If I took Colin's rule I would have to reduce the reach of all my bikes by the roughly the width of my hand, about 4 inches.
Cancer changes your outlook on life. Change yours before it changes you.

Brucey
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Re: Fit question stretched out on the hoods

Postby Brucey » 17 Mar 2013, 10:53am

The Mechanic wrote: I have always used the rule that you put your elbow on the saddle nose and your hand at right angles to your fingers. The edge of the hand then approximates where the bars should be - maybe. There is a missing hand width in Colin's explanation. If I took Colin's rule I would have to reduce the reach of all my bikes by the roughly the width of my hand, about 4 inches.


I've always used Colin's suggestion as a starting point for setting dropped bars. In several hundred goes it has rarely been very far out. Four inches more might be OK for flats (sometimes, maybe) but is crazy talk for touring drops IME. If it works for you, fine, (and after all it is just a starting point) but if so, I can only suppose that you have an odd build and/or odd position.

cheers
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Malaconotus
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Re: Fit question stretched out on the hoods

Postby Malaconotus » 17 Mar 2013, 10:59am

You can see the effect of changing stems here... http://alex.phred.org/stemchart/Default.aspx

The other variables to input from your bike, in addition to the measured 90mm stem reach, are what looks like 40mm of spacer stack, easy to measure, and a head angle of 72.8 degrees, which you need to round to 73 degrees to make the calculator work. (the rounding has totally negligible effect on the output figures) The final figure needed is the angle of the stock stem, which is usually between 6 and 11 degrees, and may well be written on the stem at the steerer end. (EDIT: says here it's 7 degrees... http://www.trekbikes.com/us/en/bikes/ro ... madone_2_1)

The below image shows the comparison between swapping a 40 degree Trek Race Lite stem suggested previously for your 7 degree stem of the same 90mm length. The differences in bar height and reach are significant, especially when you consider that the reach difference of the Madone frame is only 24mm between a 50cm bike and a 62cm bike
Image Attachments
trek stem comparison.JPG

Malaconotus
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Re: Fit question stretched out on the hoods

Postby Malaconotus » 17 Mar 2013, 11:12am

My preferred rule of thumb for reach is that a neutral riding position is one where the angle formed by arms and torso is 90 degrees. This is quite easy to evaluate by viewing the rider side on and making a 'church roof' with the fingers. An angle of less than 90 degrees is a short reach, and not necessarily undesirable for those who prefer a more relaxed upright ride at some expense to efficiency, while an angle of greater than 90 degrees is a long reach, but again not necessarily undesirable for someone wanting an aerodynamic position at some expense to comfort.

I'd be interested in how others think this compares to the stem in line with front hub and forwarm from saddle to bars methods in terms of consistency and reliability. Colin has modestly cropped his head and shoulders from the images earlier, but if his shoulders are where I think they are he seems to fit this rule rather well...
Colin 90 degrees.JPG

Mark1978
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Re: Fit question stretched out on the hoods

Postby Mark1978 » 17 Mar 2013, 11:38am

Some interesting points. I'm uncertain at this point to go for the higher angle as suggested or simply a shorter reach with the same angle.

Of course ideally I would try both back to back but as they are £40 each that's expensive!

Malaconotus
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Re: Fit question stretched out on the hoods

Postby Malaconotus » 17 Mar 2013, 11:46am

Mark1978 wrote:Some interesting points. I'm uncertain at this point to go for the higher angle as suggested or simply a shorter reach with the same angle.


A higher angle also means a shorter reach, all other things being equal. I would suggest you get a different angle as that allows for more adjustment over time by altering spacer stack height as well.

Stems are cheap, and there is no harm in having a small collection to give you the fit you are lookign for on every bike. Do bear in mind that the more riding you do the more aerodynamic a position you are likely to want and to be comfortable with.

This bike was originally built up with a 90mm, 17 degree stem....
Image

It now has a 135mm stem with a 6 degree rise, flipped, with a spacer removed. That's over two inches more reach and an inch less stack.

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Mick F
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Re: Fit question stretched out on the hoods

Postby Mick F » 17 Mar 2013, 12:03pm

Mark.
Sorry, not been on the forum much over the past 24/36 hours and this thread is on page3 and I've only just seen it!

Your bike:
Mark's Bike.jpg
Apart from the great advice so far, my immediate thought on seeing the photo is that the saddle is too far back. This may be your reach problem.

As another general rule of thumb, your saddle nose should only be a couple of inches behind the BB. It may be that it's the aspect of the photo, but yours seems too far back .............. for me anyway!
Mick F. Cornwall

Brucey
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Re: Fit question stretched out on the hoods

Postby Brucey » 17 Mar 2013, 12:07pm

seat too far back? I wouldn't leap to that conclusion on the basis of a photo taken with a wide angle lens. The seat angle is actually well over 74 degrees in that frame, and it really doesn't look it in the photo.

Cheers
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Mark1978
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Re: Fit question stretched out on the hoods

Postby Mark1978 » 17 Mar 2013, 12:12pm


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Mick F
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Re: Fit question stretched out on the hoods

Postby Mick F » 17 Mar 2013, 12:15pm

Agree, but if you consider that the brickwork has vertical lines in it, the saddle nose appears 7" behind the BB.

The brickwork line seems in line with the BB, and the saddle nose is not quite one 9" brick along.

I do say "appears". Maybe I'm completely wrong, but maybe Mark could measure to discount my thoughts?

I see there are more photos!
Thank you Mark.
Mick F. Cornwall

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531colin
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Re: Fit question stretched out on the hoods

Postby 531colin » 17 Mar 2013, 12:17pm

This is a shot of me labouring up a rather steep hill....actually riding the thing is probably a better indication than just posing on it leaning against a wall....?

Image

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Mick F
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Re: Fit question stretched out on the hoods

Postby Mick F » 17 Mar 2013, 12:19pm

I see your riding position is the same as mine.
Perfect! :D
Mick F. Cornwall

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531colin
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Re: Fit question stretched out on the hoods

Postby 531colin » 17 Mar 2013, 12:20pm

Saddle setback........

Image