blcknspo0ln

I ran across an article here on BF (click the PDF link, https://cobbcycling.com/positioning.cfm), that says the length of the back of my elbow to the tip of my middle finger should be the same distance from the front of my saddle to the center of my handle bar. What truth is there in this to a fit? Or is specific only to cobb seats?

Numbers-wise, that would be me moving from my existing 20.5" all the way to 18". Even with my slamming my seat all the way forward, I would still be 19" away. 2.5" is a huge adjustment, if this way of fitting is correct

mmmdonuts

Only for some people.

sosojeffcc

TT setup perhaps

antmeeks

Maybe to the top of your steering tube, but I can't see going all the way to the center of the handlebar... way too crammed I would think.

MikeyBoyAz

This ? [only rational reason unless you need numb hands]

tagaproject6

You can use it as a starting point. You have to start somewhere right? Then adjust according to your comfort. That type of measurement may have stemmed from the golden ratio mentality.

Campag4life

I started a saddle tip to handlebar center thread a short while back and documented a number of pro's relative to how tall they are and also with reference to saddle height.
Suffice to say that my reach is easily on average 25mm or so short of an average six foot tall pro and yet the tip of my middle finger reachs to 'less than' the middle of my 110mm or stem...way short of the handlebar center. To me of all road bike fit conventions out there...like the handlebar blocking the front hub, KOPS etc, this particular convention which I have seen before is the most inaccurate. There is no way I could ride that cramped and again pros my size ride more stretched out than I do....some by as much as 2 inches.
OP, if interested, measure your forearm to tip and look up my thread for your size to see the amount of reach pros ride.

IK_biker

Ignore it.
Another old wives' tale.
Fitters used to recommend this in days of yore.

I recall it being regarded as a valid advice in Europe in the mid-60s - when the world was a much smaller and ignorant place.

big chainring 

Works for me. Been using that measurement technique for 40 years.

datlas 

I agree this is another fitter's old wives' tale.

It might get you in the neighborhood but it's not very helpful IMO.

Awhile ago I started a thread that listed lots of these "rules of thumb" that folks have used, I will see if I can dig it up and post a link...for your reading pleasure...

link:https://www.bikeforums.net/showthread...les?highlight=

Brian Ratliff

Probably not a bad place to start. It's not like a binding law or anything. Like knee-over-pedal-spindle (kops), it's just a rule of thumb to get you in the ballpark.

I should add, if you are already in the ballpark, google maps won't help you find home plate.

lazerzxr

That fit "rule" is worthless. Completely worthless. I dont know how it ever got to "rule" status

fstshrk

For me, this would result in bringing my saddle about 4cm closer to the handlebar and probably cause intense back pain in the process. I guess my forearms are short or something.

blcknspo0ln

Man, so much information (and misinformation) on the subject. I've been screwing around with my bike fit for the past 2 years to try and remedy my constant lower back pain to no avail. I know a pro bike fit is in order, but even the inconsistency on bike fit results has my head spinning in circles.

Thanks guys!

Rimmer

My finger barely gets past the head tube.

StanSeven

Yep. I went to the site and looked at the pdf download. The setup diagram is a tt/tri bike. That makes more sense then.

gregf83 

I have a relatively long torso and short legs. I have the seat back as far as possible and I still have more pressure than I'd like on my hands. With my elbow on the seat my fingertips just cover the head tube.

Not even close for me.

fstshrk

I was in the same boat as you then I got a fit by a BG Fit Master Certified fitter. It was night and day for me. I would think either BG Fit or Retul would be a good option. Although the Retul fitter in my area
pretty much works only with tri/TT people and not as much roadies.

Brian Ratliff

Just tried mine. My fingers just make it barely past the head tube as well. So I guess not a really good rule for a road bike.

Reynolds 

For most people this is way too short.

Campag4life

Cobb is a knowledgable fitter and can't believe he would espouse the arm length method for a roadie so makes sense it is for a TT bike which are typically sized much shorter in cockpit...TT top tubes sized 1-2 frame sizes less than road bikes along with shorter head tube.

Sounds as though most of us that have weighed in have our middle finger just past the front edge of the head tube...which is how I measure as well.

badger1

As said above, I think this 'rule' must be for t/t set-up. However, I believe (no comment on its validity) this is a variation on a 'rule' I've come across many times in older set-up guides: for road bikes, it's the same but one also places one's other hand horizontally across the front of the outstretched first hand (if that makes sense), touching index finger of outstretched hand/arm to middle of first finger on other hand. Middle of bar/stem should fall under little finger of second hand. So the 'measurement' adds the width of the rider's hand to the first measurement.
Sorry ... not clear, but that's the gist.

Campag4life

Very clear in fact. We have a winner. Good catch badger. I am reminded of my dwindling memory. You are absolutely right and now in fact the convention works perfectly for me. Just tried it on my roadie and handlebar clamp center is right under my little finger.
Thanks for the clarification.

unterhausen

once you know where you like your bars, using your arm/fingers is just as good as a ruler. As a fitting method, it doesn't really tell you anything

wkg

i never really thought anything of this "method" until cyclingtipsblog put it in his april fool's day post.