Angle of Knee with fitting
06-17-17 | 11:53 AM
#2
Senior Member
Joined: May 2010
Posts: 4,340
Likes: 496
From: Bristol, R. I.
Bikes: Specialized Secteur, old Peugeot
I think all these rules of thumb are not necessarily based on logic. Just like some of the other fitting relationships, the work for some much of the time. At best, they are a starting point in fitting.
06-17-17 | 12:06 PM
#3
Galveston County Texas
Joined: Nov 2007
Posts: 33,335
Likes: 1,285
From: In The Wind
Bikes: 02 GTO, 2011 Magnum
06-17-17 | 12:40 PM
#4
Senior Member
Joined: Apr 2009
Posts: 39,897
Likes: 3,865
From: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
IMO- there's too much "science" and we've forgotten how to look at the results and fine tune accordingly.
I don't know about 30°, since I've never bothered measuring the angle. I use the very old method of using the "straight leg with the heel on the pedal" method as my basic starting place. Then I observe. My goal is to find the highest saddle position that's low enough that the hips don't rock.
Another consideration is having some room to push back on the saddle, which effectively is the same as raising the seat a bit. I prefer to use this when pushing up steep short climbs and it seems to create some added leverage and power (even if that's an illusion).
In any case, no method will be better than a starting place, because the length of the foot, cleat position, and bend at the ankle all play into things, and are harder to predict.
So IMO- everything is about finding a starting place, then fine tuning based on the rider's perceptions. Any rider with a decent level of experience will get on a bike and after riding for 5 minutes feel that the seat is either too high, too low, or in the right ballpark.
I don't know about 30°, since I've never bothered measuring the angle. I use the very old method of using the "straight leg with the heel on the pedal" method as my basic starting place. Then I observe. My goal is to find the highest saddle position that's low enough that the hips don't rock.
Another consideration is having some room to push back on the saddle, which effectively is the same as raising the seat a bit. I prefer to use this when pushing up steep short climbs and it seems to create some added leverage and power (even if that's an illusion).
In any case, no method will be better than a starting place, because the length of the foot, cleat position, and bend at the ankle all play into things, and are harder to predict.
So IMO- everything is about finding a starting place, then fine tuning based on the rider's perceptions. Any rider with a decent level of experience will get on a bike and after riding for 5 minutes feel that the seat is either too high, too low, or in the right ballpark.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
06-17-17 | 02:12 PM
#5
Senior Member
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From: CID
Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers), All-City Space Horse (hers)
