When the size charts don’t work?

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k5evr

New Member
Interested in getting a bike for casual riding. Went to Dicks sporting goods and they set me on a 18 frame that agreed with the sizing charts. Straddling the bike the top bar had about an inch play. When sitting on the seat my feet was on tip toes. On the bike when the pedal was at the top of the stroke it was quite uncomfortable. I felt cramped. It has been over thirty years since I have been on a bike perhaps I need to adjust to a new feel. The bike I was on was a mountain bike..any suggestions would help…
 
Straddle height sounds fine to me, so the bike size is in the right ballpark at least.

My guess is that the saddle is set MUCH too low. It's a common misconception that your feet must touch the ground when in the saddle. The result of this, is that when you pedal, your knees come up too high, leading to the cramped and uncomfortable riding position you describe.

Ideally, when the pedal is at the bottom of its stroke, you want your leg to be straight, but not fully extended, while at the top of the stroke you want the knee to be bent, but not too much. You'll know when it's right, because everything just feels comfortable.

So, how to set the saddle height...

Get on the bike and support yourself against a wall / with a chair. Set the pedal on the opposite side to the bottom of its stroke and put your heel on it. If your leg isn't straight, raise the height of the saddle. Repeat as necessary. You don't want to feel that you are stretching your leg though. This method will give you a height that's approximately right for you. You may get lucky and hit the sweet spot right away, but often there will be minor tweaking required. So you might want to pop an allen key in your pocket so you can effect the changes while out and about.
 

cyberknight

As long as I breathe, I attack.
Straddle height sounds fine to me, so the bike size is in the right ballpark at least.

My guess is that the saddle is set MUCH too low. It's a common misconception that your feet must touch the ground when in the saddle. The result of this, is that when you pedal, your knees come up too high, leading to the cramped and uncomfortable riding position you describe.

Ideally, when the pedal is at the bottom of its stroke, you want your leg to be straight, but not fully extended, while at the top of the stroke you want the knee to be bent, but not too much. You'll know when it's right, because everything just feels comfortable.

So, how to set the saddle height...

Get on the bike and support yourself against a wall / with a chair. Set the pedal on the opposite side to the bottom of its stroke and put your heel on it. If your leg isn't straight, raise the height of the saddle. Repeat as necessary. You don't want to feel that you are stretching your leg though. This method will give you a height that's approximately right for you. You may get lucky and hit the sweet spot right away, but often there will be minor tweaking required. So you might want to pop an allen key in your pocket so you can effect the changes while out and about.

what they said :smile: I have to slide off the saddle to touch the floor
https://bike.bikegremlin.com/360/setting-up-riding-position-bike-fitting/
 

sevenfourate

Devotee of OCD
I don’t confirm to any mainstream charts (6’2” tall; but apparently long in the Torso compared to my leg [32”] for my height) for bike sizing…..

Means I basically; normally come down a (Suggested) frame size, then have slightly higher seat, and slightly longer reach than the text-book might suggest.

Anyway - what’s ‘normal’ ? If it were me I’d purchase from a cycle shop - with knowledgeable Staff - who’ll do you a ‘Bike fit’ and save you lots of pain and hassle down the line.

Good luck.
 
1" of top tube clearance is for traditional road bikes. If the top tube is slopes you you have a couple more inches. Mountain bikes are usually designed with about 6" of clearance.
Once you have sufficient TT clearance the more critical dimension is horizontal reach. There is no rule but it should be comfortable for you and avoid locked elbows. A 45degree back angle is used by many everyday non performance riders. Racers go much lower. Ice-cream eating cruiser riders go more upright.
You set saddle height so you can connect heels on the pedsl with a very slight bend at the knee. You ride with the ball of the foot not the heel on the pedal.
 

roubaixtuesday

self serving virtue signaller
Now I like to be able to be on top toes when on the saddle, so quite often go a frame size to achieve it .

Genuine question: how does frame size help that? If you set saddle height to get your leg in the right position at the bottom of the stroke, then the only dimension relevant to getting your toes on the ground is bottom bracket clearance? And that's independent of frame size?
 

biggs682

Touch it up and ride it
Location
Northamptonshire
Genuine question: how does frame size help that? If you set saddle height to get your leg in the right position at the bottom of the stroke, then the only dimension relevant to getting your toes on the ground is bottom bracket clearance? And that's independent of frame size?
I understand what you are saying but as I stated before it's always worked for me in 40 + years of cycling .
 

Jody

Stubborn git
The bike I was on was a mountain bike..any suggestions would help…

You want room to move a MTB frame beneath you and you shouldn't be able to touch the floor sitting on the saddle stationary. You especially don't want a frame that feels stretched.

I'd prefer a frame slightly to small if anything.

How tall are you, inside leg measurement etc?
 

Alex321

Veteran
Location
South Wales
Genuine question: how does frame size help that? If you set saddle height to get your leg in the right position at the bottom of the stroke, then the only dimension relevant to getting your toes on the ground is bottom bracket clearance? And that's independent of frame size?

If he can get both feet (even just toes) non the ground while on the saddle, then he won't have the saddle set at the optimum height for pedalling efficiency.

But if it what works for him, then that is fine.
 
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