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Copied this from a BikeRadar article:
How to measure your own sit bones
Of course the measure you really want is between the centres of your ischial tuberosities – the pointy lower parts of your pelvic bone on either side. Many bike dealers have a pad that you can sit on to measure this distance, but you can do it at home too.
Take a piece of aluminium ...
34
For a standard bike in normal use you should not, from the seat, be able to touch the ground (without leaning, or except, perhaps, on extreme tip-toe).
A standard diamond frame (with horizontal top bar), for road use, should be sized so that you can stand flat-footed over the top bar with a "comfortable" margin (but no more) between the bar and the stuff ...
23
ANSWER The "frame size" is no longer a physical measurement on the bike. Instead its a "virtual" distance.
Remember traditional horizontal top tube frames? These have been "normal" for decades, and were still prevalent in the `90s
from https://fitrecovery.wordpress.com/2013/12/07/compact-sloped-or-traditional-horizontal-top-...
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None of the above techniques worked for me. I made no impression on the corrugated cardboard and the foil just showed a nice big bum-print after sitting a few different surfaces. I came up with my own technique that's a bit more trial and error but seemed to work for me.
I got two small erasers, put them on a chair, sat on them and moved them around until ...
20
If this is your first bike, go to your local bike store and have them fit you professionally. Then, ask if they have loaner bikes so that you can get a feel for the size of the bike before you invest. Some people prefer bikes on the smaller side and some prefer them a bit larger. You'll get a definite feel for this over time, but I wouldn't recommend ...
19
To complement Neil Fein's answer, the rider's position is almost entirely controlled (given a particular rider) by the geometry of the bike.
Compare the following bikes. In the first image of a hybrid bike, the saddle is slightly below the handlebars. In the second image depicting a road racing bike, the saddle is well above it, forcing the rider to lean ...
17
I know this is an old thread but it's the top one on Google and I found it helpful. I tried all the methods above and I didn't have a lot of luck so I wanted to share what I tried.
I made some playdough using the first no cook recipe I found on Google (it was fun and doesn't take long). I then put it between two pieces of cling film and pressed it to about ...
17
Rivendell bikes argues that most road bikes sold are too small. They're probably in the minority opinion as far as bike shops go, but they have (collectively) a lot of experience in frame geometry and riding styles.
Their argument is based on their belief that most shops assume that road riders should emulate racers -- experts who are willing to put up ...
17
This is why people recommend not going to Halfords. (For the benefit of people outside the UK, Halfords is primarily a car accessory shop, which also sells bikes).
If you go to a proper bike shop, the staff will insist on fitting the bike to your properly, rather than coming up with excuses not to. They'll also let you take the bike on a proper test ride, ...
16
A bike fit is not intended to make any position you can adopt on your bike work.
If the bike fitter did their job correctly, then would have set you up for your current level of flexibility, strength and desired riding style. You say you are 'very comfortable', presumably in the position you ride in most of the time, so the bike fit should be good.
If you ...
15
If your grandson is that young, he's likely to have trouble keeping up with you no matter what bike he's riding. It may be that it's your expectations, not his bike, that should be modified.
It seems really unlikely that you could retrofit a derailleur onto his current bike. A frame that small won't have room for a wider rear-wheel assembly. Mounting rim ...
14
Almost all road bikes have your torso leaning forward to some degree, meaning you have to hold your head up constantly. If you've never ridden a true road bike before, you've probably never had to do that. What's the longest ride you've done on a road bike before this two-hour ride?
Since you didn't mention your hands or arms hurting, you're probably not ...
13
I would strongly advise against that. Your legs are not going to be the problem, and neither is your overall conditioning/strength.
If you are going to be around other riders, you need to be able to stop and start and steer safely. Road bikes steer with your butt while MTB steer with handlebars. This is a big deal when you are tired and running on ...
13
Often, I get on my bike and things feel a little off. I put it down to varying fatigue, stiffness, amount of sleep, mood, stress or a hundred other things. I then try to get get warmed up, then concentrate on good technique and having fun, or, if I really am feeling off, cruising along for a bit then getting a coffee.
It sounds like you have trained ...
13
The thing about bike fit is that it's almost exclusively about relating your body position to the mechanical parts of the bike. The relationship between handlebar, saddle and pedals is unaffected by changing the wheels.
If you make a change to one wheel diameter it will be equivalent to the tiniest of slopes. Let's take a worst case: Say you go from 35mm ...
12
Try stopping with one foot down, leaning the bike over and leaving your dominant leg on the pedal with the pedal forward and up ready for a power stroke. By leaning the bike over you can get lots of clearance. I can often even remain on the saddle.
When you're ready to go, push off with your non-dominant leg (which is touching the ground) and give a strong ...
12
Is he extremely short? An 8-year-old is almost 9 years old, and: "26 inch mountain bikes are suited for kids that are 9-13 years old." Don't fix up the 12 incher. Head into a local bike shop and get a proper sizing.
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Frame fit
Primarily, a bike fits if you can position pedals, saddle and handlebars relative to each other so that they match your body's proportions. Secondarily, when these contact have been set, other frame parameters should fall into place so that the riding characteristics are as desired. That includes e.g. toe clip overlap, stand over height, bottom ...
11
There are some compelling reasons for filling vehicle tires with pure nitrogen in performance situations, but for bike tires it's just snake oil. There aren't substantial enough temperature fluctuations in a bike tire to justify the pressure consistency argument.
It's also worth noting that the air you breathe and fill your tires with is more than three-...
11
Yes. However, it varies by type of riding and conditions. All Mountain is probably the extreme example of this (and the main market for dropper seatposts). All Mountain bikes are designed to be able to climb and for that generally one would want the seat in a "high" position to be efficient. During a technical descent, however, the seat is generally ...
11
The issue with having brake levers which have travel that ends very close to the bars is that, as the brake pads wear down, the brake levers will hit the handlebars before the brakes are fully engaged.
This can be mitigated by regularly inspecting your brake pads and adjusting the brakes to compensate for normal pad wear. You could have them that close if ...
10
I've used this method which worked well:
Fill a large size ziploc bag with icing sugar. Icing sugar's fine texture means that it binds together when compressed. This is what we want - it will hold the shape of your buttprint after you get up.
Close the bag making sure to squeeze out the air.
Place on hard chair.
Sit while assuming the degree of forward ...
10
Short answer: probably. As long as the stem and handlebars are metal, or composite that can handle the stress of the reversed position you're not going to have mechanical problems.
Long answer: Unless you are riding with your hands off the handlebars what matters is the position of your hands relative to the steering axis. As long as your hands are a ...
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There are several advantages, most of which apply only marginally to bicycles. A nitrogen seller lists all of them, other sites list pros and cons. The key thing is that it's not about adding nitrogen so much as reducing oxygen, water and other gases.
Nitrogen molecules are larger than water, oxygen and most others, so they percolate through tyres more ...
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Typically your feet should not be able to touch the ground flat when you're on the seat - it is a sign that your seat is too low (you may be able to touch the ground with your toes depending on your shoe size - I wear US 13 and this is possible for me). See this link for some guidelines, but typically you get a good starting position either by experience or ...
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I disagree with the selected answer as most of the provided links are simply opinion without any analytical backing.
In terms of choosing a crank length on the basis of performance, there is very little scientific support for there being any real discernible differences widely used crank lengths (160-180 mm).
For an overview of some of the scientific ...
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Here's a link to a video that may help you:
In this technique all you need is a piece of corrugated cardboard and some chalk.
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Yes. I do this on most of my bikes so I can do a quick fit for a friend when needed and to broaden the appeal for resale. Just make sure to snug up the compression like normal prior to tightening the stem and you will be good.
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There does not seem to be a universal standard for bike sizing. Due to the variety of designs and geometry size will vary between manufacturers and intended use, touring, racing, commuting are all slightly different. You often hear about the importance of fit and it's relation to performance and comfort and this is where a good relationship with your LBS is ...
9
A couple of things to tide you over:
Obviously, put the seat down as far as you can. If the post can't go any lower, you might see if you can get a shorter post, or have the current post "chopped" to a shorter length (although that will probably cost you).
Move the seat as far forward as possible. To do this, you loosen the seat from the post using a hex-...
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