Smaller Cranks and Fitting Chainsets

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ANTONISH
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Re: Smaller Cranks and Fitting Chainsets

Postby ANTONISH » 5 Apr 2016, 8:49am

We've had this topic before.
I'm 5'5" and I experimented with 165mm cranks - I gave up after a year - I prefer 170mm.
I'm 74 and I don't suffer from knee problems. There are examples of much shorter people using standard or overlength cranks. The diminutive Jean Robic had a long and successful professional career during which he used 180mm cranks. The late Dave Bedwell used something like 160mm for most of his career but used 170mm at the end.

IMO there are a lot of factors involved in pedalling of which crank length is not necessarily the most important - except that it may feel better for you personally.
There is a lot of good advice here about setting the correct saddle height - that and kops gives you a good approximation for your saddle position.
The shoe pedal combination can also be important - ideally the ball of your foot should be as close to the spindle as possible.

Vorpal
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Re: Smaller Cranks and Fitting Chainsets

Postby Vorpal » 5 Apr 2016, 8:55am

ANTONISH wrote: ideally the ball of your foot should be as close to the spindle as possible.

That might be true for efficiency, but not everyone is comfortable like that.
“In some ways, it is easier to be a dissident, for then one is without responsibility.”
― Nelson Mandela, Long Walk to Freedom

TraceyW
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Re: Smaller Cranks and Fitting Chainsets

Postby TraceyW » 5 Apr 2016, 4:56pm

Hi guys

Well I've had an assessment of my riding position by a family run business in town and was told pretty much what I was told back when I was a kid, i.e. that I should be able to touch the ground with my toes and the very first part of the ball of the foot without having to make any effort to reach down with my foot. This is pretty much the same as is stated in the book I have (Bike Maintenance and Repair for Dummies). Believe me guys, I've done my best to go along with what everyone has suggested but nothing seems to have worked particularly the document that Colin pointed me to - that seems to be for those of the racing fraternity whilst my bike will be used as a tool purely to get fit - more of a commuter bike rather than racing.

As I say I was brought up to ride back in the 50s and 60s when there were no hybrid or mountain bikes. As far as I am aware they were called Tourers. However, that name appears to have a completely different meaning these days. Colin has perhaps had the right idea in that BBs were lower back then and if he is right about crank lengths they were 6.5 inches which equates to 165mm. As a result things would appear to have become higher/longer since I last rode hence the problems I'm having now.

Everyone is different and whilst many are happy with 170mm cranks - and far be it for me to criticise them if they are happy with their bikes - I'm afraid that does not apply to me. As a result I have ordered a 152mm chainset and we'll see how I go with that. Of course the front derailleur will need setting up and I suspect the rear derailleur is not perfectly set up so will check that (or have them checked for me) at the same time.

Thanks very much for all your comments and if I have upset anyone at all with my replies then I really am sorry - believe me I really do appreciate your efforts to help. Perhaps I'll update you all once my new cranks have been fitted and the deraileurs set up. In the meantime thanks very much.

Tracey

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531colin
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Re: Smaller Cranks and Fitting Chainsets

Postby 531colin » 5 Apr 2016, 5:31pm

170-152 = 18
So your top pedal will be 18mm lower with your new cranks, thats about 3/4" in old money.
Your bottom pedal will be 18mm higher, but that will be no use to you as you refuse to raise your saddle.
Its an awful lot of work for 3/4"

TraceyW
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Re: Smaller Cranks and Fitting Chainsets

Postby TraceyW » 5 Apr 2016, 7:35pm

Colin

...but that will be no use to you as you refuse to raise your saddle.


I HAVE raised my saddle but I am most definitely NOT happy with it. I have raised about two to two and a quarter inches - how much further do you want me to raise it? I have done my best to do what others, including yourself, have advised. However, I am definitely NOT happy with it. As it is at the moment it is at a height where I just cannot touch the ground on either side without stretching to do so and I refuse to ride it like that. I'm just not confident enough should I have to stop that I'm not going to fall off into the road. Of course I could also fall the other way but I don't want to take the chance. I just don't consider it safe at the moment and the guy at the cycle shop was in agreement. You set your bike up that way if you like but I'm not happy with it. As I say we're all different and are happy with different ways of setting up our bikes and I want a bike I am comfortable with. I've bent over backwards trying to find a setup suggested by the fellas who have responded but sadly it just hasn't happened. If I had to set up my bike as you want me to set it up I might as well sell it and forget about regaining any element of fitness.

Tracey

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Re: Smaller Cranks and Fitting Chainsets

Postby Vorpal » 5 Apr 2016, 10:23pm

Tracey, check your messages (near the top, next to 'user control panel').
“In some ways, it is easier to be a dissident, for then one is without responsibility.”
― Nelson Mandela, Long Walk to Freedom

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DaveP
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Re: Smaller Cranks and Fitting Chainsets

Postby DaveP » 5 Apr 2016, 11:14pm

Tracy I hope that you will let us know how you get on - I'm sure that we all hope that you can find a solution that works for you, and dome of us are positively intrigued - well I am at any rate!
Raleigh have used the Pioneer name for quite a long time, so I googled a picture of your version. I presume you have a ladies model? With suspension forks and seat post? When making adjustments do try to be consistent in the way you sit on the bike :) Suspension movements can complicate things a bit!
Do your tyres have 622 x something written on them? If so, then there is a good chance that the rim diameter will be about an inch bigger than the wheels you used to, and a high volume hybrid tyre would tent to increase that difference.
As mountain bikes developed, one of the changes from a traditional utility frame was to raise the height of the bottom bracket relative to the wheel hubs. Hybrid bikes take a lot of their design from mountain bikes, including the idea that keeping the pedals and chain wheels away from the rocks is a good thing. Combine that with bigger wheels and you can see why your new bike has different proportions to your old one.
In my opinion this requires a slightly different approach to riding. I find that my knees hurt if asked to bend too far, so I start to set up my bikes by placing a heel on one pedal with the leg slightly bent and adjust the saddle height to suit. This does tend to result in a situation where I cannot place both feet on the ground while in the saddle. When coming to a standstill I either stand on the low pedal, lifting myself out of the saddle and then placing the other foot on the ground just as I stop, or more commonly stretch down with one toe and allow the bike to lean over until I touch down, so that I have one toe on the ground, the other foot still on a pedal and my backside still in the saddle. It might sound a bit scary but with practice... and it avoids getting poked in the back by the saddle nose, which happens to me all too frequently if I step down.
I also tend to set my saddle quite a way back. This makes it easier for me to push with the big muscles in the front of the thigh. if you are too far forward you cant really use them. And when all that is "just so" there is the delicate question of bringing the handlebars to the hands. Its an approach. Its not the only one, and probably not even the best. I just thought you might be interested. :)
Once you have installed your new cranks you will need to start looking at your position from scratch.
You might enjoy looking at this site http://sheldonbrown.com/frame-sizing.html That page might be relevant but do explore. Sheldon was very good at explaining things. He is no longer with us, unfortunately, but the site is being maintained - quite well IMO
Trying to retain enough fitness to grow old disgracefully...

MikeF
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Re: Smaller Cranks and Fitting Chainsets

Postby MikeF » 5 Apr 2016, 11:25pm

I maybe wrong, but it sounds as though after your 30 layoff from cycling you are lacking some confidence in riding a bike; which isn't surprising after that time. Do you have any any off road cycle tracks/shared paths etc with reasonable surfaces where you could ride to regain a bit of "familiarity" with the bike you are using? From your description I agree with others that it sounds as though your saddle is too low, but if you are not confident with raising the height, then there's little point in doing so. However the consequence will be that cycling will be harder, but if it's flattish territory in Essex that may not matter too much.
Hopefully you will gain confidence, and in doing so perhaps be able to raise the saddle a little at a time and see how it goes.

From my observations it seems not unusual for women to ride with saddles that appear to me to be far too low. It looks hard work and I'm curious to know why.
Perhaps one thing that isn't often considered is that women have smaller feet than men and maybe that makes a difference to effective leg length.
"It takes a genius to spot the obvious" - my old physics master

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DaveP
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Re: Smaller Cranks and Fitting Chainsets

Postby DaveP » 5 Apr 2016, 11:35pm

MikeF wrote:From my observations it seems not unusual for women to ride with saddles that appear to me to be far too low. It looks hard work and I'm curious to know why.

Oh there are quite a lot of men do it too, usually the guys who drag their Apollo mountain bike out to go to work in the summer months, frequently pedalling with their instep...
I think you are right, confidence probably is a major factor.
The ones I don't understand are the grown men riding about the streets on Bmx bikes, knees round their ears. Thinking about the state of said knees in ten years time just makes me want to scream inside!
Trying to retain enough fitness to grow old disgracefully...

Samuel D
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Re: Smaller Cranks and Fitting Chainsets

Postby Samuel D » 6 Apr 2016, 12:55am

Inexperienced or infrequent cyclists tend to have their saddle too low. It may be that they like knowing they can easily reach the ground with their feet, even though experienced cyclists know that you can easily reach the ground with a high saddle too, merely by hoping forward off the saddle or leaning to get one foot firmly on the ground. In practice there is nothing scary about a high saddle, though it may seem scary in your head.

Colin does sound a bit grumpy in this thread, but he’s a genuine expert on fitting matters, unlike anyone you’re likely to find in your local bike shop. When you get your new cranks fitted (post again if you have any problems with that), you’d do well to give his document another look.

Also, give your body time to adjust to the demands of cycling. Even in my early thirties I had aches and pains for months when I returned to cycling after a break of a few years. I think that’s not unusual.

Good luck!

ANTONISH
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Re: Smaller Cranks and Fitting Chainsets

Postby ANTONISH » 6 Apr 2016, 9:23am

I must say that I don't agree with your LBS - saddle height should be in relation to the BB - not the ground.
You mention "Cycling for dummies" there are a number of "cycling expert" publications out there which give some very strange advice.
531 Colin's advice is very solid.
I would suggest that if you are going to change your seat height, you only do this in 5mm increments over a period of months - that gives your joints and muscles time to adjust to the new position and helps to avoid some of the problems you are worried about.

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Re: Smaller Cranks and Fitting Chainsets

Postby Samuel D » 6 Apr 2016, 10:11am

If the saddle is more than 2 inches too low, I’m not sure there’s much point in doing at least ten (!) 5 mm adjustments. You may need to grab the bull by the horns and accept the position was all wrong and start again.

If you have ridden much in the past (are confident with balance), you will find that it is much easier to do the necessary manoeuvres to get at least one foot firmly on the ground (e.g. sliding forward off the saddle on the downstroke of the left pedal while placing your right foot on the ground and braking to a halt) than it is to describe them. There is really nothing dangerous about them. It’s just in your head.

And if you start falling for whatever reason, a difference of an inch is highly unlikely to make any difference. You’ll contact the ground with whatever part you’ve extended a few milliseconds sooner with the lower saddle, but to what benefit?

If there was no downside to the low saddle, I might let it slide in the interest of preserving the confidence of someone returning after a 30-year break from cycling, but in the present case her discomfort is probably caused at least partially by the low saddle. It’s worth making a fairly serious effort to get that fixed.

wjhall
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Re: Smaller Cranks and Fitting Chainsets

Postby wjhall » 6 Apr 2016, 11:03am

Being able to put both toes on the ground probably was part of the traditional initial set up for an ordinary bicycle, although the only second millennium books I have to hand only mention putting one toe down. It goes with the traditional geometry compromises for ordinary bicycles, but, as people have pointed out, a lot of widely sold bicycles now use a different compromise. This, as has also often been pointed out, is one of the ways in which what is widely sold in the UK cycle market is less suited to everyday use than it once was.

Out of interest I tested whether I can get both toes on the ground whilst seated on my everyday bicycle, a 1984 tourer. I can just do so, but needed to support myself against a wall to get into that position. This is presumably partly a demonstration that I never normally do this, and also that riding position tends to drift upwards over time, with the experts here having said in the past that you need to try occasionally experimenting with lowering the saddle by a quarter inch to control the tendency to get too high.

However, telling Tracey that she needs to replace the whole bicycle, and that the world has gone to pot, would not really help her find an economical solution to her problem, although it is useful in understanding some of the issues that may exist.

It is normal to start with a lower saddle position whilst gaining confidence and let it drift up as the desire for greater efficiency begins to outweigh the fear of falling off, but I would not expect the initial position to be actually uncomfortable.

WJH

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Re: Smaller Cranks and Fitting Chainsets

Postby Vorpal » 6 Apr 2016, 11:05am

I have sometimes had trainees start with a low saddle. Short term, I don't think it's a problem, and if it gives someone confidence to start (or start again) being able to put a foot down easily, I don't think there is any harm. The OP is going to have to find the best compromise between confidence and comfortable pedalling. It seems likely that she may need some help doing it. A town bike might have been better suited to her situation, but there might be something that can be done with her current bike. It's difficult to know without seeing it.

'Just hop down', is easy to say for someone who has been doing it for 30 years. It's rather intimidating to someone who a) has never had to do that at all before and b) isn't confident riding a bike

I think if you read what the OP has written you will see that she isn't at all confident, and probably needs some help to get started again. It's too bad that the bike shop she went to didn't really give her the assistance she needed.

Please don't put her off trying.
“In some ways, it is easier to be a dissident, for then one is without responsibility.”
― Nelson Mandela, Long Walk to Freedom

TraceyW
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Re: Smaller Cranks and Fitting Chainsets

Postby TraceyW » 6 Apr 2016, 9:10pm

Thanks to all the fellas that have responded since my last message. I needed your input as I was beginning to get quite depressed. I think that between you you have hit the nail on the head in that I am not as confident as I thought I would be.

Some years ago I had a spell of riding motorcycle trials - but its very different to riding a cycle and currently I am somewhat more wobbly on the thing than I really expected. But then after a 30+ year layoff what more can you expect - I should have expected it.

I bought myself a bike and a turbo in an effort to get fit particularly as I have no work to cycle to. At least with the turbo (albeit a cheap one from Amazon) it is giving me the exercise I need. The reason is I had a wake-up call several weeks ago in that whilst putting the bins out I got so out of breath it was unbelieveable and finished up with a pain over the heart. A visit to the doctor resulted in my heart being tested but that is all clear. My doctor has warned that it could be arteries furring up and we have left it that I would get myself active again taking it in easy stages and the turbo allows me to do just that.

Using the turbo, however, doesn't give me experience on the road which is what I really need. I'm already using the bike to go down the shops and the surgery and I'm sincerely hoping that tomorrow I shall be able ride around the village, a distance of around 2.8 miles (but being mighty careful not to overdo it) and hopefully eventually further afield. At present I'm using the turbo for just five minutes per day and already the pain over the heart is not so obvious and neither do I get out of breath so easily. Pretty soon now I intend to start stretching that out and spending longer on it each day. Its a case of taking things in easy stages and just being patient.

Anyway, thanks for your comments guys and I will get back to you once I've sorted out my bike.

Tracey