DIY bike fit

In spite of the best attempts of cycling manufacturers there is no one size or even more accurately four sizes, fits all*.  Manufacturers size their bikes and even their individual models differently.  For example, I find Liv bikes don’t work for me but they suit many other women.  I have always, with one exception, found that Specialized bikes fit me really well.  I find Carrera bikes, at Halfords, fit surprisingly well also, but Basso frames have to long top tubes.

Riding is a lot about confidence; road confidence to hold your line and your road position in traffic, confidence in bike handling and how your particular machine behaves in different circumstances (terrain, weather, etc.), and confidence in your own abilities which can only come through practice, although training and riding with more confident people will help build this.  Confidence in performance comes from training, and that’s a different thing which I’m not going to cover here as it requires very specialist knowledge.

If you are comfortable on your bike, then everything else will be much easier and this will increase your confidence.  You shouldn’t have to be thinking about the machine, your bodies on bike position, and what bits are starting to ache or go numb as you are riding.  Operating the bike itself should become second nature, to sound a bit zen – become one with the bike.  If you are a car driver you will remember when you first started how you thought about each part of the operation, but now you’ve done it for several years you don’t.  Riding a bike should be the same – it should be fluid.

Aches and pains will have a detrimental effect on your concentration, lower your confidence, and can even be dangerous.  But it also stops it being fun and whatever else you get from cycling, it should be fun.

You can of course get a professional bike fit, and if you have the opportunity to do so then why indeed would you not.  But many bike shops charge extra for this, some times running into hundreds of pounds, and that makes it unattractive to those on limited budgets.  Specialist performance bike fitters often charge even more; I’ve seen one company who charge over £250 just to adjust your saddle height and fore/aft position correctly!  If you race, especially with a view to a potential podium finish, then it is (probably) worth it but to us mere mortals who just want to pop down the shops without their fingers going numb or our knees aching then I very much doubt we could justify the expense.

At the moment, with the Covid-19 situation, getting a bike fit is going to be pretty difficult as well.  For one thing, there is the social distancing aspect, and secondly there is the problem of demand.  Fitters within bike shops will also be either mechanics or sales/aftersales people, sometimes in smaller shops they’re both.  With the high bike sale and repair demands being experienced currently, you may find that you simply won’t an appointment.

So what can you do yourself?

Well, for starters you can make sure the bike fits you when you buy it.  If you get on the bike and it doesn’t feel right then walk away.  It doesn’t matter how good the reviews are, what sort of bargain price you can get it at, or even if it’s been suggested that this is the ‘best’ bike for you, if it feels wrong when you first get on then it will stay wrong.  At least that’s how I have found it.

Trust your instincts, even as a novice.  I have now got that I can swing my leg over a bike and say ‘yay’ or ‘nay’ the moment I get into riding position, without any adjustments.  Try enough bikes and you’ll start to form your own ‘feel’ for what works for you.  I would really encourage you to try as many bikes as you can before you part with your cash too.  Don’t be persuaded by the scarcity of bikes at the moment, it won’t make the wrong bike fit any better and it might stop you cycling in the long term.

I would also recommend buying your bike from a shop where you will get a degree of fitting included, and where you will get decent after sales service and back-up.  Buying any bike online, with only a few measurements or a frame size to go with, is just asking for trouble.  The money you save in that purchase could well be spent later, alongside a whole lot more, trying to fit it to suit you.

Bike fit is about refining, not rebuilding.  It is important to remember this.  I had a Specialized bike I bought second hand that I was determine to make fit me.  I had a choice of two at the time of purchase, one slightly smaller in frame that I needed but with better equipment.  What I did was buy that and then try and make it fit me.  What I should have done is bought the one that fitted, and then uprated the equipment to suit.

No matter what I did with it, it was never ‘right’ and I sold it (at a fairly significant overall loss).  Here is a lesson at my expense you can learn from.  I actually thought that I would never ride a road bike again after this.  I was so sure my body wasn’t suited to road bikes, when the truth of the matter was that by body actually wasn’t suited to that bike.

Since then I have tried a lot of bikes.  I tried different makes, different shapes, and different sizes.  When I found the right one I knew it instantly:  I got on and thought ‘yes, this is the one’.  It wasn’t anything I had imagined buying, it wasn’t what I went out for, and I hadn’t read a single review.  I knew enough from the ones I had looked at, that the bike was good enough specification for what I needed, in fact it probably over specified for me.  But that is rarely a bad thing.

With Tuesday, as she is called, I just knew it was going it to work for me from the test ride (around the large nearby empty yard several times), before I handed over my cash.

I rode it home, in the wet, straight from the shop.  I really wanted to get on it.  I wouldn’t have attempted that on any other bike I tried.  I didn’t even ride my Brompton home from the shop.  I put it in the car and drove it home.  How stupid is that?  I wanted to try the Brompton out on my local familiar roads.  I didn’t have a clue where the route home was from the shop Tuesday was in, and I didn’t care.  I would find it, Edinburgh isn’t that big.

I grinned the whole way home:  In spite of the rain, and not being able to see where I was going properly in my non-cycling glasses.  In spite of having wet legs and soggy trousers, because I really had gone out ‘just looking’.  In spite of having got a bit lost on the cycle paths because I was in a new part of town to me.  I arrived like the Cheshire Cat!  My partner thought it hilarious that this drowned rat was bouncing off the walls with joy.

My knees weren’t too happy but I knew that I could cure this by just putting the saddle up.  If your knees ache to the front (especially just behind the knee cap) then your saddle is too low and/or too far forward, if your knees hurt at the back then most likely the saddle is too far back, but it could also be too high.  It is rare for people to make their saddle too high, but it’s very common for them to be too low.  I would have stopped and adjusted it up on the way home, had I had the tools on me.  To be honest, I was lucky to even have a waterproof so unprepared for this delight was I.

You can see plenty of YouTube videos on correct saddle position, and there are some excellent illustrations in many bike books as well.

I am especially fond of this book:


Once the saddle was the right height I went for another ride of around 8 miles.  Then I moved the saddle up another 1/4″.  Then I went for another ride.  Perfect.  During these rides I always wore the same clothes so there were no other variables in play and always went the same route or at least part route.  Most importantly I kept the same footwear so my inside leg length didn’t change.  When I then changed to SPD pedals and cleated shoes I had go though the process again.  Ride, move the saddle up, test, move saddle again, test.  Changing pedals and shoes changed the dynamics and my saddle is now 1/2″ higher and 5mm back.  Don’t ask me why the seat post appears marked in quarter inches and the saddle rail is marked in mm, I just don’t know.

With the saddle correctly placed I then moved on to the handle bars.  I felt a little stretched and so flipped the stem so it created a higher placement.  As it is a 12degree stem I went from -8 to +12.  (It was -12 tilted down but fitted with a +4 shim)

I then went for a ride, again in the same clothes and the same route.  That felt better but still not right, so I changed the angle of the bars, tried again, got even worse numbness in my hands and so put the angle back where there had been at the start.  The problem does not arise until I’ve covered at least 6 miles, and this is important as you’ll see later.

It was also not being solved by moving the existing parts, so I did the recommended stem size test of looking at the hub of the front wheel from the correct ride position:  If you can see the hub in front of the bars, the stem is too short, and conversely if the hub is visible behind the bars then the stem is too long.  My stem was just behind my bars by around 10mm.  So I ordered the next shortest stem, which would be a 75mm instead of the 90mm that was fitted.  I ordered the same angle because I was pretty sure that wasn’t the problem, but just the next size down (15mm shorter).  I ordered a direct replacement from the same manufacturer and of the same (although newer) design, as I wanted to keep it as true to the original specification as possible as this point.  Others will think about weight advantages and so forth when swapping out parts but this is beyond my tweaking desires at the moment.

If possible I would encourage you to try a few, by borrowing them, where you can.  If you want to change your saddle, stem, and even pedals, see if you can borrow from friends or your local cycle shop.  This is where a relationship with your local shops is really a godsend and another reason why I encourage people to shop locally wherever possible for their bikes and parts.  They may well have ones they’ve taken off bikes that you can try for fit, even if you end up buying a different make it will give you the angles and length experience. (Sounds a bit rude that).

The contact points are the most important bits on the bike for comfort, so after getting the frame right which is something that you can’t change without changing the bike, your contact positions, and the rider position they create, are what makes the bike ‘fit’ you.  Your contact points will also influence your comfort – comfortable shoes, well fitting gloves and/or bar tape, and a well fitting and comfortable saddle will all enhance your ride experience no end, but only if the bike fits.

Your leg position at all parts of the stroke is very important for efficiency and preventing discomfort, and even injury.  After that your hands and arm position are important; if you get numb hands then you are putting too much weight through them.  This can be alleviated by getting the saddle height to bar height ratio correct for you, getting the right forward reach, and putting the right amount of weight through your arse and not your hands.  The position will make a huge difference, but so will using your core muscles.

Why do you think those racing snakes who look really comfortable for hundreds of miles have six packs for stomachs?  It’s because they constantly use their core muscles.  You can get a flatter stomach with cycling!  Mine is under a generous tyre of fat right now, but I’m working it, and because my position is now correct, I can actually feel my core working (and my hands don’t go numb anywhere near as much).  The six pack may arrive in time for my 55th Birthday and that would be no mean feat.

I always think with fitting a bike that it’s a lot about little tweaks – get the fundamentals right and then make little adjustments, even just a few mm can make a big difference, much bigger than I had imagined.   Adjusting one bit can also cause another bit to require adjusting, like when I changed the pedals and started with cleated shoes.  I never imagined I’d have to raise the saddle by 1/2″, but I went through the fit again and it did.  So even if you do pay for a professional bike fit, that isn’t going to be the end of it.  Change a contact point and you’ll have to make an adjustment, so you might as well learn to do some of it yourself anyway.

You also need to remember that our bodies change.  We might put on and loose weight, we are also not getting any younger and what was a comfortable position at 30 probably wont be at 40 and definitely not by 50.  It’s called wear and tear, and it affects us all.  I am 1/2″ shorter at 50 than I was at 30.  I have osteoporosis in my neck, which means I can’t be as aerodynamic, but I also like to look around in traffic so I like being more upright whilst cycling in the city anyway.  I have a dodgy shoulder from a climbing accident back in 2004/5 (it was New Years Eve so the date is totally accurate).  My stomach muscles have been sliced down the middle with surgery and so my core is always going to be weaker.  These are changes that have taken place over the last 20 years, and I will continue to change and so will my needs for fitting my bike to me.

Our clothes change too.  New shoes might mean a different inside leg measurement and therefore saddle height.  Thicker winter tights instead of shorts might raise you up a couple of mm and you can feel a couple of mm surprisingly.  At least my ancient knees can.  I can feel 2degrees in the stem angle – I went from having a +12 with a +4 shim to a +12 with a +2 shim.  When you buy a new stem you get three shims – 0 degrees, +2/-2, and +4/–4.  They include these because we can feel that slightest of difference.

Even changing the tyres will change the bikes handling and, if very different such as moving to a more ‘gravel’ or commuting tyre from racing slicks, it could alter the height very, very, marginally.  I even once met someone who couldn’t work out why his saddle was now a fraction higher off the ground (although still in the right place for his legs), and it turned out he’d bought a track pump…

Tweaking lets you get to know your bike.  It is something we should all be able to do, and if I can learn how to do the basics I am sure you can too.  Take your time, make small changes at first, test, change, and retest as required.  I really don’t think you can make an assessment from a trip around the block either, you need a few miles to settle in and then find the niggles.  This is why I am never surprised when people say they’ve had a bike fit and it’s still not right – how long did you spend riding and were you going outside on the actual road for test rides or were you entirely on a trainer?  I need six miles to fully settle onto the bike and start to feel what is wrong or right, better or worse, when I’ve made any adjustment unless it’s a really big one.

I am an ex-runner – and running on a treadmill is very different from running outside.  I can’t see how riding on a trainer can be the same as riding on a road.  A road, for a start, has a camber and you can encounter different surfaces over a short distance.  Suppose you get comfortable on the tarmac but then spend all your time riding gravel?  I can easily stretch out more on a trainer than I am comfortable with on the road.  Maybe that’s just old age?  Who knows.

So, with all these things in mind get ready to do your own DIY bike fit, because even the professional fitters are not there with you all the time, or even just 30 miles down the road in a pair of new shoes!

*the exception to this is a Brompton, with it’s multi adjustable seat and semi-upright position which three choices of handle bars.


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