Man riding a silly small bicycle.

Fit first – buy later

There is a mantra among most bike fitters that is along the lines of ‘fit first, buy later’.  Why do we say that?  Is it because we want to delay the gratification that is a new bike?  No, the real reason is that it is heart breaking to have to inform a client that the fabulous, efficient, comfortable position that we found together won’t work on their shiny new bike.  You know, the one that they have already fallen in love with!  (Not to mention spent a lot of money on.)

Now it’s almost certain that achieving the prescribed position exactly won’t be possible.  Should you be lucky enough to be buying a custom frame then the geometry can be tweaked to ensure the position is millimetre perfect.  Otherwise the limited size runs of production bicycles, the (typically) 10mm increments in stem lengths and the small number of stem angles available means that you will be a few millimetres off.  And that’s ok – for the vast majority such a difference won’t have any material impact on their performance or enjoyment.  But anything more than those few millimetres can start to become a real issue.

I can fit a rider within the constraints of an existing bike.  (In fact I do this more often than not.)  But there is a limit to the range of positions that can be achieved on any given frame.  Extreme stem lengths affect the handling of a bike and moving the saddle too far forward or back messes with the weight distribution but most of the time it works out just fine.  However there is a definite trend in the bike industry that is increasing the difficulty of achieving the desired position: integration.

The problem with integration

Integration has some real benefits for bicycle manufacturers and consumers.  By designing the system as a whole, there is more scope to achieve particular desired outcomes.  A bike can be made more comfortable, more aerodynamic and so forth.  (The fact that the manufacturer has locked the consumer into buying their house brand bars, stems, seat posts etcetera for the life of the bike is just a happy coincidence I’m sure.)  But there is a downside: the ability to achieve an exact fit is in many cases sorely compromised.

Let’s look at two quick examples…

  1. Giant (and its sister brand Liv) makes heavy use of their ‘OverDrive’ fork steerer.  Instead of the standard 1 1/8 inch, the diameter of the fork’s steerer tube is 1 1/4 inches.  This effectively limits customers to Giant’s own stems.  They sell a good range of lengths (60 – 130mm) but only one angle (8 degrees).  Need a steep stem to get low enough?  Is the steerer cut too short to allow a +8 degree stem to achieve your desired handlebar height?  You’re out of luck my friend.
  2. The Synapse is Cannondale’s endurance road bike.  In an effort to increase comfort, Cannondale have used a 25.4mm seat post which is narrower than the more common 27.2mm and 31.6mm posts.  Not many aftermarket brands make 25.4mm seat posts.  No problems… unless you need more or less saddle set-back than can be achieved with the 0-25mm offset posts available.  My go-to option in these cases, the Profile Design Fast Forward or Fast Forward Reversible which have a 38mm offset, don’t come in 25.4mm.  Again you’re out of luck.

In neither of these examples are the bikes in any way ‘bad’ – I’m sure the bikes exhibit the stiffness/comfort that the design choices were mean to achieve.  It’s just those same design choices have reduced the range of positions that can be achieved on a given frame size.  Knowing your optimal position and doing your homework before you hand over your hard earned could save later tears.

Superbikes

Finally we arrive at the ultimate in integrated bicycles: the time trial/triathlon superbike.  In the pursuit of aerodynamic gains, the frame, stem and aerobars are merged together to the exclusion of all after-market options.  The resulting bicycle’s drag numbers tend to be impressive!  They look fast just standing still!!  But here’s the thing: the biggest contributor to wind resistance as you roll down the road is you, the cyclist.  You contribute about 85% to the CdA of the whole system.  Having the most aero bike on the planet won’t mean a thing if you can’t achieve a good position on it.

Superbikes are notoriously limited in how adjustable they are.  They all have some adjustability, to a greater or lesser degree, but there are hard limits as to what can be achieved.  If your position doesn’t fall within the permissible range for the frame size in question then you either have to compromise your position or choose another bike.  If the integrated bar doesn’t allow the extensions to be angled as you like or the pads to be as wide/narrow as you need then get used to it or choose another bike.

Fit first, buy later

In summary, it’s my view that you should always get a bike fit before purchasing a new bicycle.  For a fraction of the purchase price (less than 10% of a relatively modest $3,000 bike) you get the benefit of a fit and confidence that the bike you buy will work for you.  The more integrated the bike is, the more crucial it becomes.

Most bike shops offer some kind of fitting service when you buy a bike from them.  Some do a great job and others, well, not so much.  Even aside from spotty training, equipment and experience, there is a strong motivation for the prescribed fit to match something they stock.  Perhaps even something they have in stock.  Many manfully resist the temptation to shift stock irrespective of how well (or poorly) it fits the rider.  Some don’t.  Me?  I’m Swiss (as in neutral).  I don’t sell bikes.  I’m not aligned with anyone who does sell bikes.  I’m motivated to help you find your very own winning position and give you information you need to buy the right bike for you.  So why not book an appointment now?

But even if not with me then please, for the love of all bike fitters… fit first, buy later!!!

By |2018-10-20T17:15:06+00:00October 20th, 2018|Bike fit|0 Comments