Thursday, April 19, 2018

Stem Angles and Steerer Tube Spacers

Part A: Stem Angle and Bar Height Change

By playing around with stem angle, we could achieve the ideal handlebar height in situations where:

  • The steerer tube was cut too short and there's no possibility to increase handlebar height using spacers.
  • The frame Stack is too tall and we couldn't lower the handlebar height enough.

If you're interested in knowing how much difference in handlebar height when a stem is flipped upside-down, or when swapping with a different angle stem, here's a reference guide for you:

Quick explanation on how to read the chart above:

i) Stem Flipping:

With a 80mm & 6 degree stem in the negative position (slanting down), we will get a 17mm increase in handlebar bar height when flipping the stem to positive position (slanting up). 

ii) Changing Stem Angle:

When we change a 100mm 6 degree stem to a 100mm 17 degree stem (both in negative position) the handlebar height is lowered by 17mm.

Part B: Measuring Steerer Tube Spacers

Sometimes i noticed many would make a mistake by not including the headset cover thickness when mentioning steerer tube spacer height.

As there is no common headset cover thickness, although bike manufacturers usually include a 15mm tall cover with frames, but we do get the occasional 10mm, 20mm or even 25mm cover being installed.

If we solely mention the steerer tube spacers without including headset cover, the handlebar height can be very much in the wrong position when we transfer the fit numbers onto a different frame, and this would cause upper body strain.

Here's a diagram showing the correct measurement for steerer tube spacer height:

Alrighty, that's all for now folks, hopefully the info is useful to you and wish you all a great cycling experience out there!

Feel free to contact me if you are interested in my bike fitting services:

Chuah +6012-232-4868 

One-Click Direct Watsapp:

Monday, February 5, 2018

Introducing BioMatch Bike Fit System 3-day Course

Good day to all!

The focus of this course is to equip students with fundamental knowledge and skill-set to conduct bike fits by truly understanding both “form” and “function” fit methods. Form-based fitting being the most common bike fitting method, they provide fitters with a set of statistical range to setup body posture, some of them are as follows: • Bodily measurements are keyed into formulas to estimate fit dimensions (stem length, saddle height, etc). A famous example is Lemond’s method of: inseam length x 0.883 = saddle height from bottom bracket. • Angle-based fitting with static measurement using goniometer, or dynamic measurements with computer assistance (i.e. Retul, etc). Function-based fitting focuses more on providing personalized fit to customers, and not forcing them to adhere to a form of posture governed by statistical measurements. This method requires students to: • Truly understand that a cyclist’s posture is influenced by connection between gravity, cyclist’s physical capability and body weight distribution across the bicycle. • Identify unnecessary muscle strain on upper body (i.e. core or abs) that do not contribute to pedaling efforts, and introduce Posture Reset as correction steps. Posture Reset is a systematic guide to recondition muscle memory and redistribute body weight across the body more effectively when cycling. • Analyze possible causes of discomfort from customer’s feedback, and to differentiate whether the cause is from fit settings or from pedaling habits. Course Outline Day-1: • Form-based fitting theory and practical. • Foot-to-pedal interface (cleat positioning, discomfort remedy, etc). • Every students conduct a fit on fellow student with form-based methods. Day-2: • Function-based fitting and Posture Reset theory and practical. • Every student continues their fit on fellow student using newly learned methods. • Course trainer fine-tunes fits conducted earlier, allowing students to experience a personalized fit and able to distinguish the feel of a good fit from a bad one. Day-3: • Discussion on possible issues encountered as a practicing fitter. Topics include customer’s expectations, less-common physical condition, odd-ball cases, etc. • Establish an easy reference guide based on outcome from previous day’s fits. • Measure & record fitment in universal format that fitters and mechanics understand. • Frame size recommendation and fitment transfer onto different frames by manipulating Stack, Reach, Saddle Clamp Setback and Seat-tube Angle.

The price for the course is RM3800 (Malaysian currency) and held in my Little Rock BikeFit Studio location in KL. Arrangements can be made to hold courses in bike shops, sport centers or even lecture halls.

Feel free to contact me if you are interested in this course:

Chuah +6012-232-4868 

One-Click Direct Watsapp: