Wednesday, October 16, 2013

Street Machine Gte: is factory gearing low enough?

Me (Robert) at the end of the road at the top of Whiteface Mtn. with my Street Machine Gte. The factory gearing (and my legs) got me and my luggage there okay.

On the Yahoo Group for HP Velotechnik owners, there has been an interesting sharing of perspectives on the standard gearing for the HP Velotechnik Street Machine Gte.

I share it here, edited to the essential parts about gearing:

From original poster L Campbell:

I would appreciate suggestions as to how long an axle should be for a triple and also, does the factory suggest any minimum / maximum sizes for the chainrings?

Zach Kaplan of Zach Kaplan Cycles wrote in:
The stock crankset on the Street Machine has 52-42-30 rings. They have used various brands of cranksets and spindle lengths over the years. To get lower gearing, I have replaced the stock 30T inner rings with 26T or 24T rings. I have also set up Street Machines with MTB cranksets with 44-32-22 rings which I think is a better gear range for a bike designed for loaded touring.

Writer Ed Walkling seemed to have a similar view:
When I get a new (secondhand) GT the first thing I do is change the crankset. I find the standard chainrings much too large for full camping gear touring or pulling my daughter in the trailer.
I run 22, 32, 44 chainrings as said before and also use a large 36 tooth cassette giving me a very low gear. This allows me to pull the trailer up a steep gravely hill we use often on the way back from our local town.
The axle length on your bottom bracket will be determined by the crankset you choose to install. Only the shell diameter and width is predetermined by the frame. As you have a deralieur post you should be fine fitting a triple.

My (Robert's) own view was the following.  I tried to provide context so others may translate my experience to their own terrain and habits.

I'd like to contribute to the range of perspectives about the SMGte's factory gearing since I have a different experience.
I ride an SMGte for solo, self-supported, loaded touring, carrying all gear for shelter, cooking, repairs and travel.  My last tour, this past July, was a 12-day, 750-mile rainy (cycling) trip through the Adirondacks in New York State with a brief dog-leg through Vermont.  I basically followed the Adventure Cycling Association's "Adirondacks Loop."  The trip included constant and often steep elevation changes on both improved and "unimproved" roads: paved, dirt, farm, trail, mud, broken asphalt, etc.
The steepest, longest incline during the trip was up Whiteface Mtn., the ski mountain used during the two Lake Placid Winter Olympics.  I rode up with full panniers, which, in addition, were particularly heavy due to my having been caught in daily thunderstorms without a chance to dry my gear.  From the direction I was riding, it was a 10-mile climb, in all, with long steep grades, often between 8-10% during the last five miles, and a somewhat rough winter-damaged asphalt surface.

This is the elevation profile for the Whiteface Mtn. section of the Adventure Cycling Association's Adirondacks Loop.
I rode with HPV's factory-supplied Shimano XT drivetrain with their Truvativ Tuoro crankset and their 155 mm (short) crank arms.  It was okay.  I believe the Elita crankset yields more power output and 170 mm crankarms would give a lower gearing, but I didn't leave the trip believing I needed yet lower gears.
The RPMs of my preferred cadence may be slower than those who prefer lower, mountain bike gearing; I, personally, seem to have better slow twitch than fast twitch leg muscles.  Between me and others, there may also be differences in the weight of the payload, rider plus luggage, as well as strength.

It's important to remember that the cadence speed of one rider may be very different from that of another and that cadence will hugely effect the optimal choice of gearing.  A rider with a high cadence may benefit from mountain bike gearing for loaded touring.  But a rider with a low cadence may not, and may really regret losing the higher "cruising" gears, as the chain rings are all reduced in size.

It is also impossible to predict the future.  In this case, I mean that you don't know how you'll pedal after you become an experienced rider on a specific bike.  When you're new to a bike, you may pedal with one cadence, but as you get to know the bike and grow stronger, you may develop a preference for a different cadence.  Also, on a new bike, you might begin with one seat angle or boom length (x-seam length) or cleat position or leg extension, and that may lead you to prefer one cadence.  As you become stronger and more experienced, if you're like many other people, you will tweak these things and those tweaks may effect cadence.  Also, in my own case, I find that the time I spend in the saddle changes my preferred cadence; on long trips and long days, I seem to prefer a slow cadence.  On short trips and day rides I seem be happy with a faster cadence.  Maybe I don't know what I'm doing; maybe a great coach would tune my cadence and it'd be better if I pedaled the same way always.

I continue to believe it's fine and maybe best to start with the factory's gearing, and use that to get to know the bike and yourself as a rider of that bike.  As you develop your strength and technique on a particular frame, you'll come across instances where the gearing wasn't quite what you needed -- not high enough, not low enough, not close enough, not wide enough.  Then, based on personal experience, you can experiment with your set-up and hone in on your optimal gearing.

All that said, there is indeed one good shortcut to slowly and surely putting in the miles and experimenting as you ride.  It's called "intensely putting in miles and experimenting as you ride."

Have fun and -- why not:? -- try something new,
Robert Matson
New York City Recumbent Supply
The Innovation Works, Inc.
copyright 2013 Robert Matson

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