Patrick from the Lacrosse Wisconsin area, wanted to try as extra long crank on his new Gunnar Sport. Unfortunately, putting a long crank on a regular bike frame raises the risk of hitting your pedals on the ground.
The solution? Working with Gunnar dealer Blue Heron Bicycle Works, we built a custom frame with a an extra-high bottom bracket. The normal large crank length is 175mm and the maximum bottom bracket drop is 80. To keep the pedals that same minimum distance from the ground, the bottom bracket drop must decrease by the same amount as the crank increases. So we built a frame with only 50mm of bottom bracket drop.
|
Here’s Patrick’s report (edited over a couple of emails):
“Just wanted to give you an update on what I’ve been calling the Gunnar Sport Gigantor Edition…!” How do the cranks work? “It’s great! The cranks took a bit longer than anticipated, but they finally got here and Kevin put the finishing touches on it. I was VERY impressed at the quick delivery and attention to detail that is clearly evident with the frame! I’ve attached a picture of the final product. |
(It) feels pretty weird at first. Per Kevin’s suggestion, I took it easy at first, just spinning. Finally got enough free time to hammer a couple of the monster hills around here. The combo of cranks and the 34/50 and 11-28 make pretty much any hill a breeze. The integrated BB design is uber stiff.
I feel like my whole leg is now engaged in the effort – the perception of increased torque is significant. I find when I get out of the saddle, I almost need to drop down a gear in anticipation, the acceleration is nice. Time will tell how it treats me in the long run. On the bright side the BB’s not freakishly high, so going back to 180′s would be a non-event…
As far as handling, it’s rock solid. . . . One final note – the welds/finish work/paint are gorgeous – you guys really did a STELLAR job!
It was truly a pleasure to work with you and Kevin on this build. The collaboration and overall positive experience will be something that I’ll share with folks wherever I ride…”
Extra-long cranks aren’t for everyone, not even every tall person. But we’re seeing that this might be the right alternative, when you need that extra stretch.
{ 3 comments }
Hi,
Can you add the crank length and frame size to this post?
Thanks,
Bill
It’s either 205 or 210mm.
It’s been a long time since I visited the Gunnar site. I saw this and felt compelled to post.
I’m 6’4″ and ride a bike proportional to my size, including the cranks. Knowing what I know, I wouldn’t have it any other way. Most manufacturers simply disregard sizing for people who fall outside of the bell curve. Sad. Thankfully Waterford exists. I’ve been riding my custom ‘Grand Tour’ for a little over 2 years now. It’s an awesome bike. At the time, I wanted to integrate 190mm cranks into the design/geometry. We brought the BB drop up 10mm. It worked/works. Yes, occasionally I get some pedal strike with the ground, but it’s rare enough that it doesn’t bother me.
Here is an empirically driven argument in favor of proportional crank length.
http://bicyclecranklength.blogspot.com/