Originally Posted by
Sasquatch16
I have plenty of range of motion for the 175's. I have a little less in one leg than the other. Looking to buy new bike and just checking all of the options. Specialized Roubaix is an option at 64cm but they do not make a triple anymore. I think the longer cranks will make up for the 4 less teeth on the compact vs.triple. Definitely would not buy bike with long cranks without trying first and I am about to give up on that. Most of the area KHS dealers did not even know what the 747 was and were not interested in bringing one in without me purchasing it.
The two stock carbon frames that were at the top of my list were the 64cm Roubaix and 64cm Madone. Ridley also does some realatively large frames, but, I don't know if the outlier sizes are imported to the states.
Zinn has an adjustable crank rental option. I do not know if they can be ridden on the street, or, if they are limited to the trainer for fitting purposes. That might be an option to try various arm lengths on your current frame before committing to the purchase of cranks or a complete bike.
Originally Posted by
Sasquatch16
If your measuring 40mm difference between your 180mm cranks and your 200mm cranks than the 50mm I came up with makes sense.
I am going to put my bike on trainer and lower seat 50mm and pedal awhile. This should give me some idea what it feels like at the top anyway. Better than nothing.
Bigfred any idea how large you can practically go on cranks with a standard frame? That is another option I was thinking of. If I find cranks I like than I can match them later to a frame that fits better. I could also wait till your finished and take a trip to NZ. I hear it is beautiful there.
I would be extremely careful about basing any decission on the lowered saddle experiment. Top dead center will be the same, but, the rest of your stroke will be completely different.
The maximum crank length you can run on a standard frame is going to be determined by your usage, cornering style, bottom bracket height, arm clearance at the chain stay, foot size and width, etc. One helpfull experiment is to lean your bike with shoe attached over and determine it's point of contact. For me it's the outside edge of my shoe. Cut an appropriately sized small block of styrofoam and double sided tape it to your contact point. Go for a few hard rides and see if you scrub it off or not. That'll help sort how much ground clearance you have. Pick rides with the tightest, fastest corners you are likely to experience.
Just as important is crank arm clearance. I've not measured the inside Q factor on the 200's. But, my Dura Ace 180's come within a few mm of the chainstays. Unless the 200's are measurablely wider they would certainly contact the stock chainstays.
Typically it seems that builds are usually including slightly longer chainstays as well as a higher bottom bracket when designing for individuals who warrant long cranks. The new bike certainly has more chainstay sculpting or relief further aft than my existing rig.
I should have Bierwagen finished by next weekend. That's my goal. So, start looking at air fares. It is beautiful hear. Mind you, I live in Auckland (aka The Big Smoke). But, I'm sitting on the sofa trying to ward off craps right now after completing what was a wonderful 4:00 110km Saturday morning ride through the country side and back to my door with a stop at a local cafe along the way. Leave the big city and it only gets better. The South Island has some truly spectacular scenery and I highly recommend it. The only real down side is that we have what many have agreed to be some of the coarsest chip seal in the world. I've ridden and driven many gravel roads that were smoother and faster. Some of the group rides publish intended averages with as much as 3-5 kph difference depending upon whether the ride is mostly on asphalt or chip seal.
I should have Bierwagen together within the week and intend to post plenty of photos of the initial fit process. You'll get to see plenty of comparisons of knee and hip angle at top and bottom dead center, knee positions realative to pedal spindle, etc.