Cranks

Well, it's been just over a year since I changed my 170mm cranks to 175mm.

At the time I made the change I suggested that the resulting difference in pedalling said more about technique than they did about the crank length. And after twelve months, a few Km's and plenty of advice, I'm convinved of it.

Firstly, I'd say that the increase in crank length was appropriate for me. I feel that power transfer was more efficient and considering that I'm more of a sprinter than a climber the change was noticable, especially on the flats.

Having said that, the change did "feel" arkward and took a long time to get use to. I wasn't getting any advice during the time that I was getting use to the new feel. Some time later I began getting some serious coaching and the first thing he pointed out was my "poor" pedalling technique. So I had to unlearn the poor techniques and develop a better ones.

I believe that (for me atleast) changing the crank length to fit the leg length can be good thing, but that it can't be done in isolation. Once a change has been made be prepared to look at the things that may be affected by it. In my case, a simple change in one part (crank) resulted in a whole series of changes....

In the end I think the change was for the better.

Nick

 

I've only been riding for a year or so. For some reason my LBS set me up with 72.5's - I'm 5'81/2 and my inseam is 29.75. Everything I read says I should be riding 170's or smaller. Thng is, I'm used to the longer cranks because that's all I've known. I did have a hell of a time getting my saddle dialed in. I can manage to spin at 110 or so on the flats. I sure like the power I get when out of the saddle, but can't help but wonderoif I'd be better off with 170's.

Whatcha think?

 

I run 165 on my Catrike Speed and 170 on my Vision R-42, both have Rotor Cranks. And YES, I do like them, they have helped increase my cadence, they are smoother and I am faster with them.
James

 

I think it really depends on your riding style and the type of terrain that you are training on. I am 5'11 and train on a Record 10 Carbon Crank 175mm. But, when I race, my race bike has 172.5mm on them.

Here is my time tested philosophy. J-MAT has a point, longer cranks put more strain on your knees and legs depending on your seat height. What I do is keep the seat height exactly the same on both bikes, thereby putting more strain on my legs. I train like this during the weeks leading up to race day.

Now something incredible happens to me when I jump on my bike and race criterium. I just fly like an eagle around the course. In fact, I have to look down at times to check if I even have a chain connected. I feel powerful and deliberate with every pedal stroke. Mashing gears left and right to put some hurt on the chase group.

In my opinion, training with longer cranks is like running with ankle weights. When those suckers come off, you feel like a feather, and you can run forever. It's crazy psycholigical.

Now that I let my training secret out of the bag, I'm sure the competition at the races will be even harder.

Best Wishes,
Vector7

 

This whole conversation has me thinking about a problem I have been having with my drivetrain for the past few seasons. Maybe someone could offer advice if you have been there as well.

Over the past few years I have had a "Ting" like sound coming from the crank/BB area when my right foot is in the one o'clock position and I’m cranking hard. I thought it was the BB so I replaced it with an ultegra (the older square non-ISIS type), But the sound continued, I figure maybe it was the ring bolts, replaced them and the sound was still there. I got two seasons out of the BB and then it failed, bearings let loose from the case that held them. I figured it was time for a whole new drivetrain. The old one was Ultegra all around 56/42? 8-speed rear and a 172.5 crank.

I accumulated all the necessary drive parts over the previous year watching sales and the like. My new drivetrain is DA rear cassette (11-24, combo of two cassettes to get the full range) DA derailers f&R. Ulteg BB (as the Ultegra has less rolling resistance than the 7700 DA-BB), and a (don't laugh) 105 ISIS crank (this was an almost freebie and I figured it was heavier and it might stand up to more abuse). I built it up and life was beautiful, not a sound. After a few rides I heard some of the same noise, tightened down the BB/crank bolts and the sound disappeared. After a bunch more rides the sound has returned. I have tightened the crank as much as I can tighten it, but the sound lives on. The new crank is a bit longer at 175mm and I transferred the 56t over to it. I am not the tallest at 5-7 and the thought of moving to 180mm sounds like it may be too big. I have tried to go lower gearing and higher cadence, but it just isn’t comfortable for me.

Anybody have any thoughts?

 

This whole conversation has me thinking about a problem I have been having with my drivetrain for the past few seasons. Maybe someone could offer advice if you have been there as well.

Over the past few years I have had a "Ting" like sound coming from the crank/BB area when my right foot is in the one o'clock position and I’m cranking hard. I thought it was the BB so I replaced it with an ultegra (the older square non-ISIS type), But the sound continued, I figure maybe it was the ring bolts, replaced them and the sound was still there. I got two seasons out of the BB and then it failed, bearings let loose from the case that held them. I figured it was time for a whole new drivetrain. The old one was Ultegra all around 56/42? 8-speed rear and a 172.5 crank.

I accumulated all the necessary drive parts over the previous year watching sales and the like. My new drivetrain is DA rear cassette (11-24, combo of two cassettes to get the full range) DA derailers R&R. Ulteg BB (as the Ultegra has less rolling resistance than the 7700 DA-BB), and a (don't laugh) 105 ISIS crank (this was an almost freebie and I figured it was heavier and it might stand up to more abuse). I built it up and life was beautiful, not a sound. After a few rides I heard some of the same noise, tightened down the BB/crank bolts and the sound disappeared. After a bunch more rides the sound has returned. I have tightened the crank as much as I can tighten it, but the sound lives on. The new crank is a bit longer at 175mm and I transferred the 56t over to it. I am not the tallest at 5-7 and the thought of moving to 180mm sounds like it may be too big. I have tried to go lower gearing and higher cadence, but it just isn’t comfortable for me.

Anybody have any thoughts?

C'Rider

 

Bro...what kind of bike do you ride? What is the make and model?

Best wishes,
Vector7

 

Bro...what kind of bike do you ride? What is the make and model? [If not a Cannondale] It could be the actual BB on your frame. Usually ticking noises are accompanied by some sort of mild rub or vibration. Are you experiencing any of this too? I may have a trick up my sleeve to help you solve the problem. To me the common denominator is the frame itself. Let me know.

Best wishes,
Vector7

 

Thanks Vector,

It's a C'dale. It's a bit old, last of the pre CAAD models, a 2.8 crit. (no this is not my only ride) has lots of miles and just won't die. I know you may be saying "fatigue" and you may be right, But why would the sound stop when I added the new gear, and then stop again when I tightened it down?

Thanks again,
C'Rider

 

Any one seen or use the new Stronglight Carbon fiber crank? Weight is 450 grams with 53-39 chainrings. For those who use, what BB are you using with it?

 

I saw one at the LBS.

I was talking with the guy about going to a compact FSA and he handed me one of them and said try this little baby out.

The weight was stunning.

I just kinda stood there with a stupid grin on my face hefting it up and down.

He said they get that response a lot.

It has a neat-o matte finish too, none of that hi-gloss CF that we are all so used to. Looks kind of utilitarian and hard-core and hi-tech all at once.

I think that one was an ISIS drive, but I think he said they do a Campy taper too.

I gotta figure out a way to get me one.

Whit

 

American Classic makes an ISIS BB that weighs 140 grams. Combo is only 590 grams. Dura Ace 7800 crank with BB weighs about 700 grams. Do the math....

 

I'm starting to build up a new bike, to replace by off-the-shelf (and thus ill-fitting) Bianchi. I'm 6'4", 36" inseam, and so I'm looking at a 180 crank. I like to ride hills, and I'd like to save my knees, so I want a triple or maybe a compact double. I have a slight preference for Campy over Shimano. I'd probably rather get Chorus or Ultegra rather than Record or Dura-Ace.

My question: why can't I get what I want?

The manufactures only seem to produce 180's for doubles, and seem to be limited to the top of the line. Why doesn't Campy make a 180 compact double or triple? Is this just marketing--that there is no market for a 180 compact double or triple? That surprises me, based on how much people in this thread seem to like the 180 (for taller riders, or certain types of riding). Has anyone else figured this out?

Argggh!

 

My first guess would be that it's not cost effective to do so. Even in this cycling forum 180mm cranks are used by only approx. 6% of those who posted. I'm sure the percentage is even lower when one takes into account all cyclists. It makes sense that manufacturers who do sell 180mm cranks would limit them to their most expensive brands/lines. Second, cyclists who care about fine-tuning their cranks lengths would be enthusiasts who can justify the cost of such an expenditure which a recreational cyclist most likely wouldn't. How many pros ride 180's? Not too many names come to my mind.

I do understand your frustration. I ride 180's too.

 

You haven't looked hard enough! Peter White has TA Carmina cranks which ought to do the job: http://www.peterwhitecycles.com/carmina.asp

Sizes available are from 155mm - 185mm...

TA do other cranks too, including ones Peter doesn't list. It's a shame they're not easier to find, but I guess this is a tribute to the fact that most haven't heard of anything except Shimano or Campy due to their saturation advertising <sigh>

The interesting thing is that the range of sizes available is going down if anything; most newer cranks seem to come only in 170 and 175mm, pretty worthless for short, tall or picky riders.

 

ive got 172.5 FSA carbon pro team issue on the road and 175 XT for the mtn bike

 

Huh ?? 590g ?? Where did you pluck those figures from ?

I own a FSA Carbon Compact in 172.5 size, put it on the electronic scales, they come up to 532g with BB bolts.

With the AM BB, it should come up to 672g at least. But from what I know, the AM BB weighs about 150g instead. Not 140g as claimed. So total should be 682g range instead.

Anyway, I run the DA7800 crankset too. In terms of feel, it surprised me when I swapped them, as its very clear that its much stiffer than the FSA when you start stomping up 10+% grades ! So, that measely 15-20g penalty may not be worth the trouble. Unless of course you're looking for lower gears, then, the compact is the way to go! And yes, I do think its a great crankset that allows a great deal of flexibility in daily use !

 

Stronglight Pulsion crank weighs in at 450. Am BB weighs 140. These figures come from the manufacturers.

 

Oops... me bad ...

Thought it was referring to the FSA crankset....

Apologies on that.....

 

180mm for me.

This is an interesting thread. I'll have to comment later.