Advice please!!!

[martinf]

I reckon the most suitable crank length varies from person to person.

At just under 6 foot tall, my own favourite crank length is 150 mm. This suits me better than the 175-180 mm length that should go with my height and leg length according to conventional wisdom.

With 150 mm, I spin lower gears at higher rpm than I used to do with the standard 170 mm, so go about the same speed as I did before. Apart from difficulties in finding non-standard length cranks I haven't noticed any disadvantages from using 150 mm since I swapped over 20 years ago.

150 mm crank length has two advantages for me :
- it feels more comfortable,
- I no longer get knee pains, which I used to get periodically with 170 mm.

The bicycle designer Mike Burrows advocates short cranks, and gives some reasons here :

http://www.bhpc.org.uk/short-and-sweet-a-discussion-on-crank-length-by-mike-burrows.aspx

But short cranks aren't necessarily right for everyone, I have known several short people who were quite happy with 175 mm cranks.

[Danneaux]

170mm here, Martin. They seem a good match for me 5'11" or 180.3cm and for my preferred fast, light "hummingbird" cadence of 110-120RPM, which I can do all day in comfort. What I can't do is overstress my knees pushing low cadence in high gears.

I have a fully restored 1970 Motobecane Astra U-frame Folder with a Thomson crank ( https://en.wikipedia.org/wiki/Bottom_bracket#Thompson ) and 145mm arms matched with 406mm (smaller 20in) wheels. As you might imagine, my legs are just ablur when I ride the thing. A bit short even for me, but it somehow feels about right on the little bike, equipped as it is with a Sturmey-Archer 3-sp.

As with all things, individuals vary in requirements and preference, just as you said. I think it is most important for people to get what works for them.

All the best,

Dan.

[dereksheph]

Dan,

Really interesting. I'm finding that my cadence depends on which bike I'm on. Carbon road bike = faster cadence feels comfortable. On a touring bike , I become a "masher" with low and slow. Cranks are the same length on both bikes. Evidence from this thread would suggest that it's a very  subjective call.But 130 all day in comfort ?? Once I get over 80 rpm with the rohloff, my legs start to tighten and it feels very strenuous:).

[Danneaux]

Hi Derek!

I think part of it is my low gearing, shared by all my bikes and started because I began cycling "with intent" many years ago as rehabilitation for injuries received in a car crash -- my knees removed the door-side window crank, bent the shift lever, and cracked the cover under the steering column. I think because I could not pull high gears then, I developed the knack early for spinning and stayed with low gears to prevent unpleasant twinges.

I tend to pedal in very round circles easily and with good flexibility (souplesse), but when I am tired, I pedal in quadrants to give my muscles a rest without stopping. On long (300-400km) day rides, I adjust my water intake, eat while on the bike and rest my muscles in this way to stay in the saddle for up to 17 hours. A good,comfortable saddle is key to all this. 

My Nomad is geared 36x17, and it has worked out well for me. The bulk of the gearing (both steps and splits) duplicates that on one of my favorite randonneur bikes. My most-used cruising gears are very close to the rando bike's 58-62 gear-inches, spotting in at 55 gear-inches in the Nomad's direct-drive Gear 11 and 62 gear-inches for Gear 12. Where I live, the town is surrounded on three sides by steep hills, opening out to a long Valley to the north. If I want to leave by west, south, or east, I have to climb, so the low gearing always comes in handy. To reach my beloved deserts of the Great Basin, I must first climb over the summit of the Cascades mountain range 100km away, so more climbing. Same if I wish to go along the Pacific shoreline 100km to the west; I must cross the Coast Range -- usually on logging roads and with lots of carried water (as much as 26l/26kg plus food for extended time away from resupply). At those times, the low of 15 gear-inches followed by 17, 20, and 22 are most welcome *for me*. I realize I may be the exception in my preference for low gears and a fast, light cadence, but it has worked well for me for the last 39 years of Adventure touring. I try not to think about the wear-cycles on my knee and hip joints, but so far so good.  As I often say, if I tried to pull high gears, my knees would explode with the shrapnel likely causing injury to innocent bystanders. No one wants that. 

The beauty of cycling is we can all do it differently and still do it right! I think it is important to go with what's familiar and comfortable for *you*. Cycling is very much a repetitive-motion pursuit. Get it wrong and you get it wrong over and over, with risk of injury.  Get it right, and it is almost effortless. 

All the best,

Dan.

[mickeg]

I have all my bikes (except my errand bike) set up with drop bars and nearly identical posture.  Saddle height above bottom bracket, saddle set back distance from directly above the bottom bracket, reach from the saddle to brake lever hoods, etc., just about all measurements are about the same on all bikes.  And my cadence is about the same too.  Derailleur bikes, I generally ride about 72 to 78.  Rohloff bike with a wider range between gears has a cadence about 71 to 81.  If I am pretty tired at the end of the day or am pedaling with minimal effort down a hill, then I often drop cadence down to the 60s.  My one bike with 170 crankarms instead of 175, I think the cadence on that is 1 or 2 rpm higher.

If a bike feels fast, it can make you want to go even faster.  But I often find that when I get home after a ride with an unladen bike, my actual rolling time on a bike that felt lightning fast is only a few percent faster than my rolling time on a slower bike.  And once I have gotten used to several bikes, I pretty much ride them all about the same with about the same effort.  The exception would be my errand bike which I rarely use for a ride over 5 miles (~8km), on that bike I usually pedal slow and steady without getting my heart rate up very much.  And the errand bike is a much more upright posture, so it does not really favor fast riding.

[stuartieboy]

Derek, Alan said you had round the world plans.  I got a Raven  4 years ago and it has been a joy to cycle on 3 trips through Belgium, Netherlands, Germany and France. I'll have to stop in Elgin next time I'm up north. I'm thinking about the North 500 in early May.
Stuart Morton

[Pavel]

.... My guess is he also has cranks too short, mine are 180, so should a tall guy. ...

We disagree on several topics, but I will only mention one here, crank arm length.  I am 6' 1/2", have a 32 or 33 inch inseam on most of my pants.  I have 175mm cranks on most of my bikes, but 170mm on one bike.  After I ride 40 or 50 or more miles, I find that my knees do not feel bad unless I am walking up some stairs.  Going up stairs is clearly a slower task than before the ride.  And from climbing stairs after a ride, I have concluded that my knees feel a lot better if I rode the bike with 170mm cranks than with 175mm cranks.  I am not switching from the 175 to 170 on my other bikes, but I have concluded that my maximum crank length is 175mm.

If your knees have that much additional flexibility that 180mm works for you when I have several inches of height on you, that is great.  But I suspect most others do not have that flexibility that you have.

I used to race criteriums when in college, and I don't know if it's still the same, but back then using the shortest cranks was the thing.  I'm 6 foot tall and my bare foot stand over is about 33 15/16th of an inch but I have a short reach. (I don't ever bother with a professional fit, because I've found them to be worse than useless.  They all try to fit you into a formula that does not factor aspects of morphology into it (they don't ever consider muscle type, nor do strength tests - and they certainly don't time you in the 400 meters ) and have given me horrid results) I also am naturally set up to mash, though through peer pressure I've learned to spin, but I suspect it's done my results more harm than good. Anyways though nowadays I'd be recommended 175mm cranks, I was running 160's (completely though to be wrong for someone depending on anaerobic skills and bursts of power) It worked for me like a gift from heaven.  Everything just simply went well once I increased the gearing.  So what I'm trying to say is that all the details are personal, and sage advice is not as good as experimentation.  Of course the golden rule here is to change only one thing at a time and not judge is too quickly. 

The other thing I learned was that minute shifts in position make a large difference sometimes, so work on you seat position first and then the reach.  Sometimes it feels wrong for a while, but all of a sudden performance improves, once the muscles get a chance to adapt.

Keep at it - you will get the bike working for you in time. 

[David Simpson]

Of course the golden rule here is to change only one thing at a time and not judge is too quickly. 

Excellent point, and too often forgotten in our rush to fix problems quickly.

The other thing I learned was that minute shifts in position make a large difference sometimes, so work on you seat position first and then the reach.  Sometimes it feels wrong for a while, but all of a sudden performance improves, once the muscles get a chance to adapt.

Another good point. I've found that even a 5mm difference in seat height can make a noticeable difference.

- DaveS

[Andre Jute]

I'm big on a more upright posture as you grow older, but I just wonder if in this case an unfamiliar new posture perhaps requiring getting used to hasn't conspired with it being a less efficient cycling posture than on the drops, with the combination aggravating a less powerful transmission ratio (as Dave says, there's a difference between 22 and 18 gear inches!) -- a bunch of individually insignificant straws adding up one big straw.

I would start by setting up the transmission ratio right for the rider's age and ability and intentions, according to George's (mickeg's) suggestions, with a bit of a margin. and checking the bike fit, particularly the saddle height, very carefully, as I've seen people when they first change over from drops to flat bars leaving the saddle too high.

Something that is often overlooked is that the Rohloff box is intended to be set up for normal cruising (your standard cadence at your standard load on a well surfaced flat road) not in gear 14 but in gear 11, which at 1:1 is the most efficient gear in the box, with gears 12, 13 and 14 as overdrives for downhill use or lightweight sightseeing on days off from high-mile touring. It's a small point but if a tourer is already on some kind of a limit, riding in a gear a couple of per centage points less efficient than the best available may just be the finger on the scales.

[JimK]

I tend to cruise in 8. The idea definitely appeals of adjusting my combo down the 44% or whatever 3 so gear 11 comes into view. Ah I would sure be able to climb, with three more clicks down at the bottom!

I put the Rohloff and chainglider through their paces today! Wandering around, maybe 15 miles into my ride, I am a good half mile or more down a road - ooops, kind of like a dead end. Wildfowl Management Area, a big fence and a rough road on the other side going the wrong way. But then an open gate and a rough road headed in the proper direction. Let's see! (This is why I call my Nomad "Fearless"!) Well the rough road peters out but beyond that is a kind of grassy stretch that for sure trucks or tractors have been down this year. Well another mile or so... yeah the right direction, but it just ends by a canal. Along the canal... hmmm, like a very old dirt road, all grown over with maybe clover and a hundred other wild things, quite distinct from the large open pasture alongside. I can see there's a road maybe half a mile further. So I just plow through all that vegetation. The Rohloff and the Chainglider - there is nothing to get caught by all that vegetation! It's slow going but smooth enough. Grrr, all kinds of barbed wire makes the last six feet pretty rough, but it drops me exactly where I wanted to be, right on the road home.

Not clear there'd be an easy way to get a chainglider to work with a much lower geared combo than my 38x16. The chainglider is very nice!

[Andre Jute]

I expect you know, Jim, that the sort of riding you describe isn't exactly what I meant by "cruising". You'd expect on such terrain to be in a low gear.

But if you're already down to 38x16 -- that's where I started out, too* -- and you're cruising in gear 8 (one of the two noisiest gears in the box!), than you must have an even lower cadence than mine.

That sounds like the kind of bind that a nice guy doesn't deserve. I think it is difficult to change your cadence once you've settled in as a cyclist (I tried without too much success) but I wouldn't want to give up the Chainglider and go back to cleaning the chain after every ride. Also, I'm used now to having clean trousers-bottoms.

All the same, it seems to me like out of every dollar you paid for that Rohloff box, you're not using 50¢ worth...

*Since I fitted a central motor to that bike, I've had to use a dished chainring to preserve my preferred tread with (more poncily "the Q factor"), and the smallest one that fits has 44 teeth; just as well I have a motor to help at the top of the hills in the "Rome of West Cork", though several years after heart surgery, thanks to my bike and my treadmill and the pharmaceutical industry, I'm generally quite a bit stronger than I was back when I fitted the motor.

[JimK]

For sure, picking up my bike and lifting it over a six foot high gate, after riding a mile over soft ground covered with thick vegetation, that's not exactly cruising!

Using Sheldon http://www.sheldonbrown.com/gear-calc.html - 38x16 with 26 inch wheels, a cadence of 80 rpm is 9.9 mph in gear 8. Probably my cadence tends to be more around 85. Someday maybe I will get a fancy computer to track all that. Bah, probably not.

I enjoy going back over my route and recording it when I get home. It helps me remember where I went. Today's ride: https://ridewithgps.com/routes/20813716 - 12% in that steepest bit. I wasn't watching my speedometer! But it occurs to me... someplace recently was some discussion about twitching handling in a Nomad at low speed. I have a Carradice Super C handlebar bag with a fair amount of miscellaneous junk inside. I think that really helps to stabilize the steering. Occasionally I ride without it, e.g. with cleaning oil in the Rohloff. Without the bag I do notice a bit of twitchiness. With the bag, I am often enough below 2 mph without any such annoyance. Yeah at that point my cadence ... I am just trying to maintain forward movement!

[Andre Jute]

Yes, that's the other hard point of speccing your transmission. On the Rohloff the first one is gear 11 being the most efficient so that it should be your cruising gear. But on any utility or touring bike, the second limit is that the lowest gear should be specified for the lowest speed on which you can keep your balance. (I take the view that a Rohloff owner who has to push has specified his gears wrongly.) I found by trial and error that my balance limit is about 3.5kph and specified my gears accordingly (it came to 38x16 for 622 rims with 60mm Big Apples)