bigfred 

Prepare yourselves my Freddly friends. This thread isn't going to be over quickly. Prepare for much hand wringing, rueing over decissions, flip flopping of opinion and general faffing like a teen girl before prom.

I've wondered about proportional cranks and their supposed advantages for years. But, could never quite justify the cost of a custom frame and cranks for an experiment and wasn't going to mount 200's to stock frame and risk going down from pedal strike. Yes, I mounted a 20mm foam block to the bottom of my pedal and proceeded to tear it off pretty quickly.

So, when a frame with appropriately high BB showed up on flee-bay and no one bought it, eventually it's designer and owner dropped the price to the point that I couldn't help myself. I placed the opening bid and none of the rest of you bid against me.

Subsequently, this showed up on my door step yesterday:





This project is competely off budget. There are a couple approaches I can take:

A. The "no budget" ghetto, recycled components, what I can find as cheap as possible, get it rolling now approach. I would prefer to keep my existing Cannondale whole, but, it could be canabalized if need be.

B. Build it how I want it. As funds are limited, this could take quite a while for me to acquire all the neccessary components.

Either way, the two things I must buy are: the cranks and a fork.

Oh, and the frame weighs 1480grms plus 23grms for the seat clamp.

PhotoJoe 

Sounds like a fun journey. Thanks for taking us all along.

To embed larger pix, host them on a hosting site. I use Photobucket. Upload them there, then paste the [img] tags to your post. Viola! Large pix!

TrojanHorse

What size cranks you gonna get for your frankenproject there, Edward Longshanks?

I think even at my low 6'2" altitude Zinn seems to think I need 197 cranks.

Nice going PJ - now he's going to post more self photos wearing skin tight cycling gear. At least with the thumbnails we stood a chance, now we're doomed.

chasm54

Just to inject a controversial note, I'm unconvinced about long cranks. It sounds logical until one thinks about the effects of gearing. You want to go further with each rotation of the pedals, just change up a gear. Once you have taken that into account, the only thing long cranks change is the angle at which your hips and knees have to bend, and as far as I can see it's an advantage to avoid increasing that angle, because most power will be generated when it is not too acute.

I think bicycling mag. did some study into this a while back, and found that power outputs tended to decline once crank length went over 180 or so. This is interesting...

bigfred 

With a 955mm inseam Zinn's current suggestion would be 205. I remember years ago when I first investigated this the calculations suggested 197 or so. With both of those in mind and the fact that one of the leading contenders is only available in 200mm, I'm intending to start with 200mm.

So, to what degree is the board willing to underwrite this experiment in an attempt to convince me not to proceed with the Bib Short Comparison?

bigfred 

If I was 100% convinced I would have shelled out for a custom frame and cranks years ago. There's a reason I'm referring to this as an "experiment". A personal one at that. Everyone else just gets to come along for the ride. To further confuse issues, the change in arm length will be influenced by a change in gearing at the same time. I'm currently on 130bcd 53/39 - 12/25 gearing. The new cranks will be 110bcd with either 52/36 or 50/34 rings and either my current 12/25 9spd, 12/27 10spd or 11/2810spd respectively.

I just had the very discussion you are beginning about gearing and leverage on a group ride on Tuesday. While I'm no great engineer, I would like to think that I have a reasonable grasp of the principles involved. The length of the lever arm, radius of the chain ring used and corresponding cog all factor into the equation as well as individual morphology.

There's little question that arm length plays some part in overall efficiency. The question is, "What is the ideal arm length for 'me' in the manner that I intend to use them?" I certainly experienced an improvement in performance years ago when I moved to 180mm cranks. We'll see if that is repeated with a move to 200mm. I have some real trepidation about making such a big adjustment. Moving my saddle 5mm can take a couple of weeks to adjust to. Hence, my concern with keeping my current ride intact, so I can switch back and forth if the new range of motion requires some time to adjust to.

So far though, most of the riders who have actually tried proportional cranks seem to be pleased with them. I don't recall hearing about any long legged riders trying them and not liking them.

bigfred 

Full carbon steerer? Or, carbon blades with aluminum steerer?

NOS AlphaQ CS-20, 300mm carbon steerer, w/100m epoxy in sleeve, 400 grams, $265ZNZD

Easton EC90 SL curved, 300mm carbon steerer, 350 grams, 43mm rake, $310NZD

Easton EC70 curved, 300mm aluminum steer, 530 grams, 43mm rake, $180NZD

The glue in sleeve for the discontinued AlphaQ concerns me. The bottom of it would be awfully close to the upper bearing.

My aluminum steerered Cannondale has more than a decade on it without issue. I really don't want to be worrying about fork integrity as I plummet down some pass descent. Any reason I shouldn't opt for the EC90 SL? It's not the SLX:-) I'll be fine! Right?

bigfred 

This project needs a name.

theblackbullet

fwiw I've used the ec70 that came with my bmc streetfire ssx frameset, and it flexed enough to make the brakes rub while climbing out of saddle (at 235lbs). not a fan. However, I've put thousands of miles on my secondhand cannondale aluminum steerer fork and love it!

theblackbullet

I vote cheapest fork you can find on craigslist. and somewhat ghetto built. I'm a HUGE fan of shimano 9 speed. 6500 stuff can be found cheap

bigfred 

I'm in NZ, so, I don't really have access to CL. We've got Trademe. And, I can get stuff from fleebay shipped to a realative in the states. But, I need no less than a full 300mm steerer, which generally means I'm looking for unused/uncut stock. Otherwise I'd be all over a cheap fork and some matte black rattle can.

6500? That's what I've been on for 13 years! I'm at least trying to upgrade to 10spd. Daddy wants a 16tooth cog between that 15 and 17. 6600 at the minimum. Although, I would like to try SRAM. We'll see what materializes between now and when I've got both forks and cranks in hand.

bigfred 

Did the Cannonwhale fork go into the same frame? Which Cannondale fork design? I'm happy so far with my old SI Slice Prodigy.

brawlo

If I was buying a separate fork again, I'd look at Columbus and an aluminium steerer. I had a Tusk fork on my first track frame and it was able to cope with the abuse of standing starts at the track. I upgraded to a Pro Lite fork after that and it was mega stiff, but heavy to boot. I think when you get long carbon steerers on carbon road forks, they get a little flexy. Also, from what I've seen, road forks have a thinner wall than the track stuff I've come across that allows for the flex. I was going to buy a Columbus to put on my old track frame that I'm now turning into a road fixie, but I came across a brand spanker 3T fork that was collecting dust in the corner of my LBS. He let it go for $50. The fork had only been mounted on a bike and the buyer had his own so changed it out before the bike went out the door.

As for crank length, I am of mixed opinion. From chatter getting about the finnicky track circles, the prevailing factor seems to be the speed at which your feet move. If there's a shorter crank, your feet can move at a faster rpm, but be moving at the same speed as someone who is on longer cranks but a slower rpm. There has been no real determination that longer or shorter cranks work better, just the fact that shorter cranks allow you to spin while longer allow you to grind. The difference in crank length is taken up by the gearing used. For the record, I use 180mm on my road bike, and 175mm on the track bike.

Brando_T.

Information I can use for my own build...I've been wondering where to get a cheap group.

Brando_T.

And a follow up for theblackbullet - where do you shop for your cheap 6500 stuff?

bigfred 

I can't speak for blackbullet, but, I was assuming that we were talking about the used market. So, all the regular places, CL, Ebay, Trademe or Trade&Exchage (for me here in NZ). Generally speaking the expensive components like brifters and such can be picked up for a whole lot less in 9spd variants.

Personally, I'm trying to escape the current situation of the Mrs. having 10spd cassettes on her wheels, me having 9spd and us forever changing cassettes on the spare sets. So, funds allowing, I'm very inclined to shop for 10spd stuff in either Shimano or SRAM flavours.

But, we're getting ahead of ourselves. First, the frame needs forks and cranks.

paisan

I'm not sure I understand the concern with the glue in sleeve? I have lots of experience building Cervelos and every one of those uses a similar system and I haven't heard of or seen any failures with the plug. The issue I see is if a person wants to cut the steerer in the future then you have to sort out removing the old plug. I bought a Look fork for my DeRosa a few years ago and it had the same sort of plug. I just went and bought a compression plug to use instead of the glue in. You're only concern here is that the glue in plug is also sometimes designed to act as a reinforcement for the steerer, but if you look around you can find a compression one that will do the same thing.

Here's an example of the type I am talking about. You can see that this plug has the compression device inside a sleeve that acts as a reinforcement for the steerer much like the glue in plug. Here's another. Though this one looks like a standard compression you can see it is much longer so it will support the steerer for the full height of the stem.

My point is, don't let the glue in plug be a deciding factor if thats the fork that you really want.

bigfred 

The reinforcement and its need are my exact concern. I'm going to be running the maximum spacer stack. I want to ensure that I don't create a situation that might lead to a steerer failure.

Thanks for the links. I hadn't seen such long expanders. My current thought is that if I end up with the fork and the reinforcing sleeve is a standard diameter, I'll acquire and install a full length sleeve. And, perhaps use one of those long expanders.

bigfred 

Never mind the concrete components for a moment and turning to the spiritual side of this undertaking.

Mrs. Fred has been lobbying to call it "Timmay" ala South Park for some unknown reason.

I was trying to come up with a name that somehow related to Archimedes to no avail.

But, "Bierwagen" seems appropriate for the obvious reason. The build of which is of course "Project 42":-)

Sassonian

Operation Longshanks?

Sassonian

I've been riding 210mm cranks for 3 years now. Wouldn't go back to 'Standard' sized cranks in a million years. The idea just makes sense - we start off as kids - with small wheels and small cranks - they get progressively bigger as we get older and larger. Then it all stops and we are presented with an incredibly tiny range of crank lengths as adults - even though there are large differences in size (read leg length) between riders. This is probably done so frame manufactures don't have to take this extra factor in to account when building bikes.

Proportional length cranks just makes sense to my mind - smaller circles if you ars smaller - larger circles if you are larger - but proportionally - the same sized circles - same angles...

But saying that - was also a leap of faith when I bought mine. It's hard to go against the accepted norms... Plenty of people looked at me sideways when I explained the reasoning.... So I was very nervous about forking out all this money on a good sounding idea

But I can't be happier.. Climb better, handle accellerations in races better (jumped 2 racing categories within weeks of getting the bike), and just feel way more comfortable and happy on the bike.

I did find I needed to got to an 11 tooth cog on the cassette - as you do get on top of gears quicker... Started off on a 12 and found I was running out of gears quickly on downhills and at the sharp end of races... But a quick swap to an 11 fixed the problem and have more than enough gearing now. (I also found I got better at spinning after having the long cranks for a while)

It is an adjustment - and will feel very weird to start with - but in saying that - I was immediately faster on the long cranks.

I have a tandem (a Hase Pino) that I ride with my disabled son and that has 'standard' 175mm cranks. I don't have a problem switching from bike to bike - although going from one to the other - does feel weird... (I wish the Pino had longer cranks - big heavy bike and my son doesn't contribute much yet )

I could go on and on

I'm really excited to see how this will turn out for you..

Cheers


Adrian.

bigfred 

Tell me about it. I've been told by riding partners that have never riddern anything longer than 175 that I'm going to "destroy you ability to spin", etc.

What gearing are you using? I'm going to be trading my traditional 130bcd 39/53 X 12/25 for something of the compact or mid-compact variety. Initially I was thinking that mid-compact 36/52 X 12/27 would be enouth additional low range in combination with the longer cranks. Now I find myself considering a full compact 34/50 X 11/28 set. I know cassettes and chainrings can be changed, but, would like to get it right the first time.

I've heard of adaptation taking everything from 2 weeks to a full year. We'll see how I react. I've e-mailed with one rider who spoke about the need to concentrate on keeping his butt down, while climbing out of the saddle, due to needing to bring his foot 4cm higher at the top of the stroke and retrain his knee about how far it needed to bend.


I'm sure there's going to be an adaptation period. That's largely responsible for my desire to keep my current bike in a ridable state. I would like to be able to swap back and forth if I desire.


Me too mate. Me too.

Sassonian

I run a standard double, 53x39. And an 11-28 on the rear. The long cranks make climbing easier, so this gearing is plenty for me.

bigfred 

This is a pretty small niche and I wish I could support all those who are servicing it. Alas, I can not and must pick one set of cranks to start with.

The players that I'm aware of so far are: Lennard Zinn , High Sierra , Lightning and DaVinci. To the best of my knowledge neither Bullseye nor Heiko Brechtel are currently manufacturing appropriate options.

I've spoken or e-mailed with several owners of the square taper modular cranks manufactured by High Sierra and also sold by Zinn. The common theme has been that it is not a particularly stiff option. Some of them don't weigh nearly as much as me. So, I'm eliminating them from further consideration.

I'm also eliminating the DaVinci cranks. While I haven't spoke directly to anyone using them, they look similiar in basic design to the aforementioned and I would like to make a move toward a more modern bottom bracket system than square tapered spindles.

The Contenders are:

Lightning (Heavy Duty 130kg max version), sub 600 grams incl. bb & rings, $680usd + rings
High Sierra Integrated Aluminum, upper 800 grams or more incl bb plus rings, $600usd + rings
Zinntegrated Aluminum, 893 grams incl. bb plus rings $795usd + rings
Zinn/KHS/Andel (from the KHS747), weight not yet known, incl. bb & 34/50 rings $409usd incl. rings

My dream bike would be a Parlee with the Lightnings (they utilize the same FACT spider attachment as Specialized and would take an SRM spider), Sram Red, etc.

I keep reminding myself that Bierwagen is not my dream bike, despite the fact that Mrs. Fred would endorse the purchase of the Lightnings. (I love her!)

I use my bikes as "tools" not "jewels" and this one will be no different. It a training tool and an experimental one at that. But, at the point I add some 36/52 mid-compact rings to the KHS/Andel cranks they're going to be closer to $550usd. Unless I find some used 36/52's.

So,

First choice. KHS/Andel's from Zinn and some used 36/52 rings.
Second choice. Given the realative costs, the Lightnings!

Would anyone approach it any differently? Why?

jethro56 

Crankenstein