cikal

I would like to use the following crankset on a fixed gear bike I'm building.

https://cgi.ebay.com/New-Old-Stock-Sh...ht_1022wt_1139

Is it possible to use these stack bolts (https://harriscyclery.net/itemdetails.cfm?ID=680) and a single chainring with these cranks? Also, how do I determine what length spindle to use with these cranks for the BB?

Would this bottom bracket work: https://www.treefortbikes.com/#navbar...22348410___116 ?

or this: https://www.benscycle.net/index.php?m...roducts_id=602 ?

I'm just not sure whether any square-tapered bottom bracket works on any "square-tapered" crank arm.

Any additional information will be appreciated.

Thanks for the help, guys.


cikal

Deshi

Bolts work fine. There is some measuring you could do to determine the spindle needed to get the best chainline but honestly, just get a super short bb that works with it. Id say something like a 107mm or shorter depending on the chainring and the frame you have.

f50fan

Yes the bolts should work. Dont know about the chainline though. Always a little guesswork when it comes to multispeed cranks and chainline.

xkillemallx16

You have the cranks, or are you gonna buy them from ebay?

Squirrelli

I have exactly the same crankset, I used a 110mm bottom bracket with ring on the outside. I have to say though, it is a conversion and the rear dropouts are 126mm and hub is 120. I have a spacer/washer on one side of the hub to fill in the gap, and that washer affects the chainline slightly with my 110mm bottom bracket.

Dr. Banzai

170mm? You really tall or something?

I am one to think that most people benefit from 165mm cranks.

hairnet

Can you elaborate? I don't really understand what you're trying to get at (hope this doesn't sound weird or anything)

wmgreene85

I use 172.5 length RaceFace Cadence arms but I am about 6'4" and my frame has a BB drop of 45mm

fuji86

5 mm differential on crank arm length isn't as much as anyone would think it is. Works out to 1/5 of an inch and that's middle of spindle bolt hole to middle of pedal bolt hole. Road bikes of the 80's, most have 175 mm crank arms. So 165 to 170 mm crank arm length, if you have the stamina & conditioning, the leg strength and or enough body weight to drive that lever down thru a power stroke, once you get the bike moving pedaling shouldn't be a big issue. Just me, but slower revolutions with more gear inches actually works better for me than higher revolution spinning. Powering thru and not getting that winded high rpm and leg burn feeling of not making optimal headway, whether real or psychological has a lot to do with enjoying your ride. Just out of curiousity, wonder what 5 mm adds to the distance that the pedal travels on a power stroke. And whether that becomes a timing/duration issue for a cyclist ?

Circumference = pi * diameter

165 mm = 6.496 inches
170 mm = 6.692 inches

difference is .196 inches and that would be on the radius as that is what a crank arm is (2 crank arms 180 degrees apart become the diameter), so double it to get the differential on the diameter as .392 inches and multiply by pi (3.1416) to get an additional circumference of travel of 1.231 inches. Even if a power stroke is 1/2 the circumference in duration, there's not even 5/8 of an inch more pedal travel at the circumference of the circle. The question becomes whether the cyclist gets more power out of the shorter power stroke with a slight increase in the frequency the next power stroke occurs vs a longer power stroke and slight decrease in the frequency that the next power stroke occurs ? That's where leg strength and conditioning would come in. For me, I'd rather have a slower spinning rate and still be able to get the power. To me, not only could the front and rear gear tooth counts be experimented with, but also crank arm length to get identical power outputs for cyclists that match the athlete's differences in fitness, height, weight and so on, even the difference between/amongst cycle(s) ?

cikal

Good read, Fuji.

And no I'm not tall at all. I can't find any NOS, good quality, inexpensive 165mm cranks - so 170mm will do.

Because of the age of the cranks, are they fragile or weaker than newly-made cranks?

And would either of these two bottom brackets work?

https://www.treefortbikes.com/#navbar...22348410___116

https://www.benscycle.net/index.php?m...roducts_id=602

It's just that I'm not sure whether any square-tapered bottom bracket would work on any "square-tapered" crank arm.