Newish crank arms down to 145mm

[Mark McM]

Originally Posted by mjf

If you only look at Shimano/SRAM in a vacuum, sure?

Rotor's probably the closest in availability to the broader bike brand community

Rotor Aldhu - 150-175mm. Spiders/spindle options, 110x4, 110x5, 110/80 (grx), track, etc.
https://rotoramerica.com/products/aldhu-crank-arms

Several of the many options from smaller makers that

Ignite components road/gravel set - 155-180 stock, custom lengths available. 8 bolt spider/chainrings, nearly any combo of spider/chainrings will work.
https://www.ignitecomponents.com/pro...inferno-cranks

Raketa road crankset - 145-175mm stock options. 8 bolt spider, again nearly any combo spider/chainrings.
https://raketacomponents.com/shop/pr...road-crankset/

Sturdy Cycles- 150-175mm(2.5mm increments) stock options, custom available. 8 bolt spider, again nearly any combo spider/chainrings.
https://www.sturdycycles.co.uk/produ...anium-crankset

Appleman 2xr crankset - 100mm, 130-175mm as stock options, custom available. Proprietary spider, but 110x5, 110x4, 144bcd among others as stock options.
https://www.applemanbicycles.com/shop/2xr-crankset/

WATTshop for SRM power meter based cranks track/road - 145-172.5mm, pedal thread insert to modify length. SRM spider/spindle, so whatever speed or chainring combo you can put together from SRM, track or road.
https://www.shopforwatts.co.uk/colle...igin-crankarms

Also the Dixna La crankset, which caters to smaller cyclists, and which is available in lengths from 130mm - 170mm, and which a Q factor of just 140mm. This is a sub-compact double crank with 110mm/74mm BCD.

[tommyrod74]

Originally Posted by Mark McM

But should you adjust setback the same amount as the crank length change? Force is applied through the entire downstroke, not just when the crank is horizontal. So wouldn't you want to adjust the setback just a portion of the crank length change?

For most seatpost/seat tube angles, adjusting the seatpost height will move the saddle backwards about 1/3 as much as much as it is moved upward. So simply adjusting the saddle height for a change in crank length will take care of most of the setback change anyway.

Yes, and for smaller drops in length (say, 175 to 170) or when you aren't already near the max rearward adjustment available, it should be fine. My problem is I put out power best with a lot of setback, and anything that brings the front pedal closer to me puts me out of that range.

It's roughly a 1:3 ratio with most normal STA bikes - 3 mm up = 1 mm back. If 1:1 then no rearward (or forward) adjustment might be needed at all. Of course, that would be a 45 degree STA...

[thermalattorney]

Seth's vid does a good job giving an overview of the situation as it relates to MTBs. For that side of things check out this thread from last year:

At 6'2" I'm 100% on board 165mm or shorter for MTBs, as the benefits for tech climbing are real. All my road going bikes are 170mm or longer, as I'm not using shorter cranks for fit reasons.

[dcama5]

Rotor Aldhu - 150-175mm. Spiders/spindle options, 110x4, 110x5, 110/80 (grx), track, etc.
https://rotoramerica.com/products/aldhu-crank-arms

Several of the many options from smaller makers that

Ignite components road/gravel set - 155-180 stock, custom lengths available. 8 bolt spider/chainrings, nearly any combo of spider/chainrings will work.
https://www.ignitecomponents.com/pro...inferno-cranks

Raketa road crankset - 145-175mm stock options. 8 bolt spider, again nearly any combo spider/chainrings.
https://raketacomponents.com/shop/pr...road-crankset/

Sturdy Cycles- 150-175mm(2.5mm increments) stock options, custom available. 8 bolt spider, again nearly any combo spider/chainrings.
https://www.sturdycycles.co.uk/produ...anium-crankset

Appleman 2xr crankset - 100mm, 130-175mm as stock options, custom available. Proprietary spider, but 110x5, 110x4, 144bcd among others as stock options.
https://www.applemanbicycles.com/shop/2xr-crankset/

WATTshop for SRM power meter based cranks track/road - 145-172.5mm, pedal thread insert to modify length. SRM spider/spindle, so whatever speed or chainring combo you can put together from SRM, track or road.
https://www.shopforwatts.co.uk/colle...igin-crankarms[/QUOTE]

MJF,

Wow, a wealth of information. Do you have a PhD in short crank arms?

Thanks for that! Although this could be expensive for me.

Dave

[d_douglas]

I think those Appleman cranks are just gorgeous pieces of equipment. They are so sculptural .

That guy has an amazing eye for design - I would love an appleman bike to be honest …

[glepore]

I've always been crank agnostic, but lately have found that 165's fatigue me less, but it does cost me some leverage on the 8-12% stuff. 165's are in theory long for me (29 inseam) but there as short as I want for now.