Who makes 150mm or smaller square taper quality crank arms ?

[Jay73RX]

I’m after a pair of offset jis /square taper crank arms either forged or billet aluminium,max length 150mm .
I’ve found Lekkie Buz Bars which would be perfect but they don’t do smaller than 160 .

 

[MadRhino]

Look at monocycle shops.

 

[Jay73RX]

Ok cheers

 

[Chalo]

I’m after a pair of offset jis /square taper crank arms either forged or billet aluminium,max length 150mm .
I’ve found Lekkie Buz Bars which would be perfect but they don’t do smaller than 160 .

If you mean fancy crank arms, maybe somewhere that sells BMX racing (as opposed to freestyle) equipment. You may be able to find Mini or Junior class cranks that have square tapers and are designed for plate-type chainrings, and thus don't have a spider.

If you mean the same quality as your mid drive, then unicycle.com will do fine.

 

[Jay73RX]

I’m after a pair of billet crank arms both with offset and max 155mm square taper but struggling. Has to be individual arms no spider

 

[Chalo]

I’m after a pair of billet crank arms both with offset and max 155mm square taper but struggling. Has to be individual arms no spider

I used 152mm unicycle arms on my BBS02. Very square (minimal offset), forged steel, extremely reliable and inexpensive (like $15 retail).

https://www.jbi.bike/site/product_details.php?part_number=21521

I intentionally chose low offset arms to minimize tread width. Steel construction increases stiffness a lot, and minimizes the likelihood of a crank working loose due to reversing torque through the interface.

These are also easily obtainable in 127mm and 102mm lengths. Post-trade war pricing is about $20.

 

[Jay73RX]

I’ve got a Super73 RX EU model with 10 gears and both crank arms have offset ,the drive side especially does

 

[Jay73RX]

I might get these just not sure if 160 is going to cause issues if I jump from 127mm

 

[Chalo]

I’ve got a Super73 RX EU model with 10 gears and both crank arms have offset ,the drive side especially does

Does it need offset to clear hard parts? Or is it just lazy design, like most offset arms these days?

EDIT:
Oh, you're in Blighty. Lots of trials bike activity there. Those guys often use fancy short cranks. Check Tarty Bikes or the like.

 

[Jay73RX]

Had a look on there site but no joy . The Hope tech ones at 155mm would be great but they only do isis not jis

 

[Chalo]

These have offset, they're made from tip top material, 140mm, don't cost too much:

https://www.tartybikes.co.uk/cranks_pair/jitsie_forged_kid_cranks/c514p13254.html

 

[Jay73RX]

Yeh I did see those ,I will call him tomorrow and ask about the offset . See if I can get a better view of the angle here’s mine to give you an idea .

 

[Chalo]

Yeh I did see those ,I will call him tomorrow and ask about the offset . See if I can get a better view of the angle here’s mine to give you an idea .

They say "Offset: 29mm left, 35mm right" in the description.

However, there's no reason your bike should have offset cranks. The cranks don't come close to anything, and you can cut down on the excessive tread width by using low offset, "square" cranks. It will make pedaling more comfortable. Those flared cranks don't accomplish anything except screwing up the ergonomics of pedaling. I think your bike wasn't intended to be pedaled.

Does your crank arm turn separately from the chainring? Because if it and the chainring are attached, then you need a crank with a chainring or a spider where you can mount one.

 

[Jay73RX]

Its a shit set up IMO . The torque sensor bb has splines with a reverse thread and lock ring on the drive side . The spider fits on the splines and is held on by the ring (the spline match isn’t great as you can move the chain ring back n forward by a about a mm . Then the crank arms fit on the outer spindle

 

[Jay73RX]

I thought I’d need the offset cranks to clear the chainset

 

[Chalo]

Ah, I see. That is new to me.

Your photo shows more than 20mm of clearance between arm and ring that you can work with. If you want to go narrower than that, you can remove the pants guard from the outer ring position. I'd go for the squarest unicycle cranks I could find, to try to get my feet in the same county.

 

[Jay73RX]

Looking again at my bike maybe jumping from 127mm to 160mm with those lekkie crank arms will be ok . I think I will have plenty of ground clearance and forward and back looks ok but my only concern is these bikes aren’t overly tall so the longer my pedal arm the higher my knees go ,And with those I’d be extending by 35mm which I think is poss to much .150 is probably max .

 

[www.recumbents.com]

Just ordered some from eBay. 152mm. $35. It took a couple weeks to arrive from china. They look decent.

Search for "Bicycle Crank Crankset 5 arms 152mm Length BCD110 With 5 Hole For MTB Road"

Warren

 

[Chalo]

Just ordered some from eBay. 152mm. $35. It took a couple weeks to arrive from china. They look decent.

Search for "Bicycle Crank Crankset 5 arms 152mm Length BCD110 With 5 Hole For MTB Road"

He can't have a chainring spider because it will foul the separately mounted one on his bike. The one you posted would work with a BBS02 or BBSHD, though.

 

[Jay73RX]

What I would like is a better quality torque sensor bb 120mm wide that has a bolt on spider not a spline fit type like mine . I’m not sure if all torque sensor bb are the same as in do I need a specific one to suit my controller?

 

[Jay73RX]

Ah, I see. That is new to me.

Your photo shows more than 20mm of clearance between arm and ring that you can work with. If you want to go narrower than that, you can remove the pants guard from the outer ring position. I'd go for the squarest unicycle cranks I could find, to try to get my feet in the same county.

I think maybe they used offset crank arms to help clear the battery /Mock tank maybe

Ref the bottom bracket I did see this one on AliExpress but not sure as pre mentioned if I need a specific torque sensor

 

[Tommm]

Trials cranks. I have jitsie 140mm

 

[Jay73RX]

Trials cranks. I have jitsie 140mm

Just looked at them unfortunately they have a inner thread for a free wheel on the drive side crank arm which I obviously wouldn’t need so not sure if that will cause issues with it being able to pull in tight enough on the spindle with my set up . I need one without the thread .

 

[Tommm]

Trials cranks. I have jitsie 140mm

Just looked at them unfortunately they have a inner thread for a free wheel on the drive side crank arm which I obviously wouldn’t need so not sure if that will cause issues with it being able to pull in tight enough on the spindle with my set up . I need one without the thread .

If you don't need the freewheel your job is even easier. Just google monocylce crank and you will get heap of them.