155mm ISIS crankset price range!

Mario Antony

Active member
May 5, 2023
229
179
Portugal
If you're riding a road bike 11,000km/year then of course also riding a mtb with shorter cranks will be hard because frequently switching between the two different crank lengths must be pretty difficult.

Edit:

You say: "update on software, so that the torque sensing is corrected". How can the Bosch CX Gen4 motor software in my 2022 Trek Rail be changed to take account of shorter cranks?
I did those distances...not now unfortenatly, but yes, now that I think about it, you might be right.

Bosch dealer has the tool to change that.
If you update FlowApp, there is now "eMTB short crank" mode.
 

E-MAD MALC

Active member
Subscriber
Nov 16, 2021
405
245
EAST SUSSEX
I did those distances...not now unfortenatly, but yes, now that I think about it, you might be right.

Bosch dealer has the tool to change that.
If you update FlowApp, there is now "eMTB short crank" mode.
As I said you will find that if your bike came with 165mm cranks then the software is already taking into account shorter crank lengths
 

Mario Antony

Active member
May 5, 2023
229
179
Portugal
I've added a picture regarding the issue with position, and while doing it,
I remember there are different styles while riding. I'll try to clarify, making clear some facts:

Some riders will take turns with their pedals level (lets assume riderA), while others will drop the outside pedal entering the corner and while making the corner (riderB).

With short cranks, riderA won't notice anything, maybe it will notice that their legs are less further apart, but otherwise, I doubt any rider will notice the change between pedal/handlebar while standing up.

RiderB, on the other hand, will be higher in their positioning, due to shorter cranks, and if the handlebar isn't adjusted to the new crank lenght, it will find their handlebars sitting lower than it was on "standard" cranks.
Meaning RiderB will notice (if it's sensible to changes) the distance Pedal/Handlebar. If you can't notice adding or subtracting 10mm spacer - please understand the geometry.

[added: Althought I have explained 2 styles, there can be more, or even a mix of them. At this time, what I try to describe is 2 extreme positions, so that each can think about the issue.]

SEATED POSITION:
One thing is for sure true while seaded on both riders (A & B):
IF the handlebars aren't adjusted (after installing shorter cranks, and reposition the saddle) rider will be leaning more over the front, since the height (saddle/handlebar) has been increased.

ENGINE/SOFTWARE:
If there isn't any update for shorter than 165mm, engine will sense less torque (proporsional to the new lenght difference).

IN RESUME:
Bikes started coming with lower BB, and to this new design, shorter cranks started to be used (175 TO 170... TO 165/160).
Ebikes, open new issues, since riders like to climb technical trails , and doing so, pedal strikes are an issue (Hiting rocks/roots/etc).

Going the short crank route to solve a real issue, has some drawnbacks:
- ENGINE ASSISTANCE: For equal force on the pedals, there is less torque sensed (if there aren't any Bosch update).
Due to this, riders might adjust level of assistance, adjusting for lesser torque sensed.
- ADJUSTING HANDLEBAR/SEAT/GETTING CoG HIGHER: Depending on rider technic (riderA or riderB) each person can sense differences on handlebar positioning, if it's not adjusted.
Both riderA and riderB will notice being over the front if the handlebars aren't adjusted.
If adjusted Handlebar & Seat to new crank lenght:
RiderA : will find new position to have the handlebar a bit higher than he/she was used to.
RiderB: won't notice anything, but will be riding higher (CoG higher)

PS: I'm not against or in favour of shorter cranks.
People are free to use what they want and adapts to their liking/riding. This message is to de discussed, if you like (agree or disagree). Cheers

IMG-20240226-WA0004.jpg
 
Last edited:

Mario Antony

Active member
May 5, 2023
229
179
Portugal
After having said "is just facts" you are now saying "My opinion" :confused:

So which of the two is it, "facts" or "opinion"?
Not all have english has 1st language.
One thing is Facts, other are opinions - I completly understand and have to agree with you. It was not the best words.

I'll correct it - thank you.
 

EMTB Forums

Since 2018

The World's largest electric mountain bike community.

559K
Messages
28,287
Members
Join Our Community

Latest articles


Top