E180RS ....shorter cranks.

[Mikerb]

I guess the Hope 155mm cranks have persuaded quite a few Whyte owners to change cranks....primarily to reduce pedal strikes.
I stopped getting pedal strikes on my E180 once I learned to read the trail but it still does mean having to put in half pedal rotations more than I would like......so I became curious.
I have no such issues with the e160RSX.....both bikes have 165mm cranks....but the RSX is 29er which probably accounts for the difference.
So 155mm cranks for the E180 looked a worthwhile experiment......that is until I did more research!
Firstly the Hope cranks are too expensive for an experiment and I doubt they are any better than Praxis or Race Face Affect which are considerably cheaper.
Secondly for every 5mm cranks length reduction you really need to reduce the chainwheel by one size to maintain the same gearing.
Thirdly the shorter the crank the more power you have to input to get the same result in terms of trail progress/speed and pedalling efficiency is already not a strong point on the E180.
Lastly 10 mm is huge reduction when you consider what a 20mm diameter reduction means in terms pedal rotation circumference and that in turn impacts on weight distribution and balance when stood on level pedals.
So my conclusions are to try 160mm cranks probably by Race Face or Praxis , keep the same chainwheel and accept that I will need to be in 1 lower gear most of the time.

 

[Bomble]

I’ve put 155 on my 160 and after a few minutes I couldn’t tell the difference Soon get used to them.

 

[Mikerb]

I’ve put 155 on my 160 and after a few minutes I couldn’t tell the difference Soon get used to them.

27.5 E160 or 29?

 

[Bomble]

160rsx

 

[Mikerb]

160rsx

.....ok..surprised...I have found no need on my RSX....but I am 2 Stone lighter than you so the bike probably sits a bit higher.

 

[Bomble]

I am also lacking in skills

 

[Bomble]

I’ve just mulletted my Rsx too, so I’ll see if that makes any difference. Though if you believe the figures on the Whyte site, the mullet bikes have a higher bb than the 29

 

[Jag009]

I’ve just mulletted my Rsx too, so I’ll see if that makes any difference. Though if you believe the figures on the Whyte site, the mullet bikes have a higher bb than the 29

really interested to see how you get on with the mullet ,i was thinking of doing mine , did you change the pivot point on the rear shock or leave the same as the 29 "

 

[Bomble]

I’ve put a shape it up link on.

 

[Jag009]

I’ve put a shape it up link on.

Does that lift the bb hight and did you need to flip the chip ?

 

[Jag009]

I’ve put a shape it up link on.

Ok just read a bit more about this cheers for the info
still interested how you get on with the set up

 

[Doomanic]

Secondly for every 5mm cranks length reduction you really need to reduce the chainwheel by one size to maintain the same gearing.

Can you explain this please?

 

[Doomanic]

I stopped getting pedal strikes on my E180 once I learned to read the trail

Well done, sincerely.

 

[Mikerb]

Can you explain this

Can you explain this please?

Consider the difference a longer bar makes to loosening a bolt....ie rotating it. The longer the lever the less effort you have to apply. The shorter the lever the more effort. It is the same with a crank. The longer it is the less rider input is required to turn the chainwheel in any given gear. More rider input is required if the crank is shorter. To equalise the rider effort a lower gearing is required. Emtbs invariably have lower bb because of the positioning of the motor so 165mm cranks were fitted more often than the previous 170mm/175mm norm.....but the motor assistance helped negate the additional input required....plus 12 speed gearing and smaller chainwheels.

 

[Doomanic]

Yeah, I understand all that. Changing crank length does not itself alter gearing, but may require a change to retain the perceived effort.

 

[Mikerb]

Yeah, I understand all that. Changing crank length does not itself alter gearing, but may require a change to retain the perceived effort.

yes, by "gearing" I was referring to the percieved effort............ie what gear it feels like ...sorry if that was confused.

 

[Giff]

I’ve put a shape it up link on.

Doesn't the RSX have the Shape it Up link as standard?

 

[Bomble]

Doesn't the RSX have the Shape it Up link as standard?

No it has the Shape it link.

 

[Clubby]

Sorry Mikerb but I’m calling bollocks on all the perceived effort nonsense. Back in my singlespeed days I changed from 180mm to 170mm and noticed no difference. I’m also running 155mm Hopes and notice no difference in the gears I’m using. Huge reduction in the number of pedal strikes on my gen 1 rs150.

Yes there’s a reduction in lever length but add in the length of your leg and it’s not as big a percent as you think.

 

[Mikerb]

Sorry Mikerb but I’m calling bollocks on all the perceived effort nonsense. Back in my singlespeed days I changed from 180mm to 170mm and noticed no difference. I’m also running 155mm Hopes and notice no difference in the gears I’m using. Huge reduction in the number of pedal strikes on my gen 1 rs150.

Yes there’s a reduction in lever length but add in the length of your leg and it’s not as big a percent as you think.

I am happy you are pleased with the change you made but that may not be the case on a different bike. A 5mm reduction in crank length translates to a reduction the circle circumference they create of over 31mm, meanwhile your leg length is not part of the lever.........only your leg extension, and that is reduced. Of course a lot does depend on the the starting point in terms of chainwheel diameter and gear ratios on the cassette on any particular bike such that crank length reduction may or may or not be that noticeable.

 

[Jag009]

For all you guys discussing crank lenth an interesting article

What is the best crank length for cycling?

How crank length affects power output and bike fit

www.bikeradar.com

 

[BeBiker]

I went from 165mm to 160mm to avoid pedal strikes.

Didn't like it, and after a few rides I changed it back.

 

[Clubby]

Power is equal to torque x speed.
Shorter cranks are theoretically easier to spin faster, although I know on my Bosch if you spin too fast the assistance definitely tails off.
On an ebike you have an easily accessible 85Nm of torque which depends very little on the strength of the rider. I just think it’s a non issue within the narrow range of cranks lengths available.
Feel is a different matter and all about personal preferences.

 

[Mikerb]

Interesting article but obviously mostly about road cycling. Something similar but focused on emtbs would be good. We have lower bbs, a motor, and when seated adopt a more upright position on the bike.......many of us also spend a lot of time standing on the platform provided by the cranks. So a lot of differences. A relevant point was made in the article about steeper seat tube angles and that is a feature on quite a few of the latest emtbs but mostly only talked about in terms of better climbing rather than its impact on power through the cranks.

 

[Giff]

No it has the Shape it link.

Thanks Bombie…..what is the difference and did you think it worth changing?

 

[Walkea]

Been thinking about changing from 165 to 155 cranks prmpted by this article. It is a few years old but it is MTB specific. https://www.leelikesbikes.com/shorter-cranks-for-my-stumpy-evo.html

 

[Jag009]

Been thinking about changing from 165 to 155 cranks prmpted by this article. It is a few years old but it is MTB specific. https://www.leelikesbikes.com/shorter-cranks-for-my-stumpy-evo.html

Have a look at this

 

[Jag009]

Interesting article but obviously mostly about road cycling. Something similar but focused on emtbs would be good. We have lower bbs, a motor, and when seated adopt a more upright position on the bike.......many of us also spend a lot of time standing on the platform provided by the cranks. So a lot of differences. A relevant point was made in the article about steeper seat tube angles and that is a feature on quite a few of the latest emtbs but mostly only talked about in terms of better climbing rather than its impact on power through the cranks.

Have a look at this

 

[Walkea]

Have a look at this

Don't follow embn. On the odd occasion I have watched the channel most of the videos seem full of fluff and very little real content. However I liked this video because it is a subject I was researching.
What would be interesting is a follow up video testing crank length on more varied UK type terrain as 165 to 150 maybe too much of a difference but 165 to 155 may be more of a sweet spot.
Thanks for posting it.

 

[Jag009]

Don't follow embn. On the odd occasion I have watched the channel most of the videos seem full of fluff and very little real content. However I liked this video because it is a subject I was researching.
What would be interesting is a follow up video testing crank length on more varied UK type terrain as 165 to 150 maybe too much of a difference but 165 to 155 may be more of a sweet spot.
Thanks for posting it.

I have been toying with the idea of going from 165 to 155 myself , so have been researching and asking fellow riders ,most have said 155 are the way to go , now just need to see what ones to go for and how much i want to spend