2022 Instinct shorter cranks possible?

[TaosMtb]

RM Customer Service told me you can not change out the 170cm cranks on a large frame to 165cm cranks due to a RaceFace Spindle compatibility issue. Anyone know anything about this? I would love less pedal strikes

 

[Rusty]

A bit on the longish side for an ebike. Have 165 and they are OK, but would be more than happy to go to 160, but if I rode with flats I really would have to go 160 - or 155.
170mm with flats would almost be like having a kick-stand

 

[Rusty]

Oh, and RM customer service is full of shit - ....

Specs as from Rocky Mountain
Race Face Aeffect Cinch 34T | 24mm Spindle | Crank Length: SM - MD = 165mm | LG - XL = 170mm

 

[TaosMtb]

In a follow up email they did tell me to ask my RM dealer about ordering shorter cranks. Perhaps I’ll try to get the 165 from the medium bikes.

 

[leftside]

For the Altitude, I spoke to my LBS and they said any 34T 24mm spindle cranks will work. These ebikes are not like usual ebikes where you need specific cranks.

I'm thinking of 160mm cranks if I can find some.

 

[TaosMtb]

For the Altitude, I spoke to my LBS and they said any 34T 24mm spindle cranks will work. These ebikes are not like usual ebikes where you need specific cranks.

I'm thinking of 160mm cranks if I can find some.

Thanks for the info. If you find something that works please let me know.

 

[leftside]

Thanks for the info. If you find something that works please let me know.

Yeah will do. I noticed quite the difference when going from 165mm to 155mm Miranda cranks on the Decoy.

 

[bonzoo]

For the Altitude, I spoke to my LBS and they said any 34T 24mm spindle cranks will work. These ebikes are not like usual ebikes where you need specific cranks.

I'm thinking of 160mm cranks if I can find some.

Are you sure about that? You have to install the spiderclutch on your cranks. AFAIK the clutch can be installed on RaceFace cranks. There's also a version for SRAM cranks but I'm not sure if it's compatible with the current Powerplay generation since all the models use RaceFace cranks.

 

[leftside]

Are you sure about that? You have to install the spiderclutch on your cranks. AFAIK the clutch can be installed on RaceFace cranks. There's also a version for SRAM cranks but I'm not sure if it's compatible with the current Powerplay generation since all the models use RaceFace cranks.

I'll double check. I have to admit they have got a few things wrong when it comes to ebikes...

 

[Pritchett]

For the Altitude, I spoke to my LBS and they said any 34T 24mm spindle cranks will work. These ebikes are not like usual ebikes where you need specific cranks.

I'm thinking of 160mm cranks if I can find some.

Your LBS is only partially correct. I was hoping to switch cranks as well, but since the spider clutch is only available with the Race Face spline, you will need crank arms that also have the Race Face spline - which seems to only be Race Face cranks.

I’m unsure of spindle length and chainring offsets required to play nicely with the Dyname motor. Since there are so many dang options, even for just race face cranks, I think I’ve decided to sit this one out for a while and see what ends up working for others.

I’d be really excited to find that Shimano or SRAM/Cane Creek cranksets will work, but a new spider clutch would be needed.

 

[S13]

Any progress with the shorter cranks?

The stock 170's on my altitude are too long imo, and my LBS has problems even finding a 165mm. They contacted raceface and got a pair of 165's but the spindle was too short. Go figure.

Anyway, i liked the 150 miranda's on my previous spectral on, so would be great to have something like that again.

 

[TaosMtb]

Need n

Any progress with the shorter cranks?

The stock 170's on my altitude are too long imo, and my LBS has problems even finding a 165mm. They contacted raceface and got a pair of 165's but the spindle was too short. Go figure.

Anyway, i liked the 150 miranda's on my previous spectral on, so would be great to have something like that again.

Need new BB92 30mm spindle 41x92 and Rocky 30mm lock ring to run Race Face Atlas 165mm. Lots of other suggestions on the PowerPlay Facebook group.

 

[Docste]

Oh, and RM customer service is full of shit - ....

Specs as from Rocky Mountain
Race Face Aeffect Cinch 34T | 24mm Spindle | Crank Length: SM - MD = 165mm | LG - XL = 170mm

Hi everyone!
My Altitude PP C70 (size M) was delivered with 170mm cranks instead of 165. I immediately asked my dealer to change them (under warranty), but I'm still waiting because it seems they won't be available soon.
If it were possible, I would mount an even shorter size because often, during riding, the pedals touch the ground in the most delicate passages. However, it seems that it is not that easy to find a compatible component

 

[S13]

Another problem with those 170mm Race Face cranks is that they apparently use the same crank mold for 175 and 170mm. The only difference is that the 170 has the hole drilled in a different place. But effectively the 170 crank is just as long as the 175. Thats not helping either!

 

[Docste]

Another problem with those 170mm Race Face cranks is that they apparently use the same crank mold for 175 and 170mm. The only difference is that the 170 has the hole drilled in a different place. But effectively the 170 crank is just as long as the 175. Thats not helping either!

I got the same impression...

 

[S13]

Ok, so one thing i did is to change the rear suspension flip chip from position 2 to 1, and that raised the bottom bracket about 5mm. That should be somewhat helpful at least.

 

[TaosMtb]

I got the same impression...

The new version no longer does that it’s a true 165 or 170.

 

[Docste]

The new version no longer does that it’s a true 165 or 170.

sorry, in what sense? thank you!

 

[Docste]

Ok, so one thing i did is to change the rear suspension flip chip from position 2 to 1, and that raised the bottom bracket about 5mm. That should be somewhat helpful at least.

do you mean the ride4? because from position 2 to 1, the bottom bracket goes down ...

 

[S13]

ok yeah apparently default is 3 and i moved it to position 4.

 

[Doug Stampfer]

Are there any downsides to running shorter cranks? Does it feel different when pedaling? Does it affect assistance levels at all? I'm running 170mms & wondering if it would be beneficial to run a shorter cranks

 

[Rusty]

Personally I see no downside to running shorter cranks on an ebike. Heck, having short legs I prefered 160 or 165 on my human powered bike The thing about crank lengths on a non ebike is that most are riding with a crank length that does not suit their leg length. Always used to swap them on many bikes. With an ebike I could run 150 or 155, giving way less chance of pedal strike and any leverage I lose is covered by the motor.

 

[Doug Stampfer]

Just checked & I am actually riding 165s. Luckily I didn't confirm the order...

 

[S13]

So ive searched everywhere and this is what i found so far...
Miranda isnt responding to my questions, so dont expect much from them any time soon.


On the Facebook powerplay group the best solution i found comes from Norman Cobb and involves buying a set of Atlas cranks and drilling them down to 155:

This applies to the '22 Altitude, but should also fit other powerplay bikes i would think.

What you need is:
- Atlas 175 crank, dont know the spindle size yet (Atlas Crankset)
- Larger 30mm bottom bracket (something like this?: BB92 Double Row CINCH 30mm)
- a 30mm lock ring from Rocky Mountain specifically for the clutch spider (dont have a part# yet)

You could also just get a 165 Atlas crank if that is all you need, then you dont have to drill the holes.

Very expensive if you ask me, but seems like this route is our only option now.

 

[DrChris]

What is the required spindle length on the Aeffect cranks? I've tracked down availability for some 165mm Aeffect R cranks but want to make sure the spindle is long enough.

Thanks!
DrChris

Any progress with the shorter cranks?

The stock 170's on my altitude are too long imo, and my LBS has problems even finding a 165mm. They contacted raceface and got a pair of 165's but the spindle was too short. Go figure.

Anyway, i liked the 150 miranda's on my previous spectral on, so would be great to have something like that again.

 

[S13]

The Aeffect R's are the smaller 24mm BB cranks just like the standard Ride cranks that come on lower specced Rocky Mountains.
So if they are similar to the Ride cranks you must buy them with the right spindle length from factory (no aftermarket swapping to a different spindle length possible, unlike the bigger 30mm cranks). And that means you must have the AM83(156.25) spindle, which is OEM Only. Good luck finding those!
In my other post ive linked to a document that might be of interest, it explains spindle sizes.

 

[DrChris]

Great, thanks for that, very useful info!!

The Aeffect R's are the smaller 24mm BB cranks just like the standard Ride cranks that come on lower specced Rocky Mountains.
So if they are similar to the Ride cranks you must buy them with the right spindle length from factory (no aftermarket swapping to a different spindle length possible, unlike the bigger 30mm cranks). And that means you must have the AM83(156.25) spindle, which is OEM Only. Good luck finding those!
In my other post ive linked to a document that might be of interest, it explains spindle sizes.