Post Your MUni here!

[mowcius]

Aggressive downhill runs don't end well with short cranks.

Now that's why you roll with a disk brake (or HS33).
The only reason I found for long cranks was for powering up hills, long cranks downhills are far too bouncy and try and throw you off - smooth pedalling with shorter cranks and steady braking is a far better plan.

[JacobSpera]

Originally Posted by entropy

Good to know.

Aggressive downhill runs don't end well with short cranks.

Just need brakes, and a pair of jumbo size balls or a pea size brain

[entropy]

Originally Posted by mowcius

Now that's why you roll with a disk brake (or HS33).
The only reason I found for long cranks was for powering up hills, long cranks downhills are far too bouncy and try and throw you off - smooth pedalling with shorter cranks and steady braking is a far better plan.

I think our ideas of "aggressive downhill" are perhaps wildly divergent.

[jogi]

especialy in such rough terrain i love my 140mm (26" magura) cranks cause i have much more clearance to ground / rocks

i can remember rides were my friend cant ride cause his cranks (without brake) were to long for the narrow eroded path...

[magicollin]

Originally Posted by entropy

I think our ideas of "aggressive downhill" are perhaps wildly divergent.

Whoa, that's gnarly! I'm trying to figure out where you are descending from, or if you just mounted near where you're at and had the photo snapped.

[mowcius]

Originally Posted by entropy

I think our ideas of "aggressive downhill" are perhaps wildly divergent.

Nope, I'll happily ride things like that with my disk brake, HS33 not so much. Looks fun though!
Riding a 24" rather than my 29" down the most technical stuff is normally the best plan.

especialy in such rough terrain i love my 140mm (26" magura) cranks cause i have much more clearance to ground / rocks

i can remember rides were my friend cant ride cause his cranks (without brake) were to long for the narrow eroded path...

Very true - I have knocked longer cranks on rocks/ground many times where riding space is tight.

[rob.northcott]

I think entropy knows what he's doing mate! I suspect he rides long cranks because they work for his riding, not because he doesn't know any better He's quite good you know (look up some of his older posts)

[Nurse Ben]

think entropy knows what he's doing mate! I suspect he rides long cranks because they work for his riding, not because he doesn't know any better He's quite good you know (look up some of his older posts)

Yeah, that's some gnarly stuff, I wouldn't want to roll that and have to rely on short cranks and a brake. But, some folks seem to prefer short cranks and brakes, so it's probably an issue of style and what you're used to.

I've ridden short and long cranks, I am now back to 165's on my 29er and 150's on my 26er, 170's on my 36er. Long cranks can be spun just fine, all you need to do is ask a biker if they can spin 170-175;s

I rode my 29er and my 26er over the weekend, and though my 26er was easier to maneuver due to the smaller wheel, I felt like the relatively shorter cranks made the uni less stable; I'm thinking of bumping up to 160's. I like spinning the more flowing trails on shorter cranks, but on tech stuff at slower speeds I want the longer cranks to reduce bobble and to maximize power as I roll obstacles.

This reminds me of discussions over the optimal use of a geared hub for muni. I've seen some pics/vids of highly skilled riders managing high gear off road, but those trails are relatively tame, so I think the trail conditions really dictate what works best, though obviously skill level plays a part. In Entropy's defense, no one is riding that sort of DH with short cranks, not even Kris and his peers.

Anyone who runs a brake knows that there is a downside to short cranks: brakes can not incorporate balance and speed control, so you lose fine control over the wheel. Also, brakes tend to grab and can force your wheel off line, esp disc brakes which pull the wheel to one side.

With long enough cranks I can ride a tech downhill on crank power alone, but I can't say the same with short cranks and brakes.

Now that I have long cranks again, I have more control on the down, more power on the up, and I use the brake less.

[entropy]

That previous pic is of Eyal from five years ago; he is indeed descending along a trail, albeit carefully. These days I tend to 29er that sort of terrain.

I would point to this post by Kris about crank length. The backstory for the trip is that we forgot to bring his muni on the second day in Squamish, so he was borrowing Eyal's for large sections.

That said, muni setup is definitely all about what works best for you and your trails. I tried short cranks for a year or two once upon a time and unlike a lot of muni folk, I did not enjoy it all that much. I found that pedal strikes were easily averted by taking the high line. A rim brake never was and never will be an option (true rims are for riders with technique ), but my knees might someday be convinced to try a disc brake on the 29er.

Bringing my foray in this thread full circle: I'm clearly in the minority with respect to crank length; rugged long cranks (above 165) are difficult to find!

[Nurse Ben]

Hey Entropy, you're not alone in the long crank perference

Like you, I tried shorter cranks, and though I liked them in some ways, like smooth spinning on my 29er, I found they just didn't provide the same level of control and power I was used to, so I went back. I have 165's on the 29er now, but prev ran 170's.

In terms of knee pain, I think short cranks increase knee issues. I started having knee issues last year AFTER I started playing with short cranks. At first I thought it was an offset thing, riding with my feet to close together, but I am not convinced that the short cranks were putting excessive pressure on my knees during climbs and descents. Since going back to long cranks my knees have been fine.

For ISIS splined hubs, there are a number of trials cranks that can be had in 175, maybe even 180. I'm looking at some 175's now, just need to find a place that has them in stock in the USA; most are in the UK.

ISIS Crank choices: QuAx Chromoly Tubular Street Cranks 170mm, I run these on my 36er, super durable and lightwieght.

Trial Tech 175: http://www.biketrial.si/shop/product...products_id=80
Tensile COmp or Urban 175: http://www.rocknrollbikes.com/trials...tml#Size=170mm
Onza 175: http://www.rocknrollbikes.com/trials...itanium%20Grey
Middleburn 165-180: http://www.middleburn.co.uk/cranks_rs7.php

[entropy]

Originally Posted by Nurse Ben

Hey Entropy, you're not alone in the long crank perference

Brothers in (crank) arms.

In terms of knee pain, I think short cranks increase knee issues.

I've had similar thoughts.

For ISIS splined hubs, there are a number of trials cranks that can be had in 175, maybe even 180. I'm looking at some 175's now, just need to find a place that has them in stock in the USA; most are in the UK.

If you do find a source in the US, post a follow up. Lately I've had to rely on imports to maintain my habit.

[mowcius]

I think entropy knows what he's doing mate! I suspect he rides long cranks because they work for his riding, not because he doesn't know any better He's quite good you know (look up some of his older posts)

Oh I'm not doubting that, I was just making the comment that my idea of aggressive downhill is no different

[napalm]

um- but he also admitted to not using a brake. I will admit, that if 90% of the trails that I rode all the time was like the one in entropy's picture i'd be on a 26 with 150s and a brake. Contrary to what some people think, when you can actually use a brake in technical downhill (instead of just drag braking on a slighter, more constant slope) you have MORE control than with leg power alone. It takes a long time to get to that point- but it once you do, only then will you understand.

At UNICON in wellington in the Super DH course I was one of only a very small group of riders who cleared a particular section of really steep, ledgy, loose and rooty trail in the actual race. Even David W (Current World Champ who does not run brakes struggled here). You can see the footage in this vid at 1m 30.

UNICON XV - YouTube

Anyone who runs a brake knows that there is a downside to short cranks: brakes can not incorporate balance and speed control, so you lose fine control over the wheel. Also, brakes tend to grab and can force your wheel off line, esp disc brakes which pull the wheel to one side.

I agree that in some circumstances brakes are a compromise. For example, when I was using 125mms on my 24"GMuni. They were just too short to be appropriate for super gnarly DH- even with skilled braking. That was a compromise I was willing to make because I very rarely rode purely DH muni. But to say that brakes can not incorporate balance and speed control is ridiculous! What are they there for then? To look good?! Any day of the week i'd take a 26 with 137s and a good brake than a 26 with 175s and nothing.

Different strokes/different folks- But I think a shorter crank+ brake set up is going to be much more versatile for most riders,

Mark

[MadFurai]

Originally Posted by napalm

Any day of the week i'd take a 26 with 137s and a good brake than a 26 with 175s and nothing.

Different strokes/different folks- But I think a shorter crank+ brake set up is going to be much more versatile for most riders,

Mark

Again, I think the biggest factor is what type of terrain you prefer to ride. Sure, if all you do is DH or XC, then 137's on a 26 might be fine. However, some of the hills I climb are fairly difficult with 150's on my 24. I'd be surprised if many riders could clean them consistently with 137's on a 26.

Also, I don't think Kris was stating that brakes don't give you any balance or speed control. However, shorter cranks mean less leverage, and that equates to giving up a certain amount of speed control and balance. With experience, a brake can compensate in some cases, but not all.

For the most versatile setup, I think average crank length and a nice brake gives you the most options. Shorter cranks are always going to limit your climbing and hopping ability.

[mowcius]

I don't think any of us can deny that longer cranks can have some advantage on some terrain and with practice, a brake can also provide a lot of control.
If cranks are too short then I also agree, there can be times when your feet also need to play a part in control on uneven dropoffs etc and this would be more difficult, but even more so without a brake at all.

Anyone who runs a brake knows that there is a downside to short cranks: brakes can not incorporate balance and speed control, so you lose fine control over the wheel. Also, brakes tend to grab and can force your wheel off line, esp disc brakes which pull the wheel to one side.

I'm still dubious about the grabbing comments, yes my HS33s grab very slightly more in some places on my 24s rim than in others, but I've never found it throw me off-line, merely a bit too far forward or back.
With my disk, I have as of yet with plenty of riding on it, not experienced any kind of pull to one side or the other - presumably the only way you would get this would be twisting of the frame due to more of a pull on the disk side.
The disk most definitely voids the fine control comments though, once you've learnt the bite point of your lever, fine control can be absolutely fantastic, in some ways better than with your feet as you can brake in between pedal strokes.

However, some of the hills I climb are fairly difficult with 150's on my 24. I'd be surprised if many riders could clean them consistently with 137's on a 26.

This obviously depends on the rider - and we can't judge anyone else here.
The larger the wheel, the slower you have to pedal to maintain the same speed which can have a large effect on traction going up a hill. Longer cranks can also enable you to power over larger bumps going uphill but as far as smooth hills go.
I find keeping momentum and a more even pedalling rhythm going up hill far preferable to trying to slow down and power up with longer cranks (even on the steeper climbs). I've always been a bit of a hill racer

When did we get onto long cranks and uphills anyway?