I'm looking at upgrading my 3x to a 1x and will more than likely be ordering the SRAM GX Eagle groupset this afternoon. I know the general trend is to go to a shorter crank length on tri bikes, but I'm struggling to find any info on mountain bikes. I've spent some time researching it and the anecdotal results seem to be inconclusive I'm 5'10 with a shorter inseam and was considering going with 165 cranks or maybe 170, but I know mountain bikes are usually spec'd with 175. A few people have said that the shorter cranks have helped with lower back pain, which is a huge issue for me on the mountain bike, but that's anecdotal at best. Any thoughts/experience?
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Re: Mountain Bike Crank Length [Toefuzz]
[ In reply to ]
This has worked for me:
165mm - TT.
170mm - Road/CX.
170mm - MTB
165mm - TT.
170mm - Road/CX.
170mm - MTB
Re: Mountain Bike Crank Length [Toefuzz]
[ In reply to ]
The push for shorter cranks on a TT bike is driven by position. Is your MTB position going to be similar to your TT position? (Hint: no).
I wouldn't go any shorter than 170, although you may not even notice the difference between that and 175 when out on the trail.
I wouldn't go any shorter than 170, although you may not even notice the difference between that and 175 when out on the trail.
Re: Mountain Bike Crank Length [Toefuzz]
[ In reply to ]
Something to consider is pedal strikes - longer cranks will result in more impact on rocks, logs, and when pedaling through ruts.
Re: Mountain Bike Crank Length [Toefuzz]
[ In reply to ]
I have back pain on the MTB as well, but that's really more to do with all of the upperbody movement required than crank length. 175's are fine, and the leverage is nice to have when you are trying to power your way through a tricky section and forget or didn't have time to shift.
don't forget, shortening your cranks will result in higher saddle and higher bars, raising your centre of gravity.
Swimming Workout of the Day:
Favourite Swim Sets:
2020 National Masters Champion - M50-54 - 50m Butterfly
don't forget, shortening your cranks will result in higher saddle and higher bars, raising your centre of gravity.
Swimming Workout of the Day:
Favourite Swim Sets:
2020 National Masters Champion - M50-54 - 50m Butterfly
Re: Mountain Bike Crank Length [Toefuzz]
[ In reply to ]
aside from the "fit" aspect, many current mtbs have dropped the bottom bracket substantially. That could play into your choices as well. I ride 165 on my Pivot 429 Trail but 170 on most everything else. ymmv
Re: Mountain Bike Crank Length [Toefuzz]
[ In reply to ]
Get the 175s. Bike Position on the trail varies as does seat height with the dropper post. Don't worry about pedal strike, this is technique. Level the cranks where needed to avoid pedal strike and use the ratchet technique in the ruts. I'm 5'9" with a 30 inch inseam and have no problems with the longer cranks.
Re: Mountain Bike Crank Length [ChrisT]
[ In reply to ]
ChrisT wrote:
Something to consider is pedal strikes - longer cranks will result in more impact on rocks, logs, and when pedaling through ruts.noticed this big time switching to 170 from 175 on my XC bike.
Re: Mountain Bike Crank Length [roubaixman]
[ In reply to ]
roubaixman wrote:
Get the 175s. Bike Position on the trail varies as does seat height with the dropper post. Don't worry about pedal strike, this is technique. Level the cranks where needed to avoid pedal strike and use the ratchet technique in the ruts. I'm 5'9" with a 30 inch inseam and have no problems with the longer cranks.not always true, depending on trail.
Toefuzz wrote:
I'm looking at upgrading my 3x to a 1x and will more than likely be ordering the SRAM GX Eagle groupset this afternoon. I know the general trend is to go to a shorter crank length on tri bikes, but I'm struggling to find any info on mountain bikes. I've spent some time researching it and the anecdotal results seem to be inconclusive I'm 5'10 with a shorter inseam and was considering going with 165 cranks or maybe 170, but I know mountain bikes are usually spec'd with 175. A few people have said that the shorter cranks have helped with lower back pain, which is a huge issue for me on the mountain bike, but that's anecdotal at best. Any thoughts/experience?Don’t order that group. Literally and by far the fussiest, most poorly designed group set I’ve ever dealt with. The B limit tolerance is a head ache that requires a special tool and the two narrow wide cogs on the cassette make a tooth skipping shift unavoidable. Check mtbr.com as I’m not alone. XT Di2 is $550 or so right now with a trigger shifter and holy hell is it infinitely better