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It seems like a good portion of 29" hardtail's have low bottom brackets. I took one for a test ride and was pedal striking roots that are easily cleared on my 26" hardtail.

How do you compensate for the lower bottom brackets? Do you have to learn to become a better/stronger pedaler? Does it require greater 'muscling' of the bike to be able to lean away from potential pedal strikes?

I guess you can also spend money on thinner pedals and/or shorter cranks, but I don't think those would eliminate the problem entirely.

Thx.
 

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I think it depends on the design of the bike. On prior bikes with a lower bb, I had more strikes than my current bike.

The benefit of a higher BB - fewer pedal strikes.

Benefit of a lower bb - more stability, and more of a feeling of riding "in" the bike verses perched up "on" the bike.

In retrospect, I would go with the lower bb in the future. I just learned to time things more with respect to obstacles.
 

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Although many companies and gravity riders seem to push the low BB, I tend to like just the opposite. For example, the RM Vertex is the most flickable amazing 29er hardtail I have ever ridden. It has a 56mm BBD, which is a fairly small BBD/fairly high BB height. Scott Spark 29er feels much better with the geometry chip in the high setting which yields a higher BB than its low setting.
 

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Assuming it's true (I don't feel like looking at BB numbers for a large sample of bikes to prove or disprove the assumptiion), you can also run a longer fork. That slackens the steering a little bit, but sometimes that's a good thing. I run a 140mm fork on my Honzo, which was designed for a 120mm. Works great.

Personally, I don't like the trend towards low BBs on any wheel sized bike. I run the EBB on my SIR9 in the high position (12 o'clock to 3 o'clock) to prevent pedal strikes when climbing uphill rock gardens. You can try to time your pedal strokes by backpedaling strategically, but that's a pain in the butt.
 

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ballbuster
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It seems like a good portion of 29" hardtail's have low bottom brackets. I took one for a test ride and was pedal striking roots that are easily cleared on my 26" hardtail.

How do you compensate for the lower bottom brackets? Do you have to learn to become a better/stronger pedaler? Does it require greater 'muscling' of the bike to be able to lean away from potential pedal strikes?

I guess you can also spend money on thinner pedals and/or shorter cranks, but I don't think those would eliminate the problem entirely.

Thx.
Heh... I like low bottom brackets. It makes the bike feel more like it's on rails in roller coaster singletrack. Pedal strikes? meh... learn to time your pedals. Really, if you're pedal technique really requires that extra 1/4" of clearance, it seems like you are riding with micrometers for eyes.
 

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learn to time your pedal cadence and you will be fine. The lower BB definitely makes the bike feel more stable going down and through fast turns.

Are you on the east coast?
 

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Although many companies and gravity riders seem to push the low BB, I tend to like just the opposite. For example, the RM Vertex is the most flickable amazing 29er hardtail I have ever ridden. It has a 56mm BBD, which is a fairly small BBD/fairly high BB height. Scott Spark 29er feels much better with the geometry chip in the high setting which yields a higher BB than its low setting.
I'm confused by your analysis. You claim to favor higher bottom brackets, yet you like the Vertex, which has a lower bottom bracket than the Spark in either of its positions.

Spark (high) = 41mm BBD / 12.8" BBH
Spark (low) = 48mm BBD / 12.5" BBH
Vertex = 56mm BBD / 12.2" BBH
 

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Bigger tires will also bring the BB up if you have the clearance on the frame / fork.

I can't say whether I like a low or high BB. It depends on whether I'm going up or down. Low BBs corner and descend better. High BBs make technical climbs easier.

Keep in mind that if your BB is on the low side, you will eventually get better at knowing when to pedal, and how to ratchet your pedals. Each pedal strike is like getting a little electric shock that says "don't do that".
 

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What are we calling "low" or "high"?

Most every MTB I've ever owned (26ers and 29ers) had a BB at ~12". One StumpJumper was 11-3/4. That seems to be an average BB ht. range. I run 175mm cranks.

The full sussers bother me the most, though, since the BB ht. goes from 12" to 8" or 7".

In any case, I strike pedals all the time on my downstroke if it means I will continue forward in a low-speed technical scenario. If you have any momentum, though, you shouldn't be having pedal strikes. In that case, you ratchet pedal, or steer, or hop (maybe sideways), or back up and adjust your line.

-F
 

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I'm confused by your analysis. You claim to favor higher bottom brackets, yet you like the Vertex, which has a lower bottom bracket than the Spark in either of its positions.

Spark (high) = 41mm BBD / 12.8" BBH
Spark (low) = 48mm BBD / 12.5" BBH
Vertex = 56mm BBD / 12.2" BBH
My point was that for a hardtail 29er, I seem to prefer a high BB relative to other hardtail 29ers. For example, some HT 29ers have a BBD of 65mm which is a durn low BB height. Re the Spark, my simple experiment on only one model of one bike shows that I prefer the higher BB to the lower BB position on the same bike. I haven't compared hardtails to FS. Fyi I am an tight singletrack east coaster looking for a climber rather than a descender.
 

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transmitter~receiver
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It seems like a good portion of 29" hardtail's have low bottom brackets. I took one for a test ride and was pedal striking roots that are easily cleared on my 26" hardtail.
Why does it seem like that? One test ride?
The numbers don't bear that out... and they don't lie. It may be an adjustment you have to make for something you're not used to, but it's not lower bottom bracket.
 

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Wow. I just started randomly looking at Bike sites and looking at bottom bracket height and they're really not that low, yet I was under the able impression as OP. Turns out my old scale that I used to run 180mm cranks on (and not pedal strike almost ever) had the exact same bb height as my current f29.

Note the the Cannondale site lists bb height but the Scott site only lists offset. It had the scale at -2.5, so I did the following: (29÷2)-2.5=12. Please tell me if I'm wrong here.
I guess than it would have to be other factors like wheelbase and Q factor that would have to be the explanation.

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The 12 on my f29 is pretty low, in my opinion. (especially compared to the 13.3 on my trail rig)

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Comparing BB height between an XC hardtail and a trail "rig" is not really apples-to-apples, especially if your "rig" is full suspension.
Cannondale's own bike specs show the skew in your claim:
  • The Trail (HT 26") has the same 12" BB height as your F29.
  • The full sus Trigger 29 has a BB height of 13.7" which is only 0.1" lower than the Jekyll... and both are higher than your "rig."
 

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Comparing BB height between an XC hardtail and a trail "rig" is not really apples-to-apples, especially if your "rig" is full suspension.
Cannondale's own bike specs show the skew in your claim:
  • Cannondale's "trail" HT 26" has the same 12" BB height as your F29.
  • The "trail" full sus Trigger 29 has a BB height of 13.7" which is only 0.1" lower than the Jekyll.
Yeah I had that thought after I posted it. Realized it was stupid because the OP was comparing 2 different wheel sizes and both my bikes are 29ers. So yeah, I'm dumb Lol.

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Yeah I had that thought after I posted it. Realized it was stupid because the OP was comparing 2 different wheel sizes and both my bikes are 29ers. So yeah, I'm dumb Lol.
You're not dumb... some things like that are counter-intuitive, which is why it takes looking at the numbers to really know. Plus there are plenty of peopl (especially MTBR posters) who will just say crap like that without knowing, spreading the myth.
Many people experience more pedal strikes when they switch to 29" wheels, but it's not because of BB height.
 
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