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  1. #1
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    Do you have both an SL/SLR and an HD and use Strava?

    Shot in the dark here:

    In my experience owning a mojo c and an HD, I've observed what some others have: the HD gives up a bit on the climbing for being a few lbs heavier and a bigger build but it doesn't feel like it really gives up that much.

    I'm curious if anyone has quantified how much they lose on the climbs. It seems to me like a good experiment would be one person with both bikes, and a record of multiple rides on the same routes with each. Just curious if anyone's got such a record, and would be interested enough in the answer to post some averages (e.g., average X minutes slower per 1000 feet).

    FWIW, no interest in reverting from the HD - totally worth it whatever the answer is.

  2. #2
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    I have both and use strava, but the bikes have a 5lb+ difference.
    I can say for sure the Mojo is faster uphill, but likely only due to weight.
    I have not quantified this, and likely never will.
    Those who know, ride a Mojo AND a Mojo HD.
    Quadzilla
    Quote Originally Posted by benja55
    Ok, whatever, cold water on my bike boner right there.

  3. #3
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    The HD actually climbs a little better, but 5 lbs is a lot to overcome. I'll throw a wild ass guess out there and say it would be about the same at a 2 - 3 lb difference if the rolling resistance was the same. Fast tires and shock tuning throw everything off though ; )
    That's going to be a hard test to do without controls for the other influential variables.

    H
    Hans
    Ibis Cycles, Inc.

  4. #4
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    Hans, where does the HD140 fit in there? Better then the 160 on climbs?

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    Quote Originally Posted by Bones2 View Post
    Hans, where does the HD140 fit in there? Better then the 160 on climbs?
    IMO, the HD 140 "should" climb slightly better since it's using a 68* head angle versus the 67* angle on the HD 160.

    With that said, they should be pretty damn close so long as each shock is properly tuned for the terrain as Hans noted above.

    It would be interesting to see a website or mag do a comparison of the Mojo SL, the SL-R, and the HD options. In a perfect world, you'd have two different builds and be able to see how each frame handles both extremes. Lightweight XC on one end and bomb-proof riding on the other.

    Personally, I'd love to see if anyone saw a major advantage for the HD 140 over the SL-R. For me, I'd take the weight savings any day.

  6. #6
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    Quote Originally Posted by d-bug View Post
    I have both and use strava, but the bikes have a 5lb+ difference.
    I can say for sure the Mojo is faster uphill, but likely only due to weight.
    I have not quantified this, and likely never will.
    Thanks - if ever you take a peek at a set of some segment times on each bike, would be interesting to see how far off you are. But i hear you - I time my rides in 1/2 hour increments, so wouldn't be one to crunch numbers for this purpose myself.

    Quote Originally Posted by hanssc View Post
    The HD actually climbs a little better, but 5 lbs is a lot to overcome. I'll throw a wild ass guess out there and say it would be about the same at a 2 - 3 lb difference if the rolling resistance was the same. Fast tires and shock tuning throw everything off though ; )
    That's going to be a hard test to do without controls for the other influential variables.

    H
    Now that is an interesting observation. Are you suggesting that the HD climbs efficiently enough to negate 1/2 of the efficiency lost to the extra build? (5lb vs. 2-3lb difference?). That would be astounding.

    And yes on the experiment. I'm more interested in big bike/little bike comparison than frame/frame comparison. Average difference over a number of rides to get a guesstimate would be good enough for me. Law of large numbers etc.

    Just curious to ballpark how much I'm giving up in suffering on the climbs for the privilege of the downs on the HD. Again, not that it would change anything about my bike choice

  7. #7
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    The HD 140 and 160 should be about the same climbing, all else being equal...

    Here's some food for thought: Let's say you have a 175 lb guy with a 25 lb bike, for a total of 200 lbs (nice round number) who is going to climb a steep hill (slow, not much aerodynamic loss) that takes about 10 minutes putting out 300 watts.

    In this case a 2 lb increase will be 1% of the total weight. Since most of your energy is going into lifting your weight up the hill when climbing at low speeds, it's probably roughly proportional to scale the climbing time to the weight. Very rough, but OK for a quick and dirty comparison.... So, a 10 minute climb (600 seconds) with an extra 2 lbs (1%) added might become about 6 seconds longer. (1% of 600)

    Now another virtual test: Different tires
    It's pretty easy to see 10-20 + watt differences in tire rolling resistance on mountain bike tires, so let's say you swap to some fast tires and save 15 watts. That is 5% of your power total saved and will get you up the same hill about 30 seconds faster. You're getting closer to that Strava KOM : )

    If the suspension kinematics or shock tuning can save you 3 watts (1% of your power), they can equal out a 2 lb increase on the 200 lb bike / rider combination (1% of your weight).

    OK, that's enough imprecision for one night, but you can see the point.

    Saving weight off your bike is helpful for climbing but other factors can be more influential than people realize. It's easy to weigh a part or a bike, but not that easy to check other aspects like rolling resistance and suspension efficiency.

    One test I used to do was a 3.5 hour 5000 ft of climbing ride and I'd time it with different tires. The fastest tires saved 30 minutes over the Nevegals I started with. They were sketchy and I had more fun on the Nevegals, but the speed was really noticeable. I bet there was a 30 watt difference or something like that.

    G'night!
    H
    Hans
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  8. #8
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    Quote Originally Posted by hanssc View Post
    The HD 140 and 160 should be about the same climbing, all else being equal...

    Here's some food for thought: Let's say you have a 175 lb guy with a 25 lb bike, for a total of 200 lbs (nice round number) who is going to climb a steep hill (slow, not much aerodynamic loss) that takes about 10 minutes putting out 300 watts.

    In this case a 2 lb increase will be 1% of the total weight. Since most of your energy is going into lifting your weight up the hill when climbing at low speeds, it's probably roughly proportional to scale the climbing time to the weight. Very rough, but OK for a quick and dirty comparison.... So, a 10 minute climb (600 seconds) with an extra 2 lbs (1%) added might become about 6 seconds longer. (1% of 600)

    Now another virtual test: Different tires
    It's pretty easy to see 10-20 + watt differences in tire rolling resistance on mountain bike tires, so let's say you swap to some fast tires and save 15 watts. That is 5% of your power total saved and will get you up the same hill about 30 seconds faster. You're getting closer to that Strava KOM : )

    If the suspension kinematics or shock tuning can save you 3 watts (1% of your power), they can equal out a 2 lb increase on the 200 lb bike / rider combination (1% of your weight).

    OK, that's enough imprecision for one night, but you can see the point.

    Saving weight off your bike is helpful for climbing but other factors can be more influential than people realize. It's easy to weigh a part or a bike, but not that easy to check other aspects like rolling resistance and suspension efficiency.

    One test I used to do was a 3.5 hour 5000 ft of climbing ride and I'd time it with different tires. The fastest tires saved 30 minutes over the Nevegals I started with. They were sketchy and I had more fun on the Nevegals, but the speed was really noticeable. I bet there was a 30 watt difference or something like that.

    G'night!
    H
    This is a great explanation - thank you.

    What I like best is that it puts things in context well. The interesting part of this to me is that, based on your back of the envelope numbers, the biggest moveable levers here are a) rolling resistance and b) fitness, that these two are probably similar in the amount of change one can reasonably make in a short time, that either of them outweighs the potential changes from of bike weight and suspension by an order of magnitude.

    So, given that I'm not worried about seconds, this help me to conclude: enjoy the HD, but think about paying some attention to training as opposed to riding if I want to keep the 2.4s on it.

    A follow-on question would be: how do I improve the suspension kinematics on my HD? I have just learned that going from 36/24 chainrings to a 34/24 might be better optimized for dw-link. If this is true, I will see if I can get a "free" 1% that way

  9. #9
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    I've tried something like this. Im on strava and have a mojo hd 160. On longer rides with lots of climbing I used to switch the rear to 140, but leave evey thing else the same. I thought the less travel would equal easier climbing. Well, I quickly found that it felt the same in 140mm as it did in 160mm mode just that I was giving up travel. My strava times confirmed this. I no longer bother switching back in forth on the rear between 140mm and 160mm. Now If I was to switch the rear to 140 and also put a lighter fork, wheels and tires then Im sure I would see in improvment. That improvment would come from a lighter bike and not less suspension.

  10. #10
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    It also depends what you're climbing. Around these parts we don't ride more than 1/2 a mile of fire roads in 3-4 hours. It's all single track and the climbs are typically, steep, techy, rocky, punchy affairs. I am quicker on those climbs on my 160mm dual suspension 31 lb bike than I am on my 100mm dual suspension 23.5 lb bike. This is because i dab way more on the shorter travel bike. But on the truly long non techy climbs the light bike wins.

  11. #11
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    Quote Originally Posted by wilks View Post
    It also depends what you're climbing. Around these parts we don't ride more than 1/2 a mile of fire roads in 3-4 hours. It's all single track and the climbs are typically, steep, techy, rocky, punchy affairs. I am quicker on those climbs on my 160mm dual suspension 31 lb bike than I am on my 100mm dual suspension 23.5 lb bike. This is because i dab way more on the shorter travel bike. But on the truly long non techy climbs the light bike wins.
    Excellent point. The travel and grippy tires really earn their keep when you are on the edge of making a section or not.
    Hans
    Ibis Cycles, Inc.

  12. #12
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    I found Hans's explanation that the HD is a slightly more efficient climber than the SL to be in line with my observations when I switched from a SL to an HD. I ordered my XT equipped SL in 2010 with a Talas 36 with plans to move all for the parts to an HD. Once I got my HD the only difference between the two bikes was the frame/shock, Hope/Flow wheels and a new chain. I even moved my used tires to the HD. I was very surprised after my first couple of rides to find the HD climbed better than the SL. I was expecting just the opposite. I have been riding the same trails for twenty years so I immediately notice small differences in bike setup.

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