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Thread: the crow is in

  1. #51
    Harmonius Wrench
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    Wheel height or diameter?

    Bruce, I am curious if the over all height of your Delgado Disc/ Crow set up is similar or much different than any other combos you might use, like the XR with the DD rim, for instance. Maybe it's similar in over all diameter to a 1.8 XR.

    The reason I ask is that I am wondering if the diameter is more than one to two millimeters in difference. If it is, does that affect trail measurement enough for you to notice it in the handling department?

    Maybe I'm splitting hairs here or maybe I'm full of it, but I am curious.

  2. #52
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    Quote Originally Posted by BruceBrown
    ...I need to mount one of the Crows up on one of my Dyads to get the "official" volume index to mate with Shiggy's excellent specifications data...
    I will be getting The Crow soon.

    I have not received Karmas yet.
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  3. #53
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    Quote Originally Posted by Guitar Ted
    Bruce, I am curious if the over all height of your Delgado Disc/ Crow set up is similar or much different than any other combos you might use, like the XR with the DD rim, for instance. Maybe it's similar in over all diameter to a 1.8 XR.

    The reason I ask is that I am wondering if the diameter is more than one to two millimeters in difference. If it is, does that affect trail measurement enough for you to notice it in the handling department?

    Maybe I'm splitting hairs here or maybe I'm full of it, but I am curious.
    Splitting hairs? Or are you trying to get me to putter around tomorrow on yet another one of my precious vacation time days?

    I could take some comparison measurements on the DD rim with a few tires until I get tired of changing tires (XR 1.8, 2.2/2.25; ACX's; Nanos; Exi's; Klaws - anything in particular you want for comparison's sake?).

    The XR 1.8 will measure narrower and shorter than the Crow on the DD rim, but I'll have to wait until tomorrow to run that calculation as I am in my Jams about to hit the sack. I'm pretty sure it is more than 1 or 2mm in both measurements as the Bonty measurement on the tire says 44/46.

    The Crow is a legitimate 2" mountain bike tire. Handling is good with both tires, but different. Due to the narrownes of the XR 1.8, I found that a higher psi needs to be used which causes the ride to get a tad harsh. But not a problem for certain terrain to ride that way. No harshness with the Crow at 30 psi and rolling resitance does not suffer at that pressure. I tried 'em at 35 - 37 as well and frankly, couldn't tell any difference in speed and resistance at 30 - so I left them there. If I had to choose some sort of subjective description - in spite of the Crows being lighter, I feel more anchored to the ground with them which in turn improves my handling. Not sure that makes any sense outside of my mind, but that's what is running through my thoughts in describing it. About as close as one can get in another 29"er tire on the market that I own and have ridden would be the Nanos. Very similar feel - except for the weight.

    I have a rather large "Honey Do" list looming for tomorrow. Damn I hate landscaping. It all dies and gets covered in snow in 5 months anyway.......... Not to mention we've only had .13 of an inch of rain in June making all that tilling, shoveling and planting kind of pointless in this drought. I'll try that excuse on the wife tomorrow to see if I can get some puttering time with the tires for you to get some more measurements.

    BB

  4. #54
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    Quote Originally Posted by Soupboy
    50-60%? Where is that figure from? At what point does the effort to eliminate rolling resistance begin to eliminate traction? Seems to me that there is a high correlation there so you can't have it both ways. It comes down to the surface you plan to ride on.
    The faster you ride, the greater the air resistance chunk is, as air resistance ramps up prograssively, whereas rolling resistance is liniair.
    With MTB's on knobby tires, riding bumpy trails that are often somewhat soft, speeds are slower. Most of your energy gos towards deforming tires and trail, not folding up air.
    If you average 12mph on your off-road rides, try rolling 12mph on a slick tire bike on the flat, see how little effort it costs. On the MTB, you get the same air drag give or take, all the extra energy is rolling resistance.
    No rolling resistance would make an MTB faster than a road bike, scary :-)

    Distantly related : on the moon, there is no atmosphere, so no air drag. Imagine a long smooth road, and a bike with unlimited gears. Your top speed would only be limited by drivetrain losses and RR, making 100mph not impossible. Watch out if there are bumps in that road, though, you get serious airtime :-)
    Klok - XC - Skate - Ski

  5. #55
    Harmonius Wrench
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    Thanks Bruce!

    Thanks! It sounds as though the XR 1.8 is going to yeild the "shorter" height, so my theory on the Crow looks to be hogwash anyway. Don't get yourself in any "hot water" on my account with your wife and certainly do ask to go out for a ride instead! No sense in wasting time off measuring tires for a greasy shop mechanic in Waterloo!

  6. #56
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    Unless I'm mistaken, the trail measurement shouldn't change. You'd have to change the distance between the hubs for that to happen. The tire hits the ground directly below the hub, no matter what size it is.

  7. #57
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    Quote Originally Posted by one1spede
    Unless I'm mistaken, the trail measurement shouldn't change. You'd have to change the distance between the hubs for that to happen. The tire hits the ground directly below the hub, no matter what size it is.
    You are mistaken. Trail has nothing to do with wheelbase.

    All about head tube angle, fork offset and wheel/tire radius. For the same HTA and offset a smaller diameter tire decreases trail, a larger tire increases trail.
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  8. #58
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    Cool, thanks for keeping me inline. Appreciate the info.

  9. #59
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    Quote Originally Posted by Guitar Ted
    Thanks! It sounds as though the XR 1.8 is going to yeild the "shorter" height, so my theory on the Crow looks to be hogwash anyway. Don't get yourself in any "hot water" on my account with your wife and certainly do ask to go out for a ride instead! No sense in wasting time off measuring tires for a greasy shop mechanic in Waterloo!
    Ted, we had rain this AM which took me off the hook for the "Honey Do" list for a few hours. So I was out in the garage with a cup of coffee, KGGO from Des Moines blasting heavy metal rock from my era on the Bose and mounting tires for you.

    Using this page on Shiggy's site:

    http://www.mtbtires.com/tech/measure.html

    I took a few measurments using Shiggy's model (in a quasi sort of way while dancing to the music) and here are the key measurements I took with the full explanation of those measurements at Shiggy's link:

    CW - casing width
    CH - casing height
    TW - tread width
    CH + T - casing height + tread (top edge of rim to top of tread which is my own blended measurement and not one Shiggy uses)
    R1 - overall radius

    Measured all tires at 40 psi using a Bontrager 29"er tube. Used the Delgado Disc rim (29mm width on the outside) and the Velocity Dyad rim (24mm width on the outside). All tires have been used and stretched for more than 72 hours. I took 3 measurements and averaged for the final number. My numbers may obviously differ from his due to the tools used, variations in the tires we own and amount of coffee consumed. What's a partial mm here or there?

    I also have 6 photographs to give you a "visual" of some of the tires mounted up on the Dyads and Delgado rim to add to the numbers. My main focus was the Crow, Nanoraptor and XR 1.8. I threw in the XR 2.25 since it is the fullest volume tire currently available and the ACX since it was already mounted on the Dyad rim when I started the project this AM.

    ============================

    Bontrager ACX mounted on the Dyad rim at 40 psi

    CW = 51mm
    TW = 53mm
    CH + T = 50mm
    R1 = 371mm

    The Crow mounted on the Dyad rim at 40 psi

    CW = 49mm
    TW = 45mm
    CH + T = 47.5mm
    R1 = 368mm

    Nanoraptor mounted on the Dyad rim at 40 psi

    CW = 50mm
    TW = 47.5mm
    CH + T = 50mm
    R1 = 371mm

    XR 1.8 front mounted on the Dyad rim at 40 psi

    CW = 42mm
    TW = 46mm
    CH + T = 40mm
    R1 = 359mm

    XR 2.25 front mounted on the Dyad rim at 40 psi

    CW = 52mm
    TW = 54mm
    CH + T = 52mm
    R1 = 375mm
    ====================================

    Delgado Disc Rim

    The Crow mounted on the DD at 40 psi

    CW = 51.5mm
    TW = 46.5mm
    CH + T = 48mm
    R1 = 368mm

    Nanoraptor mounted on the DD at 40 psi

    CW = 52mm
    TW = forgot to measure
    CH + T = 50.5mm
    R1 = 371mm

    XR 1.8 mounted on the DD at 40 psi

    CW = 43mm
    TW = 46mm
    CH + T = 42mm
    R1 = 359mm
    ==============================

    How all of that is uesd with regard to "trail" between the Crow, the XR 1.8 and the Nanoraptor - I will leave up to you to figure out. At least it shows, that the Crow is fairly similar in overall size to the Nanoraptor, but the XR 1.8 is a smaller, lower volume tire. Should we call it a 28"? Probably - just as Schwalbe calls their Big Apple 2.0 a 28" tire. It also shows that the Delgado Disc rim gives a tad wider footprint to tires than a rim in the 24mm width range such as the Dyad.

    Sun is out and the "Honey Do" list usurps any more puttering for today.

    BB

    Pix with all tires mounted at 40 psi on the Dyads and DD....
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    Last edited by BruceBrown; 06-20-2006 at 12:14 PM.

  10. #60
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    Crow on the Delgado Disc rim...
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  11. #61
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    Quote Originally Posted by lanpope
    And sometimes it fails miserably...

    Your URL yields this message.
    "Sorry - no matches. Please try some different terms."

    bb

  12. #62
    Harmonius Wrench
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    Thanks Bruce! : Again!!

    Wow! That's awesome, Bruce. I had no intentions for you to go to such lengths, but it is very appreciated.

    The pics and specs you measured of the Crow indeed make me want to compare it more to the Nano, as you seem to have done. The XR 1.8 was also what I had expected.

    As Shiggy duly noted, the difference in diameter does affect trail, but since the Crow and Nano are so close in diameter, it doesn't explain why you were able to take a tighter line with the Crow. Must be another reason there?

    Anyway, thanks again and- oh yeah! Good luck with the chores!

    p.s. Opera singers listening to heavy metal while working on mountain bikes. What a visual!

  13. #63
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    Way beyond!

    Wow, man, that was way beyond the call of duty! Thanks! Those tires look great!

  14. #64
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    Is QBP currently carrying the Crow?

  15. #65
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    Quote Originally Posted by Maxrep
    Is QBP currently carrying the Crow?
    I don't know. I got mine directly from NoTubes.com.

    BB

  16. #66
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    Quote Originally Posted by Guitar Ted
    As Shiggy duly noted, the difference in diameter does affect trail, but since the Crow and Nano are so close in diameter, it doesn't explain why you were able to take a tighter line with the Crow. Must be another reason there?
    Good question. One I've been mulling over myself. Was it....

    A. Weight of tires (Crows being lighter than mo-mo Nano's)?
    B. One particular XC race course was easier than others?
    C. Sudden over night improvement in my handling skills with the Dos Niner?
    D. The psi and tire combination just "clicked" into the sweet spot for me?
    E. Conditions of the course (dry) as opposed to other races including mud?
    F. A combination of several - if not all of the above?

    In spite of all that, the Nanos and Crows do feel and handle with similar traits based on what I personally feel while riding with them. I've got the Nanos on my Sugar now and the Crows on the Dos thanks to the summer drought.

    Quote Originally Posted by Guitar Ted
    p.s. Opera singers listening to heavy metal while working on mountain bikes. What a visual!
    I have no need to listen to the music I work with day in and day out in my career during my freetime. Besides, opera and heavy metal are pretty close as they both involve a lot of screaming.

    BB
    Last edited by BruceBrown; 06-21-2006 at 10:40 AM.

  17. #67
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    I got a pair delivered a few days ago and got to try them out yesterday morning. Coming off of a set of Ignitors, obviously the weight and rolling resistance difference was night and day. In fairly dry conditions on twisty rolling singletrack, I was clearly in a gear higher in many wide open sections. I'm in Cincinnati, so there are no long downhills, but on the "longer" ones with the brakes off, I was definitely coming into the slowing points much hotter. The Crows rocketed up the climbs too, obviously. The trail was a little slick in spots from a light rain, so I started out ultra-cautious . I initially was crapping my pants thinking of those things sliding out at speed, but gradual I warmed to them and started leaning over more. I definitely wasn't laying it out on the turns, but by the end of the ride, I was confident enough with the edges that I felt comfortable at 80% of so cornering speed vs Ignitors. Probably after a couple more rides, I'll know what the deal is with the cornering. Bottom line, they look scarier than they perform. As per volume, I thunked a rim on a root a few times more than usual. These tires are ultra supple, the casings are sweet - so even with the volume down, the ride IMO is better than with the larger Maxxis. I haven't lost it yet hard in a corner, but if I do, I'll update from the hospital bed, cause these tires are fast!

  18. #68
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    I just got my pair - I haven't weighed them yet but they are LIGHT LIGHT LIGHT!!!!

    I'm looking forward to running them....I'm excited if you guys are able to drop one gear lower!

    ~Brett
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  19. #69
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    Quote Originally Posted by 2melow
    I just got my pair - I haven't weighed them yet but they are LIGHT LIGHT LIGHT!!!!

    I'm looking forward to running them....I'm excited if you guys are able to drop one gear lower!

    ~Brett
    Let us know how you like them. Then tell us how you think they would roll on that nice Orbea Alma you got to use for a couple of weeks.

    BB

  20. #70
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    Quote Originally Posted by BruceBrown
    Let us know how you like them. Then tell us how you think they would roll on that nice Orbea Alma you got to use for a couple of weeks.

    BB

    Dude, that Orbea Alma with those tires would FLY. I bet you could build a sub 22 pound bike if you had a race wheelset and those tires. I was already a gear lower with the stock setup and 580 gram ignitors....imagine another 100 grams off each tire!
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  21. #71
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    Haha, grams are not gears!

    But we'll see, I've got a pair on the way too, if all works out.

  22. #72
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    I raced a pair of these yesterday at the World Cup in Mont Sainte Anne, Quebec, they are awesome race tyres. No problem in rooty muddy stuff, just rolled over the roots and gripped without a problem. No washing out on the descents even the mud slide descent in the trees. They were also incredibly quick to accelerate out of the corners on the start loop.
    I was running about 16psi front and rear with stans solution on his Olympic 29r rims.

  23. #73
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    Quote Originally Posted by Nowork
    I raced a pair of these yesterday at the World Cup in Mont Sainte Anne, Quebec, they are awesome race tyres. No problem in rooty muddy stuff, just rolled over the roots and gripped without a problem. No washing out on the descents even the mud slide descent in the trees. They were also incredibly quick to accelerate out of the corners on the start loop.
    I was running about 16psi front and rear with stans solution on his Olympic 29r rims.
    16 psi? Wow!

    I had them mounted up for a race yesterday and took a pre-ride lap following a rain shower. I almost decided it was too muddy on one of the climbs to hold like I wanted, and thought about going back to the car to switch to XR's before the race. Saw the sun poking through the clouds and figured it would dry out as the race got going. Of course, 10 minutes after the race started, the rain came again and it wouldn't have mattered what tire I was running by the 4th lap. Everyone had to walk the steeper hills by the last laps as it was greased clay. Descents were dangerous and for the expert race after our sport class, they actually closed some of the dangerous spots and re-routed the race course.

    I thought I was riding the Crows with a sense of adventure at 28 psi, but 16?

    Survival became the race strategy in the mud and my problems were with the amount of mud collecting on the chain as it was causing massive chainsuck in the middle ring without even switching gears. With one final climb and switchback to go to get out of the forest and singletrack before the final sprint in the open grass/meadow area of the park - my chain got jammed and 6 guys passed me as I was stuck right in the switchback trying to get my chain free. Dang! Tires = good. Mud and water = bad for chain. I nursed my way to the finish line chanting with every revolution of the pedals "Rohloff or SingleSpeed. Rohloff or SingleSpeed. Rohloff or SingleSpeed.".....

    BB

  24. #74
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    I'm really excited about trying these tires...especially after hearing the first reports.

    I can always throw them on my current wheels (speedcity) but I am building up a pair of Stans olympic hoops to get the real experience. Can't wait!
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  25. #75
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    I'll be curious to hear what you guys think about reliability with these. I'm looking for a fast race tire for some races this fall, like Chequamegon and Iceman. I'm considering the Kharma, Crow or Nano. I currently have Ignitors, which seem great for all around riding. However, with those races, (assuming it will be pretty dry) a lower profile, lighter tire that rolls quickly could be a good thing. Will be used tubed, at least initially.

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