My Road Bike has Low Flop Steering
11-11-15, 08:43 AM
#26
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The article linked in post 23 was very helpful to me when one of my bikes needed a replacement.
11-11-15, 09:39 AM
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11-11-15, 09:53 AM
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11-11-15, 09:56 AM
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If small differences in trail were so important, every time the HTA changed, so would the fork rake. It doesn't take much inspection to see that doesn't often happen. In fact, a 43-45 mm fork will work well on just about any standard road bike geometry. You have to get pretty far out in HTA for that to not be the case and for the trail and its effects to be negatively impacted.
11-11-15, 10:02 AM
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And, as I said, without specifying the size he really hasn't specified the geometry. Except for fork rake (which, by the way, is really significant) the numbers vary all up and down the size range. If we don't know the size, we can't speculate on the geometry or the identity of the bike.
If small differences in trail were so important, every time the HTA changed, so would the fork rake. It doesn't take much inspection to see that doesn't often happen. In fact, a 43-45 mm fork will work well on just about any standard road bike geometry. You have to get pretty far out in HTA for that to not be the case and for the trail and its effects to be negatively impacted.
If small differences in trail were so important, every time the HTA changed, so would the fork rake. It doesn't take much inspection to see that doesn't often happen. In fact, a 43-45 mm fork will work well on just about any standard road bike geometry. You have to get pretty far out in HTA for that to not be the case and for the trail and its effects to be negatively impacted.
IMO, Rolobikes found a new way to sell the same old product to rubes that don't know any better.
Look at this pile of horse**** from their website.
"The low flop bike will not fall into the turn at a sharp radius. Being responsive into and throughout the turn, it allows the rider to dial in the correct and appropriate radius to hit the apex of any curve; the rider is able to carry more speed into and through the turn. A low flop bike that allows you to corner at a constant radius throughout longer turns with a higher likelihood of hitting the apex will also better handle a variety of situations throughout the turn because the rider can precisely adjust its trajectory if necessary."
Last edited by BoSoxYacht; 11-11-15 at 10:05 AM.
11-11-15, 10:08 AM
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11-11-15, 10:13 AM
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And, as I said, without specifying the size he really hasn't specified the geometry. Except for fork rake (which, by the way, is really significant) the numbers vary all up and down the size range. If we don't know the size, we can't speculate on the geometry or the identity of the bike.
If small differences in trail were so important, every time the HTA changed, so would the fork rake. It doesn't take much inspection to see that doesn't often happen. In fact, a 43-45 mm fork will work well on just about any standard road bike geometry. You have to get pretty far out in HTA for that to not be the case and for the trail and its effects to be negatively impacted.
If small differences in trail were so important, every time the HTA changed, so would the fork rake. It doesn't take much inspection to see that doesn't often happen. In fact, a 43-45 mm fork will work well on just about any standard road bike geometry. You have to get pretty far out in HTA for that to not be the case and for the trail and its effects to be negatively impacted.
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11-11-15, 10:14 AM
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...
.....https://mitpress.mit.edu/books/bicycling-science
I think the current edition might be a little dated, in terms of all the tech advances that have been coming fast and furious.
.....https://mitpress.mit.edu/books/bicycling-scienceI think the current edition might be a little dated, in terms of all the tech advances that have been coming fast and furious.
Rubbish.
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11-11-15, 11:05 AM
#36
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... I need to correct that: I made a mistake and put in 4.5 instead of 45. It should have been head angle and fork offset of 73.5° / 45 respectively for a Wheel Flop of 15 (with 25 tires) -- even lower than the Rolo example that some believed was simply Rolo engaging in phony marketing by making the case for the benefits when at the low end of the spectrum. It's the spec for a CAAD10 and looks to be about where it ought to be for good handling.
Last edited by McBTC; 11-11-15 at 11:26 AM.
11-11-15, 12:30 PM
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... I need to correct that: I made a mistake and put in 4.5 instead of 45. It should have been head angle and fork offset of 73.5° / 45 respectively for a Wheel Flop of 15 (with 25 tires) -- even lower than the Rolo example that some believed was simply Rolo engaging in phony marketing by making the case for the benefits when at the low end of the spectrum. It's the spec for a CAAD10 and looks to be about where it ought to be for good handling.
...what's "good" in reference to bicycle handling?
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11-11-15, 01:45 PM
#39
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'Good' in this instance would not be what, for example, Dave Moulton would describe as his ideal; but, Moulton says his 'design philosophy' calls for more trail than we see on bikes produced today (which according to his graph should be more like 67 trail instead of 54 for a 73.5 degree head angle). According to Moulton's design philosophy, having the same offset of 45 both the CAAD and Z85 should have a 71 degree head angle for ideal bike handling instead of 73.5 and 72.5 respectively. Going down Moulton's road, however, would result in an increased amount of wheel flop -- the calculaor gives it a 19 -- and Rolo bike's 'design philosophy,' or example, disagrees with that.
https://static1.1.sqspcdn.com/static/...dlingGraph.jpg?
Last edited by McBTC; 11-11-15 at 02:16 PM.
11-11-15, 03:53 PM
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... I need to correct that: I made a mistake and put in 4.5 instead of 45. It should have been head angle and fork offset of 73.5° / 45 respectively for a Wheel Flop of 15 (with 25 tires) -- even lower than the Rolo example that some believed was simply Rolo engaging in phony marketing by making the case for the benefits when at the low end of the spectrum. It's the spec for a CAAD10 and looks to be about where it ought to be for good handling.
11-11-15, 04:20 PM
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I guess my custom bikes have the geometry all wrong, Since I love their steering and since I specified the angles and rake, I guess I am all wrong also. I like quick steering bikes, bikes that are easy to no-hand into corners, easy to steer around obstacles I didn't see. Head tube angles pushing 74 degrees. Fork rakes pushing 50 mm. Low trail. Years ago I raced a 59 cm bike with a 75 head angle and probably the same fork rake as the smallest bike of the line. Very quick. Hard to ride straight when I hadn't been on it for a while. But cornering! It just plain wanted to. (I also steered through crashes where I have no idea how I found the path.) Granted, that bike was a little much and not a keeper once my racing days were over.
Ben
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11-11-15, 05:05 PM
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I hear you but I think that really depends on your definition of a mistake as it pertains to purchasing a fork.
11-11-15, 05:13 PM
#44
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That is an aspect of bicycle manufacturing that presents some interesting issues. Cannondale now has CAAD12 and the rake on fork for the aluminum version is 45mm throughout the frame sizes whereas the head tube angles get more slack as the frame size increases. Accordingly, the trail changes across the sizes as well: the trail is sub-60mm beginning at size 52 which is 59mm. That's close to the largest size 61 Z85s at 60mm. CAAD12's largest size 63 (which has a little shorter wheelbase that Z85's 61) comes in with a trail of 54mm.
11-11-15, 05:15 PM
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'Good' in this instance would not be what, for example, Dave Moulton would describe as his ideal; but, Moulton says his 'design philosophy' calls for more trail than we see on bikes produced today (which according to his graph should be more like 67 trail instead of 54 for a 73.5 degree head angle). According to Moulton's design philosophy, having the same offset of 45 both the CAAD and Z85 should have a 71 degree head angle for ideal bike handling instead of 73.5 and 72.5 respectively. Going down Moulton's road, however, would result in an increased amount of wheel flop -- the calculaor gives it a 19 -- and Rolo bike's 'design philosophy,' or example, disagrees with that.
https://static1.1.sqspcdn.com/static/...dlingGraph.jpg?
https://static1.1.sqspcdn.com/static/...dlingGraph.jpg?
11-11-15, 05:30 PM
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... I need to correct that: I made a mistake and put in 4.5 instead of 45. It should have been head angle and fork offset of 73.5° / 45 respectively for a Wheel Flop of 15 (with 25 tires) -- even lower than the Rolo example that some believed was simply Rolo engaging in phony marketing by making the case for the benefits when at the low end of the spectrum. It's the spec for a CAAD10 and looks to be about where it ought to be for good handling.
11-11-15, 05:30 PM
#47
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I'm not saying Moulton is wrong but the extent he may be more right than others, the size 63 CAAD12 above would have a trail close to 70mm not 54mm (i.e., it should have a rake of ~30 not 45).
11-11-15, 05:33 PM
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That is an aspect of bicycle manufacturing that presents some interesting issues. Cannondale now has CAAD12 and the rake on fork for the aluminum version is 45mm throughout the frame sizes whereas the head tube angles get more slack as the frame size increases. Accordingly, the trail changes across the sizes as well: the trail is sub-60mm beginning at size 52 which is 59mm. That's close to the largest size 61 Z85s at 60mm. CAAD12's largest size 63 (which has a little shorter wheelbase that Z85's 61) comes in with a trail of 54mm.
11-11-15, 05:37 PM
#49
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https://www.cannondale.com/USA/Bike/P...d-b3a386243e89
11-11-15, 06:03 PM
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Look for yourself: the head tube angles go from 71.5 to 73.4 degrees.
https://www.cannondale.com/USA/Bike/P...d-b3a386243e89
https://www.cannondale.com/USA/Bike/P...d-b3a386243e89