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#11
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Increase trail or longer front center
On May 18, 9:27 am, "John Verheul" wrote:
"Tim McNamara" wrote in message ... I think the issue may be other than trail. Before you commit to spending money for changing your bike, borrow one with the front end geometry you're thinking and give it a try. 45 mm fork offset with 74 degree head angle and 700 x 23s is a bit unusual but not beyond the pale. After all, lots of perfectly ridable bikes have trail numbers down into the 35 mm range (and up to 60 mm or so). That's kind of the thing, the last bike I won a crit on (and felt more comfortable cornering on) was my 2004 Cannondale team bike, which had a bit more trail at 73.5 w/45mm rake. It's only in the last year or so I've been able to choose my own bike, I always had a team bike before this. How does if feel in fast corners? Do you feel like the front end is going to wash out? Does if feel like the rear wheel is going to come around and slide out? The latter, I feel like any line adjustment I have to make I'm going to put too much weight on the front wheel and wash the rear. Last tough descent I raced was a couple weeks ago (points as steep as 17%, with switchbacks), and I literally did slide the rear around a couple of the corners, which didn't help my confidence. To be fair, the guy dropping me is an ex-euro pro, but other local nobodies like me are able to hang better than I. This is what got me thinking about the front center distance. But the weight distribution tells me that's not so much the issue. Are you faster around left hand bends than right hand bends (or voce versa)? Not really. Have you tried different tires (e.g., 700 x 25 slicks)? Have you played with tore pressure (100 psi vs 110 psi vs 120) to see if that beneficially changes the feel of the bike? Yes on all accounts, and no not really any difference. Are your shoulders tense? Death grip on the bars? Craning your neck to see the line through the corner? All of those can slow you down. Some fine tuning of your position might benefit. My front end is already pretty high for a racer (drop to bars is 10cm, has been as much as 13 at points in my life), and the position is great for everything else. I should mention I do professional bike fits myself. Relaxing in corners...yeah I practice that, and I know that staying loose on the bike is key. Sliding the rear wheel doesn't help with that (although I caught the slides and stayed up), there just seems to be some feedback coming from the bike, the "too far forward" sensation that's making me less comfortable in high speed corners. I should add, I'm fine on straight descents...get up over 50mph no problem, feel comfortable, typically can move up in groups in these situations. Same for low speed (25mph) corners in crits. It's just when we go fast (and selections are made), I'm closing gaps after every corner. I've thought of one other thing. I heard once that one of the Carney's (the brothers, not folks who travel with carnivals) suggested setting up your brakes so that they don't really grab all that well until just before the levers contact the bars. That way when you 'panic' you don't make things worse by over-breaking. It may help if you don't brake so much and loosening your brakes may help with that. I don't really suggest disconnecting them altogether. |
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#12
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Increase trail or longer front center
In article ,
"John Verheul" wrote: "Tim McNamara" wrote in message ... I think the issue may be other than trail. Before you commit to spending money for changing your bike, borrow one with the front end geometry you're thinking and give it a try. 45 mm fork offset with 74 degree head angle and 700 x 23s is a bit unusual but not beyond the pale. After all, lots of perfectly ridable bikes have trail numbers down into the 35 mm range (and up to 60 mm or so). That's kind of the thing, the last bike I won a crit on (and felt more comfortable cornering on) was my 2004 Cannondale team bike, which had a bit more trail at 73.5 w/45mm rake. It's only in the last year or so I've been able to choose my own bike, I always had a team bike before this. How does if feel in fast corners? Do you feel like the front end is going to wash out? Does if feel like the rear wheel is going to come around and slide out? The latter, I feel like any line adjustment I have to make I'm going to put too much weight on the front wheel and wash the rear. Last tough descent I raced was a couple weeks ago (points as steep as 17%, with switchbacks), and I literally did slide the rear around a couple of the corners, which didn't help my confidence. I imagine not. To be fair, the guy dropping me is an ex-euro pro, but other local nobodies like me are able to hang better than I. This is what got me thinking about the front center distance. But the weight distribution tells me that's not so much the issue. I still am not thinking that trail is the issue, although I could certainly be wrong due to bias (I like bikes with about 55 mm trail best, but I am also riding on wider tires which makes a difference). Usually low trail gives the steering a light feel that some people don't like. However, low trail bikes also tend to be less responsive to leaning the bike to turn- requiring more handlebar input- and maybe that's what's making the difference for you. This sort of thing is a real puzzle to figure out. |
#13
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Increase trail or longer front center
Usually low trail gives the steering a light feel that some people don't
like. However, low trail bikes also tend to be less responsive to leaning the bike to turn- requiring more handlebar input- and maybe that's what's making the difference for you. That sort of strikes a chord with me...maybe this low trail bike (all my previous bikes have been 51 or more) just requires more hb input than I'm used to and/or comfortable with. Maybe I just need to grow a pair, dive into a couple fast corners and steer the damn bike. It's not like I don't have health insurance...or scars already. This sort of thing is a real puzzle to figure out. Indeed. Thanks everyone for the thoughts so far. |
#14
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Increase trail or longer front center
On Fri, 18 May 2007 09:27:48 -0600, "John Verheul"
wrote: . It's only in the last year or so I've been able to choose my own bike, I always had a team bike before this. Cry me a river ;-) -- JT **************************** Remove "remove" to reply Visit http://www.jt10000.com **************************** |
#15
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Increase trail or longer front center
On May 17, 5:31 pm, "John Verheul" wrote:
Since moving out west (US) a couple years ago, practice as I might I just can't quite descend with riders who are otherwise of my ability. Recently, I've also been having a hard time cornering in criteriums at high speeds (over 30mph). Lower speed laps I'm fine, but I'm closing gaps on fast laps, and getting caught when I attack because I'm just not carrying as much speed as my competition. I practice plenty (have a 14 mile climb behind my house with switchbacks, and a local training crit), and it's my 21st season of racing, so I'm going to assume I've maximized the skills area as much as I can. The bike is also fine when at training speeds, it's just in relatively high speed descending/cornering situations I cannot get around the turns as quickly as I'd like. I'm slightly taller than average at 6'1", and don't use a lot of setback on my road bike (7-8cm), so I suspected I might have too much weight on the front wheel. Bathroom scale measurements indicate I don't. It's right around 43/57 front/rear. So now I'm looking at frame geometry. I'm using a frame that has a steep 74' head angle, and a 45mm raked fork. With a 23c tire that's only about 4.9cm of trail, very low by most standards. Bike also has a pretty short front-center of 60cm (on a 60cm frame). My options to improve handling as I see it a 1) Get a 40 or 43mm raked fork, which would increase trail to 5.1 or 5.4 respectively, more in what most people seem to feel is a more average range for a racing bike. 2) Get a frame with a longer front center to move cg even further back in the wheelbase, thus keeping more weight off the front wheel in steep descending corners (but perhaps leading to front wheel washout in flat crit corners?). Any opinions? If I pick option 1, would you get a 40 or 43 rake fork, and why? As others have said, there may be more to it than geometry, like adequate frame stiffness. What bike are you on now? As far as steering geometry goes, I've ridden tons of different bikes and can relate. Skidding the rear in tight switchbacks too: I did that a couple of times a month or so ago in Mallorca while on a club training week there. Scared by teammates, and me too! I'd 1) get a stiffer frame (Scott and Cannondale measure stiffer than many others; the CAAD 5 a bit stiffer than the CAAD7), or 2) try a fork with less offset to get more trail (more like your old bike). I wouldn't mess around with 43 mm; go for 40 or so. IMHO, 2 mm just isn't enough of a change to know if adjusting trail is what you're after. Just looked up the head angles on Scott (73 or 73.3 on the larger sizes) and Cannondale (73.5 on the CAAD5). Both of these, especially the Cannondale, are closer to what you said your old bike was. |
#16
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Increase trail or longer front center
Any opinions? If I pick option 1, would you get a 40 or 43 rake fork, and why? ----------- from someone who is not a racer, and doesn't like to descend. wider tires help, especially in the front. always counter-steer, don't lean. always descend on the hoods, not the drops (this helped the most, as the upright position does most of the braking, can actually see the road) With the wind pushing on your torso it pushes the weight back, as opposed to braking which puts the weight up front. Also you can ride on the pedals, instead of the saddle, and helps when you hit bumps. It took me a long time to figure this one out. I have bikes with less trail, and more trail. The more trail one is harder to turn, but gives you confidence because you really have to be active on the bike. With less trail the bike can turn on it's own, but sometimes makes you feel uneasy because you feel like a passenger on a run-away train. I perfer more trail, even though it's harder to turn, because it makes you feel like you are in control, also it seems to put the weight farther back. |
#17
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Increase trail or longer front center
"Callistus Valerius" wrote in message ink.net... With less trail the bike can turn on it's own, but sometimes makes you feel uneasy because you feel like a passenger on a run-away train. This is the sensation I have...I'm thinking more and more it's the trail. |
#18
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Increase trail or longer front center
wrote in message oups.com... As others have said, there may be more to it than geometry, like adequate frame stiffness. What bike are you on now? Specialized E5. Oversized aluminum. I'd 1) get a stiffer frame (Scott and Cannondale measure stiffer than many others; the CAAD 5 a bit stiffer than the CAAD7), CAAD5 was my team bike in 2001 - 2002, then we got CAAD7's from '03 - '04 (and I kept riding through 2006, until a friend of mine fell on it and creased the seatstay). Yeah, these were better...but I don't have access to a C-Dale deal right now, so I was hoping to make the E5 a little better. or 2) try a fork with less offset to get more trail (more like your old bike). I wouldn't mess around with 43 mm; go for 40 or so. IMHO, 2 mm just isn't enough of a change to know if adjusting trail is what you're after. Since I can get a fork for pretty cheap, I think I'm going to try this. |
#19
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Increase trail or longer front center
On May 18, 8:27 am, "John Verheul" wrote:
"Tim McNamara" wrote in message That's kind of the thing, the last bike I won a crit on (and felt more comfortable cornering on) was my 2004 Cannondale team bike, which had a bit more trail at 73.5 w/45mm rake. It's only in the last year or so I've been able to choose my own bike, I always had a team bike before this. How does if feel in fast corners? Do you feel like the front end is going to wash out? Does if feel like the rear wheel is going to come around and slide out? The latter, I feel like any line adjustment I have to make I'm going to put too much weight on the front wheel and wash the rear. Last tough descent I raced was a couple weeks ago (points as steep as 17%, with switchbacks), and I literally did slide the rear around a couple of the corners, which didn't help my confidence. To be fair, the guy dropping me is an ex-euro pro, but other local nobodies like me are able to hang better than I. A lot of descending and cornering is mental. If you think it's the trail, then changing the trail is likely to help. I don't know if this is a placebo effect or if that's unfair since it's a genuine confidence issue. That said, I never liked bikes with a steep front end that are harder to ride no hands, and think this also makes descending sketchier. That said, I am a crummy descender anyway (for a racer; in the century-rider population there are even worse). Another thing. You mentioned not hanging with the locals. This doesn't apply to crits, just hills, but some places in the US just have way more long technical descents than others and so the locals get more practice. In Norcal there are plenty of tight twisty roads that drop 1000-2000+ feet elevation. I'm sure there are some in New England, but not so much in some other places (like Pennsylvania). And one last thing. I never could hang with the locals on sketchy descents in Norcal (Alpine Road in particular), but they gave me a great piece of advice: "Never follow a pot smoker downhill." Ben |
#20
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Increase trail or longer front center
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