kehoe@reed.UUCP (Dave Kehoe) (06/10/85)
OK, net.bicyclists, here's the sum of my ten years and 20,000 miles of cycling experience and five years of bicycle shop experience. These points are in order of relative importance. 1) Position, Clothing and Training. I recommend spending $50 on a Bell helmet before you even think of riding fast. Next, spend $25 on a "Fit Kit." This is the most effective way to get your position correct. You can't ride efficiently or even safely if your feet are in an incorrect position, your handlebars too close, etc. No saddle will be comfortable if it's too high or too low. I don't find clothing to be that necessary. Lycra shorts, wool jerseys, and cleats are nice for long-distance comfort, but I commute in my street clothes. A bright yellow Gore-Tex jacket is necessary (maybe those of you not in Oregon don't need the Gore-Tex part :-)). Training is important, but riding long distances seems to be less effective than a) riding every day and b) riding as hard and as fast as you can. 2) Tires. At speeds below 20mph most of your energy is spent in overcoming rolling resistance in your tires. You can reduce rolling resistance in 3 ways: a) increasing air pressure; b) using more flexible tires; c) using latex inner tubes. Latex inner tubes are ineffective for commuting because they need to be pumped up every day. Flexible tires, such as Specialized Turbos, are faster than stiff tires, such as the Kevlar-belted Specialized K4's. The lighter tires should get more flats, but I haven't noticed this. I rotate Specialized Touring tires at 1000 miles and replace them at between 1500 and 2000 miles. I replace my tires after I get 2 flats because 90% of your flats are in the last 10% of the tire's life. *Be careful* riding new tires in the rain -- new tires are very slippery for the first 100 miles or so. I've put 2000 miles on a pair of Specialized K4's without any flats yet. Increasing air pressure is the most effective way to increase speed. I run my Specialized tires at 130psi. I've heard stories of Turbos run at 150-170psi, and Specialized claims they've put 220psi in their tires, but I'm skeptical. I've never had a blowout, but one of our customers misread a gas station pump -- he thought it said 70psi when it said 170psi. His Rigida 13-20 rim blew apart, and he went to a hospital because of hearing damage. He couldn't hear anything for 3 days because of the ringing in his ears. I've heard blowouts at 95psi, and they're *loud*. *Do not* pressure Rigida 13-19 rims above 95psi -- the tires will blow off. I'm not familiar with using sew-ups at very high pressures: the Olympic team's funny bikes use 200psi tires, Continental claims 150psi for their road tires and 180psi on their track tires, but I blew apart a cheap Wolber at 95psi. 3) Wheels. Light wheels are important because they are revolving weight, i.e. 1 pound of tires feels like 3 pounds of frame, derailleurs, etc.; 1 pound of rim feels like 2.3 pounds; and 1 pound of spokes feels like >2 pounds. Light wheels (including hubs) also improve handling and comfort, because they are unsuspended mass (also known as unsprung weight). I've had good luck with Super Champion Gentleman and Ambrosio Elite rims, and bad luck with Rigida 13-19's and 13-20's. Matrix Titan's (made by Trek) are supposed to be the lightest. Spokes are a little thought-of but important component. 14-16-14 gauge spokes weigh 105 grams less than straight 14's (for 72 294mm spokes). That's the equivalent of nearly 1/2 pound off, for only a few dollars more. I've put over 12,000 miles on 15-16-15 gauge spokes and I find them equally strong as straight 14's. I've used only 36-spoke wheels, but I intend to build a pair of 28-spoke wheels. Lon Haldeman uses 14-spoke front, 24-spoke rear (2 cross, high flange, 15-16-15). But he told me that he puts on 36-spoke wheels at the tops of hills. All the European pros use 32-spoke wheels. Most hubs are about equal. I think high-flange hubs build stronger wheels, but I doubt it's much of a difference. I also prefer Hi-E or Phil Wood hubs to Campy, because Hi-E is lighter and stronger. 5) Gearing/Drive Train. Efficient gearing is necessary for efficient cycling. The only crankset that I like is the Stronglight (model 93, I think). It's one of the few cranksets that allows you to experiment with different chainring sizes, and the only one that allows you to do this without spending a fortune. The crankset costs $60 (with 3 chainrings), and spare chainrings cost $12, and you can interchange inner and outer rings. I also like SunTour Ultra-6 freewheels because it's easy to get spare sprockets for (though I see the advantage of a cassette freewheel whenever I try to remove my Ultra-6 with a crescent wrench). The gearing that I found best (by experimentation) is 28-36 front, 13-21 rear. I spin 100-120rpm. The 36-inch low is necessary in Portland, and the 74-inch high spins out at 33mph, above which I rarely ride (going down hills you'll go faster if you stop pedaling and get into a tuck. Plus my drivetrain is 3/4 pound lighter than a 42-52 14-28, and the chain moves 1/3 slower. This seems to make spinning easier. 6) When riding at night I use a Soubitez halogen bottom bracket generator light, reflectors, Belt Beacon, and a yellow Gore-Tex jacket. -------------------------------- You'll note that none of the above mentioned frames, derailleurs, etc., which is where most people spend their bucks. In fact, most of the above costs very little money. A stiff frame is great for climbing hills, but is unpleasant, and even unsafe, anywhere else. With my tires at 130psi the frame needs a fair amount of give to keep the tires on the road at all times (such as hitting a pebble while cornering at a high speed). Also spokes break *solely* because rear triangles are too stiff (why haven't my motorcycle's spokes ever broken in +35,000 miles? They're not much heavier than bicycle spokes. Because my motorcycle has shock absorbers). Also, I need a 72-degree seat angle to get my seat into the most efficient position. I don't like long rakes or high bottom brackets because these make the steering to squirrelly. To make brakes more effective, use Scott/Mathauser brake shoes and Campagnolo cables. Don't use Elephant housings. With equal pads and cables, I find very little difference between my $10 Dia Compe sidepulls and my $100 Campies. This should keep net.bicycle interesting for at least two weeks. -- Dave Kehoe tektronix!reed!kehoe (503) 230-9454 "Why my thoughts are my own, when they are in, but when they are out they are another's." -- Susanna Martin, executed for witchcraft.
sasaki@harvard.ARPA (06/10/85)
Actually, the best way to go faster is to ride more and to lose weight.
Riding more will strengthen you muscles and losing weight means you won't
have to expend the energy to haul around the fat.
--
----------------
Marty Sasaki net: sasaki@harvard.{arpa,uucp}
Havard University Science Center phone: 617-495-1270
One Oxford Street
Cambridge, MA 02138craig@hp-pcd.UUCP (craig) (06/10/85)
A few comments on "How to make your bicycle faster". Most of the information I agree with (I like to see other peoples experiences with what works for them and why). Wheels and hubs: I build all my wheels with DT stainless double butted spokes. 8+ pairs have yet to break a spoke. I use Mavic "heat treated" rims mostly - they are heavy but very durable and are very easy to build with. I lighten up the wheel by using alloy nipples (very light and seem to be strong - just be careful with the spoke wrench and use Neverseez on the spoke threads) and "lite" gauge spokes. "Heat treated" rims make 28 and 32 spoke wheels much more practical than nonhardened rims. The "soft" rims took about twice as long to true and dented much quicker. For my high zoot wheels I use Mavic 28 hole CX-18 rims ($$$ but 300 gm) Campy hubs "lite" spokes front, "heavy" rear. I use the front all the time and love it - I haven't retrued it since I built it (3+ months) because there is no reason to. I'm convinced that 32 hole "heat treated" wheels all I'll ever need (I guess I should say I'm ~150lb catagory II racer - I don't tour but I have put in a few 200mi days). Matrix Iso rims seems strong but aren't all that light - 300gm without the steel washers needed to keep the nipples from pulling through the rim. Those washers also make the wheel a bit of a pain to build and tend to chew up alloy nipples. I got them on my track bike and their' working very well. I like Campy hubs over Phil (I have about equal numbers of each) because the Phils get sloppy after a while and you can't adjust out the slop (because the sealed bearing are replace only). It does take a long time for the slop to get anoying (unless you have them on a mountain bike - you'll think your frame is broken after you pack the hubs with water and mud a few times). Both hubs are very well built and expensive. I use Phils because I'm lazy and don't have to repack them after long rides in the rain. Frames: here I have a big bias: light, tight and stiff. Nobody seems to build the bike I want so I build my own. Seat angle 74, head angle 75, wheel base about 37.5in and bottom bracket height close to 11.25in. A rolling torture rack you say? not according to me. It goes where I point it, when I pedel it moves, I can drink at 45+ mph, etc and it even goes in a straight line. Not a cush ride but then I ride to cover distance fast. The stiff frame feels more "secure" in corners where a "frame with give" tends to let the rear wheel do a little steering which leads to wander in corners. (This is personal opinion). The "how to ride fast" article mentioned that rear wheel spoke breakage was due stiff rear triangles. I would have to disagree. First my bike does not have a problem and is rather stiff. Second, if the wheel hits a bump, the shock is transmitted through the seat stays which don't give (because of trianglation). They difference between a stiff and lazy rear triangle is latteral loads. I think spoke breakage is due more to poorly built wheels and body weight on the saddle when the bump is hit. Standing up allows the bike to bounce and keeps the shock from being absorbed by the wheel. Craig Durland
oyster@uwmacc.UUCP (06/11/85)
In article <1644@reed.UUCP> kehoe@reed.UUCP (Dave Kehoe) writes: > >1) Position, Clothing and Training. I recommend spending >$50 on a Bell helmet before you even think of riding fast. >Next, spend $25 on a "Fit Kit." This is the most effective >way to get your position correct. You can't ride efficiently >or even safely if your feet are in an incorrect position, your >handlebars too close, etc. No saddle will be comfortable if >it's too high or too low. What is a "Fit Kit", where can one get one, and why should I have to pay $25 for something that some kind soul should be able to tell me in a more-or-less public forum (hint, hint)? -- - joel "vo" plutchak {allegra,ihnp4,seismo}!uwvax!uwmacc!oyster "Take what I say in a different way and it's easy to say that this is all confusion."
msw@drux3.UUCP (Mike Walpole) (06/12/85)
>OK, net.bicyclists, here's the sum of my ten years and >20,000 miles of cycling experience and five years of >bicycle shop experience. These points are in order of >relative importance. > >1) Position, Clothing and Training. So ya' think equiptment will make ya' fast. Good equiptment will help to a point, but the rest has to come from training. >Next, spend $25 on a "Fit Kit." This is a good idea if one realizes that the "Fit Kit" will only get them in the ball park. Your fit on the bike is a personal thing and will take some experimentation to get it right. Alot of racers including myself change the saddle height 3 to 4 times a year. (We never move it much though.:-)) The best part of the Kit is cleat adjustment. If you ride with cleated shoes this will prevent a lot of knee problems. >Training is important, but riding long distances seems to be less >effective than a) riding every day and b) riding as hard and as >fast as you can. Good. You're going to make everybody a one speed rider. To ride really fast it takes more than just riding as hard as you can everyday. It takes a combination of distance work and speed work. The formula is complex and varies from rider to rider depending on their physical makeup and their personal goals. Here in Colorado their are a lot of bike riders who can only ride one speed. (About 20 mph.) They are almost worthless to ride with since they can never go fast (25+ mph) or slow (15 mph). If you ride hard every day then that is what will happen. Most of the racers that I know do not ride faster than 18 mph during the week in the summer, then they race at 25-30 mph on the weekends. As far as bikes and equiptment consider your needs and go to a good bike shop. Read the bicycling magazines.(Bicycling, Winning, Cycling, etc.) If you want to ride fast there are a lot of good Triathalon - Sport Racing bikes in the $350 - $700 price range. This part of the market is really strong. Most of these bikes weigh 23-25 lbs and have very good performance. As far as tires and wheels use reliable equiptment. It doesn't really matter if you use clinchers or tubular tires and wheels. The weight and reliability is about the same unless you are building exotic racing stuff. Then tubulars are lighter. The best advice is to join a club (racing, touring, etc). If there is not a club that caters to your interests start one. If you really want to go fast find a racing club with a coach that has a good reputation. Mike Walpole inhp4!drux1!msw Olympic coach: "Here Rory wear this aero helmet." Rory O'Reily: "Will it help? I've never worn one before." Rory O'Reily lost at the Olympics because his aero-dynamic helmet slipped over his eyes and he could not see.
az@ada-uts.UUCP (06/12/85)
> 3) Wheels. Light wheels are important because they are revolving > weight, i.e. 1 pound of tires feels like 3 pounds of frame, While 1 pound of tires might FEEL like 3 pounds of frame, it actually takes only 2 times more energy to accelerate 1 pound of tires than 1 pound of "static" components.
fred@varian.UUCP (Fred Klink) (06/20/85)
> > 3) Wheels. Light wheels are important because they are revolving > > weight, i.e. 1 pound of tires feels like 3 pounds of frame, > > While 1 pound of tires might FEEL like 3 pounds of frame, it > actually takes only 2 times more energy to accelerate 1 pound of > tires than 1 pound of "static" components. In setting the world's hour record last year, Francesco Moser used wheels with *heavy* rims (I don't recall the actual weight). The theory was that while a little slower to accelerate, the momentum of the heavier rim would require less energy to keep going than a conventional, very light track rim. His bike also had a number of other radical design changes like delta frame and moon-disks. In any case, the heavy wheels didn't hold him back: he shattered the hour record and went out the next day and broke his own, new record again. In the past breaking the hour record has shattered the rider and is often implicated in shortening a racer's career. However, Moser used energy so efficiently that he not only broke the record twice but has continued to race and win some of Europe's most demanding races. PS: Moser is 33 years old.
msw@drux3.UUCP (Mike Walpole) (06/26/85)
>> > 3) Wheels. Light wheels are important because they are revolving >> > weight, i.e. 1 pound of tires feels like 3 pounds of frame, >> >> While 1 pound of tires might FEEL like 3 pounds of frame, it >> actually takes only 2 times more energy to accelerate 1 pound of >> tires than 1 pound of "static" components. >In setting the world's hour record last year, Francesco Moser used >wheels with *heavy* rims (I don't recall the actual weight). The >theory was that while a little slower to accelerate, the momentum >of the heavier rim would require less energy to keep going than a >conventional, very light track rim. The wheels were made of spun aluminum. The rear wheel weighed 4.5 lbs. The disk wheels used at the Olympics were graphite and kevalar and the rear wheel weighed 3.5 lbs. This winter Mike Melton at the Huffy Tech Center got the weight down to under 1.5 lbs. This is lighter than a regular rear wheel. Disk wheels are used primarily to reduce wind drag. A bike equipted with disks front and rear will get up to a 60% reduction in drag. That is about 2.5 to 3 mph at racing speeds. I believe that the rear disk improves wind drag by 25 - 30%. Moser said that the wheels were weighted to keep them at speed longer. (Conservation of momentum) However, I believe that he was just using the only availible technology. Mike Walpole
keesan@bbnccv.UUCP (Morris M. Keesan) (06/27/85)
Actually, among the best ways to make your bicycle faster are the various
things you can do in the way of streamlining -- e.g. adding fairings.
Wind resistance is very significant in slowing you down. Unfortunately, if
you race you're rather limited in this area, since the various organizing
bodies that sponsor racing worldwide are rather stick-in-the-mud when it comes
to radical technological advance.
There was an excellent article on this subject in Scientific American a
year or two ago. The cover of the issue has a picture of a very streamlined
two-person human-powered pedaled vehicle -- I don't remember whether it was
a bicycle or something with more wheels.
--
Morris M. Keesan
keesan@bbn-unix.ARPA
{decvax,ihnp4,etc.}!bbncca!keesanblanken@uiucdcs.Uiuc.ARPA (07/03/85)
The issue of Scientific American you are speaking of featured an HPV (human powered vehicle, although it has been updated to HPLV to specify that it is a "land" vehicle as opposed to, say, the Gossamer(sp?) Albtross) that is called the VECTOR. It was the world record holder for the HPLV land speed record. For your information. Windsor at the U of I