Path: bloom-beacon.mit.edu!hookup!swrinde!cs.utexas.edu!howland.reston.ans.net!wupost!news.miami.edu!usenet.ufl.edu!mailer.acns.fsu.edu!grep!adchen From: adchen@cs.fsu.edu (Tony Chen) Newsgroups: rec.skate,news.answers,rec.answers Subject: Rec.skate FAQ: Wheels, Bearings, and Brakes (2/10) Supersedes: Followup-To: rec.skate Date: 2 Apr 1994 14:51:12 GMT Organization: Florida State University Computer Science Department Lines: 585 Approved: news-answers-request@MIT.Edu Distribution: world Expires: 05/02/94 Message-ID: References: Reply-To: adchen@cs.fsu.edu (Tony Chen) NNTP-Posting-Host: grep.cs.fsu.edu Originator: adchen@grep Xref: bloom-beacon.mit.edu rec.skate:13629 news.answers:17216 rec.answers:4731 Posted-By: auto-faq 1.24 Archive-name: rec-skate-faq/part2 REC.SKATE FAQ - PART 2: WHEELS, BEARINGS, AND BRAKES Inline Wheels ------------- (written May 17, 1992) (last changed July 19, 1993) TECHNICAL INFO Inline wheels are made of polyurethane. Although wheels are classified on three criteria: diameter, durometer (hardness), and rebound, you will usually see only the diameter and durometer marked on the wheels (e.g.,76mm 78A, or 70mm 82A, etc.). DIAMETER The diameter of the wheel is basically how tall the wheel is. The usual diameters are 80mm, 77mm, 76mm, 72.5mm, 72mm, and 70mm. More recently, 82mm wheels have been introduced. Also new are short stunt wheels, 52mm in diameter, with a high durometer to allow for rail slides and other tricks. Generally, racing skates will fit up to 82mm wheels, high-end skates up to 77mm, and the rest of the models up to 72.5mm. Although these are the designed ranges, skates can take slightly taller wheels than what they're supposed to. For instance, the Bauer XF/3's, with the front and heel wheel spacers moved in (for a shortened wheelbase), can use 76mm wheels for all four positions. Extension modification (i.e., scraping down) of skates are need for wheels much larger than the intended size. Although still subject to some technical debate, in general, taller wheels will let you go faster (i.e., 76mm are faster than 70mm) but there is a point where taller wheels will only make you go slower with added weight (harder to start rolling) and less manueverability. Shorter wheels are cheaper, but in general don't last as long since they have less material to wear down overall. DUROMETER (hardness): Durometer is a relative hardness measure frequently used for rubber and plastic products. There are several scales, with the "A" scale (hence the 78A, etc.) used for wheels. The number is the rating from 0-100, with 0 being no resistance and 100 being very hard plastic. Inline wheels generally run from 74A to 93A, with 78A, 82A, and 85A being the most common. For outdoors, the softer the wheel, the better the shock absorption on bumps, cracks, pebbles and other vibrations. The trade-off is that softer wheels last a shorter time. Harder wheels, since they have less drag, are preferred on indoor surfaces which are usually very smooth. Hockey players may prefer harder wheels because it allows them to slide somewhat. Rebound: This is how much the wheel will return the energy when your wheels are compressed. So a higher rebound, will provide more response on each stroke. There doesn't seem to be a rebound scale (is there?) as there is for durometer. HUBS The hubs are very important to the overall performance of the wheel. Hubs which are too large will not hold the bearings tightly enough. This can allow the wheel to become "cocked" so that it rubs against the frame. Only one wheel needs to be out of alignment to mess things up. Misalignment is a serious problem, not only because it causes drag, but because it heats up the wheel. This will soon cause it to seperate from the hub and expand, and eventually destroy the wheel. I have noticed this on several sets of Kryptonics Turbo-cores. The first sign is that the wheels creak as you switch your weight on the skate. If you remove the wheel from the frame, you can see an arc clear of dirt and dust where the wheel was rubbing. If you notice this, put your hands on your wheels after a long fast skate and see if any of them are much warmer than the others. If so, they are probably rubbing. This can happen a lot easier on frames like the Mogema and the Darkstar that have very close tolerences and the side of the frame is close to the side of the wheel. I'm not sure if is as big as a problem (or a problem at all) for recreational skates like the Aeroblade. The creaking is bothersome in any event. AXLE KITS Another important aspect of your wheels is the axles. There are several axle replacement/upgradd kits (such as the Hyper Hop-up Kit and the Blading Edge Kit) designed to let your wheels roll much faster than your stock axles will allow. These kits are usually made of aluminium and steel. What they consist of is two axles per wheel, each screwing into the threaded bushing in the wheel. This also prevents overtightening, which is common with the regular axle system. When putting your wheels back, make sure the wheels are just snug enough so they don't move around. Anything more just increases the friction on your bearings. MAINTENANCE Wheels of any durometer will wear out, given enough mileage. There's only so much polyurethane on your wheels, while there's thousands of miles of asphalt out there. Much less wearage occurs for indoor skating, however. In general, your wheels are due for maintenance when your skates are much slower and not rolling as smoothly as when new. The inside edges will wear more quickly, which you will eventually notice: | | | | inside | | outside inside \ | outside edge | | edge edge \ | edge \____/ \__/ new wheel worn wheel There are two things you can do to get the most from your wheels: rotate and flip. Rotating your wheels means to switch the positions of the wheels. Different positions (like the heel or toe wheels) receive varying amounts of wear. By rotating the wheels, you can even out the wear on each wheel. Flipping your wheels means to turn each wheel so that the worn edge now faces the outside. This lets you wear down the other edge of the wheels. There are several patterns for wheel rotation. The one you use isn't crucial, since there's no "magic" rotation formula that works for all situations. The main point is to maintain an even wear on your wheels. Often times you may find yourself swapping wheels at random until you get a good wearage distribution on your skates. Some common rotation patterns: The front wheel is "1" and the back wheel is either "4" or "5". For 3-wheel skates: 3->2, 2->1, 1->3 For 4-wheel skates: 4<->2, 3<->1 OR 4->3 3->2 2->1 1->4 For 5-wheel skates: 5->3, 4->2, 3->1, 2->5, 1->4 OR 5->3, 4->5, 3->2, 2->4 Whiled you're rotating and flipping your wheels, you might as well wipe off your skates, rails, wheels and bearings with a damp cloth. Some people wipe down their skates everytime they go out, even if they don't do any rotation, but I recommend you do it at least everytime you rotate your wheels. This keeps the amount of dirt on your skates and wheels to a minimum, which helps keeps grit out of your bearings. ROCKERING YOUR SKATES Having skates non-rockered means the axles and wheels are all at the same height. This is the way the skates come when you buy then (usually). What many skates allow you to do is to change the height of some or all of the axles, to provide a different "blade" to skate on. Rockered skates then, have the middle two wheels lower relative to the front and heel wheels. This is accomplished by having oval spacers with an offset axle-hole; each spacer can have an up or down position. Racing skates are also adjustable, but only in the horizontal direction, allowing for a longer or shorter wheelbase. Although subject to some disagreement, many skaters find rockering provides much more maneuverability due to the curved "blade" of the wheels. Whether you rocker or not is really up to you. Many hockey players prefer to have their skates rockered for sharper turns on the court, while racers keep their blades flat for more stability at high speeds (rockers at high speed will produce speed wobble). Artisitic skaters may also prefer rockered, while extreme skaters may opt to keep them flat. Depending on your skates, there are various rockering configurations possible. If your skates can adjust the height of only the middle two wheels, you can have your skates flat or rockered: Flat : ==frame== 1 2 3 4 Rockered: ==frame== 1 4 2 3 If your skates can adjust the height of all four wheels then you have the positions of short even rocker: ==frame== (wheels closer to boot, for more control) 1 4 2 3 tall even rocker: ==frame== (taller, for sharper turns) 1 4 2 3 front-lift rocker: ==frame== (a little more stable than regular rocker) 1 2 3 4 front-lift, : ==frame== (tilts skates forward) rear-down, rocker 1 2 3 4 Wheels generally run from $4.25 to $8.00, depending on the quality and size of the wheel. The three main inline wheel manufacturers are Kryptonics, Inc. and Hyper Inline and Labeda. ============================================================================== NEW WHEELS for '93 From: pae@blackcat.stortek.com (Phil Earnhardt) Subject: Hyper's 1993 wheel line Here's a list of the various kinds of Hyper wheels available in 1993. Note: this is from their marketing literature; you may or may not be able to find all of these wheels (particularly in all colors). I'll include selections of the "hype" from the brochure. Your mileage may vary. Superlite "America's #1 preferred replacement wheel for all inline skates ... increased traction, smoother roll ... [they'll] last longer ..." 72mm 78A teal, black, yellow, clear, pink, purple 72mm 82A teal, black, yellow, clear, pink, purple 72mm 85A black, pink, purple 72mm 93A teal, pink 76mm 78A teal, black, yellow, clear, pink, purple 76mm 82A purple, black Redline Racing Series (tm) "Developed to win [races] ... more speed ... more gold" 76mm 75A orange 76mm 78A yellow 76mm 82A purple 82mm 75A orange 82mm 78A yellow 82mm 82A purple The 76mm skates are available with two different types of hubs: LS and SS. It's unclear from the brochure exactly what is different between the two. Hockey wheels "H-250 [wheel] compound for longer wear and increased slide control. 'Big Foot' riding surface." 70mm 78A black, purple, clear, teal 70mm 82A black, purple, clear, teal 70mm 85A black, purple, clear, teal "Fat Boys" "Fully tested for the ramp, pool, or street. Hubs are bonded together with the 'Fat Boy' landing surface" 70mm 80A black, purple, yellow, silver 70mm 84A black, purple, yellow, silver The brochure provides a fair number of guidelines for wheel choice. The softer hockey wheels and the trick wheels are both welcome developments! ======================================================================== THE BEARING MAINTENANCE FILE ---------------------------- (written May 2, 1992) (last changed July 19, 1993) Compiled and edited by Tony Chen Contents: * General Info * Sealed or Shielded? * Bearing ratings * How to maintain your bearings 1st method : If you don't mind taking off the seals. 2nd method : If you don't want to pry off the seals. GENERAL INFO Inline skates all use 608 bearings. The "608"r means that the bearings are from the 600 series, with a 8mm inner diameter (the width of the hole i.e., internal bore). The "6" appears to be for the 6mm difference between the inner and outer radii (from the outside edge to the edge of the hole). 608 bearings are also the standard size for skateboard bearings. Quad skates use either type 608 (8mm internal bore) or type 627 (7mm internal bore). The 608s for quads are the outdoor bearings. If your bearings have letters following the "608" (like "S", "Z", or even "ZZ" or "SS") it is the manufacturer's way of denoting sealed or perhaps double shielded bearings. To make sure what they mean you should probably check with the manufacturer, since it varies from company to company. A little cross-reference on part numbers for bearings, the 7MM ones are for quality indoor skates, the 8MM ones are used for in-lines, other indoor skates and skateboards. Double Shielded: NTN Fafnir MRC ND SKF HCH YW 7MM 627-ZZ 37KDD 37FF 77037 R7-2Z 627Z 60027 8MM 608-ZZ 38KDD 38FF 77038 R8-2Z Double Sealed (neoprene rubber): NTN Fafnir MRC ND SKF 7MM 627-LL 37PP 37ZZ 99037 R7-2RS 8MM 608-LL 38PP 38ZZ 99038 R8-2RS Single shielded/sealed bearings usually delete one of the doubled prefix/suffix characters. (Thanks go to George for the above chart). Bearings for in-lines generally come grease filled. Some bearings like GMNs are sold either greased or oiled (but usually greased). SEALED OR SHIELDED? There are basically two types of bearings: shielded vs sealed. Most likely you will have shielded bearings, which all stock skates come with (as far as I know). Shields make it hard for dirt and grime to get in, but they certainly aren't dust or watertight. For superior protection against the elemnts, you need sealed bearings. There are three kinds of shielded bearings: 1) two shields (metal), 2) one metal shield & one pop-out cap for maintanence, 3) two pop-out caps. If you have types 2 or 3, you'll have an easier time re-lubing your bearings (see below) Sealed bearings have a teflon or rubber lip seal that actually touches the brace and come packed with a fairly heavy grease. These are quite impervious to dust or water. Rollerblade sells sealed bearings under the name Max Trainers. You may find other brands as well. The advantage is that they should last a long time without any maintenance at all. The trade-off is that these bearings generally cost more and you also encounter a much higher rolling resistance. Slower bearings are not necessarily bad, since many people like the added resistance for a better workout. BEARING RATINGS Bearings are rated on the ABEC (the Annular Bearing Engineering Council) scale. The main brands are NMBs (stock ABEC-1 bearings), Powell Swiss (ABEC-1), GMNs (ABEC-3), Fafnirs (ABEC-5) and Black-Hole (various ABECs). Buying bearings rated any higher than ABEC-5 will probably not do any good since they aren't be meant for use in in-lines. The higher precision will be lost to contaminating dust and dirt anyway. (If it's speed you want, cutting down wind-resistance and improving your technique is a better way.) Really precise bearings are only used in high speed (read: rotational) applications, as in machinery. The next higher grade up from in-line bearings are in machines which are rotating at speeds of at least 10,000 rpm which is around 80+ mph. You probably won't want to go that fast on your skates 8-) At 50,000 rpm you would be traveling 400+ mph. So which happens first? the wheels melting, or the skin ripping off the skater? Gives new meaning to shredding 8-) WHEN TO CLEAN AND RE-LUBRICATE YOUR BEARINGS Exposure to dirt and water are the main reason that your bearings slow down. Bad bearings will be ones which don't let your wheels spin for a respectable amount of time (the definition of "respectable" depends on on your type of bearings). If you hear or feel the vibrations of metal rubbing on metal, chances are your bearings are in need of some maintenance. If some of the balls or bearing surfaces have become roughened, there's basically nothing you can do. They won't get any better, but they may last a long time anyway. You can always replace your bearings a few at a time. Take care of your bearings by cleaning and preping them as needed. Assuming normal usage, they should last through several sets of wheels, depending on how much skating you do. REPLACING YOUR BEARINGS You can replace your bearings if (1) any of your bearings have somehow stopped spinning well, despite all the cleaning you do or (2) you want to change to different types of bearings (racing or sealed or whatever). HOW TO TAKE CARE OF YOUR BEARINGS 1. Remove your wheels from the skates, and push the bearings out with a spare bushing (the plastic/metal part that goes between the bearings) or one of the several types of bearing tools available on the market. 2. If you have shielded bearings with pop-out caps (Powell Swiss or Black Hole brands), simply pry off the plastic cap on each bearing. If you have NMBs, GMNs (Germans), other brands, or sealed bearings, FIRST make this decision: do you want to take the shields off? Some people tell you to never pry off a shield/seal, some say it's okay. It's really up to you. Whatever you do, lubrication always helps. NOTE: if you have sealed bearings you might not want to pop the covers since you'll ruin the seal integrity somewhat, which is what you're paying extra (vs regular bearings) for in the first place. However, if you feel they've gotten dirty enough, try relubing just a single bearing and see if it's any better. If so, re-lube the rest of your bearings. If you decide "NO" then skip down to the section marked "2ND METHOD" If you decide "YES" then carefully puncture or pry off the shield (or seal) on one side. When removing the covers of entire sets of bearings at once, be careful to only take off one cover per bearing. Otherwise you'll be left with a shieldless/sealless bearing (which won't last long against outdoor conditions). Once you have the cover off, you should be able to see the ball bearings inside, held in place by a brace. You won't need the old metal covers anymore. In Bones bearings the cap is ALSO the brace, so you won't see a brace. Bones users should obviously keep the plastic cap when reassembling their bearings. NOTE: You don't want to take the ball bearings out since they aren't meant to be removed and replaced. 3. Soak the bearings in paint thinner, naphtha, Simple Green*, or any other handy solvent. In any case, the choice of solvent isn't crucial so long as you can get all the dirt and old grease cleaned out. Avoid low-flash point solvents like gasoline, xylene, lacquer thinner, etc. which are dangerously flammable. Also wear latex/chem lab gloves if possible. Solvents are no fun to ingest or absorb through your skin. An alternative is to use a pair of tongs or tweezers to handle your bearings. How long you soak depends on how dirty and dried out your bearings have gotten. Previously maintained bearings won't need to soak very long. Bearings that have gone dry and have lots of grit in them may need to soak overnight, or even several days. If necessary use a brush or swirl your bearings around in your container to make sure everything breaks loose. Small coffee cans, peanut jars, or even those little black film canisters, all make decent containers. You don't really need large amounts of solvent. Just enough to immerse your bearings. You also don't need to refill with clean solvent with each bearing unless the solvent you were using has gotten really dirty. The essential thing is that the dirt and grease is broken up. Step 4 will remove most of the gunk. WD-40 is generally not recommended as a solvent since it leaves a sticky, dust attracting film on the bearings. Ultrasonic cleaners is ideal for cleaning bearings. If you have access to one, you can clean your bearings en mass and avoid getting your hands dirty. *Simple Green. Just soak the parts in pure Simple Green and rinse with water. Thoroughly dry everything off and lubricate immediately. Simple Green is water soluble, so take care to dry it well, since it can cause rust otherwise. Parts come out much cleaner and much faster than with other solvents. You should stay cleaner and there are no nasty fumes to inhale. Simple Green should be available in most grocery or hardware stores. 4. Now rinse out your bearings with hot, soapy water to make sure you clear out all the solvent. You now have some clean bearings. Clean, unlubricated bearings appear to have the lowest amount of unloaded friction, but don't expect them to last very long if you skate on them. After a fairly short time, the surface of the balls will start to flake and roughen and they won't spin very well. 5. Use a hair dryer or just air/sun dry to make sure that all traces of water are gone. Using a hair dryer or basking in the sun also preps the bearing nicely by heating the metal somewhat. 6. Now lubricate with your favorite lubricant. You can use Tri-flow or one of the specialty lubricants distributed for bearings. Bones bearings come with their own Speed Cream. You can use grease or oil as you prefer. Oiled bearings have slightly less resistance, but need to be maintained more often (as often as once a week). It is very helpful to have a little hypodermic style oiler with a long needle to let you put the oil right where you want it. Grease works well because after a while most of it gets shoved out of contact with the balls and only a little bit smears onto the workings. However, newly greased (or heavy oil) bearings, will take a while to expel any extra grease and move the rest out of the way. For oiling, light oil, like sewing machine oil, or 5W-20 motor oil is a good choice. Household oils (3-in-one, etc) may gum up after a while and the teflon-based lubricants have little particles of teflon that are only in the way. Some people recommend that you use a 50-50 mixture of lighter fluid and baby oil to lubricate your bearings. This mix should result in not having to clean them out as often, only lubricate more often. Let the bearings sit for an hour, and wipe them off. 7. Put one bearing back into the wheel, with the open face towards the inside of the wheel. Insert the bushing and then put on the second bearing (with the open face towards the inside again). It is pretty hard for contaminants to get into the bearings from the inside. 2ND METHOD (for keeping the shields on): First do Step 1 (from 1st Method). If your bearings are permanently sealed (or you don't want to remove the seals) you can still soak in solvent (see step 3) for several hours or as long as you feel necessary. Enough solvent should soak through to remove some of the grease. Then you can lubricate the seams and/or press some in with your fingers. Enough oil should seep through to lubricate your bearings (see step 6). ======================================================================== From: pae@netwise.com (Phil Earnhardt) Message-ID: <1992Mar8.040301.26807@netwise.com> Date: 8 Mar 92 04:03:01 GMT First off, note that there are 3 types of brakes available for the Rollerblade "square" brakes (used on current Rollerblade high-end skates -- Lightning, Aeroblade, Racerblade, etc.): o Black Brakes. What used to come on the skates by default; what dealers stock as replacement brakes by default. Marking and squeaky. o TRS Brakes. They gray guys. About twice as expensive. Marking. Somewhat squeaky, but less than the black ones. o Polyurethane Brakes. These appeared near the end of the summer of 1991. They come in bright blue, pink, green. Priced near the price of the TRS Brakes. No squeako at all (sometimes, they hum -- it's kind of nice). No marking at all. By my metric, they last longer than the Black guys but not quite as long as the TRS Brakes. The braking action is a bit grabby; some may view this as a problem. WRT brake life, I'm sure you'll get some subjective opinions. However, I have never observed the Poly brakes crumbling and coming off in chunks. Remember, the wheels are just polyurethane, too -- do you see them come off in chunks? It might be possible to lose chunks of polyurethane on extremely rough roads; I'd recommend avoiding such surfaces. =END OF PART 2==================================================================