Bicycle Technology and Patents » Drivetrain & Gearing

Removing a Bicycle Cassette, by trikebldr

shaver — Fri, 13 Jan 2012 01:56:33 +0000

To remove a “current generation” of Shimano’s Hyperglide cassette from the freehub of a rear wheel you will need two rather specialized tools besides a 12″ adjustable wrench. First, the lock-ring that holds the cassette on the freehub has 12 internal splines, as can be seen in the first picture.

Park Tool’s #FR-1 or #FR-5G will fit this lock-ring. FR-5G has an alignment pin that makes the job of loosening the lock-ring a lot easier. Without the pin, the tool is hard to hold in place while also holding the cassette with a chain-whip. Using a quick release skewer lightly snugged up will also hold the tool in place. In the second picture you can see FR-1 on the left and FR-5G on the right. The third picture shows FR-5G in place for loosening the lock-ring.

The next tool you will need is some kind of device to hold the cassette from rotating backwards (counter-clockwise) as you loosen the lock-ring. Large ChannelLock-type pliers will not do it as they tend to bend or nick the teeth of the cogs of the cassette. An old piece of chain used with a pair of Vice-Grips will hold the cassette well enough for loosening. The best way to hold the cassette, however, is to use Park Tool’s SR-1 chain-whip, or equivalent, positioned as seen in picture four, to the left.

A 12″ adjustable wrench, a 1″ open-end or box wrench, or even a 26mm open-end or box wrench will turn the FR-5G tool to loosen the lock-ring, as seen in the fourth picture.

Holding the chain-whip, turn the adjustable wrench counter-clockwise to loosen the lock-ring. The lock-ring and the smallest cog of the cassette have serrations on their mating faces to help prevent loosening while riding, so you will hear some clicking as you loosen the ring. Once it is loose, remove the chain-whip and wrench and also the ring. It should look like picture five.

Now, simply lift the cassette off of the freehub, but be careful to hold onto the two smallest cogs of the cassette because they will not be firmly attached as the rest may be. Take special care to notice how they fit onto the cassette for replacement later. Notice how their flanges face, and how they also have a larger spline tooth and smaller groove like the rest of the cogs on the cassette. These must all line up.

Most cassettes are held together by a single screw that keeps all but the two smallest cogs together for easier handling and assembly. Some cassettes have all but those two smallest cogs rivetted to an aluminum spider, too! But, some cassettes have all of their cogs and spacers simply assembled onto the freehub’s splines one-at-a-time. Be very careful about keeping everything in order and be sure you know exactly how all of the spacers and cogs fit onto the freehub. Each spacer has two small pins that MUST fit into the correct holes of the cogs. If they don’t, they will hold two cogs just slightly too far apart and that will ruin the alignment that allows for index shifting. If you are not absolutely sure you know how all of the spacers and cogs fit together, then if they all feel loose as you try to lift the cassette off the freehub, stop and take it all to your local bike shop for servicing.

The freehub with the cassette removed should now look like picture six.

The majority of freehubs are made from hardened steel. Some road freehubs were made with aluminum spline shells to help save weight. Once the cassette is finally removed, these softer splines will usually show where the cogs have dug into the edge of the spline over time and under heavy loading. It will also make it hard to remove the cassette on these freehubs.

To replace the cassette on the freehub, just line up the large spline tooth of the cogs with the large spline groove in the hub’s shell and slide the cassette onto the hub. Be careful to get the flange of each of the last two cogs facing the wheel. Screw the lockring on and tighten it with the special tool and wrench. It doesn’t need to be “stand-on-it” tight. Park Tools lists it as needing about 260-434 in/lb. (about 21.7-36.2 ft/lb). Since the freehub’s ratchet will stop the cassette from turning clockwise as you tighten the lock-ring, you do not need the chain-whip for installation of the cassette.

Chainlines for 2 wheeled ‘bents

shaver — Thu, 23 Sep 2010 02:49:13 +0000

Not to leave the 2 wheelers out of the collection, here are some chain lines of two wheel recumbents.

Says Bruce: Stephen (tennbent) and I wanted to eliminate the inherent problems on his Optima Baron that also exist with the chainlines on a lot of mid and low racers. The picture above shows the chain crossover between idlers.

The picture above shows the revised chainline, with crossover issue resolved. First, we wanted to clear the front tire/fork, and also to eliminate any chain cross-overs. We also did some other minor chainline mods to clean up the line. I won’t go into all of the details of HOW we did this, but the pics show the results. And, it works quite well. Stephen says it quieted the whole chainline a lot.

Admittedly, the change added another small bend in the power chain line, which technically adds pedal effort, but Stephen says he can’t feel any extra effort, and most folks won’t either. Maybe Lance Armstrong could feel it. The extra bend is about what most trikes experience in chain line bend. Bruce

The picture above shows one wheelbase-version of the Musashi, with chain crossover problems.

Another version of the Musashi, with chain crossover issues.

Chainlines, Idlers, and Tubes, oh my!

shaver — Wed, 22 Sep 2010 01:47:41 +0000

Chain lines on trikes seem to generate a lot of experimenting and novel approaches. The pictures below show a bunch of different approaches to making a chainline quiet and efficient, on all Catrikes I believe.

Hopefully the creators of these setups or those who have tried similar ones will comment on the likely quietness and efficiency of each of these setups. Send additional pics of chainlines of any type of bent, and I’ll post them.

Above: Bruce’s Speed. Bruce says this is the cleanest, quietest, most efficient setup he has used.

Above: Dr. Duk’s version of chain tubes. Says Bruce: “…shows the easiest, and best way to give the tubes the loosest float possible, and this is a good thing.”

Above: Flying Tiger’s version

Bruce’s orange Catrike. “This is the overly complex, and expensive, chainline that I tried on two of my Speeds. I had four goals for it: lift the return chain higher off the ground, push the power chain under the front axle, raise everything above the bottom of the main frame tube, and eliminate all tubes. It did all four quite well, but at the expense of expense and more noise. Both trikes are back to a single tube on the return chain, with just some tape on top of the axle to protect against the power chain slap. ”

another trike set up, by Jerry Mckee.

Bruce: “Jerry McKee’s is close, but the idlers should have been placed behind the front axle. Also, by pushing the power chain under the front axle, you alter the angle of the power chain to the der post and der. This can hurt the shifting, and at the least, it limits how small you can go on the small ring. I know this because on my Tony Trike, I couldn’t go smaller than a 30 tooth ring when I did this arrangement.”

Above: John Rooker’s Expedition. Says John: “I have the same setup on my present Trail. This is simple, effective, quiet and costs almost nothing once you’ve purchased the return side idler.”

Utah Trikes photo, on an Expedition. “…just insanely wrong! All of the Expo’s cherished ground clearance is lost with that arrangement. That idler should have been placed in front of the axle, as Pat Franz has designed those clamp-ons to be placed.”

photofinish

photofinish 2

photofinish 3

Bruce’s opinion – “Photofinish’s setup is a good example of a common myth about chainlines, that running the return chain in a straight line gives less drag. Wrong! It increases the drag compared to a slightly curved tube run underneath. If you let the chain hang naturaly with no tube, it has no frictional drag, so what better way to “tube” it than to run it through a tube that follows it’s natural curve as much as possible. Ideally, if the tube’s curve matches the chain’s curve, the tube will not be supporting the chain at all, and therefore will not induce any drag. But, if you lift the chain up and run it through a straight tube above where it wants to hang naturally, the tube is then carrying all of the chain’s weight, and that creates a LOT of drag, not to mention more noise. It may look cool, but it will cost you in pedal effort and extra noise. If you look at the first pic of my Holey Spokes, the tube has been curved to match the natural droop of the return chain as close as possible. With generous flares, it is almost silent all the time.”

rexpedition

Bruce’s Opinion – “pretty close to stock and about the best you can get. Quiet and efficient!”

another one from Utah Trike

Chain tube attachment by HP – Velotechnik, sold at Hostel Shoppe. A long spoke held under the idler bolt and tied to the tube as far along the tube as possible will allow the tube to move around as much as it needs to in reaction to chain movement, with very little restriction. The longer the spoke, the more flex is would have.

Terracycle floating tube holder. They also sell flared sections of chain tube. Although the floating tube holder is cool, the bike has chain routing and crossover issues. Without tubes the chain would rub itself, causing it to “snag” on itself as the pin ends catch each other. Also, the chain runs along the side of the fork, rubbing it almost constantly. Even with a tube, the tube rubs the fork. It also limits the turn radius, because the tire will rub the chain with very little turn input. Bruce

PhattKat’s setup, from his blog. Note the attachment of both the power side tube and the return side tube to the idler. These attachments look solid. Also full coverage of the chains, as shown below. How does one keep a chain so clean!!?? My trike is a mess by comparison.

Phatkatts chain tubes.

Chainlines for 2 wheeled ‘bents

Joules, the cycling robot

shaver — Wed, 23 Dec 2009 15:59:01 +0000

Specifically, Joules is a robotic stoker for your tandem bike, when you are riding solo on a tandem.

This project definitely has a steam punk flair, and combines some art, whimsy, and a good deal of engineering. Joules was built by engineer Carl Morgan with his son, a former pro cycling racer. The web page with more information on Joules is here.

Carl has a great U tube video also, linked below.

Front Wheel Drive Recumbent, 1950

shaver — Mon, 26 Oct 2009 22:54:23 +0000

What is the big deal about front wheel drive recumbents? Here is one that is really cool, from 1950. It has an internally geared hub, and a very stylish body. This would be a cool bike!

Early FWD Recumbent

shaver — Thu, 22 Oct 2009 21:34:02 +0000

Thomas Traylor’s 1982 design patent for a front wheel drive two wheeled recumbent, very similar in design to a Cruzbike Silvio. Considering Maria Parker’s new 12 hour record, set on a Cruzbike, maybe Traylor was ahead of his time!

Rear Suspension Bike, 1891

shaver — Thu, 02 Jul 2009 01:44:00 +0000

Here is a rear suspension bike from 1891 which used springs in a tube to give some give to the rear wheel.

Harry Lawson’s Bicyclette

shaver — Sat, 27 Jun 2009 01:00:00 +0000

James Starley’s Rover of 1885 was the first successful bike in which pedals and a crank drove the rear wheel with a chain, but he was not the first with that design. In 1879 Englishman Harry Lawson designed and patented a version of a large front wheeled bike with a smaller rear wheel driven by cranks and a chain. Lawson’s bike was not very well received, and he went on to design bikes using levers for power transmission. The Bicyclette was a commercial failure, but he had hit upon a superior design feature.

This artwork of the Bicyclette is a version featured on cigarette cards. This and other bicycle art is found at bicyclegifts.com. Framed versions of these beautiful cigarette cards, posters , cards, and other bicycle art recognize that brilliant design is art.

The First Rear Suspension Bike, 1891

shaver — Sat, 20 Jun 2009 01:30:00 +0000

Here is another candidate for the first rear suspension bicycle design, from 1891. Its modern counterpart is shown below.

Facing Bottom Bracket Shells on the Catrike

shaver — Sun, 07 Jun 2009 04:48:42 +0000

Yesterday I did a bottom bracket shell facing and thread cleaning job on Bob Shaver’s Speed. I took lots of pics of the job showing the steps in getting clean faces on each end of the shell.

After reading the text below each pic, it’s very interesting to watch them all in slideshow mode. The progress shows up much better that way.

This is the bottom bracket face before it was faced, showing the layer of powdercoat. The external bearing cups press down on this face, and if it is not perfectly flat the bearings are cocked to one side.

This is the Park tool for facing the bottom bracket faces.

This is the cutting tool cutting away the powdercoat layer, and a tiny bit of metal.

This is the face showing slight chatter marks from the tool.

The chatter marks are smoothed off and the face made perfect with emery cloth pressed in by the cutting tool.

The face after the final smoothing and polishing.

This facing of the bottom bracket edge is part of Bob’s upgrade to ceramic bearings in the BB. They are typically much tighter than the steel bearings that come in most bottom brackets, so they will not tolerate as much misalignment as the steel bearings. This is why the faces of the shell must be absolutely parallel with each other and perpendicular to the axis of the bottom bracket spindle when converting to ceramic bearings. The Park Tools threading and facing tool is a very precise piece of equipment that does a beautiful job of truing up a BB shell, even if it is very expensive. Most shops will do this job for about $50 if they have the tool, but most mechanics, in fact very few, know how to do the job correctly. They usually leave the chatter marks. That’s OK, actually, as long as they are even all the way around the face.

As can be seen in some of the pics in Bruce’s flicker photos (linked below), a lot of powder coating gets deposited on the surfaces where the bearing cups tighten. This uneven buildup causes the cups and bearings to cock sideways, as the powder coat is never perfectly smooth. Cheaper and sloppier steel bearings will absorb a lot of this alignment displacement, but better ceramic bearings won’t, and it will often cause bind in the better, tighter bearings. Pictures iL1, L2 and L3 in Bruce’s flicker pics show the non-drive side of the BB shell with a huge buildup of powdercoating. This is enough to cause bind in even a steel bearing. If you look really close at these pics, you can also see the only three small areas of contact that the bearing cup had with this face!

Besides the powder coating buildup, warpage from welding will distort the shell faces. This is shown in the pics as small areas at a time of bare aluminum showing up as cutting progresses. If they had been absolutely true from the start, the aluminum would have shown up all at once as soon as the powdercoating was removed.

If any Catrike riders intend to put ceramics in your BB, or you feel some resistance and just want to feel sure about your’s, and your lbs can’t do this job. Contact Bruce and if you ask nicely he may do it for you. You will need to send him your bare boom/BB and return postage. (Oh, and a pan of brownies!)(Hey! it never hurts to ask!) Contact Bruce at rbb@antelecom.net

This is the link to Bruce’s pics on flickr

Bruce

P.S. mikeatlbch made a comment that jogged Bruce’s memory, and he is right. mikeatlbch notes that facing the bb is needed only for external bearings, not for cartridge bearing assemblies. Thus the Speed, Expedition, and 700 model Catrikes, which all have external bearing assemblies, need to be faced. Other Catrike models or any bike/trike with cartridge bearings don’t need to be faced.