Reader Grego posted a comment with a link to Sheldon Brown's article on squeezing cogs onto freehubs technically too narrow for them. Rather than leave this in the comments I wanted to put it on its own post.
When I wrote the post I was going to say that I was sure greater minds than mine had thought of the idea years ago, but somehow in the press of time I forgot to put it in. Suntour launched the narrow chain movement in the 1970s with Ultra 6 freewheels that put six speeds on bikes that formerly had only five. If anything my post showed how slowly my mental wheels grind, not how rapidly.
I tend to make do with whatever I have. Especially when it comes to complicated devices like brifters and temperamental items like skinny chains I really try to resist the expense and complexity, weighing the advantages against the disadvantages for the self-supported cyclist. So it took me a long time to want that extra cog on the old seven-speed.
Laboring in a cycling backwater, and not addicted to reading about it on the Internet or in books, I receive my information as it drifts in. Presented with a customer problem I will do intense research. Then I go home and think about something else. So in a way, the fact that I independently developed the 8 of 9 concept validates the research of the true pioneers.
Sheldon also thought brifters were nifty. His article tells how to get those infernal mechanisms to work with the improvised cassettes, which is work you can skip if you declare your independence and shift in friction. He also prescribed skinny chains, where I'm running my 8-speed, reserving the option to go to nine if I notice any problems with chain width that did not appear on my test ride.
Showing posts with label things that shouldn't work but do. Show all posts
Showing posts with label things that shouldn't work but do. Show all posts
Saturday, July 26, 2014
Friday, July 25, 2014
8 of 9 on 7
You can easily get caught up in the bike industry's definitions of things and start arguing in their terms, forgetting to analyze problems at their most basic level. Nowhere does this seem to exert more control than in drive trains.
I spend a lot of time getting people's shifting to work. I spend time getting other things to work, too, but shifting occupies a lot of brain space, working out compatibility issues and remembering what can and can't be fixed at all.
Aside from the fixed-gears, my other bikes have seven or eight speeds. My faithful old road bike had seven because I had never re-spaced the frame to 130 mm and I had a wheel with a seven-speed hub without too many miles on it. But commuting to work I discovered two things: First, I wanted a slightly lower low gear. The old 26-tooth cog, even with a 34 ring up front, was good enough for the relatively easy commuting route, but gave me no reserve for longer, nastier climbs. Second, I liked the 50-26 (The Ned), but I feel guilty using it.
I wondered if I could build an eight-speed cassette from nine-speed cogs and spacers that would then fit on a seven-speed freehub.
Yes I can.
When the Miche cogs and spacers came today I test-stacked them on a seven-speed hub from the box of salvage in the basement. Perfect! But would it work with my eight-speed chain? Not a big deal. Nine speed chains are a little more expensive, but still cheaper and more durable than 10- and 11-speed chains. I'd done some experiments on particularly troublesome drive trains that indicated you could run eight on nine and nine on ten in a pinch. And that was on indexed brifter systems. Shifting in friction opens up a lot of other options. If I didn't mind joining the Chain-of-the-Month Club I could make 11 on eight. Ten, anyway, but that's not exotic.
The road test disclosed no problems. I can shift the whole range from both chain rings. I've got my former Ned as a legitimate choice. The new Ned works, too. The chain was long enough.
Of course the disclaimers say you should never mix brands and types of cogs, bla bla bla. If you needed precise indexing performance that would be true...ish. I've mixed cogs for special needs indexing customers as well as friction shifting privateers. It's dicier when indexing is at stake, and downright impossible for the obsessive shifting-geek who thinks a Wippermann chain is "too noisy and slow." Someone that addicted will sell an organ and a couple of kids to have a directional Dura Ace chain when he needs it. Face REALITY, dude! You need help!
Shifting a crowded cluster in friction takes a light touch. Actually, this latest Frankencassette is not as touchy as I though it might be. The Campy Veloce derailleur was already very quick compared to the agglomeration on my Cross Check. Closing up the spacing and adding a cog has not made it unmanageable.
I spend a lot of time getting people's shifting to work. I spend time getting other things to work, too, but shifting occupies a lot of brain space, working out compatibility issues and remembering what can and can't be fixed at all.
Aside from the fixed-gears, my other bikes have seven or eight speeds. My faithful old road bike had seven because I had never re-spaced the frame to 130 mm and I had a wheel with a seven-speed hub without too many miles on it. But commuting to work I discovered two things: First, I wanted a slightly lower low gear. The old 26-tooth cog, even with a 34 ring up front, was good enough for the relatively easy commuting route, but gave me no reserve for longer, nastier climbs. Second, I liked the 50-26 (The Ned), but I feel guilty using it.
I wondered if I could build an eight-speed cassette from nine-speed cogs and spacers that would then fit on a seven-speed freehub.
Yes I can.
The road test disclosed no problems. I can shift the whole range from both chain rings. I've got my former Ned as a legitimate choice. The new Ned works, too. The chain was long enough.
Of course the disclaimers say you should never mix brands and types of cogs, bla bla bla. If you needed precise indexing performance that would be true...ish. I've mixed cogs for special needs indexing customers as well as friction shifting privateers. It's dicier when indexing is at stake, and downright impossible for the obsessive shifting-geek who thinks a Wippermann chain is "too noisy and slow." Someone that addicted will sell an organ and a couple of kids to have a directional Dura Ace chain when he needs it. Face REALITY, dude! You need help!
Shifting a crowded cluster in friction takes a light touch. Actually, this latest Frankencassette is not as touchy as I though it might be. The Campy Veloce derailleur was already very quick compared to the agglomeration on my Cross Check. Closing up the spacing and adding a cog has not made it unmanageable.
Thursday, November 07, 2013
The wrong way to put on a Cannondale Headshok boot
While I was replacing the air spring O-rings in a customer's early-21st Century Cannondale F600 I noticed that the fork boot had a rip in it. The Headshok has many fine qualities, but it all goes to hell if the boot does not remain sealed against contamination. The needle bearings on which the fork slides so smoothly get all gritty and crunchy. Then you have to rebuild the fork. That will force you to face some of the more vexing idiosyncrasies of the design.
I had not done a boot replacement in years. The last Headshok that needed a boot was on a bike already so beat that my field-hospital repair was good enough. I cut a section of inner tube and slid it down to cover the tender parts. But a little research found a source for real pleated shock boots with nice little clamps, at a place that styles itself as "The Cannondale Experts."
When the boot arrived yesterday I knocked the fork out of the frame and started trying to work the boot down over the large diameter outer tube of the shock to reach the skinnier part it is supposed to protect. The boot has a large end and a small end. Unfortunately, the small end is supposed to go on the bottom, making the boot basically impossible to stretch over the larger diameter seat at the bottom of the upper tube, where the larger opening gets fastened when the boot is in place. Lubing it and working gently with various blunt objects was getting nowhere.
Not to be defeated, I turned the boot inside out so I could lead with the large opening. Once I had it down on the skinnier part of the shock I was able to roll it back right side out with the help of one more blunt object. Ta daah!
I looked on line today and all the advice I saw said you have to tear down the fork to change the boot. But in case you don't want to bother, do it the wrong way. It worked for me.
I had not done a boot replacement in years. The last Headshok that needed a boot was on a bike already so beat that my field-hospital repair was good enough. I cut a section of inner tube and slid it down to cover the tender parts. But a little research found a source for real pleated shock boots with nice little clamps, at a place that styles itself as "The Cannondale Experts."
When the boot arrived yesterday I knocked the fork out of the frame and started trying to work the boot down over the large diameter outer tube of the shock to reach the skinnier part it is supposed to protect. The boot has a large end and a small end. Unfortunately, the small end is supposed to go on the bottom, making the boot basically impossible to stretch over the larger diameter seat at the bottom of the upper tube, where the larger opening gets fastened when the boot is in place. Lubing it and working gently with various blunt objects was getting nowhere.
Not to be defeated, I turned the boot inside out so I could lead with the large opening. Once I had it down on the skinnier part of the shock I was able to roll it back right side out with the help of one more blunt object. Ta daah!
I looked on line today and all the advice I saw said you have to tear down the fork to change the boot. But in case you don't want to bother, do it the wrong way. It worked for me.
Tuesday, November 05, 2013
Shifter Noodle Update
The Serotta tri bike on which I installed the shifter noodles in April came back for some adjustments, including shifting problems. The junction ferrules I installed did not stand up to the twisting of the housing, so the linear wires of the housing were starting to push through. When that happens the shifting will not stay adjusted. The tension keeps easing as the housing collapses.
The rider also wanted to replace the old Deore XT derailleur I put on there to handle her wide-range gears with a newer model that might work more precisely on her 10-speed cassette.
Ten-speed is about to get shoved way down-market, along with derailleurs mechanically operated with cables. Did you spend thousands of dollars on a bike with a ten-speed cassette and mechanical shifters? Sucker.
The next stage after SIS (Shimano Index Shifting) and STI (Shimano Total Integration) is SMEGMA: Shimano Mechanical-Electrical Gear Manipulation Apparatus.
Until SMEGMA gets applied to every bike and imitated throughout the industry, we in the mechanical trade still have to keep people's old garbage more or less working. So I'll be upgrading the shifter noodles to try to make them as close to trouble free as anything can be.
The New XT derailleur has no cable adjuster on it. The system has no other adjuster, so an in-line adjuster may help as I try to replace the failed ferrules with something more robust. Lots of ideas jostle in my brain like clowns in a tiny car right now. We'll see who gets out the door first.
The solution may include 4 mm housing. A 4 mm ferrule might fit inside the junction ferrule of a standard brake noodle. Or I might try flat-wound housing, used on brake cables, because the progressive, bar-con shifters are not quite as fussy as brifters. And I will need to incorporate an in-line adjuster on the right side, at least, because adjusting the rear shifting without a fine-tuner is a huge pain.
Tomorrow I'll start collecting potentially useful bits for the next phase of experimentation.
The rider also wanted to replace the old Deore XT derailleur I put on there to handle her wide-range gears with a newer model that might work more precisely on her 10-speed cassette.
Ten-speed is about to get shoved way down-market, along with derailleurs mechanically operated with cables. Did you spend thousands of dollars on a bike with a ten-speed cassette and mechanical shifters? Sucker.
The next stage after SIS (Shimano Index Shifting) and STI (Shimano Total Integration) is SMEGMA: Shimano Mechanical-Electrical Gear Manipulation Apparatus.
Until SMEGMA gets applied to every bike and imitated throughout the industry, we in the mechanical trade still have to keep people's old garbage more or less working. So I'll be upgrading the shifter noodles to try to make them as close to trouble free as anything can be.
The New XT derailleur has no cable adjuster on it. The system has no other adjuster, so an in-line adjuster may help as I try to replace the failed ferrules with something more robust. Lots of ideas jostle in my brain like clowns in a tiny car right now. We'll see who gets out the door first.
The solution may include 4 mm housing. A 4 mm ferrule might fit inside the junction ferrule of a standard brake noodle. Or I might try flat-wound housing, used on brake cables, because the progressive, bar-con shifters are not quite as fussy as brifters. And I will need to incorporate an in-line adjuster on the right side, at least, because adjusting the rear shifting without a fine-tuner is a huge pain.
Tomorrow I'll start collecting potentially useful bits for the next phase of experimentation.
Sunday, October 06, 2013
We provide...leverage
Trust the bike industry to create a compatibility issue in something as simple as a front shifter.
A customer had us build a bike for him for the Mount Washington Hill Climb back in 2003. He used it in the race every year until last year, when he asked us to convert it to a flat-bar road bike.
The frame was a Trek 5900 SL. The carbon fiber road frame uses a bracket for the front derailleur rather than a derailleur with its own clamp. This was irrelevant on the original build, because we did not mount a front derailleur. In fact, the frame had no derailleur bracket when he had the bike delivered for its road conversion. Finding a bracket to fit a frame that was nine years old -- prehistoric in current bike industry terms -- was a treasure hunt. It was easily resolved once we found someone who knew the right part number at Trek. So we were all set, right?
Come on. This is the bike industry we're talking about. The business that's been killing the wounded and eating the dead since the 1990s. The group that puts its elderly out on the ice floe to die before they're even out of grade school.
Our customer wanted grip shifters. He also believed that the road conversion would be a simple matter of adding the parts the climbing bike had done without. It's a reasonable assumption if you don't work with this machinery all the time. Even I felt that the front shifting would be the least of our worries once we rounded up a very basic array of parts. A ratcheted front Gripshift is a simple device for pulling cable. A front derailleur is a simple device for pushing a bike chain toward a chainring with which you want it to engage.
Trigger shifters and road brifters only pull a specific amount of cable. A compatibility issue there is no surprise. It's expected. The customer's request for the closest thing to a friction shifter seemed to get us around that. But the shifters we use technically come from the "mountain" category and the only front derailleur that would work with this frame mount and gear range comes from the "road" category.
The shift to the middle ring on the triple crank went well enough, but that last little twist to make the big ring was incredibly stiff. And no matter how much cable tension I put in the system, the arm on the Sora FD-3503 is too short, and angled in such a way, that it barely swings far enough to clear the ring. The shifter never manages to pull it all the way to its limit screw.
With no alternative parts, I had to make these work. Introducing the Cafiend Leverage Enhancer.
A customer had us build a bike for him for the Mount Washington Hill Climb back in 2003. He used it in the race every year until last year, when he asked us to convert it to a flat-bar road bike.
The frame was a Trek 5900 SL. The carbon fiber road frame uses a bracket for the front derailleur rather than a derailleur with its own clamp. This was irrelevant on the original build, because we did not mount a front derailleur. In fact, the frame had no derailleur bracket when he had the bike delivered for its road conversion. Finding a bracket to fit a frame that was nine years old -- prehistoric in current bike industry terms -- was a treasure hunt. It was easily resolved once we found someone who knew the right part number at Trek. So we were all set, right?
Come on. This is the bike industry we're talking about. The business that's been killing the wounded and eating the dead since the 1990s. The group that puts its elderly out on the ice floe to die before they're even out of grade school.
Our customer wanted grip shifters. He also believed that the road conversion would be a simple matter of adding the parts the climbing bike had done without. It's a reasonable assumption if you don't work with this machinery all the time. Even I felt that the front shifting would be the least of our worries once we rounded up a very basic array of parts. A ratcheted front Gripshift is a simple device for pulling cable. A front derailleur is a simple device for pushing a bike chain toward a chainring with which you want it to engage.
Trigger shifters and road brifters only pull a specific amount of cable. A compatibility issue there is no surprise. It's expected. The customer's request for the closest thing to a friction shifter seemed to get us around that. But the shifters we use technically come from the "mountain" category and the only front derailleur that would work with this frame mount and gear range comes from the "road" category.
The shift to the middle ring on the triple crank went well enough, but that last little twist to make the big ring was incredibly stiff. And no matter how much cable tension I put in the system, the arm on the Sora FD-3503 is too short, and angled in such a way, that it barely swings far enough to clear the ring. The shifter never manages to pull it all the way to its limit screw.
With no alternative parts, I had to make these work. Introducing the Cafiend Leverage Enhancer.
The arm of the derailleur is extended with part of an old brake cable
adjuster. It's bolted to the arm, where it braces against the cable
routing flange to keep it from rotating downward when the cable gets tighter.
At the shifter end, the diameter of the grip seemed a little small too. We've had older riders complain that they have trouble with that. Lacking anything more elegant, I built it up with several layers of inner tube. If he likes that but wants something a little zootier I'll get some of that black foam insulation they use on air conditioning lines, and snug it on there with some super-fat shrink tubing. He won't be back until next summer, so we'll have to wait and see.
The system works. Shifting is easier. I have one more brake adjuster that's a little longer if he wants that, but we start to get a little close to the rear tire then. If the rider wanted to put on something cushier than a 700X23 things could be tight.
Friday, April 26, 2013
Full frontal noodlety
Here's a short exploratory video of the shifter-noodle arrangement and some better pictures of the final version. It's on its way to St. Croix next Thursday for the St. Croix International Triathlon.
Gripping stuff here:
Mumbling in a cold garage...but it's at least as good as the subject matter deserves.
Here are the stills:
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Gripping stuff here:
Here are the stills:
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Sunday, August 05, 2012
Exorcism update
On the bike that kills front derailleurs we installed a Shimano Sora 9-speed compact crank. Brand new. Fresh start. The bike now shifts perfectly, according to the owner, who retrieved it and test rode it a few days ago. We're on to new crises now.
Our illustrious leader got his Shimano Ultegra rear derailleur to shift successfully on a SRAM 12-32 cassette, launching us on a little spree, defying compatibility recommendations. A customer venturing into hill climbs from her familiar realm of triathlons got the 12-32 treatment. The Zipp 404 wheel on which we put the cassette functions very well on her Surly Pacer and extremely adequately on her Serotta. Who woulda thunk it?
Our illustrious leader got his Shimano Ultegra rear derailleur to shift successfully on a SRAM 12-32 cassette, launching us on a little spree, defying compatibility recommendations. A customer venturing into hill climbs from her familiar realm of triathlons got the 12-32 treatment. The Zipp 404 wheel on which we put the cassette functions very well on her Surly Pacer and extremely adequately on her Serotta. Who woulda thunk it?
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