|how much jockey wheel play?||sodade|
Apr 1, 2002 3:58 AM
|I noticed that one of my jockey wheels (the highest one)on my >300 mile DA deraileur has a noticable amount of side to side play - maybe 1-2 MM or so. The other wheel has virtually none. I tried to tighten the hex bolt, but it wouldn't budge and I nearly rounded it. I have been trying to track down this nagging drivetrain problem where every 10th (roughly) link will not seat all the way on the two biggest cogs. I have replaced the chain and cogset (I needed a bigger gear anyway). Could this play be the source of my problem? How am I going to fix it?
Thanks in advance - especially if you don't know the answer and you go check your to see if it is normal...
|Why people should trust professional mechanics...||TJeanloz|
Apr 1, 2002 5:22 AM
|Jockey wheels are supposed to 'float' from side to side. If they didn't have this play, you would have real shifting issues.|
Apr 1, 2002 6:10 AM
|SHIMANO upper jockey wheels have lateral float. Campy does not.No major shifting issues. Shimanos can be replaced with aftermarket ones that have no float.No major shifting issues.|
Apr 1, 2002 6:34 AM
|I was foolish to not say that I was addressing his jockey wheels specifically (which were Dura-Ace). However, you will not get great shifting performance if you replace the floater with a non-floating aftermarket version. Trying to use a Carmicheal or other fancy pully can be an exercise in frustration.|
|You're right, (not)||mtnpat|
Apr 1, 2002 9:24 AM
|Not if your deraileur is properly adjusted! Non-floating jockey works fine.|
Apr 1, 2002 8:11 AM
|Actually Campy does have float. At least sinc 8 speed came along.|
|re: how much jockey wheel play?||Spoke Wrench|
Apr 1, 2002 7:11 AM
|I don't think that jockey wheel float is your problem. It's a design feature with Shimano products and the majority of bikes use them successfully.
When you say "every 10 links" that's twice per revolution on your largest cogs. Does the problem match up with the oddly-shaped teeth on the cog? I wonder if you need a b-screw adjustment to pull your derailleur a bit farther back.
|re: how much jockey wheel play?||sodade|
Apr 1, 2002 8:52 AM
|Interesting - I actually have my b-screw set so that the derailleur is as close as possible - I will back it off and see what happens...
The funny thing about this problem is that when I pedal backwards, the chain seats fine.
|re: how much jockey wheel play?||grzy|
Apr 1, 2002 11:03 AM
|It's pretty hard to do a good job trouble shooting your drivetrain without seeing it. There are some common things and then some very uncommon things that could be at work here. A skilled mechanic could diagnose your problem in less time than it takes to write this. The float in your pulley, as pointed out, is supposed to be there - it's a patented design by Shimano (dunno if the 17 years are up). You need to consider things like a stiff link, a damaged or worn out chain, a messed up cog, a bunch of crud in the gears, the correct lock ring, a snug cassette body, bent der. hanger, proper b-screw setting, good cable and housing runs, etc. |
Doing it on your own means you need to play detective, but if you're not familiar with all of the things that can affect the drive train it's hard to do the correct diagnosis - sort of like being a MD. It's part of human nature to start thinking of complex and obscure failure modes when in fact the explanation is often simple. If everything appears to be in order, installing a new chain can solve a lot of mysteries. If it's not the chain then hang on to it for a spare and look at more complex things. Getting a good maintenance book will save you time and money.
|hard to get good help these days...||sodade|
Apr 1, 2002 12:24 PM
|The problem is, the only trustworthy shop is deep in the heart of the Boston traffic zone and not even next to a freeway. On top of that, this shop is so popular that they have week-long lead times. The other local shops are all for selling garage wall hanger bikes with fat gel saddles for zigzaging on bike paths. These shops all seem to employ the same dude - you know the pierce your ear with a nickel dude who gets phat air off curbs on his freeride bike. There is a shop that is close to my house that sells Trek road bikes, and does service, but when you walk in to the store the owner is a fat dude smoking cigarettes! In the fricking store! When he asked me if I needed help, I literally said "yeah - right"
So I figure that I need to learn all there is to know about my bikes so I can fix it myself. Being a computer dude, I know that the best way to troubleshoot hardware is to methodically swap out parts (and if I end up with extra stuff, I will always need it in the future, or I can sell it on ebay and get most of my $ back. Starting with a brand new bike, I have replaced the chain and the cogset. The reason I asked about the jockey wheels is to figure out if it makes sense to replace the deraileur. I have read through Zinn's book (which I think is overrated IMHO - would it be so difficult to put the pictures with the right text?) and the bike shifts beautifully. I need to back out the b-screw, but beyond that, I have tried everything except replacing the rear der. and having the hanger inspected.
|Which Boston are you talking about?||samcat|
Apr 1, 2002 12:57 PM
|"hard to get good help these days...
The problem is, the only trustworthy shop is deep in the heart of the Boston traffic zone and not even next to a freeway. On top of that, this shop is so popular that they have week-long lead times."
1. Try Wheelworks in Belmont, Ace in Somerville, Harris in Newton. All are extremely good, each an easy ride from the city, all open evenings and all will do "while you wait" emergency work or same day stuff, during midweek, if you call ahead and explain your problem...
2. there are no "freeways" in New England...
3. Parts swapping may work fine for "a computer dude". Smarts and some common sense works better for most of the rest of us...
4. Zinn is about seven feet tall and dislikes having his leg pissed on by know nothings...I'd watch my mouth...
|Which Boston are you talking about?||sodade|
Apr 1, 2002 5:40 PM
|The problem is, I live in NH. Wheelworks is the shop I was refeering to. They told me a week, plus they are a nightmare to get to.
New England needs freeways (although, what do you call 95/128?) - sorry, but I come from Ca and freeways keep nice country roads nice and country. (Until overdevelopment gets there too).
I am just saying that Zinn's book is overrated - not that I know more about being a bike mech. It should be laid out cleaner. Also, he ripped on the Sram chain saying that "in practice nobody can get the powerlink apart" - I do it all the time...
|Those are highways,||TJeanloz|
Apr 2, 2002 5:46 AM
|In Boston, we have highways and one turnpike. There are no freeways.
We have no need for these 'freeways' as we have an excellent public transit system (at least in Metro Boston).
Apr 2, 2002 9:47 AM
|Since the MBTA is so good why the Big Dig? Big Dig really means that the politicians and their croonies get to dig deep into the tax payers pockets and demonstrate new and creative examples waste, fraud and abuse. |
The roads absolutely suck in and around Boston and this is coming from a native. 128 is just a long skinny parking lot, Rt. 3A is an excercise in frustration, driving in the breakdown lane is a semi-legal sport, and a red traffic light means that only four more cars can go. Then there is that "highly efficient" organization that is the DPW. An MDC cop's biggest concern is where his next donut is coming from and how much overtime he's going to get watching his DPW buddies lean on their shovels.
Yeah, Boston the model for an efficient modern city meeting the needs of it's people.
|While we appreciate your perspective,||TJeanloz|
Apr 2, 2002 10:53 AM
|Since you haven't lived in the city since disco was king, I think you'd be surprised by how much has changed. The T is no longer the urine-soaked homeless shelter that it once was. There are even female and minority T drivers (who saw that one coming?). The Big Dig will create (if it's ever finished) one of the largest new public open spaces ever in a modern city.
Route 128 (now rebadged as I-95) flows smoothly except for 45 minutes or so in the morning- and even then, it's MUCH better than Denver traffic. Red lights remain largely disregarded.
The DPW does most of their work at night, so you don't see them leaning on their shovels. Of all the American cities I've lived in, public transit in Boston is the easiest and best.
|I'm glad somebody finally mentioned that Zinn's book||scottfree|
Apr 2, 2002 9:23 AM
|is overrated. Not only do the illustrations not match the text, the text itself never quite achieves that balance between assuming you know nothing and assuming you know a lot more than most of us do. He's always telling me too much or too little.
Plus there's that thing he says about handlebars being replaced every few years because they are destined to fail. Huh?
|Before you know it, somebody may mention that Gary V Hobbes||scottfree|
Apr 2, 2002 9:26 AM
|Zinns book may be overrated but what's the alternative?||ColnagoFE|
Apr 2, 2002 9:54 AM
|I've never found a modern "fixit" manual that tells me as much as Zinn so I can handle most of my own basic repairs, but doesn't baffle me with esoteric stuff I could care less about like Barnetts does.|
|Hard help is good to find...||grzy|
Apr 1, 2002 2:47 PM
|Or something like that....;-) |
Swapping out parts is the *most* expensive way to troubleshoot - I leave that to my friends in the military. It's better than nothing when you don't understand the system or have the tools to fix the actual problem. You could swap everything and find out that your hanger was bent (I don't think that this is your problem BTW). The chain is the thing that wears out most often and can cause all sorts of problems, they're pretty cheap, and sooner or later you'll need it.
Start by getting a set of the Shimano rear deraileur instructions that came in the box with the new der. - it's got the best procedure on setting it up - RTFM as the saying goes. The special little Park brush for cleaning cogsets up works great. In fact starting with a clean bike is a good idea - use the Pedro's process detailed under their Pit Kit. You might be amazed to see what a really good clean and lube can do. A bit of a twig in the cogset can really cause some problems and make a chain "hoP like you describe.
I guess the rub is that you want to learn more about fixing and maintaining your bike so you have to start somewhere. Unfortunately getting the shifting dialed in is one of the trickier things. I have friends that get their bikes back from less desirable LBS's and find that they're not set up right. MTB dudes can do a fair job, but if they don't know the fine points of road bikes there is only so much they can do. They do see a lot of mangled drivetrains so they know how to get back to square one.
Maybe you have a riding buddy that's a pretty good wrench - he could probably diagnose your problem very quickly.
Yeah Boston - a good place to be from. Got my first 20 years there - now I just visit. All the good shops that I knew are gone - the Bicycle Exchange in Cambridge being one of them.
|Help hard is find to good...||sodade|
Apr 1, 2002 5:55 PM
|I agree that swapping parts is expensive, but it is not a bad thing to have two of most things right?
The whole drivetrain is anal-retentively imaculate. From what I can tell, it is set up perfectly. It shifts smooth as a baby's ass. I have done plenty of RTFMing, from Zinn to parktools web site to fourms. I like to be self-sufficient, but it looks like I am going to have to ride the sweat laden old Bianci (trainer bike) while I leave my new girlfriend at some distant bikeshop. sniff - I get all teary just thinking about it...
|Good find - hard help||grzy|
Apr 1, 2002 6:18 PM
|Dang - if the whole thing is squeaky clean it should be pretty easy to see what's happening. Get it up on a stand in some bright light and turn the crank by hand and ask yourself "Why?" Why is the chain jumping - it could be something as simple as adjusting the cable length - you can get the rear dialed in so that it's close, but will still do a little hop in one certain gear combo. This is the fine tuning - you're probably only one or two clicks away from having the thing running perfectly. It takes time and patience to get it just right, plus the knowledge that it can be done by people with half your IQ.|
|The difference between derailleurs and computers||Kerry|
Apr 1, 2002 4:57 PM
|Is that there ARE user serviceable parts inside. On the rear derailleur, there are 4 adjustment screws (5 if you count the adjuster on the down tube) that are MEANT to be adjusted to improve shifting. Think of it like old time electronics that were full of trim pots, adjustable capacitors, etc.
The most common shifing problems are caused by cable "tension", and adjusting that (barrel adjuster on rear derailleur/adjuster on down tube) fixes most shifing problems. (You really are adjusting the length outside the housing, but everybody calls it tension.) Next comes the "b" screw, which adjusts the angle of the derailluer body and brings the upper (floating) jockey wheel closer to/farther from the cogs. Finally, there are the upper and lower limit screws (not likely your problem) that control the limits of travel of the derailleur and prevent shifting off the largest cog into the spokes and off the smallest cog into the dropout. Unless you have crashed your bike in the first 300 miles, replacing anything is not likely to fix your problem. Bikes are relatively simple devices, and if you find an experienced rider, they can show you, in five minutes, everything you need to know about rear derailleur adjustments.
|re: sounds to me like the cable's too tight.||dzrider|
Apr 1, 2002 11:17 AM
|I can't see it from here, but it sounds like what happens when the derailleur moves the chain enough for the ramps to catch it but not enough to cause a shift. Just a guess, but it's worth trying free and easy fixes first.|
|re: sounds to me like the cable's too tight.||funknuggets|
Apr 1, 2002 2:47 PM
|Interesting, to me it sounds like you need to upgrade to a 7 speed RSX rear derail with >2000 miles to match with your float. You see, since the slightly used derail flexes slightly, it will help your chain seat better. You know what, I just happen to have a rear 7 sp RSX derail (see previous posts). I would consider an even trade for your D/A rear derail.|| |