Author Topic: Bike problem (Read 7389 times)

OUWxGuesser · « **on:** January 03, 2011, 04:14:08 PM »

So here's the deal. Winter commuting is going great so far. The other week, I spent some time degunking my drivetrain, cleaning the chain, and reoiling. I also adjusted the derailleurs to the best of my ability, which went OK... although probably no where near to perfect.

The last few days I have had a problem with chain tension when I'm either coasting or back-pedaling (usually when I'm stopped and I'm positioning it for a good take-off.) When either of these occur, the chain sags and loses tension. Then when I go to pedal, the lack of tension makes it feel as if I'm in the lowest gear and causes me to have a rough take-off/lose balance. There is also the roughness on the sprocket when you finally regain tension. My thinking was something with the rear deraileur/freewheel is snagging and not letting the chain move fluidly.

The funny thing is I was just now trying to recreate the problem in my office, however, I can't get it to do it. It spins just fine in reverse and tension is appropriate. This makes me think it is temperature sensitive problem. It might also be only occuring for certain gear combinatioons... I'll try mixing that up on the way home.

Any suggestions? Majorly annoying for the commute as I look like an idiot when I lose all torque trying to launch from a stand-still.

OUWxGuesser · « **Reply #1 on:** January 03, 2011, 11:03:56 PM »

Go figure, it didn't behave poorly on the way home. I tried a few different gear combinations and couldn't get it to act up.

Sal Atticum · « **Reply #2 on:** January 04, 2011, 08:23:13 AM »

Do you take your bicycle inside where it can warm up between rides, or do you leave it out in the cold all the time?

Plantains · « **Reply #3 on:** January 04, 2011, 12:40:44 PM »

When you freshly oil a chain, if you use the wrong lube, your links will freeze or become stiff. This could also be a condition of whatever cleaners you used.

If the solution doesn't present itself through the answers received from these questions, you will need to adjust your tension screw (perhaps you adjusted it on accident thinking it did something else) which will POSSIBLY require re-tuning the entire rear drivetrain.

What lubes and cleaners did you use, and what are the temperature variations with your bike (as beek mentioned)

OUWxGuesser · « **Reply #4 on:** January 04, 2011, 04:36:11 PM »

I keep the bike indoor at home and in my office.

Cleaner was chain brite from park tools. Can't remember the lube. White/yellow container recommended by Ski&Bike. General purpose for chain and other components.

Plantains · « **Reply #5 on:** January 05, 2011, 01:23:45 AM »

White lightning?

Wax based lubricants are a no no in colder weather. The wax will become MUCH too stiff to allow the chain to do what it does. You should be using a lube that is designed for wet conditions or specifically for the cold. I can't think of any off the top of my head designed specifically for cold, but there are plenty out there for moist conditions.

Also, instead of degreasing your chain, you should just apply more grease. By all means clean it, but degreasing is controversially a bad idea.

Mario · « **Reply #6 on:** January 05, 2011, 09:05:15 AM »

From my experincae, it very much could be a freezing grees/lubricant in your free wheel hub. I had that happent to my all the time during winter in "colder" temperatures. Chain lubing as guys mentioned may be part of it, but I'm more convinced it is free body hub that frezes up. The reason why I say that is becasue it happens when you cruze (you don't move your chain at all at that point, but your free wheel spins). So as you cruze, your free wheel tries to free up the cassette, but becasue the grease got stiff it actually pulls on cassette cousing the slack in the chain-you don't pedal, so you don't compensate for that created slack (I'm assuming the slack is created on the top portion of your cahin). The solution to it is not simple, for you would have to take your free body hub appart and apply different lub...Ask SBS to do it for you.

Sal Atticum · « **Reply #7 on:** January 05, 2011, 09:45:32 AM »

This happened to me one or two days before break...if it doesn't happen all the time, I wouldn't worry about it. It's up to you to determine how much of an annoyance it is.

Mario, you don't think a frozen link or two running through the dérailleur would cause the same thing? I only ask because it happened shortly after he lubed everything. I don't know if the grease would freeze up unless it was really cold that day, but maybe your links wouldn't freeze up unless it was really cold either.

Mario · « **Reply #8 on:** January 05, 2011, 09:52:40 AM »

Well, like I mentioned, when he cruzes it does not matter if the link is stiff or not. It's the free body that rotates at all time. Stiff link would couse a click or skip while pedaling. The only situation when very stiff link would couse the slack in the chain is when you pedal backwords, and the stiff link gets stuck in the deraileur.

Sal Atticum · « **Reply #9 on:** January 05, 2011, 10:08:33 AM »

I gotcha, I had to go read the post again and see that it happened when he was coasting too.

OUWxGuesser · « **Reply #10 on:** January 05, 2011, 08:09:15 PM »

Apparently the key is to mention it in the forum and then the problem goes away. Another problem free commute. If it pops up again, I'll look into it further, but alas I'm lazy if it is this intermittent

Plantains · « **Reply #11 on:** January 06, 2011, 11:04:41 AM »

Yeah... bottom line is that shit freezes.

OUWxGuesser · « **Reply #12 on:** January 18, 2011, 10:02:49 AM »

Well, that sucked. Got 2/3 to school and then I had the issue. This time, however, I was dead in the water. I was able to shift a couple times at fix the solution temporarily. Once I got a bit farther, however, I was done.

Basically, I still think there is a chain tension issue to some extent. There may also be some freezing going on... the rear derailleur would catch sometimes if you pedal backwards.

The biggest issue, however, is even if pedaling forward, the cassette will rotate with the chain and not move the wheel. Once in awhile it would catch momentarily, but then it would slip again permanently. I'm guessing this is is definitely a freewheel/hub problem - given the temperature dependence, I assume moisture/lube in there is freezing up and preventing it from catching?

So final question - how hard is it to clean this thing out? Do you need any special tools?

Mario · « **Reply #13 on:** January 18, 2011, 10:20:01 AM »

Well, it might required some specila tool, or it might need just an allan wrench. There is a lot of different ways how companies mount the free body hubs. Your best bet would be to take it to SBS. Is it really cold today/yesterday? By the way, I would say you were more dead in the snow/ice, than dead in the water

OUWxGuesser · « **Reply #14 on:** January 18, 2011, 10:23:53 AM »

Haha true. Dead in the water may be more appropriate in say... April

Plantains · « **Reply #15 on:** January 18, 2011, 12:39:30 PM »

Oh no... thats just the pawls inside the freehub body sticking. Its a pretty common problem on lower end freehubs, and it may just need to be disassembled and cleaned. The reason that the derailleur is skipping is probably because you were inbetween gears, or (more likely) your derailleur hanger is misaligned. The misalignment is pretty common on big box bikes... they'll align it so that it runs very smooth in the forward motion, because it compensates for the crappiness of the rear drivetrain on lower end bikes, but this causes it to catch when pedaling backwards.

Things you can try:

1. Bang on the hub when in the field and you may just knock those pawls loose.
2. Ride fixed gear in the winter. Not only is this a big reason why people do this (less to go wrong) but you also get INFINITELY better control.
3. Buy a new hub or wheel
4. Do a total disassembly and clean and relub the internals of the freehub body.

I assume (no offense) that this is above your paygrade, but if you want to look into whats involved with the process, you can look in our resource thread at both Sheldon Browns website and the Parktool website. Sheldon will have lots of details, and park will have a how to.

In the meantime, here's a pic to sort you out.

Plantains · « **Reply #16 on:** January 18, 2011, 12:48:46 PM »

Those poinky things are the pawls that cause the freehub to click when you're freewheeling, and to engage when you're pedaling. This is a higher quality model, so yours might not look as pronounced and it might use actual coil springs which will shoot all over the place if you touch them, so watch your eyes and make sure you're prepared to catch them!

Questions, ask... we/I can probably guide you through it well enough if you decide to have a go, and the SBS is only a few mins away worst case scenario.

Mario · « **Reply #17 on:** January 18, 2011, 12:57:22 PM »

ha, ha, Dave. As you were typing your second message I was typing mine. Check the similarity: "That's actually nice free hub. You might have only two powel. Also there might be springs instead of steel leaves." Great minds think alike, right,ha,ha.

OUWxGuesser · « **Reply #18 on:** January 18, 2011, 01:40:45 PM »

Options options... my general philosophy on this bike is to upgrade as I go. I have already upgraded to better v-brakes when the originals went on the fritz.

In an ideal world, I would upgrade the wheelset to something disc compatible and also the drivetrain. I don't care too much about weight... I just want something solid that works. Is this possible on my current budget... eh probably not. I'd be curious to see what sort of $$$ you think I would need to do this.

Going singlespeed in the back is also an option that is appealing. No clue what the $$ involved for that is.

For now, I'll probably dump the hub off at SBS and see if they can repair it. On the other hand, I hate spending $$ to fix something that I would want to replace within a year or two anyway.

FYI the current components in the rear are Shimano altus/deore

redtailin · « **Reply #19 on:** January 18, 2011, 02:25:27 PM »

if you want to go SS (keep in mind SS is not the same as fixed), but should you choose to go SS, I grabbed a crappy full squish frame from a dumpster that had a SS chain tensioner on it. It is a pretty nice aftermarket one, but I haven't pulled it off to determine how operational it is, but it seems to be in pretty nice shape. If it works and thats what you wanted to do, ill just give it to you

Remember though, that this will not solve the problem of the paws on the hub not engaging.