Bicycle Mechanics - what have I done to my bike??
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03-10-05, 08:05 PM
background - the bike was working fine when I bought it, so I know the bike SHOULD work normally. But we had to take off both wheels to get it into my car. Here's what happened when I tried to put it back together:
Ok I'm not the handiest guy around tools, obviously - I'm a doof. But I'm a doof who is determined to learn. So I got my baron this week and put the wheels on - having to put the chain back on the rear wheel as well. How hard can that be, right? it goes in a big S-curve before resting on the rear cassette. just like my other bikes.
I've screwed up somewhere. Went to ride it for the first time a few minutes ago, and things started out fine. Then I tried to shift gears, and thought I had succeeded until I heard this grinding from the front chainring. Didn't see any problem there, but I stopped and walked my bike back to the house. What's happened while I was pedaling is this:
The chain shifted fine onto the biggest ring up front, and was working it's way to a bigger ring in the back, and then it's like it ran out of play. The derailleur arm shifted back and back and now it's stuck. The whole chain is so darn tight I can't budge it and loosen it so that derailleur will relax back to a normal position. What have I done? I can't figure out how I installed it wrong, and can't figure out why I can't loosen the chain at all - it's like the chain is too short for the bike! There should be some play - it's only on the 3rd smallest gear in the back. I can't force any slack on the chain to re-run it or anything.
here's a picture that shows how much tension is on the D.
Also, when I turned the bike around I heard a metallic PING and saw this thing lying there. I think it was just road debris, because I can't see where this could have fallen from, but maybe you guys can tell me if it's a piece off my bike:
Sure like to see what's going on at the cranks. That chain looks too scrunched together to fit around the big chain ring. And that metal piece looks like part of a cheaper seat bracket.
03-10-05, 08:50 PM
Can you post a picture that shows all of the chain and the front rings and rear cogs at the same time? Or one of the rings in front too. The chain can't be going around the chainrings ? Did you shift the front and rear at the same time? I'm guessing the chain is caught in between something in the front and off the chanrings. It's likely in between the granny gear and the bottom bracket.
What brand and model bike is this?
I agree with dbg that's part of an inexpensive seat clamp.
03-10-05, 09:00 PM
I can't show the front and rear at the same time, since it's a recumbent and the chain is super-long. here are a few pics of the front chainring.
And if that's from my seat, I have no idea where it could go back. Everything that attaches the carbon fiber seat to the frame is bright alumium. Musta been a part from someone else's machine and I just ran over it. I have no clue!
03-10-05, 09:24 PM
You need to add some links to your chain. When you adjusted your boom out to the proper length for your leg length, you forgot to account for the fact that the chain might be too short. I had to add 6 links to my baron chain. get a chain tool. On a baron, when using your big ring, you still want to be able to get into your lowest climbing gear in back. The baron chain when adusted right will accomodate a 58 tooth ring up front and a 34 ring in back and still not gain too much chain slack when in the middle or granny ring up front. Also, make sure you are comfortable with the boom length postion before adding links to your chain.
03-10-05, 09:33 PM
OK that's helpful. Did you just have the bike worked on before you put it in the car?
Some recumbents have the chain going under the seat using different methods. Some use a plastic tube to guide the chain, some use little pulleys, some use another set of chainrings. So far it looks like something in there. Can you explain or post a pic of that area?
Again ~ What make and model ? This may allow others to understand, by finding pictures or information on line. Or they may have one! Or they may even work for that company.
I agree, you just ran over that part.
03-10-05, 09:35 PM
also, yes that is part to a clamp mechanism to a childs bmx bike most likely. If you go to the yahoo groups baron owners website, Don Smith will also gladly school you in everything baron related.
Check out the postition of my chain and rear derailleur postion while in the big ring. I have a few more links of chain than you do. Looks like you are gonna need at least 6 or 7 links.
Also, if you are interested, that optima tailbox is now for sale. 400 bucks and it already is modded and prepped to fit a baron directly. When you buy a tailbox new, you have to figure out how to mount it to the bike. That means cutting the box to fit around the wheel. New boxes are still $525.00 I believe. The tailbox will add on some free speed to the bike. If you aren't ready to get that deep into it right now, don't worry about it...... we will steer you in the right direction later on when you decide to get one.
heres a shot from when I was racing it in Chicago and won national superstock championship at the Arlington Crits.
03-10-05, 09:47 PM
[QUOTE=lowracer1]also, yes that is part to a clamp mechanism to a childs bmx bike most likely. If you go to the yahoo groups baron owners website, Don Smith will also gladly school you in everything baron related.QUOTE]
So that's what a Baron is. Nice bike, looks very fast. I'm getting to the point where I'm going to suggest some kind of standard post for Mechanical questions. So that they all have to start with...
I have a. Brand...... model.......... year......with a ........group. That should be the beginning of every mechanical question.
I didn't even know if that was a pet name for his bike. You may have had the answer on the very first posting.
How about a longer shot of the whole chain? It doesn't cross over itself by any chance does it?
03-10-05, 10:02 PM
no, we already had him drop his chain for better efficiency. heres a pic to what a baron looks like with the second and third idlers added with the chain tube. Its fine if you want to turn tight circles on the baron, but that hardly ever happens, so what we do for road racing is get rid of the 2 extra idlers and drop the chain. Less friction and straighter chain pull.
here is another pic of one with the chain dropped and no second and third idler.
heres a bunch of high quality pics showing a baron set up with carbon parts and exteme track racing.
here is a few pics of an even faster carbon lowracer owned by the same guy Jim Scazzafava.
These pictures here best show correct chain management on a lowracer. Best pictures on the net that I've found. awesome high quality closeups. All these pictures will apply to an Optima baron setup.
03-10-05, 10:49 PM
Chris, I just got the Baron over the weekend - I wouldn't know how to drop a chain if you wrote me a manual. :) My chain route looks exactly like the one on the optima website with the three idlers and the long chain tube.
Not only am I new to recumbents, I'm new to bike maintenance at all. I've never even had to change a flat - that's how new I am :) So I apologize for the lack of information.
Also, Chris - I haven't changed the length of the boom at all. It's exactly the same as it was when I bought it from the previous owner. So the chain length SHOULDN'T be an issue, as far as I know (although that was my first thought as well). I've just managed to screw something up. I managed to take the wheel back off and will endeavor to put it back on tomorrow.
Bike is a optima baron, ultegra group, Magura Julie disc brakes (could that be the problem? I've not done something correctly to the discs when I flipped the wheels back onto the bike.
Also, yes I'm very interested in the tailbox. You and I should talk more about that later.
03-10-05, 10:55 PM
Do you and the previous owner have the same x-seam? Where abouts do you live anyhow? You could always plan a weekend road trip and I'd have your bike dialed in within a few hours. It is very important to get the boom extension length correct for your pedaling position. Too long and you stretch too far while pedaling. Too short and it will be hard on the knees. If you are within 6 hours driving distance, It might be worth your while before spring or summer hits to get your bike set up right. Your local bike shop won't have a clue on how to set up a baron. If you are too far away from me, there are other baron owners in the baron group who might also be willing to help that may live way closer to you.
The chain is too short. You must not have test ridden the gear combination you photographed. You need to break the chain, add a bunch of extra links, then wrap the chain around the largest chainring, the largest cog, pull tight, add two links, and remove the excess.
If you're not comfortable doing this, take the bike to any LBS and they'll set it up for you.
03-11-05, 07:30 PM
I dont think your chain is too short.I think its just because your in those gears.You shouldnt have chain on both largest gears at the same time.If u look at from the top down at chain it should remain as straight as possible. I know for sure that now ur running at a pretty drastic angle for a chain.This puts too much stress on the chain.
Yes if it was longer this wouldnt be a problem, but if was then you may run into problems in other gears being too long.This is just my guess.Trial and error,take to a shop and see what they think.
Sometimes this sint a problem but often times it becomes one.
I don't believe the chain was on the largest rear cog. It looked to be only about 1/3 the way up from the smallest cog. It was hard to be sure because the OP did not provide good angles in the photos.
Nonetheless, good practice is to allow enough chain to be in the big/big combination. It's obvious that this setup does not do that.
03-12-05, 09:26 AM
I dont think your chain is too short.I think its just because your in those
gears.You shouldnt have chain on both largest gears at the same time.If u look
at from the top down at chain it should remain as straight as possible. I know
for sure that now ur running at a pretty drastic angle for a chain.This puts too
much stress on the chain.
The question has already been answered. The chain is too short. We are talking about a lowracer recumbent here. It takes 3 chains put together on an optima baron. On a baron, you can run the big ring in front and even a 34t in back. This is a desirable combination on a lowracer.
The idler located in the center of the bike also takes up excess chain slack when the bike is in motion when you are in smaller rings. These bikes differ greatly from a regular upright bike that only can depend on the derailleur travel.
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