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Old 10-17-15, 07:57 AM   #1
mozad655
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Will my rear deralliuer suffer under this tension? (pic)



The chain itself does not feel too tight and it will occasionally fall off if I pedal while hitting a big bump. What I am worried about is the effects on the deralliuer when its in that position. Is it a problem? The setup is 9x1. I only use one gear (second largest cog) which is the position that is shown in the picture. Chainline is fine as I moved the big chainring to where the small chainring used to be in the front.
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Old 10-17-15, 08:07 AM   #2
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Interesting picture.

Looks like the derailleur is within it's intended range of use.
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Old 10-17-15, 08:07 AM   #3
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I've read that 45 degrees is the max you'd want to let your derailleur go but mine with stock drive from Fuji was a little more than that when cross-chained front and rear. Is your chain falling off from the front or front the rear, sounds more like the stops aren't adjusted right but that would show up when changing gears not hitting bumps. Is there any noise from misalignment?
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Old 10-17-15, 08:19 AM   #4
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RDs have a cage travel stop at both ends of the working range. Some lack a stop on the tight side, in which case they're designed for the tension pulley to travel above a lower loop in a straight line front to back (that's too short a chain).

The springs used have multiple turns to allow proper function and spring life throughout the working range, so there's no difference to the spring or RD regardless of idler cage position or "tension".

In short, if it isn't torn off immediately, it's fine as it is.
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Old 10-17-15, 08:23 AM   #5
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Chain falling off doesn't rly bother me now that I can predict and avoid it (would fall at front down on pedal). This would happen when I had 2 chainrings and it was cross chained (big/secondbiggest)

I have since removed the smallest chainring and moved the big chainring to the inner position towards the bracket. I don't know if the chain will fall off now that the chainline is much better.

Main worry is the deralliuer though, and sounds like you guys think its fine.

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Old 10-17-15, 09:01 AM   #6
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Re: dropped chain:

Problem Solvers
Chain Keeper | Paul Component Engineering
Chain Guides | Chain Reaction Cycles

etc.
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Old 10-17-15, 09:39 AM   #7
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I'd be more worried about it being all mounted on the wrong side of the bike!!!

Seriously though, if you can still push the lower pulley forward and make the chain loose, you're OK.
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Old 11-10-15, 07:41 PM   #8
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Quote:
Originally Posted by robbie_d View Post
Does this look okay? Is the chain too short? It sure doesn't look correct to me.
If you're saying your derailleur looks like the one in the image below, then yes, your chain is too short. Take it back to the shop.

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Old 11-10-15, 07:42 PM   #9
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Hi all,
I am new to the forum and i didn't want to start a new thread to ask my question seeing as this thread addresses what i need to know. I am sorry that i am really busy and don't have time to read all the posts tonight. I want to bring my bike back to the shop tomorrow morning based on your opinions.

I live in Montreal, Québec, Canada and i ride my bike all throughout winter.

I just got my 21 speed, Trek 800 Antelope (winter) mountain bike back from the shop after having them replace my whole "transmission" ie: crank, cassette, derailleur and chain.
I noticed my derailleur looks like the one in the pic below with the chain on the large sprocket on the crank and on the large sprocket on the cassette.
Does this look okay? Is the chain too short? It sure doesn't look correct to me.
I searched for a pic on google images to show you how my derailleur looks right now in the gear described above in bold font, and this pic is pretty much exactly how mine looks in that gear.

Should i ask for a proper chain length?
Also, how should the derailleur look in the gear described above in bold font?
And finally, if the shop tells me it's okay as it is, what should i tell them could happen with this chain as is - like could this ruin my new transmission?

Thanks for any and all opinions.
Rob
That looks a bit too short. Does it shift into big-big combination easily?
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Old 11-10-15, 07:44 PM   #10
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If you can shift into the "big-big" combination (largest chainring and largest cog) without the chain getting too tight to make the shift, you are ok for chain length. You should avoid that combination anyway since it's hard on the chain. The angle it has to assume accelerates it's wear. It is essential for safety that the chain be long enough for that gear since sometime you will inadvertently shift into it and it must be possible.
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Old 11-10-15, 08:31 PM   #11
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looks fine to me
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Old 11-10-15, 08:58 PM   #12
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It does?
Hmm. It looks really odd to me. My other two bikes are not set up like that.
I am getting confused now lol.

Thanks.
Your other bikes probably have slightly longer chains.
If you can shift into big-big, then it's long enough.

Big-big can be used, it's the sideways flex that stresses the chain more than a straight chainline does, so riding big-big should be minimized. There will be a similar gear available with the small ring that does not stress the chain quite as much.
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Old 11-10-15, 09:29 PM   #13
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Hi Hillrider,

Please read my response to Homebrew.

I do use all the gears and i'll shift from one extreme to the next depending on the roads and snow. So, i expect my gears to work. I don't believe that i should not use a specific gear. If i should not use a specific gear, then the bike should not offer that gear. But i do understand what you are saying about THAT gear combo but sometimes we must do what we must do temporarily as you know.

Thanks.
You are free to use any gear you wish as long as the bike will safely shift into it. Your bike, your choice. However, the ability to use every and any gear doesn't mean it's sensible. You could, of course, drive your car completely across country using only first gear but there are better ways to do it.

Cross chaining is hard on the chain and really unnecessary. You can find a very similar or even identical gear ratio in the smaller chainring and a smaller cog and it's easier on the equipment. Plot your gear tabve and you will see how many duplicate and near-duplicate gears there are in a nominal 2x9 or 2x10 gear train.
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Old 11-10-15, 09:57 PM   #14
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I agree 100% but does it look normal my chain?
Which picture are you referring to ?

The picture showing the chain almost straight through derailleur, is shorter than I would use, but it is not "wrong" if it shifts through all the gears.
A chain can also be too long if it goes slack when on the the small-small combination, so there is a range of chain length that is "correct" as long as it does not cause problems.
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Old 11-10-15, 09:58 PM   #15
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Hi Hillrider
I agree with you 100%. However if i am in a gear that is close to the big-big combo, and i have to gear down to speed up temporarily, then i will do that.
I did not imply that i will use that gear exclusively as in your example with the car cross country in 1st gear.
What i am saying is that 1st gear is a "gear" and it should be able to be used when needed.

That's all i am saying.



I am really not a technical rider. Maybe i should be.

I do keep my gears on the middle sprocket usually and i use all the cogs at some point during my trip. It all depends, of course.

I have no idea what a "2x9 and 2x10 gear train" means, though. You don't have to explain if you don't want to. It probably won't sink into my skull. I am eager to learn new info, though.

Thanks for your comment
.
Yes, all gears should be usable.

2 chain rings on the crankset, and 9 or 10 cogs on the rear wheel.
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Old 11-10-15, 10:06 PM   #16
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Hi Hillrider
I agree with you 100%. However if i am in a gear that is close to the big-big combo, and i have to gear down to speed up temporarily, then i will do that.
I did not imply that i will use that gear exclusively as in your example with the car cross country in 1st gear. What i am saying is that 1st gear is a "gear" and it should be able to be used when needed.

That's all i am saying.


I am really not a technical rider. Maybe i should be.

I do keep my gears on the middle sprocket usually and i use all the cogs at some point during my trip. It all depends, of course.

I have no idea what a "2x9 and 2x10 gear train" means, though. You don't have to explain if you don't want to. It probably won't sink into my skull. I am eager to learn new info, though.

Thanks for your comment.
I don't want to belabor this and I agree you can and should use any available gear if the situation demands it. All I was saying is that using the cross-chaining gears isn't good practice and should be avoided when possible. Done.


As to what 2x9 and 2x10 means, Homebrew01 defined it well. You will also come across mention of 3x9, 3x10 and other drivetrain variations. The definitions are in the same manner.
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Old 11-11-15, 05:32 AM   #17
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You can ask for a longer chain. If it works in all gears, they may tell you it doesn't need a longer chain.
If it bothers you, buy a longer chain. Most come with a master link and can be installed without tools, although a basic chain tool is needed to shorten a chain if it is too long.
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