Derailleur Issue

[pflyman]

First things first. I love the Sofrider V2. I ride it farther and more often than any bike I've ever owned. I love the 16 gear options even more than I liked the 24 options available on my Raleigh Hybrid.

Having said that, I find myself limited to slightly more than 1/2 the gears due to what I will call "chain chatter". Let me try to explain. In the low range, I have no problem in the lowest 6 ranges (i.e. 1- 6). Starting with 7 and more so with 8, I experience the chain noise; therefore, I avoid these gears. In the high range, I have no chain chatter from 6 through 8; however, 1 - 5 has the chatter and I therefore avoid them.

I have access to only one bicycle mechanic locally and haven't been able to get the problem solved using that route.

Does this description suggest a reasonably easy problem to fix? If so, can you point me toward a solution?

Thank you

Dave

 

[JohnMHammer]

Chains and Angles

What you are hearing is a result of the chain and the rear sprockets being not quite precisely aligned while in those gears. This is normal, but it shouldn't be that noticeable, nor should it prevent you from using all your rear cogs regardless which front chainring you're using. But on any bike with both a front and rear derailleur, the chain is going to be more poorly aligned in the lower (larger rear) gears when using the higher (larger front) chainring; and more poorly aligned in the higher (smaller rear) gears when using the lower (smaller front) chainring.

On my current bike (a 1991 21-speed Schwinn: 3-ring front derailleur and 7-cog rear cassette) I can comfortably run through all 7 available gears when on my middle chainring, but when using the smallest chainring (lower gear ratios) I can only comfortably use the lowest 5 gears (the largest 5 rear cogs) and when using the largest chainring (higher gear ratios) I can only comfortably use the highest 5 gears (the smallest 5 rear cogs). I can get into the "uncomfortable" gears, but there's little point to doing so since I can essentially duplicate those gears using other combinations which don't take the chain so far out of alignment. In practice, I ride my 21-speed bike as if it were a 12-speed bike (all 7 "middle" gears, 2 "high" gears, and 3 "low" gears) because all the rest are basically duplicates of other gears but with the chain not running quite as straight.

You're probably just experiencing the same thing with your Sofrider. If you manage to get access to another bike technician in the future, have that person take a look because the issue shouldn't be that severe with the Sofrider's stock chainring and cassette. If you don't ever have that opportunity, I think it's something you can just forget about and become used to.

By the way, I'm jealous of your bike! I've decided to stick with my current ride until spring 2013 and then snag either a Sofrider or Quest, depending on which one I like more after trying them both.

 

[leakyduck]

You really don't have a problem with your derailleur, it's just the way it is. Imagine my shock back in the 60's when I first got my brand new Schwinn Varsity and now had 10 speeds, but I got these grinding noises and went back to the bike shop to complain. He pulled out the gear charts and wrote down pretty much as I have listed for you below (courtesy of Sheldon Brown) The top row (34-48) represents your cranks and the list (11-32) represents your cluster. The numbers in the colums represent you Gear Inches for each combination of crank and cluster.

34 48
11 77 109
13 65 92
15 56 79
18 47 66
21 40 57
24 35 50
28 30 43
32 26 37

You will see that of you 24 gears about 10 are duplicates (or near duplicates) of each other. There is no way to avoid this. If you ride on mostly flat land I would simply use the 48 tooth down to where it starts to grind and at that point change to your 34 and move your rear up to where it is quiet.

Your local mechanic should have given you this same explanation, too many mechanics see a recumbent (of any flavor) and think that it is "different" and can't fix them.

 

[Charles.Plager]

Hi,
It is true that many of

Hi,

It is true that many of the gears overlap. But that doesn't address the noise.

And for shorter chain bicycles (like the Sofrider but unlike most other 'bents), it's considered bad to have the chain on the big ring up front and the big ring in the back (or the small ring up front and the small ring in the back) because this causes a lot of friction on the chain that will eventually cause it wear and stretching. On many bents, there is no issues at all and all of the gears can be used without any problems.

All of that being said, you should be able to get into the big ring the front and the 5th gear in the back without excessive noise (where, unfortunately, it isn't really clear what "excessive" means). If there really is excessive noise, it does suggest that something isn't aligned quite right ( e.g., the front wheel, the derailleur hanger, the derailleur itself). Given that the drive train is of pretty much standard length, any bicycle mechanic worth their salt really ought to be able to diagnose this.

Cheers,
Charles

 

[pflyman]

Derailleur Revisited

Thank you all for your input. I assumed that there was a significant amount of duplication- even with the 16 gears on the Sofrider. I would be more than satisfied with a minimum or 1 or perhaps 2 more gears in at the low end of the high range.

"Excessive" in this case means that, not only can I hear the chatter, but I can feel it as well. I have to believe that is not good for the chain. I would like to believe that there is a simple explanation, i.e. bent hanger or perhaps a simple adjustment is needed. I suspect that my best bet is to focus on the local mechanic and perhaps even demonstrating the problem. I may not have adequately communicated the problem. Thanks again for weighing in.

 

[magnusw]

Derailleurs

I got so mad with the derailleurs on my 16 speed V2 (usually the chain coming off when pushing hard) I replaced them with a Shimano Alfine 11. Problems solved.

 

[MrSteve]

Derailleurs

Here's another thing to look for.

Alignment of your chain, or, lack of alignment of your chain
with your cogs are causing the excessive noise and vibration.

If the hanger that your rear derailleur is bolted to is properly aligned,
but the problem persists, then check your derailleur.

Specifically, check the pivot.
That's where the bolt that connects your rear der. to the rear der. hanger goes through.

If your rear derailleur can be wriggled from side to side, then it is loose
enough to allow your chain to scrub on the sides of cogs adjacent to the driven cog.
More on just a few gears... just like yours.

Mine was like this, loose on it's pivot.

I fixed it with shim stock, which took up the slack.

Of course, replacing your wobbling derailleur with a better-fitting new unit will fix
your problem (maybe!).

Good luck,

-Steve

 

[Doug Burton]

All of these comments...

... are spot-on.

For a double chainring, the center of the space between the large and small chainring is carefully aligned with the middle of the cassette, generally 47mm from the centerline of the frame tube for the type of crank we use (this is called the "chainline" dimension). This reduces the chain mis-alignment that naturally occurs when the rear derailleur moves the chain across the cassette, better aligning the large ring with the small cassette cog, and the small ring with the largest cassette cog. "Cross-chaining" won't hurt anything, but it won't be as quiet, either.

The only thing I haven't seen mentioned here is chain lubrication. If the chain is running dry, the chain side plates will apply more friction to the cogs and the noise will be louder.

Cheers,

Doug