shift lever for rear derailleur
 

Hi,

Last fall I bought a seven speed bike. The shift mechanism for the rear dérailleur is on the handle bar near the hand grip and you rotate it like a motorcycle throttle to change gears. It clicks into place when you change gears - which means you have to have the dérailleur adjusted exactly right otherwise the dérailleur might be in between gears when the shift control is clicked in place.

The last time I had a bike was thirty years ago. It was a ten speed and the shift levers didn't click into place, they moved continuously, you just adjusted them until the chain was on the gear you wanted.

I am wondering if the "click" into gear is something new on a lot of bikes today or is it just for cruisers, and comfort bikes and such like.

The reason I am asking about this is it seems hard to me to get the adjustment exactly right. Sometimes I shift and the gear doesn't change, then I shift again and it moves up two gears. I am wondering if it is really worth the effort to get the thing adjusted exactly right or should I just get a different shift lever that doesn't click into place? The chain doesn't derail past the low or high gear so the width of the derailleur movement must be right and I don't see how it could not be aligned with the intermediate gears. Does anyone know any tips that could help adjust this?

Or, can anyone recommend a decent but not too expensive shift lever that allows continuous adjustment rather than fixed positions that would work with a 7 speed rear dérailleur ?


Thanks

The click is called indexed shifting and is standard on many, many bikes now. It sounds like the most likely cause of your problems is not the adjustment but rather the shift cable not moving freely. Take it to a shop, describe your problem as you have above, and they should be able to fix it at a reasonable cost.

A lot of the time if you just set the shifter and DR in the highest gear position where the cable length is at its shortest and just adjust the slack out of the cable this will fix the problem.

One cannot diagnose and correct a problem with "a lot of the time." One needs to take the symptoms, combined with knowledge of how the entire shift system works together, and then decide what the most likely cause is. If the OP shifts to a gear and it doesn't move because the adjustment is too tight, then the same thing would occur on the next gear.

The fact that it jumps two gears the next time most likely means that the cable is binding, and the derailleur is pulling on the cable hard enough after two shifts so that it finally gives way. Imagine pulling something along a floor with a rope and it hits a rough patch of floor. You pull harder and harder, and when it finally gives way you fall on your butt, because once you overcame the initial friction the object's momentum allowed it to jump forward.

I totally agree with your first paragraph.

Second paragraph - not so much. On a bike this old I'm betting on a bent derailleur hanger.

Here's a good place to check out.

http://www.parktool.com/blog/repair-...illeur-systems

I don't think that's a good bet, and it's an odd one if you agree with the first paragraph. You don't give a reason other than age (how old is the bike?) for the bent hanger, and don't explain how it would be more likely than a friction issue.

A bent hanger tends to give the same problem in the same gear combinations. If the hanger had been bent inward, which is the most common occurence, someone would have had to know how to readjust both limit screws and the cable tension (to get the bike to shift OK after the hanger was bent) but not know enough to see a bent hanger, as the two extremes work fine and the shifting is mostly OK, just inconsistent.

The OP may not have given us all the info, but I believe his complaint is "sometimes" getting bad shifts to the smaller cogs. That is a classic friction/binding symptom.

It's not too terribly hard to get twist shifters dialed in but it could be tough to diagnose without some knowledge. (BTW Retro, the bike's only a year or so old.)

Simple answer to your question, is to get these shifters and install the right hand one:

http://www.amazon.com/Falcon-frictio.../dp/B0025UH44I

http://ecx.images-amazon.com/images/...uL._SS500_.jpg

I would caution you that the above is not necessarily "simple." There is quite a bit of strength and reach required to move the lever through the full range of 7 gears, and of course you may have to readjust if you did not get it just right or vibration moves the lever. Also, if there is a problem with cable binding you will have exactly the same issue as you do now.

Actually I did not address one issue I should have. If you purchased this last fall, was it bought new from a bike shop? Generally there is a free adjustment period for all bikes, and even after that a minor problem like this may be addressed at no charge.

True that it may not solve the OP's problem and may present new ones if some possible underlying current problems don't get solved.

BUT, it is a simple answer to this question in the OP:

Depending on what "not too expensive" means, another option I like is a DX thumbshifter in nice shape. I think they still go for $30 or so on eBay. 7-sp index/friction option.

XC-Pro or XT for a little more dough.

+1, a little past the typical 1-year window, but hopefully let you slide and dial it in for you free of charge.