Do I need to put inline adjuster for RD without adjuster?
 

Or do I use only the adjuster at the shifter?

I notice new RDs do not have adjusters. Do I put an inline adjuster somewhere after the cable stop or do I not need that and use only the adjuster on the shifter?

Regardless of what is on the shifter or the der., I find in-line adjusters to be convenient and a worthwhile item to have so when I replace cables i put them on if they are not there already. Location depends but before the cable stop. I even have them on my dedicated indoor trainer bike.

The ability to adjust cable "tension" (actually the casing length...) is essential to fine tune the shifter/rear der relationship. Having a back up or second device to do this isn't wrong. Those who say otherwise have likely never faced the situation when their one device was unable to work and something had happened to make the adjusting need vital to continuing their ride. At work we see this loss of an adjuster's ability to work fairly often. usually from neglect (corrosion causing the threading to freeze up) and sometimes from an incident. But it has been fashionable to reduce the bike to the least needed (and sometimes less...) in search of either least cost or weight. Andy

Maximizing your adjustment capability will make your life easier. I have adjusters at both the head tube stops and at the RD, and I use them both.

The more complex our system, the more sources there are for failure. Since we can never predict all failures, it can help to minimise the sources of risk by simplifying the system.

Many decades ago I had a lighter and some flame-meltable solder in my on-bike toolkit. So there I was half way up a mountain in the Alps and the nipple came off a cable at the lever end. Yes, I was able to solder it on and get home, but no number of adjusters would have saved me from that failure. That is the nature of risk and preparation.

Might depend on two questions.

• How often do you need to adjust your DR? I put inline adjusters on my two builds and only used them maybe one handful of times in ten years. If you aren't so savvy about setting up your DR's then they will help. Or at least let you believe you are doing something.
• You have an adjuster on the shifter? Do you mean derailleur? Shifter is on the handlebar or downtube. If it is on the shifter, do you need another adjuster?

I've tied knots in a cable to emulate a cable end and then used the adjuster to fine tune der position for a couple of riders over the years. But never resoldered an end back on. Andy

If you go the route of adding an inline adjuster, be sure and put a good quality one. In setting up my touring bike some years back with a rd without one and shifters that didn't either, I made the mistake of using a low quality inline one, and had ghost shifting issues that I kept thinking were related to my genevalle shifters.
once I figured it out, and put in a good one , all was fine.

also be sure to place it so the housing won't force the adjuster if the housing shifts down a bit and then if the bars swing, can force and kink it. I've had this happen once, full handle bar bag not helping with extra force. Learned my lesson with that also but will change it only when I change housings one day.

That you have an adjuster at the shifter should be enough. Make sure you have all the slack out before using it.

An indexed shifting system needs at least one adjuster to effectively tune shifting performance. More than one adjuster gives you more adjustment range without having to manually take up cable slack at the anchor bolt, but as Andrew notes, at the cost of increased complexity.

A friction shifting system doesn't really need any cable adjuster.

My SLX 9sp shifter has an adjuster and I have a couple Jagwire metal inline adjusters. I was going to put it about 50-70mm rearward of the chainstay cable stop.

I expect the real mechanics here would have a better opinion, but wouldn't it be better to be in a higher up, not horizontal position for less rain entrance? Don't forget too it rubbing against frame?

I’ve used Jagwire Direct Sport adjusters at the rear derailleur and shifters. They were designed to fit into Shimano STI shifters with the external cable routing.

I picked them up for some thumb shifters so I could have a bit of an adjustment and they worked great. What was better was that they fit into one of the Shimano mtb RD that wasn’t mfg with one. They would not be my first choice for an area with little clearance for the larger barrel.

I’m not a mechanic, but rain is not an issue. Most Shimano RD had adjusters and picked up all sorts of water. Admittedly, some mtb ones had a boot, which I never used.

Multiple adjuster are great. Having one on the shifters or at the head/down tube allows for tweaks while riding. An adjuster at/close to the RD makes it easier to fine tune it, rather than reaching forward while turning the pedals by hand.

John

I'll suggest that if you have more than one adjuster, bottom out whichever is least convenient. The ones on the RD have stops but many others have a tendency to creep. If you have to live with a creeper you can use a dab of paint as a telltale.

Ditto. My "new" bike also has Jagwire inline adjusters just forward of the head tube, and the next time I recable the bike they're coming out. In my opinion, the only reason for them is to be able to fine tune while riding. If I try that with these adjusters, I have shifting problems until I can bottom them out and adjust at the RD.

I won't replace them. My cycling isn't so competitive or critical that I can't stop for 10 seconds and tweak the rear adjuster once a month or so. With that in mind, if I had shifters with adjusters, I'd be okay with not having a second adjuster. Probably saves a few dollars and won't affect my cycling.

I also heard somewhere never to "tighten" the cable under tension with in-line adjusters. They're likely to strip. I certainly believe that of the ones I have.

Re adjusting while riding. Yes it's nice, both my drop bar bikes have this ability, but my experience shows that it's so rare to have to adjust, it's not a big deal. Once settled, my bikes go years without any adjustment, and I have learned the lesson that when adjustments are needed down the road, it's usually the sign of hidden fraying,so time to change a cable.

re rain, I was just thinking it would be better with an inline one with two housing cuts to have it either less horizontal or a less splashy location, but could be totally wrong on that.

Life is easier if you have at least one adjuster, either on the RD, or on the shifter. If you have neither, I would say an inline adjuster would be a good idea.

I don't think there is a RD made without a tension adjuster.

I would have thought the same until I changed the setup on my XT equipped bike to dropbars and saw that the XT rd didnt have one.

The Shimano mt. groups seem to have the cable tension adjustment on the trigger shifter, thus not on the R derailer. The road rear derailers, Ultegra to Claris all have barrel adjusters

indeedee, and up until about 4 years ago, I had no idea.

Shimano and Sram do not have adjusters on many of their MTB RDs now. Most if not all Shimano shadow style RDs do not have adjusters. Even some 10 years old 9sp RDs don't have them like M772 or M592.

Yea - dirt and water are a concern. My thought was to put one along the chainstay to replicate the adjuster that used to be on the RD since newer ones dont' have it anymore. On my bike the cable is open along the down tube and most of the chainstay; the only covered parts are about 100mm along the chain stay to the RD and from shifter to under the downtube.