canklecat

(Note, 5/11/16: Rather than bumping this thread, I'm updating it.)

Turns out the original RevoShift was cracked beneath the rubber grip shell. Probably began with a small crack and gradually got worse, so I didn't notice any sudden difference in shift effort. Over time the crack got worse, interfering with shifting. Then the spring began digging into the plastic pawls, making it even harder to shift.



A new RevoShift cleared up the problem. Feels good as new. While I wish the mechanism was better made, it cost only $12 via Amazon same-day delivery and was easy enough to replace that it won't be a huge pain in the neck to replace it every few years.

Only potential problem with the new RevoShift for the rear derailer is the supplied cable is about 6"-8" shorter than the original supplied with this Globe Carmel. Not a problem for me because I'd already lowered, flopped and reversed the upright handlebar. But a rider who preferred the original upright position with stem fully extended would need a longer inner cable.



Fortunately it's not too difficult to pull out the supplied cable and thread in a longer replacement. Only partial disassembly might be required, and it's easy to fabricate a simple tool to compress the soft plastic snap fasteners without damage. I just cut the plastic from an ordinary blister pack (of AA batteries), made four thin shims, and used those to compress the plastic snap hooks on the RevoShift outer shell. No damage to the snap hooks, so they'll reassemble good as new.

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Original post/question follows:

I need to replace the stock Shimano RevoShift 3x7 twisty grip shifters on my Globe Carmel (Shimano Altus derailer), pronto. Dang things are aggravating my arthritis something awful. My right wrist and thumb joints are literally popping and cracking every time I shift, with jolts of pain. Nope, the shifters aren't broken. They work the same way they always have. But my 58 y/o joints don't work so well anymore, especially after several injuries (including a recent fall that re-injured my right wrist and thumb), and won't get any better with this abuse.

I didn't even realize how stiff the RevoShift is until I test rode a used Trek 7.5 fx at the LBS and felt how much easier and smoother some shifters can be.

Don't care whether it's another type twisty grip or trigger shifter. But it's gotta be cheap and easier to shift. I'm trying to save up toward a lighter bike for exercise and longer rides, and devote the Globe to errands and short rides.

I searched the archives but the OP in the most recent relevant thread ("Newb with a broken front grip shifter...") ended up replacing the shifters and brakes with a new set. I'd rather avoid that expense if possible, as the existing Tektro Eclipse levers work fine (with some generic linear pull brakes).

On the other hand, another thread discussed EF-51 7 speed EZ-fire combo shifters/brake levers. No idea whether those are compatible with my existing brakes or cable set.

Other suggestions included Shimano Altus SL-310 rapid fire trigger shifters. Suits me, as long as it's compatible with my existing stuff.

I seem to recall a recommendation for SRAM shifters, but I have no idea whether that would necessitate replacing the derailers too.

Again, I'd like to keep costs as low as possible, including keeping the existing cables if possible. I just want to make this bike functional before my right wrist and thumb joint suffer any more damage.

JonathanGennick 

There are only a handful of options for triggers. Pay the shop if you cannot afford a mistake. Looking at Jenson, I see the Shimano M310 shifter levers, the Shimano EF41 combined shift/brake, and Sunrace's M53 triggers. Get whichever suits your fancy. You'll land in the $20-30 range no matter what.

SRAM used to have an Attack shifter set that would work. I don't immediately find it for sale. Maybe it's been discontinued.

dsbrantjr

I have the M310s on two bikes and they have been perfectly satisfactory. I prefer separate brakes and shifters so that I can adjust the position and angle separately but the EF-51s are well spoken-of. I have the similar EF-27 as original equipment on my Trek 750 and it seems fine.

easyupbug 

I have arthritis in my hands but do not like the thumb pressure of a set like Shimano Altus SL-310. I am running Sram Attack twist shifters on a Shimano 3x8 drive train which is serving me well. You can post on the ISO (in search of) Classic & Vintage Forum and someone may have easy shifters they would trade parts for or sell. If you can't find any there or on EvilBay I could help as I have spares of SRAM Attack 3x8 twist shifter and Sram 800X 3x8 that I keep for this very reason.

Retro Grouch 

Only you can know what makes your arthritis act up.

If twisters are serving you badly, I wouldn't try another set of twisters. The left shifter in particular often requires a lot of twist grip.

Trigger shifters can require a lot of thumb pressure.

Thumb shifters are an option and are cheap (under $20.00 for 7-speed indexed) to boot.

However you decide to go, the brake levers might be an issue. You'll want new hand grips too. If your shifters and brake levers are combined on one clamp you'll have to separate them. The "A" solution is to buy new brake levers but I've hack sawed off the shifters and reused the existing levers a couple of times.

MichaelW

You could add some paddles to the revo-shifters to give some leverage and to avoid having to apply grip to rotate.
You can glue them on with epoxy or mould them in SUGRU.

squirtdad

just go for cheap friction thumb shifters........ with the ramped and toothed teeth on the rear cogs the shifting is really smooth and you wont miss indexing

cheap Amazon.com : Sunrace SLM10 Friction Shifter Set : Bike Shifters And Parts : Sports & Outdoors

expensive IRD Silver SOS power ratchet Thumb shifters

ThermionicScott 

Someone really needs to come out with electronic friction shifters. Yeah, it would be more expensive than anything else mentioned in this thread, but much easier to work.

dsbrantjr

That sounds like the worst of both worlds; no tactile feedback and dies when you forget to charge the battery. Easy to move, though.

Hydraulic, maybe?

ThermionicScott 

Heh, can't argue on the lack of feedback to the hands, but you'd still have feedback through the legs and ears. It was a half-formed thought.

Andy_K 

Hydraulic downtube shifters would be awesome. Imagine how smooth that could feel.

canklecat

Thanks, all, that'll give me something to gnaw on.

I suppose replacing the entire derailer setup might help. But that will be a project for later. I'd like to get another, lighter weight bike for exercise and longer rides first.

I just tried adjusting a few things again, tweaking the rear derailer, but all it accomplished was slightly smoother gear changes. And the cables move freely enough inside the housings. No improvement in ergonomics. Feels like my thumb is popping out of joint with every shift.

This RevoShift contraption isn't indexed, per se, but has some clickers that apparently are supposed to give some tactile feedback. In my case they just add another level of arthritis-aggravating obstacles. Feels like there's some spring loading in the setup that's stiffer than necessary. Or maybe it's necessary to prevent accidental shifting, I dunno. First bike I've had with anything other than 1970s era 10-speed lever shifters.

I could probably get accustomed to friction shifting and less tactile feedback again. My last bike, many moons ago, was a 1976 Motobecane Mirage with ordinary friction shift levers. Only change I made was to replace the handlebar stem shifters with a downtube set, mostly because it was handier from shifting from the drop bars.

Darth Lefty 

Shimano EZ-fire shifters take a good solid effort with the thumb to shift to bigger rings or cogs. I like them, have them on three bikes. But I had a hand injury earlier this year, tendinitis or something in my left thumb, that turned my 24-speed into an 8-speed for a while! I've heard that the higher groups like XT are a lot easier but I can't confirm

Microshift makes 8-speed thumbies that would probably work with 7-speed, or any local bike co-op probably has a big box of 7-speed thumbies.

JanMM

I really like the X7 and X9 (9-spd) SRAM triggers on two of my bikes but its a very long throw to the big chain ring on both of them.

canklecat

BTW, recently I tried a used Trek 7.5 fx -- not sure which year model or components. While the thumb shift was a long throw it wasn't particularly stiff. Certainly nowhere near as stiff as the RevoShift twisty grip doodads. My thumbs are freakishly long so the long throw didn't bother me. Unfortunately those orangutan thumbs have been injured so often playing ball, boxing and just falling down that they don't work as well as they used to. Seems to run in the family -- my granddad had similar hands and his thumb joints were so badly deteriorated by age 70 he had a hard time with anything requiring dexterity.

Darth Lefty 

The 7.5 should have Rapid Fire shifters of Tiagra or Deore level, which are supposed to be a step up generally from the EZ-fires which go with Altus & Acera

canklecat

Tried a bike with the SunRace thumbs-only shifters. Those were even worse, if that's possible. I'm going to need something with a lot more mechanical advantage, or some sorta magical super slick lube.

CliffordK

Stem shifters can be easy to use. And cheap. Some can be fairly long.

I was able to barely fit an old Suntour stem shifter to a 1 1/8" quill.

https://www.bikeforums.net/classic-vi...l#post17716210

Bill Kapaun

Keep trying different types when you can..
Sometimes a bit of repositioning/rotation can make a lot of difference.

canklecat

Ahh, interesting suggestion. My bike does have a quill stem -- not sure about the diameter. It would be an odd combo, being a comfort hybrid with cables routed through the frame. But I'll keep it in mind. Years ago I did swap my Motobecane's original stem shifters for downtube, which was pretty straightforward with better shifting from the drops.

I might also try shortening the cables, which are unusually long to accommodate the long stem fully elevated, plus the upright bars. But now I've lowered the stem and flopped the bars so they're sorta like flopped North Road bars. So there's a lot of unnecessary cable looped across the front of the bike.

squirtdad

That is really interesting...... the cheapie sunrace I use on a 1x8 setup takes very little effort (or so it seems to me) simple nudge back to shift up and bit a a push to shift down. Sram 8 speed cassette with deore derailler.

good luck with your hunt

canklecat

Yeah, those SunRace thumbers would probably be fine for folks with healthy thumbs. The left shifter wasn't too bad because my left thumb and wrist don't ache as much or as often.

Ideally, I'd rather have trigger finger shifters, at least where the most physical effort is needed against spring resistance.

After re-examining the entire shifter and derailer mechanism, I'm going to try tuning it first. I can see a couple of places where the RevoShift is hindered by rubber-on-rubber contact. Some smooth nylon spacers and shims might smooth it out without causing other problems (such as lubing the mess willy nilly).

And I've never been happy with the Shimano front derailer, so this is as good an excuse as any to take it apart. I can never seem to get it adjusted to avoid rubbing on either extreme of the rear cassette (1st or 7th) while in the middle chain ring. So I may mount it at a slightly different angle. And the front derailer is easier to mess with than the rear, so it'll be easier to see whether a complete cleaning, re-lubing, cable shortening, etc., make enough difference to tackle the rear. All this was done by the LBS last fall, but I've ridden a lot of gravel and gritty rural chipseal since then.

squirtdad

I am a bit confused as how this would help, as I recall, "trigger" shifters take a lot of thumb pressure for shifts moving from smaller to larger cogs

I am thinking a previos suggestion of stem shifters might be a good consideration. You could find a set of the old suntour power ratchet (I might have some in my parts mess)

or a more expensive option, but one that looks like the levers have a lot of leverage would be the rivendell shifters and stem mount

Silver Downtube Shifter Kits - 17101
IRD Stem Quill Shifter Mount


good luck

canklecat

I was thinking of pull-only type shifters, to be operated only by the fingers rather than the thumb. Something like a sequence of short pulls for single gear shifts, and a long pull to reset. No idea whether such a thing exists.

Yup, coincidentally I was browsing Rivendell's site last night for ideas.

I do like the concept of the twisty grip shifters, not having to move my hands off the bar while shifting. Just not fond of the execution. Supposedly SRAM twisty grip shifters are better, but I'm not sure whether they're compatible with the Shimano Altus rear derailer, or cost effective.

canklecat

Managed to improve the left (front derailer) shifter a bit just by reducing rubber-on-rubber contact. The outer rubber surface around the RevoShifter was rubbing against the rubber grip on one side and the plastic housing of the shifter itself on the other. Trimming the rubber shell and/or some nylon spacers will help.

But the inside housing of the right (rear) shifter appears to be cracked, and spreading apart under twisting pressure while shifting. Won't know until I peek inside whether that's causing the worst of the stiffness.

Good enough excuse to find a better replacement.