Replacement for grip \ twist shifter ??

Hi - I have a Terra Trike Cruiser - about 15 years old - it has under seat steering, with the original grip shifters, mounted vertically - the cables have been replaced, but the grip shifters are getting worn and becoming increasingly difficult to twist with the beginnings of arthritis in my hands. As I look into replacing the grip shifters, given that they're mounted vertically, the part of the shifter that I need to twist engages with the heel of my hands, the weaker part of my grip, versus engaging with the thumb\forefinger part of my hand, the stronger part of my grip - what type of grip do you recommend that wouldn't require a strong grip with the heel of my hands - some kind of trigger shifter? Something else ?? Thanks in advance for any suggestions !

 

If you're using a Shimano derailleur, you might look into Microshift bar end shifters.

 

Greetings! "And Now for Something Completely Different"... I just purchased a recumbent with an amazing rear shifting setup - except it doesn't use gears! It's called a CVT, or Continuously Variable Transmission! Just like in hybrid cars, except that its for the rear hub of your bicycle! It's called a "NuVinci" and it is a real breakthrough. No gears, only internal belts and bearings. It's really a remarkable shifter and I have quickly come to love it - and I can't figure out why it is so insanely cheap on Amazon (only a hundred bucks). Highly recommended and worth a look... the only drawback is because it's an internal hub, you'll need to build a wheel around it.

 

Thanks for the recommendation! It seems like something like you describe would be a good fit for my riding habits - about 12 miles a day, at a 12MPH pace, relatively flat terrain with a few easy grades (North Texas). More and more I'm finding that my grip shifters have been taking some "hunting" to find a good connection without mis-aligned chain-chatter - maybe they just need to be adjusted, but it can get annoying. I have a CVT in my Honda CR-V, and that approach to gearing has always made sense to me.

A few questions, please:

With my Terra Trike Cruiser, I have front and rear derailleurs now - with the rear hub that you describe, I'm assuming that I won't need the rear derailleur any more - will I still need the front derailleur and the three chainrings, or just a single chainring without a derailleur on the front, given that almost 100% of my riding now has the chain staying on the middle chainring (about 7" diameter)?

Just a single shifter to change the hub gearing, right - it seems like no need for front AND rear shifters, assuming the front gears go away?

I'm guessing that the chain will need to be shortened, too, without a rear derailleur.

When you say "you'll need to build a wheel around it", what exactly does that mean? My rear wheel (drive wheel) is 20", and there's not much room at all to go any larger - what exactly does "build a wheel" mean in my situation? Is it re-spoke the current rear wheel (32 spokes) to accommodate the larger NuVinci hub?

I'm sure I'll have more questions - thanks for the suggestions!

 

Hi, sure, here are some response:
- Yup, you will still retain your front derailleur (if you want it), this CVT eliminates the rear derailleur.
- No need to mess with the chain at all - the CVT comes with a single gear ring for attachment (think of the derailleur as being inside the rear hub)
- I wish I could send you a picture (I'm a new member and still on the probation process for this site) the CVT IS the rear hub, so you would literally attach the rear spokes to it!) So it can't be simply switched out like a regular derailleur, it's built into the rear wheel. As soon as I can send a picture, I will, it's easier to see than describe. BTW this CVT is installed on a 20 inch wheel, so that's not a problem at all.

- here's a link to a great explanation bike site which talks about this, and some others...
enviolo-cvt-hub-explained-internal-gear-bicycle-hub

Hope this helps - it is a slick and fun solution, like recumbents!

 

I had the same problem on my HPV Streetmachine Gte with USS. However, I found a solution to avoid replacing the Twist Grip shifter.

After measuring the outside diameter of the rubber grip on my Twist Grip shifter, I realized that the inside diameter of the TerraCycle "Vertical Rear Light Mount" (SKU: ACM376.9) with the 1-1/4 inch clamp was only 1 mm smaller than the outside diameter of the shifter. I had to replace the bolt in the clamp with a longer one, but it allowed me to shift using the tube and eliminated the pain in my old (75 yo) hands. I now live in Florida (i.e. flat) so I only hacked the rear derailuer. While I was at it, I also shortened the shifter rubber mount, rearranged the brake lever location, and added a "T" handle with a leather hand grip.

I have been using this setup about a year with no problems. Hope it helps. I tried to upload photos, but the site won't allow me to do that until I have 3 posts. Sorry

 

I hadn't realized the photo was accepted. Here is the other photo on the handle bar's right hand controls.

 

Thanks very much Walt! I sent you a PM asking about a 1:1 conversation to get some more information directly from you - sounds like a very, very good suggestion that might solve my rear shifter problem - the more I look into this, as much as I like that rear hub, it’s getting to be a problem finding somewhere to get it done - my local my local bike shop has been much less than reliable on any kind of service lately, and I really don’t depend on them to do much of anything if there’s any complexity to it, given that I’d have to have the wheel rebuilt and stuff like that if I were to put in the hub shifter I’m just not comfortable putting the task to them and having them do it - like I said I’ve had nothing but problems with them lately, so Walt your suggestion looks like it would be the “Holy Grail” for me. Thanks.

 

I have not used FaceTime (only Zoom), so you'd have to teach me that technology. But I'd be more than willing to talk. This is my recollection of my conversion hack. From the attached three photos, (I hope) you can see 1) the way the right side of the steering bar came when I bought the bike used, 2) how the "Vertical Rear Light Mount" attaches to the right side of the shift grip, and 3) what the right side of the handle bar looks like now. The photo that was published with my post was rotated 90 degrees. If the three photos below aren't attached, send me your email, and I'll send them to you that way.

1. First, measure the outside diameter of the Twist Grip where the "locking swiveling clamp system" of the "Vertical Rear Light Mount" will clamp on. The outside diameter of my Twist Grip (where your thumb would normally wrap around the shifter if in a horizontal configuration) was just slightly over 1-1/4 inches. So I ordered the mount with the 1-1/4 inch "Clamp Size."
2. Once I had the Mount from TerraCycle, I removed all three existing components from the right side vertical steering handle - the rubber hand grip, the twist grip shifter, and the brake lever. I don't recall unhooking or adjusting any cables. Then I started to reassemble the shifter and brake lever.
3. I think I cut off (shortened) part of the Twist Grip shifter that was just a rubber grip. This was necessary so the shifter wouldn't be so low (i.e. so close to the ground). Then I slid the shifter back on the handle bar with the cable exiting downwards.
4. Next I attached the TerraCycle rear light mount onto the shifter. I was able to get it to clamp around the shifter if I used a longer bolt. However, if that hadn't worked I was ready to use a razor blade to shave some of the shifter's rubber off to make it fit.
5. Then I installed the brake lever (on top of the shifter).
6. I had to adjust them so the cables didn't interfere with one another. I also needed to adjust the tube from the Vertical Rear Light Mount so it would shift all seven gears. It is best to do the adjustments while seated on the bike, to ensure they are comfortable to use.
7. OPTION: I found that Tee Handles also from TerraCycles allowed me to steer with the palms of my hands horizontal - more comfortable for me. I had to use the "Cockpit Mini" on the left since I have a bar end mirror there.

If the photos don't transmit, send me your email address. If you'd like to talk, send me your phone number.

Walt

 

Well, guys, thanks for all the suggestions, and thanks especially for the discussion about the CVT hub - THAT was intriguing! Unfortunately, I don't have the expertise or physical capabilities myself to get it implemented with my recumbent trike, and I don't have a bike shop that I'm comfortable with doing the implementation it for me - so, I've decided to get the original grip shifters replaced, along with new cables and cable guide liners, a new chain, and adjusting the rear derailleur. Not what I wanted, but I'm hoping that it'll get the job done. I was able to find a bike shop with a mechanic that's been working on bikes for 40 years, AND he has experience with recumbent trikes.

 

I had the bike out a couple of times since I had the grip shifters replaced - much easier to shift, BUT along with replacing the shifters, they recommended a new chain - the old chain had apparently stretched (distance between the rollers) and it was out of spec - so the put a new chain on the trike - an SRAM PC-850 Chain - 6, 7, 8-Speed, 114 Links. The derailleur on the bike is an SRAM Acera (8 chainrings).

I'm noticing that when I switch gears on the rear derailleur, gearing up or down, sometimes it takes a bit for the chain to seat itself (engage with) completely onto the gear chainring that I switched to - it's a different feeling than when chain is between the chainrings after a shift and the derailleur needs an adjustment - I've been back to the shop and they said that the derailleur was adjusted correctly. Sometimes when I change gears, it seems to go onto the new gear and I can pedal the bike OK, but then a bit later - maybe a few revolutions of the pedals or maybe a couple of minutes of pedaling - the chain feels like jumps and has finally seated completely onto the chairing - every time this happens, and it happens regularly, the pedals jump forward a bit - that's why I'm thinking that maybe the chain wasn't fully engaged with the sprocket, initially when I shifted. It never happens when I switch to the highest gear - it looks like for the highest gear, there's no interference from the next closest chainring, so the chain fully engages right away on that chainring.

The shop says that the derailleur is adjusted properly.

I'm seeing that there are different widths for chains, and I'm wondering, maybe they put the wrong type of chain on the trike, and is the new chain on the bike maybe a bit too wide for the distance between the chainrings on the rear derailleur, causing the chain to not fully engage with the chainring right away?

 

If it's the original 8 speed cassette, it may need replaced as well. If a chain is run for way too long the chain and cassette can wear together, and it really shows up when the chain gets replaced. If that's the case, I'm surprised the bike shop didn't catch it. But cassettes aren't expensive, it's worth a shot. I think the old rule of thumb is that cassettes get changed after every second or third chain. Since I have several bikes and limited riding time each bike gets low annual mileage, so they last a while.

Maybe you need more bikes!!!

 

Thanks !

 

Thanks for the idea, A.D., but the shop that did the work put on a new chain when they replaced the grip shifters - when I messaged them about the chain issue (they're 40 minutes away from me, one way), they replied "It may be the derailleur cable tension or the freewheel. We replaced your chain but not the freewheel, but can check both." - I'm thinking that they should have checked those potential issues - LOL, maybe the new bike shop ain't gonna be my favorite bike shop after all.