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-   -   Grip twist shifters (https://www.bikeforums.net/showthread.php?t=1254253)

_ForceD_ 06-28-22 10:47 AM

Grip twist shifters
 
A friend asked me to do some work on a couple of Huffy mountain bikes that they picked up on Craigslist for real cheap for their kids. For a Huffy, they’re in otherwise good condition. Just needed lubed, brakes adjusted (disc front, rim rear), wheels trued, shifting adjusted (3x6) grip twist shifters. Now I know Huffys are inferior quality bikes. And that’s certainly a separate discussion. But I’m asking about the grip twist shifters, particularly the front. At best, after lubing and working everything, it’s difficult for an adult (me) to twist that shifter and get the chain to shift. With the cable disconnected, the grip twist moved freely and easily. Likewise, the derailleur moves in and out freely and easily. And the cable moves freely the entire length through housings. But with the cable connected, it’s hard to twist that thing. Is there some secret to getting that shifting action easier? It’s similar on both bikes. And looking more closely at the derailleur, it appears that they (manufacturer) might have designed this combination with the wrong derailleur. The cable clamp arm looks like it might be too short to provide enough leverage for the twist shifter. That arm is certainly shorter than the clamp arm on my road bikes. Any ideas (quality of the bikes notwithstanding)?

Dan

base2 06-28-22 10:55 AM

Grip shifters are not worth the time, effort, or expense. They are designed as disposable from the outset.

Do yourself a favor & get these. They work better, last longer, & are the same cost & maybe cheaper than even the least expensive grip shifters.

Leisesturm 06-28-22 11:32 AM

Agree w/post #2 except I would substitute Rapidfire (trigger shifters).

Andrew R Stewart 06-28-22 11:39 AM

Dan- The portion of the der that the cable is clamped to (the "arm") is engineered to be what it takes to move the pulley cage a certain amount per the grip's click. So, changing its length will upset how far the chain is being moved per click. On a front system with a grip that has only 3 indexing spots (thus 2 clicks...) the shifting will be poor and resulting chain rub will be very annoying

What you describe is common when there's too much friction along the cable's path. I speculate this friction is in the twist grip's interior. When you say you lubed the system did you take the grip apart and apply plastic friendly grease on the sliding surfaces? Checking and or replacing the cables/casings is pretty straight forward but these also want to be free of friction when the cable is under tension (and that's the rub {bad pun} how to test only the cable routing friction without also involving the shifter or the der. It can be done but often is easier with the cable out of the shifter).

I have never liked the twist grip shifting "feature" since Sears had their 3 speed bikes equipped with one. That's a long time:) Andy

Trakhak 06-28-22 11:41 AM

Gripshifter haters are alaways quick to advise junking them. Not sure why. I've been riding derailleur bikes since 1963, and the gripshifters on my Cannondale hybrid errand bike work as well as any shifters I've ever used.

I suggest checking for Youtube videos on troubleshooting those shifters. At worst, you'll have to buy a cheap replacement shifter. If you do get a replacement gripshifter for the front derailleur, make sure that it's the type with multiple clicks rather than the type with only two or three clicks.

vespasianus 06-28-22 12:19 PM

Are they "real" SRAM grip shift or some cheap knockoff?

Gripshift stuff was never disposable - especially in comparison with Shimano. There were a few internal parts and you could take it apart, clean it and put it back together with little effort. Shimano shifters have 100's of parts and is a nightmare to take apart and put back together again.

My old 9 speed Gripshift with Gore cables was one of the best shifter systems I ever used. I could go up or down the cassette with ease.

t2p 06-28-22 12:42 PM

I'm not a fan of Gripshift shifters - prefer Rapidfire (and similar)

but I have Gripshift 7 spd shifters on a few old bikes - and they work well

(have 400, 500, and 600 series 7 speed shifters)

they appear to be fairly durable and require little maintenance

also fairly easy to find and inexpensive

t2p 06-28-22 12:45 PM


Originally Posted by Trakhak (Post 22556755)
Gripshifter haters are alaways quick to advise junking them. Not sure why. I've been riding derailleur bikes since 1963, and the gripshifters on my Cannondale hybrid errand bike work as well as any shifters I've ever used.

I suggest checking for Youtube videos on troubleshooting those shifters. At worst, you'll have to buy a cheap replacement shifter. If you do get a replacement gripshifter for the front derailleur, make sure that it's the type with multiple clicks rather than the type with only two or three clicks.

have both types of front shifters - with and without trim

the shifters without trim also work fairly well

2_i 06-28-22 01:03 PM

To test the possible friction along cable length, I would disconnect the cable from the derailleur side and pull the cable, either with the shifter or by hand on the derailleur side. Besides the friction along the cable, the culprit could be hardened rubber of the shifter's grip. Then, without gripping with a large force, the hand just slides over the grip, creating general impression of the shifter being ineffective. While replacement grips may be available commercially, their cost may be higher than the value left in the shifter.

For the interior of the shifter, silicone grease may be used. I doubt, though, it could help much. If the interior were causing excessive friction, I would expect the cable to be ran incorrectly through that interior.

Bill Kapaun 06-28-22 01:27 PM

I've ran into the same problem on Huffys and their twist shifters.
The 2 I dealt with I could NOT turn them.
I have no idea if the RDER is even compatible with anything else.
I simply avoid Huffys. They are a can of worms.

I gave the bikes away and felt lucky they didn't charge me to haul them off.

Camilo 06-28-22 01:34 PM

This is why I really avoid doing any work, except maybe pumping tires, on friends' bikes any more. It often turns into something I don't want to get into and/or be responsible for. I used to but not any more.

andrewclaus 06-28-22 01:44 PM

Some low-end bikes are built with way too much housing length, like one size fits all. If loops are too large and cause extra changes in direction, pull some cable out, cut the housing, and reinstall. See Sheldon Brown's article about cables. Also check the ends of the housings and replace them if you can see any of the stiffening wires poking out. Those can grab the cable under tension in the frame stop.

Often the cable is routed incorrectly at the FD. There's usually a tab at the pinch bolt, usually facing the downtube, that the cable must route over. If the cable is routed under that tab, as it often is, the leverage needed to shift is increased and the pull ratio is incorrect.

_ForceD_ 06-28-22 03:37 PM


Originally Posted by Camilo (Post 22556917)
This is why I really avoid doing any work, except maybe pumping tires, on friends' bikes any more. It often turns into something I don't want to get into and/or be responsible for. I used to but not any more.


I may resort to this practice in the future.

All … when I disconnected the cable from the front derailleur, the shifter twists easily and freely; the cable moves through the entire routing easily, no snags; and the derailleur itself moves in and out freely. But with the cable connected the shifter is just hard to twist. So my feeling is that it’s just a poor design. The grip shifter doesn’t provide enough force, and the derailleur arm looks too short to provide the amount of leverage needed to easily move the cage.

Dan

rydabent 06-28-22 03:38 PM

I love my Sram twist grip shifters. They work great!!!!

veganbikes 06-28-22 08:42 PM

Quality grip shifts are different from stuff on a Huffy let's make sure to avoid conflating the two. When SRAM first made them they were great and their high end stuff is still decent but low end stuff is going to be hard for a lot of folks to shift especially kids and these are going to be even worse. Those cheap sunrace friction shifters are going to be worlds better, I would look for those.

Leisesturm 06-29-22 01:30 AM


Originally Posted by _ForceD_ (Post 22557050)
I may resort to this practice in the future.

All … when I disconnected the cable from the front derailleur, the shifter twists easily and freely; the cable moves through the entire routing easily, no snags; and the derailleur itself moves in and out freely. But with the cable connected the shifter is just hard to twist. So my feeling is that it’s just a poor design. The grip shifter doesn’t provide enough force, and the derailleur arm looks too short to provide the amount of leverage needed to easily move the cage.

Well, even though I prefer other types of shifters, I stop short of believing that a GripShifter setup could be as bad as what you are describing. There are top pull front derailleurs and bottom pull front derailleurs. Are you sure your shifter is pulling on the cable clamp in the right direction? It's time for some pictures to be uploaded. We may not all prefer GripShifters, but we can make them work by gum. Standing by.

_ForceD_ 06-29-22 06:42 AM


Originally Posted by Leisesturm (Post 22557522)
It's time for some pictures to be uploaded.

Here ya go. (FYI the chain is wet lubed. Just the red oxidation showing through the oil.)

https://cimg0.ibsrv.net/gimg/bikefor...5548ac654.jpeg
https://cimg2.ibsrv.net/gimg/bikefor...286589fed.jpeg

squirtdad 06-29-22 09:19 AM

I am a vote for throwing friction thumb shifters on. this is what a bike charity I wrenched for in the past does.

benefit is it will work, and keep working even with huffy lowend components any thing with indexing is going to be sketchy even with rapid fire

I would much rather kids had something that works, than something that worked when a knowledgeable person set it up, but doesn't after the abuse kids give bikes

This is also my personal choice/experience when helping neighbors/friends who know I a am a Bike guy

_ForceD_ 06-29-22 09:57 AM

I’ve informed the owner of the bikes of my feelings about these shifter, and the opinions of those expressed in this thread. I provided them the link to the thumb shifters, and volunteered to install them. So the ball is in their court.

Dan

Bill Kapaun 06-29-22 12:07 PM


Originally Posted by Leisesturm (Post 22557522)
Well, even though I prefer other types of shifters, I stop short of believing that a GripShifter setup could be as bad as what you are describing. There are top pull front derailleurs and bottom pull front derailleurs. Are you sure your shifter is pulling on the cable clamp in the right direction? It's time for some pictures to be uploaded. We may not all prefer GripShifters, but we can make them work by gum. Standing by.

It's a Huffy. That's what they do.

2_i 06-29-22 12:15 PM

I am baffled about the manner in which conclusions are arrived here. Every twist shifter on Earth basically applies nearly directly the force of hand to the cable. Most common derailleurs have at least OK arm. The room for poor design/operation, after cable friction got eliminated, is in the position of cable stop, here below BB. Mountable cable stops could help.

2_i 06-29-22 12:21 PM

The 'against twist shifter sentiment' posts have one tangential value to me of quickly populating the bin of 'do not follow their advice' in matters where my expertise is weak.

hokiefyd 06-29-22 12:34 PM

I like twist shifters in general, and in particular, the old school SRAM SRTs and the higher end Shimano Revoshifters (SL-RS45 and above is a different beast than RS35 and below). However, there are indeed some notably poor examples out there as well. I imagine some especially cheap ones are made in ways such that twist motions to shift cause all sorts of unnecessary friction inside the unit, making them more difficult to turn. I have experienced these myself from time to time, especially on donate bikes. One thing to check here is ensuring the rubber grip is not jammed up tight against the twisting grip, causing friction. Name brand twist shifters have various ways of mitigating that, but knock-offs might value engineer that sort of thing out.

And there do exist some indexing thumb options, if you want to go that route. Look at Shimano's TZ500-6R shifter. It's a low cost indexing thumb shifter that should work with a six speed freewheel. I have the 7R version shifting a seven speed cassette on an older bike and it works perfectly. The shift effort seems about right and it just works well. It's an option if you don't want to go full friction.

Leisesturm 06-29-22 12:44 PM

<gulp>Agree w/squirtdad, some friction thumbies are not a bad idea at all. Rapidfires would be a waste on that bike. But, I did notice that both limit screws are backed out to near maximum, if not maximum, and wonder how well it can shift like that. When you say it moves easily, is that through the full range of motion necessary for a shift? I also find it hard to imagine that the cable core isn't seized in the housing somewhere. Have you checked how free (or not) the cable core of both shifters are in their housings? What is the condition of the guide that routes the FD cable around the bottom bracket? Is there a guide that routes the FD cable around the BB? Even thumbies will appreciate that kind of groundwork taken care of for them. Good luck.

squirtdad 06-29-22 01:13 PM


Originally Posted by 2_i (Post 22558103)
I am baffled about the manner in which conclusions are arrived here. Every twist shifter on Earth basically applies nearly directly the force of hand to the cable. Most common derailleurs have at least OK arm. The room for poor design/operation, after cable friction got eliminated, is in the position of cable stop, here below BB. Mountable cable stops could help.


Originally Posted by 2_i (Post 22558116)
The 'against twist shifter sentiment' posts have one tangential value to me of quickly populating the bin of 'do not follow their advice' in matters where my expertise is weak.

There is, in my hands on experience, a huge world of difference in quality between high end and low end twist shifters in areas such as durability, function, materials

I am not against twist shifters, but have lot's of experience with cheapo ones on BSO from big box stores. They simply don't work well or last, especially combined with the over all low end level of components overall.

when I have worked on bikes like that my goal is to get them working, reliably for the owner, especially if owner is a kid or not bike mechanics knowledgeable, hence the recommendation for friction thumbshifters. They work.

so listen to experience or not.... your choice

now get off my lawn
:50:


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