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Thread: twist shifter not indexing lowest gear

  1. #1

    Default twist shifter not indexing lowest gear

    hi! i am back to the forum. i have been building an aluminum bolt together recumbent delta trike with a split axle. i bent the drive axle somehow. i replaced it and am now trying to set up the rear derailleur and twist shifter with great difficulty.

    everything worked fine before i bent the axle and had to replace it. now, the shifter will not index to the number "1". the gears will move from smallest to second largest fine, but the grip shifter will not twist past 2 to the 1 position.

    details-
    -shimano 8 speed cog set that the largest cog is 34t.
    -three chain rings but trying to adjust while on the middle one.
    -double checked chain length to proper length (large ring to large cog)
    -derailleur- shimano acera rd-m390 8 speed
    -"microshift" twist griip numbered 1 to 8 mounted on "U" shaped underseat steering in the vertical position. the "microshift" twist shifter is supposed to be shimano compatible.

    -there are two gentle bends from the shifter to the derailleur but no different from what was working before.
    -with the chain disconnected the derailleur will move between the smallest cog and the largest cog by hand.

    i can adjust the derailleur to hit smallest cog to second largest cog or largest cog to the second smallest cog but not both.

    if there is much tension on the shifter cable the twist grip will not go past 2 to 1. the shifter gets harder to twist with the more tension on the cable there is. the shifter cable moves smoothly when not attached to the derailleur and will index on each number

    i have tried every different adjustment method i could find on the internet bike forums/topics to no avail.

    shifting worked fine on my first steel trike and fine on this one until i replaced the axle. i can not figure out what i am doing wrong here.

    any ideas on what i did wrong would be appreciated.

    thanks george tarleton
    Last edited by george t; 11-12-2017 at 02:09 PM. Reason: wrong wording

  2. #2

    Default Re: twist shifter not indexing lowest gear

    A few thoughts - Are you using shifter cable housing? Could your derailleur hanger be bent out of proper alignment?

  3. #3

    Default Re: twist shifter not indexing lowest gear

    Another thought: have you checked the whole straightness of the frame? Did it get bent as well? Or at least out of alignment from before? Did the shift cable become stretched?

    With no cable attached- can the derailleur be physically moved from smallest to largest by eyeballing movement?

    Is the rear to front gears parallel - in other words are both front and rear on same vertical plane with each other? One is not twisted from the other?

    A few things to check if you haven't.

    How did you bend the axle? Is it steel? And how did you remount it? Did you use same method as you built it?

    Is the axle still 90 degree's Tee across the main boom? With all deltas we mount a single axle then cut once roller bears are mounted to keep it all aligned.

    Again these are just thoughts that I am just considering out loud without know what you have done already.

  4. #4

    Default Re: twist shifter not indexing lowest gear

    nothing on the frame was changed. i am not sure how it got bent. it has not been more than 100 yards off the stand. no crash. i noticed it as i was working on the free wheel sprocket which had come loose. the only thing i can think of is when i was torquing the double nut on the wheel. i was really torquing on the nuts by hand wrench.

    yes. with no cable attached the derailleur can be moved by hand from smallest to largest. also the grip shifter can twist through all the numbers with not cable attached.

    axle still 90 degrees.

    i will try using a new cable even though the first one was not that old. but with all the messing about it could have stretched.

    i think the frame is still right but have to check.

    i did use a brake cable housing as the problem existed with the shifter cable housing. so i tried the brake cable just to see if it would make a difference. it did not. i am out of shifter housing but on order.

    i re-mounted it the same way i mounted it. i did cut the axle the right way.

    does the way the cable is run make a difference. i mounted the cable similar to the way i did on my steel trike. i also zip tied the cable to the frame. how much loop should the shifter cable have from the frame to the deraileur?

    the deraileur hanger seems to be straight. there is a photo of the derailleur and hanger on the thread "bolt together aluminum trike".

    thanks for the advice.

    nice to hear from you dtd.

    george t

  5. #5

    Default Re: twist shifter not indexing lowest gear

    i found some shifter cable housing i did not know i had. i put a new cable and housing on the deraileur. no joy.

    george t

  6. #6

    Default Re: twist shifter not indexing lowest gear

    Quote Originally Posted by george t View Post

    yes. with no cable attached the derailleur can be moved by hand from smallest to largest.
    How much adjustment do you use on the lowest and highest gear? If there is no adjustment left to use on the lower gear but plenty on the higher gear the derailleur is out of line.

  7. #7

    Default Re: twist shifter not indexing lowest gear

    the adjusting screws for both the low and the high have plenty left for either adjustment.

    i have tried every suggestion on this forum and the bike forum. no joy with any of the suggestions.

    at this point i am ready to buy a new derailleur and a higher end twist shifter.

    thanks - george t

  8. #8
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    Default Re: twist shifter not indexing lowest gear

    We use friction bar end changers with good results . Then you only set up the system with only the limit screws.
    It can't rain all the time

  9. #9

    Default Re: twist shifter not indexing lowest gear

    Sorry your so frustrated with this.
    I'm not sure if the following will help but here it goes.
    1) Back out derailleur stops. They limit range of movement.
    With no cable the Derailleur should be aligned with the smallest gear. And if you pedal it the chain will stay on that gear. If it is not staying on that gear then realign the mounting to get chain to run on that gear with no cable. Do not adjust derailleur stops you are setting baseline for gearing. You may have to realign the freewheel mounting to achieve this. Not sure how it is mounted. Or you may have to realign how the derailleur is mounted.

    2} Mount cable with shifter to 8. Ensure the chain stays on largest gear while pedaling.

    3)Move the shifter to the lowest setting while pedaling. Do not worry about where the chain is.
    Now that you are there. Tension the cable on the derailleur to point where the chain is aligned with the largest gear. Actually you should go just beyond it. And tighten the cable. Then adjust the stop to bring it in alignment. IF you cannot go beyond the largest gear your derailleur may not have a large enough range. But you had it working before.
    Attempt to pedal it through the whole range using the shifter. If it does your are done.

    For reference: Smallest gear is the highest speed or 8 has the fewest teeth. And largest is 1 and has the most teeth. Just so my explanation makes sense. The Derailleur is a tension device that has no cable tension on the smallest gear and max tension when on largest gear. The stops and tension are all that move it. If the cable cannot tension it then it won't reach the lowest gear. Thus the reasoning for new cable. The other thought is the grip shifter range is not pulling to correct steps to achieve the tension required to get it to the lowest gear.
    But you gave the impression the whole set was working before. So the suggestions I have have mentioned should have it working in the full range and we are missing a piece of the puzzle.

    And before you get a new derailleur, if the above is not effective. Then I would take it to a local bike shop and get another opinion and see if they can assist. Id suggest going to Bicycle Kitchen but your an 8 hour drive from them. They are non profile and assist in bicycle repairs and adjustment. They also have work shops on various aspects of bicycle repair.

    I hope this helps, but then you may have already done this. Not sure what would have changed other than the freewheel mounting to the axle as you change it.

  10. #10

    Default Re: twist shifter not indexing lowest gear

    to all that responded- thank you very much for your help. because i kept trying all the different solutions you folks suggested, i spent alot of time looking at the derailleur. i kept looking at my wife's 2 wheeler and how the derailleur was positioned on the frame. i looked at the derailleur hanger on her bike and then on my trike and i finally realized that the bolt the connects the hanger to the derailleur was in the wrong place. instead of being at the 7 o'clock postion it was in the 5 o'clock position. i must have put it back wrong when i changed the axle not realizing that the pivot bolt position was in the wrong place. heck,i did not even know what the right position was. i did not have any witness marks. it was not until i looked at the derailleur mounting thread that the penny dropped!

    still, all the suggestions helped me learn how to trouble shoot and tune a derailleur, so our efforts were not wasted. it was also nice to hear from some zombies i had not had contact in awhile.

    so, thanks again. i may even get the bolt together aluminum delta finished before christmas. sure would like to try it out before the snow flies.

    have a great thanksgiving. george t

  11. #11

    Default Re: twist shifter not indexing lowest gear

    Happy endings are cool. From now on you'll be obsessing about derailleur mounting on every bike you see, at least for a little while! lol This will be seared in your mind for the foreseeable future.
    K.I.S.S. - Keep It Simple Stupid
    Use it up, wear it out, make it do, or do without

  12. #12

    Default Re: twist shifter not indexing lowest gear

    I glad you did not give up. I revisited the old thread on the bolt together. I had forgotten what it looked like.
    I am not sure all thread will be a heavy enough axle. If you bent it just tightening the nuts. But you can always change it if it doesn't work out.
    Cold rolled steel is much stiffer and less prone to bending. To make it bolt together you could thread the attachment points where you need it. Granted it will add to the expense of the axle with tap and die tools. But I believe it will be more reliable should the present axle give out.
    Again i is just a thought. And glad you figured out the issue with the shifting.

  13. #13

    Default Re: twist shifter not indexing lowest gear

    dtd- thanks for that idea. is threading the cold rolled steel something i could do myself? i have the die and tap of the correct size. the strength of the threaded rod is not something i had thought about.

    i did not know much about metals and their properties or welding before doing my first trike, the timber wolf with the samagaga rear end, though i have gotten a bit better with my welding. been doing horseshoe gifts for my friends. horseshoes are very forgiving for novice welders. tough to blow a hole through but i can manage.


    thanks- george t

  14. #14

    Default Re: twist shifter not indexing lowest gear

    I am not sure. But hopefully someone can answer that is familiar with cold rolled steel. I do know it is Brass preferred material due to being strong and straight. In comparison to hot rolled steel rod.

  15. #15

    Default Re: twist shifter not indexing lowest gear

    thanks. i can check with my welding buddy.

    i made this bike with 26" wheels just see what they are like on logging roads. if they do not, i will try 20" wheels again.

    also, if the split axle with one drive wheel does not work out, i am thinking of going back to the samagaga rear end and use what ever size wheel works best for me.

    i will pm you when start posting again on the bolt together aluminum delta trike if you are interested. i did post photos of my stuff a couple of moonths ago.

    george t

    george t

  16. #16
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    Default Re: twist shifter not indexing lowest gear

    Quote Originally Posted by darnthedog View Post
    I am not sure. But hopefully someone can answer that is familiar with cold rolled steel. I do know it is Brass preferred material due to being strong and straight. In comparison to hot rolled steel rod.
    we use EN51 steel for the axle on the quadem

    regards emma
    It can't rain all the time

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