My lads Scott Voltage has shimano revo shift gripshift style shifters running a 6 speed rear cassette. He is struggling with the brakes and gripping generally as the rotating grip is quite large diameter compared to the remaining grip.
I was mulling over some trigger shifters but cant seem to find any for six speed so could I put a 7 or 8 on the same freehub body.
The current rear hub assembly looks a little “agricultural” and doesn’t appear to have the lock ring arrangement.
What would you reckon?

6 speed on ebay as trigger shifters and well worth it IMHO
My kids can use these

http://www.ebay.co.uk/sch/i.html?_odkw=6+speed+shifter&_osacat=7294&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0&_nkw=tourney+6+speed+shifter&_sacat=7294

sounds like its an older freewheel style cassette block, not freehub style. Could still be possible to swap tho.

junkyard…is your link for the trigger style shifter or the old style single lever type sis shifter?

ignore that..I now see its a big thumb button for shifts and a finger trigger to drop.

Looks like it might be OK.

You might be able to swap the 6 speed free wheel for a 7 if there is enough space

Won’t a seven speed shifter work fine with a six speed? Will just have an extra ‘click’

You should be able to fit a 7 speed frewheel on the back. Beware, some of those trigger shifters need quite a lot of force. My sons were happier with twist shifting and found stabbing the with the thumb to change down pretty tough – had to teach them to rotate the wrist with a fixed digit. Better 7spd shifters may have a lighter action, but it was not as simple as you might think for my boys.

what size voltage? A friends son had a 24″ one with an 8 speed set up.

Edit, pretty sure this was with the original wheels.

It’s a 20″ wheel bike.
And I think it is the bolt on cassette rather than the screw on lock ring one.

Shimano TX50 6 speed shifters (£24.99) will work and be much easier to use than the twist grip.

would these be ok?

http://www.ebay.co.uk/itm/New-Shimano-Tourney-SL-TX30-Shifters-3-X-6-speed-/330924812142?_trksid=p5197.m1992&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D14%26meid%3D7752788846701889151%26pid%3D100015%26prg%3D1006%26rk%3D1%26sd%3D330924812142%26