Bicycle Mechanics - Replacing thumb shifters with twist grip

I need to replace Shimano Deore XT thumb shifters with twist grip shifters...my wife has arthritis in her thumb. This is on a 21 speed mountain bike. The bike is older but lightly used, and we aren't hard charging riders. Lower cost items are good if they're reliable. The derailleurs are Deore XT.

I'm looking at SRAM MRX Pro 7 speed twist grip pair. Right choice?

I can probably saw off the tab on the brake lever where the thumb shifters bolt on...or will I need new brake levers? If so, recommendations, please.

Should I renew the cable? Cable recommendation?

Online vendor recommendations? (Bikepartsusa.com OK?)


Thanks,
Ken

I can probably saw off the tab on the brake lever where the thumb shifters bolt on

I can't believe I have never thought of this...


Should I renew the cable? Cable recommendation?

Online vendor recommendations? (Bikepartsusa.com OK?)


The shifters will probably come with new cables.

And I always like to check out icyclesusa.com. Cheap stuff, and if you can find enough excuses to spend $100 you get free shipping.

If you need a home for you old thumb shifters...

1. MRX shifters will work fine as long as the number of speeds matches your cassette.
2. You can cut your old brake levers and shifters apart or, for a more deluxe look, get new ones.
3. The new shifters will come with cables installed. That's a good thing with the MRX shifters because you have to take them apart to replace the cables.
4. Your existing handgrips will be too long. You can cut them off, like the brake levers, or get new ones for the more deluxe look.

I have arthritis and found grip shifters to be just as hard as thumb shifters considering you must grip the shifters between your thumb and fingers, which I found just as painful with my thumb. My solution was to mount my thumb shifters at the very ends of a moustache handlebar turned vertical so I could shift them with my palm. Just check out the photos of my setup.
http://i143.photobucket.com/albums/r154/n4zou/Hpim0204.jpg

http://i143.photobucket.com/albums/r154/n4zou/Hpim0203.jpg

http://i143.photobucket.com/albums/r154/n4zou/Hpim0202.jpg

If you want a more upright riding position you can flip the moustache handlebar over or get albatross handlebars.

Hi Ken,

A few years later--now 2012, not 2007. My husband is helping me customize a bicycle to adapt to arthritis in my thumbs! So, I find your post interesting. I've tested SRAM grip shifters in the bike shops and find that they engage my thumb- with pain. So, I'm on to another idea, a nitto mustache handle bar and a bar end shifter.

Is everyone still riding? Hope so.

best,

Katie
Portland, Oregon