Bicycle Mechanics - 9speed shifter can be used for 7speed derailleur?

Here's the situation I have.
I converted a drop handle bar to a straight handle bar, shortened 2 inches both ends, on my road bike. I love how it rides. The conversion made my bike a lot more agile, into a perfect street bike. I replaced the brake levers with MTB levers but kept the down tube shifters as they were. Now I want to convert it to a grip shifter for quicker acceleration. My rear derailleur is made by Suntour but can be used with Shimano shifter. These days it's hard to find 7 speed shifter, so I have to settle for higher capacity one. I found one I like at Bike Nashbar and it's 9 speed. So, here's my question.

Can 9 speed grip shift lever work with 7 speed derailleur just by setting a limiting screw accordingly? Or it can't be done?

Here's the situation I have.
I converted a drop handle bar to a straight handle bar, shortened 2 inches both ends, on my road bike. I love how it rides. The conversion made my bike a lot more agile, into a perfect street bike. I replaced the brake levers with MTB levers but kept the down tube shifters as they were. Now I want to convert it to a grip shifter for quicker acceleration. My rear derailleur is made by Suntour but can be used with Shimano shifter. These days it's hard to find 7 speed shifter, so I have to settle for higher capacity one. I found one I like at Bike Nashbar and it's 9 speed. So, here's my question.

Can 9 speed grip shift lever work with 7 speed derailleur just by setting a limiting screw accordingly? Or it can't be done?

I am not an expert but it sounds a bit doubtful. Logically the 9 rear cogs must be thinner and closer together than in an 8-cog or 7 cog set up (since the space allowed for 9 cogs is the same as for 8). This would presumably mean that the indexing would be slightly off if you use a 9 speed shifter with a 7 cog set up. You could try looking on ebay for a 7 speed shifter- I have seen 7 speed shfters there

I am not an expert but it sounds a bit doubtful. Logically the 9 rear cogs must be thinner and closer together than in an 8-cog or 7 cog set up (since the space allowed for 9 cogs is the same as for 8). This would presumably mean that the indexing would be slightly off if you use a 9 speed shifter with a 7 cog set up. You could try looking on ebay for a 7 speed shifter- I have seen 7 speed shfters there

9 speed gears and chains are narrower than the others. I believe 6, 7, and 8 are all the same width. I don't think 7 speed shifters would work, but 8 should. You should be able to find plenty of decent 8 speed shifters. I don't know if this would work for sure, but you should just be able to adjust the limit screw like you said.

Thanks for the response. I have researched a bit since I posted my original message and what I found out confirms that your informations seem to be true. I got to have 7 speed shifter. I have looked into eBay and there are a few of them. I will also try LBS and see if they have old parts.

I forgot to say I will also look into a possibility of 8 speed like bg4533 said.

I have a selection of 7speed gripshifts in my shed as I have changed a few bikes to rapid-fire levers. Just a pity I didn't live a bit closer.

Can 9 speed grip shift lever work with 7 speed derailleur just by setting a limiting screw accordingly? Or it can't be done?
Not if youu have a 7 speed casette.

9 speed gears and chains are narrower than the others. I believe 6, 7, and 8 are all the same width. I don't think 7 speed shifters would work, but 8 should. You should be able to find plenty of decent 8 speed shifters. I don't know if this would work for sure, but you should just be able to adjust the limit screw like you said.6,7,and8 is not all the same. And why woldn't 7 speed shifters work with his 7 speed setup??? DOH?

Nine speed shifters will not work with a 7 speed drivetrain because the indexing in the shifting is too close. However I do have some Suntour 7 speed twist shifters, and some questionable shimaNO twist shifters. Most any LBS should be able to get you some SRAM twist shifters in 7 speed.

7-speed Sram shifters are listed in two common bicycle wholsalers catolouges.

Here's the situation I have.
I converted a drop handle bar to a straight handle bar, shortened 2 inches both ends, on my road bike. I love how it rides. The conversion made my bike a lot more agile, into a perfect street bike. I replaced the brake levers with MTB levers but kept the down tube shifters as they were. Now I want to convert it to a grip shifter for quicker acceleration. My rear derailleur is made by Suntour but can be used with Shimano


Wouldn't this work: Shimano compatible, 7 speed option

http://www.nashbar.com/profile.cfm?category=104&subcategory=1195&brand=&sku=6231&storetype=&estoreid=&pagename=

Thanks to the last two posts. It seems that SRAM still makes 7 speed shifters and many of them. I just had to go beyond thumb nail pages to find out. Now I have many options, eBay, LBS, online stores. I like the idea of LBS when it comes to old parts. I can make sure it works before I pay for it.