etherhuffer 

I am trying to get some clarity on converting this 7 speed. When you do this, do you just lose your high or low gear depending on how you set the stop on the derailler? No need to alter the cassette per se? Sheldon Brown's article was good but didn't say which cog you lose.

Ex Pres 

Uniglide or Hyperglide hub? On Uniglide, you have to use the small threaded cog (unless you get another in a different size), so you need to loose whichever makes sense. EG, if you have a 12-27 cassette and a 12t threaded cog, you'd ditch the 12t HG cog.

If HG, you'll need that "serrated" small cog from the HG cassette to tighten the lockring to, so you'll have to ditch the large cog. You could try an intermediate, but it probably won't shift as well.

And just to make sure you understand the whole deal, if you want indexing you'll have to change shifters, but you'll only be shifting 8 cogs with a 9s shifter. In this case you'll have to limit out one shift - I'd limit out the big cog.

etherhuffer 

I want to keep the big cog for a granny and loose the small one. I understand the shifter issue. I have priced out 8 vs nine speed stuff, and 8 is harder to find than nine, and actually more pricey. So.... new cassette, new rear derailler, new 9speed shifter, new 9 speed chain. And a shiney new crank just because!

Ex Pres 

If your hub is an HG, ....(edited out)...... I'd try losing the next to largest, that way you'll retain your bail-out.

edit: later posts indicate you can lose the small cog, so read those.

HillRider

You can ditch the smallest cog and use the second one in as the top cog. If you tighten the lock ring properly, the serrations are not essential.

Bezalel

If the smallest two cogs are 11 and 12, you can get rid of the 11T cog. The 12T cog can be used in either of the top 2 positions. Shimano makes different lockrings for 11 and 12 teeth.

FastJake

OP: I feel like maybe you don't understand the entire issue here. Do you have a Uniglide or Hyperglide Freehub? Some models are compatible with both. You probably don't need a new rear derailer. Also, the derailer doesn't determine which gears you "lose" or "have." That depends on what gears you leave on the cassette. The derailer (should) shift through all of them.

+1

Having a bigger jump to your largest cog is pretty nice sometimes, and you don't lose much. I had a 12-23 cassette on my road bike. I replaced the 23 with a 28, so now I have a 12-21 + 28 acting as a granny gear. Trying to lose the smallest cog(s) can get tricky as you can sometimes run into lockring issues.

etherhuffer 

I understand the low/high ring differences/lockring stuff. In losing one cog, I am trying to retain a bailout, but I could do that as noted, by dropping a next to top ring. How well does that shift when you are under some load though?

Deraillers are not a worry, its shifters. 8 vs 9 speed shopping shows much more nine speed stuff out there. Plus, if there is a part failure, finding eight speed shifters vs 9 using only 8 of 9 is better.

Why even go to anything more than 7! marketers!

FastJake

7 speed cassettes are still available, if that's what you prefer to run. 8 speed is my personal choice, so far I've never had a 9 or 10S rear.

Mine shifts from the 21 to the 28 just fine, although I'll admit it's not perfect. It is quite a jump for the RD to make.

shelbyfv

I removed the 11 and 12 from an 11-28 and replaced them with a 12 and lockring from a 12-26. I can't remember if the extra shift is at the top or bottom. It only worked well one way, so try both.

hybridbkrdr

How about using Falcon friction shifters?

etherhuffer 

I am rebuilding this for a friend and she wants to stay with indexed. I just built a bar end set up, an old Fuji Touring bike. I am learning to love bar ends. cheap, fail proof.

joejack951

Swap out the freehub for a 8/9/10 speed freehub. Buy a whole rear hub and scavenge the freehub, axle, and drive side cone, locknuts, and spacers. Then you don't have the worry about losing cogs. It would help to know what the rear hub currently is to assist you in finding a good donor hub.

Fred Smedley

https://www.ebay.com/itm/SHIMANO-7-SP...item19c861341e

dwellman

Yeah. I did this on a FH-6400 Uniglide. Swapped the freehub body ($14 for the body, $4 for a cone wrench, $8 for 2mm-10mm Allen wrench set). I used a SRAM cassette and ditched the 11 tooth cog. Sold the 7sp Uniglide cassette (being replaced) on Ebay for twenty something.

I did have to replace the left cone due to wear/pitting, though. That was another $10 or so, but these things have to be done sometimes. You might be luckier.

Never a bad idea to ahead and have spare cone and 1/4 inch ball bearings handy, just in case.

etherhuffer 

I dug through my stuff last night and found an HG40-aw 11-32 8 speed. So I think the freehub body swap is my way to go. Anyone have experience with Shimano ST-R500 8 speed shifters? Can't tell what build level these are. The old 7 speed on the bike are RSX level.

hybridbkrdr

If you check the Amazon.com customers reviews there are some pretty good comments about the R500 shifters.

dwellman

ST-R5xx are comparable to. . . let's say right between Tiagra and 105 or maybe just re-purposed RX100 (ST-A550 design. . . which again kind of around Tiagra (if it were 9 speed) 105 (if it were 10). . . Shimano: What's old is new again!

I have ST-2300 and they shift fine. . especially for $66 I paid for the set.

etherhuffer 

OK, got an 8 speed hub tonight, and can't tell about the fit. My cs-hg40-aw cassette has a 1 mm spacer tha t the tech doc shows going behind the 13t cog in the exploded view. I can't see why it is used and it won't allow the 11t to seat on the hub. Works without it though.

What is up with this?

Medic Zero

Maybe uses same parts as 9 speed and thus the spacer?

dwellman

The 13 and 11 have built in spacers. I'm not sure what the extra one is for, either, and even if the built in spacer for the 13 was 2.56 mm instead of 3.00 mm, 0.44 mm difference on the last two cogs isn't going to throw anything off. . .

I remember seeing an extra thin spacer in a 7 sp Uniglide cassette.