BikingGrad80

Hi all I have a question.


I have a road bike with 53/39 crank and it came with ultegra 9 speed 11-23 cassette. I find the gearing a bit high especially for the hills in Wisconsin so I am thinking of switching to 12-25 or even 27.

If I took off the 11 tooth and added a 25 would I have a functional 12-25 or do I need specific 12 tooth outer?

DMF 

No. The top cog is special, and the big 4 or 5 are in riveted sets.

Just go ahead and buy the new cassette. (Note that the lock rings aren't interchangeable either.)

HillRider

The top cog is special but I've seen people use the second position cog as the smallest with no problems. In fact, some second position cogs are grooved like a top cog to help retain the lockring. A 25T can go behind the current 23 to give the ratios you want but you will need an extra 9-speed spacer for it.

The lockring for an 11T cog is smaller diameter than the one for a 12 or bigger smallest cog but I expect it will work any way. If not, any LBS should have a bunch of the 12T and larger lockrings as surplus since they come with every new cassette.

DMF 

To make rabbit stew, first catch a rabbit.

Shimano apparently doesn't supply cogs or sets as repair parts. I have had zero luck trying to find some new. If you cannibalize another cassette (which you have to buy/find anyway), you have to take a whole set — 21-23-25 in the case of a 12-25. The 17-21 shift wouldn't be much fun. (There are loose 25s on the junior clusters, but just try to find one of those.)


If you have a source for new cogs, please let me know.

BikingGrad80

Ok so I guess it is save up for a full 12-27. I guess I'll probably need a longer chain too. Guess I'll wait until I need a new chain. Does anyone really need a 53-11 gear?

DMF 

I use a 52-11 all the time.

No you don't need a longer chain (probably). And if you do, just bum an end from your LBS. All chains come too long and need to be shortened to the particular bike. They'll have a big bucket of them in the back.

However! That doesn't mean you don't need a new chain. How much is your present chain worn? Know how to check it? If you have measurable wear, you might want to keep the current chain with the current cassette (i.e. in a freezer bag) and put both new on.

Terrapin Tim

If you have a source for new cogs, please let me know.[/QUOTE]

I have done exactly what you are describing using loose cogs from Harris Cycle.... the rivets holding together the top gogs dill out super easy leaving you with spacers and cogs... now mix and match.

I picked up a 13t low cog and 27 & 29t mid/final cogs from H arris. I used the 15 17 19 21 23 and 25 from the original casette and the 13 27 and 29 cogs from Harris to build a super climbing casette for around $25. (13,15,17, 19,21,23,25,27,29 ) The good news is I can still hang with most of the Hammerheads on my training rides by bumping my cadence up 10%

All of this works on my stock 105 RD with minor tuning and tensioning of the "B" screw. Check your chain length, or better yet spend th $20 on a new SRAM Chain with the powerlink and make it perfect length.

Easy and Cheap... just the way I like it

Tim

DMF 

'Course, the real solution is to change to a triple crankset and keep the 11-23. I've tried different combos - I keep coming back to that.

Iowegian

Shimano and most LBS will tell you that you need a new cassette, but as mentioned above, if you're willing to do a bit of drilling/grinding to get the rivets out of your old cassette, it can be done. Once again, thank you Sheldon!

I'm about ready to go the same route, since there are some serious grades here in CO. Plus, I like the idea of being able to change gears by just removing the lock ring and swapping rings. Isn't that what cassettes are supposed to be about~!

Terrapin Tim

Plus, I like the idea of being able to change gears by just removing the lock ring and swapping rings. Isn't that what cassettes are supposed to be about~![/QUOTE]


+1 10 min tops for a ratio change....

I am also considering going to the XTR rapid rise RD makes shifting while climbing under load much cleaner (or so says Lord Sheldon) ... also opens up the possibility of a true Bailout Gear... I'm training for the San Francisco -> Los Angeles Aids Ride and there are some spots where a 34t might not be such a bad idea !!!!! Better to have it and not use it than need it and not have it... especially if you can change it out in 10 min

DMF 

And how is that different from swapping the whole cassette?


All this mixing and matching sounds great until your cogs start getting different levels of wear. Then they won't be compatible with each or the chain.

Build a custom cassette if you want, but then leave it together.

HillRider

Most of the Shimano cassettes (105 or below) I've seen have bolts holding the largest cogs together and they come out with a 1.5 or 2 mm allen key. No grinding needed.

Of course, you can't successfully take apart the clusters that are on a spider as Shimano does with their Ultegra and Dura Ace level cassettes. The cogs aren't full "plate" type and can't be used individually.

Harris Cyclery offers a couple of custom Ultegra level 9-speed cassettes in 13x30 and 13x32 made from 12x27 cassettes by deleting the 12 and 13T cogs, adding a 13T top cog and a 30 or 32T cog behind the 27.

I've made a custom 13x27 also starting with a 12x27 and deleting the 12 and 13, adding a top gear 13T and a 16T loose cog (these are HARD to find). This is the ideal combination for me as I have no use for a 52x12 and, of course, even less use for a 52x11. Actually the ideal cassette for me is Campy's 13x29 10-speed but that's another story.

I agree with DMF that if you customize a cassette, leave it together for it's lifetime. The uneven wear from swaping cogs while in use is going to cause skipping and shifting problems sooner rather than later.

waffenschmidt

But who uses individual cogs in such a way that they all wear at the same rate? I would think most people would tend to use the middle cogs more frequently, thus wearing those out sooner than the ones at the extremes.

DMF 

So what?

erader

if you buy an HG-50 cassette all you need to do to separate the cogs is drive out three pins to loosen the cogs, which are not on a carrier.

i buy the 11-32 cassette, drop the 32 and add a 13-tooth cog to make a custom 11-28 cassette for my 1 x 9.

ed rader

erader

i've always swapped cogs on my cassettes with no problems. i just replace the worn cogs. not really rocket science .

ed rader

waffenschmidt

Hillrider made the point that uneven wear from swapping cogs while in use will cause skipping. My point is that you'll get uneven wear on individual cogs even if you keep a cassette together. Besides, if someone is going to swap cogs back and forth for specific conditions, they're not likely to change their "favorite" middle cogs anyway. For instance, someone might add a larger "granny" cog for hilly routes or loaded touring, removing one of their lesser-used smaller cogs. That sort of swapping is not likely to result in uneven wear.

BikingGrad80

Well my bike and drive train are almost new less than 300 miles so I don't want to toss out a new cassette. I was driving through southern Wisconsin and some of the hills made me cringe, I was nervous driving up them. I just don't know if it is possible with a 39-23 lowest gear. When I was there last month on my Trek 520 I spent a lot of time in the 30t ring. But my road bike is much lighter and climbs better than my trek 520 so maybe it is possible.

Iowegian

Brief update, I built up a bike for my son this weekend and needed a cassette. I got a SRAM 850 for him and a new (but discontinued) 8-speed Ultegra cassette for me. Turns out, the Ultegra cassette comes apart with 2 mm hex key and the SRAM also comes apart with a 1.5 mm hex key. Then while looking for an 8-speed wheel for my son's bike, I found some old 7-speed cassettes in my 'pile' that were riveted together. On these the pins would have be punched out or the heads would have to be drilled/ground to get them out.

So I guess it all depends, but I think your 6500 cassette should come apart easily. Then it's just a matter of finding some cogs. And come to think of it, I have a 27 tooth cog that I'll probably never use. I got it for the exact reason you're discussing but ended up getting a 12-27 cassette instead. The 12-27 is 9-speed and I'm still running 8-speed but after researching this whole thing a bit, I think I can just swap the 9-speed cogs into my 8-speed cassette for those days when I know I'm going need it. If you want the 27 tooth ring, PM me and I'll send it out.

DMF 

Don't toss it. Either keep it for a more appropriate time, or sell it on eBay. There's a good market in lightly used cassettes. Probably worth $30 there, properly presented.