Clydesdales/Athenas (200+ lb / 91+ kg) - Replacing Gears

Roark, my 2007 Trek 7.5 fx, has "9-speed, 11 - 26 teeth" gears, whatever that means. What changes can I make that will give me more, lower gearing? My touring load is about 40 pounds, and anything I can do to make hill climbing easier makes touring easier. Is it as simple as getting a new chainring?

You can usually get an 11-28, which will help a little. Do you have a mountain crank or touring? A mountain crank will give you all you could possibly need with a 28 and a 22 tooth granny gear. You'l almost be going backwards.

You could change the rear cassette to a 11-32t 9 speed type, you will also need a new rear derailleur such as a Deore RD-M531.

Does your bike have the Shimano M-443, 26/36/48 crankset?

The granny gear on this crank should work well on steeper hills.

Edit: This cassette will give you a >10% improvement without changing anything else on the bike, see: http://sheldonbrown.com/harris/k7.html#9 ;

"CS922 Century Special 112.95 13 14 15 17 19 21 24 27 30
310 grams
The "Century Special" is our most popular custom cassette. It works with all modern derailers, even short cage models.


Michael

Assuming this (http://www.bikepedia.com/QuickBike/BikeSpecs.aspx?Year=2007&Brand=Trek&Model=7.5+FX&Type=bike) is your bike and it's still set up like that:

The official limit on the rear derailler is 27 tooth with a total capacity of 37 teeth, your current set up has a total change of 37 ((largest ring 48 plus largest cog 26) minus (smallest ring 26 plus largest cog 11))...however the late, great Sheldon Brown says that those estimates are fairly conservative and designed so that novices can't mess up. If you take care not to abuse the system (using the largest ring with the largest cog and smallest ring with smaller cogs) you can exceed those limits by quite a bit. He states that most road derailleurs can handle a 30 tooth cog comfortably, even short cage ones. You could therefore probably get by with an 11-30 rear cassette. However if you're like me and don't ever use the smallest cogs (except maybe downhills, where you could just take the opportunity to rest) you may want to look at the custom cassettes that Mr. Brown's old shop assembles, like their 13-30 "Century Special" this would give gearing options that are closer together in your normal cruising range, reducing the likelihood of having gaps where one gear is just a bit too low and the next just a tad too high, while giving you the low gear grunt of a bigger cog in the back.

Pretty good advice so far...I've been able to use a 28-t large cog (not always a 30) with nearly every rear derailleur I've ever had, so that's probably an option. Don't expect miracles, though--two teeth isn't much. I've also swapped the useless 30 tooth granny on my crankset for a 26 on one bike and 24 on another, which was well worth the effort. Don't know if that will work with a modern driveline, though--mine are a few years old and I shift in friction mode.
If you decide to go with a cassette swap, think it through. if you need lower gears now, you probably aren't using the 11-tooth cog at all, and maybe not the next one up, 13 or whatever it is. Instead of using something like an 11-30, go with a 13-30 or 13-32. You'll have closer spacing and one less cog you don't use.

An upgrade to a long cage deore LX and a 9 speed 11-34 cassette should cost in the vicinity of 100 dollars. Install might add another 50 or so since this will also involve tuning and just for good measure throw in a new cable and chain.

This will by far be your cheapest option. Option B involves the previous upgrade plus a new mountain bike crank.

Roark, my 2007 Trek 7.5 fx, has "9-speed, 11 - 26 teeth" gears, whatever that means. What changes can I make that will give me more, lower gearing? My touring load is about 40 pounds, and anything I can do to make hill climbing easier makes touring easier. Is it as simple as getting a new chainring?

This means the rear gear cassette has 9 cogs, with the smallest being 11 teeth and the largest being 26 teeth. Your bike also has a three-chainring crankset, with 26, 36, and 48-tooth chainrings.

As others have pointed out, you can change to a wider-range cassette in the rear. A 34-tooth large cog is as large as Shimano makes, and it will require a new rear derailleur and a longer chain. With this combination (26 tooth chainring, 34 tooth cog), your low gear will move you along at just above walking speed. It's what I've had on a couple bikes- I don't use it often, but when I need it, I need it!

I agree with bautieri. I did a similar upgrade to my Cross Check to get a wide hill-range of gearing.

Go with a 11/32 MTB cassette with a Deore or better rear derailer. The same shifter will work, but will need a new and longer chain.

You can go as low as a 24t on a standard road triple.. If you choose this combo you will also need a little item called a Deda dog fang, to help keep the chain from dropping.. If you switch to a MTB rear derailleur you can also use shimano MTB cassettes with no issues, MTB and road cassettes use the same spacing in 9 speed.

http://www.cambriabike.com/shopexd.asp?id=34792&page=DEDA+DOG+FANG+CHAIN+DEFLECTOR%29

I have used a setup of 48/38/24 on my cross bike so I can climb all the trails I normally do on my MTB..

Harris Cyclery still offers wide range customs cassettes.. http://sheldonbrown.com/harris/k7.html#9

You can go as low as a 24t on a standard road triple.. If you choose this combo you will also need a little item called a Deda dog fang, to help keep the chain from dropping.. If you switch to a MTB rear derailleur you can also use shimano MTB cassettes with no issues, MTB and road cassettes use the same spacing in 9 speed.


You only need the "Fang" if you don't know how to adjust a front derailleur. I have a wider range than you (24-42-53 front, 11-34 rear) and my bike never drops the chain.

You only need the "Fang" if you don't know how to adjust a front derailleur. I have a wider range than you (24-42-53 front, 11-34 rear) and my bike never drops the chain.

This is true on a road bike but for a cross bike when I am offroad and the chain is being banged around it is usually necessary.. Many cross rides have fangs on there doubles because of all the bumps in the trail.

Thanks for the comments so far, friends. Let me add that I do have the "stock" gearing on the 7.5fx.

Geez Historian, I'm even more impressed with your riding now that I know your bike's gearing! My knees are aching at the thought of climbing hills with that setup. On my bike I have the 12-34 cassette on the rear and 26,38,48 on the crank. I can just relax, spin, and climb a hill at walking pace if I need to. I'm much more into lows gears that go-fast high gears. With all the riding you do, I would recommend getting the 11-34 or 12-34 cassette and a new rear derailleur.

Also, if you go to a lower front ring, say 22 or 24 (i have a 22 on my recumbent), or have trouble with the chain jumping off the front rings, I use the Jump-Stop,

http://www.gvtc.com/~ngear/

on 2 of my bikes and it works very well. I adjust my front derailleur to over shoot, so shifts are quick and the Jump-Stop throws the chain back on the ring.

I have a 2009 Trek 7.3FX and just changed the shifters to Deore LX, new 9 speed chain, and 11-34 Sram cassette. I did not change the RD.
I shifts really well - no problems. With the 11-34 I think I could climb a tree!

http://www.bikepedia.com/QuickBike/Side2Side.aspx?BikeIDs=95737b+17581b

I agree with several of the others, and would get a 11-32 cassette for the rear, and replace you rear derailure with a 9-speed Deore. Your shifters will work, and it is cheaper than getting a different set of cranks. Bombproof too.

I have a 2009 Trek 7.3FX and just changed the shifters to Deore LX, new 9 speed chain, and 11-34 Sram cassette. I did not change the RD.
I shifts really well - no problems. With the 11-34 I think I could climb a tree!

http://www.bikepedia.com/QuickBike/Side2Side.aspx?BikeIDs=95737b+17581b

That will work with the Deore rear, but the OP's Tiagra won't handle that large a cassette.

That will work with the Deore rear, but the OP's Tiagra won't handle that large a cassette.

Really? This stuff gets complicated for me. Please explain why the Tiagra would not handle a larger cassette. I really want to understand these issues....

The largest sprocket Shimano suggests on the Tiagra is a 27t. As has been stated, this is a conservative rating. Depending on the bike model a 30t might work. For a derailleur to work with larger cogs, the derailleur needs to articulate with enough range to accept the larger OD of the the larger gear.

The largest sprocket Shimano suggests on the Deore is a 34t.

Michael

The arm on the Tiagra rear derailure is just not long enough to handle that big a difference in gears. It would rub and grind something awful.

Tiagra shifters and front derailure are fine. No problem there.

Historian - On my self-supported tour before the camping on the ground aggrivated my back.. i was riding with a 12-24T and it was INSANE! i had to stop start some hills almost from the start which was a new for me.. after around 250 miles good shop hooked me up with a 11-34 and it made all the difference.. still hit some stinkers but never felt like i couldnt get up it.

I know PA is Hilly! so i think it would make it more enjoyable for sure.. Take lots of pics and you got me thinking about my next tour!!! all i know is i cant camp on the ground anymore...back = broke! ahhah

Go with a 11/32 MTB cassette with a Deore or better rear derailer. The same shifter will work, but will need a new and longer chain.

As others have said, this is fine advice... I just finished building a road bike with this combo and it works great.

SRAM 950 11-32 cassette: $25
Deore XT RD high normal: $70
Chain: $40ish

Match the cassette cogs to your shifter, not derailleur.

The arm on the Tiagra rear derailure is just not long enough to handle that big a difference in gears. It would rub and grind something awful.

Tiagra shifters and front derailure are fine. No problem there.



If it's the Tiagra GS rear, you can shoehorn a 32t cog under there and fiddle around with the tensioner screw to keep the top pulley from riding the teeth on the cassette. It's not the best solution, though. I did this for a while with my Cross Check, before I swapped out for Deore rear derailleur (which works much better!)

To the OP, Let us know what your solution is. Im on a TREK FX 7.6 and could use a bit more "granny" on occasion for my local hills.

An upgrade to a long cage deore LX and a 9 speed 11-34 cassette should cost in the vicinity of 100 dollars. Install might add another 50 or so since this will also involve tuning and just for good measure throw in a new cable and chain.

This will by far be your cheapest option. Option B involves the previous upgrade plus a new mountain bike crank.
I have a FX 7.5 with a similar setup of 11-34 and have had good success with the stock rear deralier. There slight noise when in the lowest gear but i don't climb much :lol: or i got stronger at climbing and don't need to shift that low :roflmao2: and still have enough high gears for flats.

I have a FX 7.5 with a similar setup of 11-34 and have had good success with the stock rear deralier. There slight noise when in the lowest gear but i don't climb much :lol: or i got stronger at climbing and don't need to shift that low :roflmao2: and still have enough high gears for flats.


Cool, I'm glad that it is working out for you! What year is your bike and what rear derailure are you running? If it is the same year as Neil's then this might be all he needs to do to get the extra climbing gears he needs when touring. Were you able to re-use the stock chain or did you have to buy a longer one?

Cool, I'm glad that it is working out for you! What year is your bike and what rear derailure are you running? If it is the same year as Neil's then this might be all he needs to do to get the extra climbing gears he needs when touring. Were you able to re-use the stock chain or did you have to buy a longer one?

2007, Sora rear derailure same chain.

The 07 FX 7.5 came stock with a Tiagra rear...still, if you are saying your stock set up is working with an 11-34 then the total price is going to be about 50 bucks.