Gearing on my Trek 7200 Commuter
 

Hello,

I just recently purchased a trek 7200 and have been using it for my 12 mile round trip commute. Im having a great time with it and have put over 200 miles on this month (the first month i've ridden a bike since i bought my car 12 years ago).

I find that I don't use the big chain ring at all. My 7200 came with a 48/38/28 crank set and a 11-32 8 speed cassette. On my biggest downhills i find that I can almost push the 38/11 gear but as soon as it starts to flatten out i need to down shift (about 27mph).

Should i think about trying to find a smaller crankset? Do I just need to ride more and build up more strength?

It seems silly to have a chain ring that I don't use at all.

James
Michigan

You could probably take it off and then adjust the derailleur limit screw to not go that far out. Personally, I'd just leave it. Doesn't hurt anything and you won't be really improving anything. Most people talk about removing the smallest ring. This is a first I've heard the opposite direction.

I suppose I could do that but I don't see the benefit. If I were to narrow the gear range though I would have more options in the range that i actually use. Not just less options. Does anyone know of a narrower crankset?

The problem with making a narrow range crankset would be that deraillers are set up for a certain difference between the number of teeth on chainrings. You might have a tough time getting a 44/38/32 (or similar setup) shifting right although it may work. No one sells such a thing as far as I can tell but you could make one yourself by buying the individual chain rings and bolting them on to your crank.

But, to me, it's hardly worth it. If you ride in more areas, you'll eventually find a big enough hill that you can hold 35+mph on and then the 48 tooth ring will come in handy for keeping your speed up. That same hill might require the little ring to get back up it.

How much of the cassette's range do you use? Do you ever use the little ring either? You could change the cassette to a 12-23 or similar so that you actually use the different chainrings more if this really is a concern of yours. The tighter cassette would allow you adjust the gearing better for holding a certain cadence which can be nice if you like a certain cadence.

27mph in 38/11 on a 7200? My first commuter was a 7200. That must be some hill.

Assuming the above is correct(are you using a properly calibrated computer?),you're spinning too much. Shift up.

Do you use the 28t chainring? You could just go 1x9 (or 1x8 or however many are on your cassette) and free yourself of front derailer concerns. I was seriously considering going 1x9 on my commute (if I could have justified keeping a commuter bike separate from the one I need to pull the kids' trailer to daycare), and it would have been the 39t middle ring I would have kept. I am an advocate of erring on the spinning rather than mashing side.

Coincidentally, the person who bought the bike I would have gone 1x9 on did take off the big ring, but kept the 26t granny.

Ist, by riding more, you will build up strength. Haven't you already noticed that?
A much simpler change is to a different cassette. Maybe a 12-23/26 or a 13-26?
Do you use the small ring?
Look to these links for some of the available cassettes-
http://sheldonbrown.com/harris/k7.html#8
http://aebike.com/page.cfm?PageID=30...ory=556&type=T

Look at this link. It's a gear calculator-(I just use a spreadsheet myself so I can look at various options side by side.
http://sheldonbrown.com/gears/

Thanks for the replies.

I understand about the de-railer movement and how that could get funky with other gear spacings.

I usually use all the sprockets on the back except the 11. I do use the granny gear when necessary, so I don't want to remove that.

I have noticed my strength increasing in just the past month and do see the possibility that the big ring will eventually be useful, it just doesn't seem so now. If I really push I can average 17mph over a mostly flat slightly downhill 6 miles, where a month ago i couldn't do better than 10.

I'll check out the gear calculator and see how this all works out. It almost seems to me that I could loose a couple teeth off each of my front sprockets, get a lower granny gear, and a slightly lower range overall.

dynaryder: Im pretty sure my computer is calibrated correctly. Overall distance over 30 miles is almost spot on as compared to routeslip. Are you saying that is fast or slow? Im confused :)

I'm saying my 7200 was a slow bike. It would take something to push it to near 30mph,especially in 38/11. My Buzz's max gearing is 38/11,and I can spin that out easily on several hills here in DC.

If you really are in that gearing,going that fast,on that bike,then you are spinning way too much and need to shift up. But I'm having trouble believing someone this new to biking(according to your post you've only been riding a month) is going that fast on a comfort bike in that gear. BTW folks,this is what he's riding:
http://www2.trekbikes.com/images/bik...lacksilver.jpg

Just leave it. On the street you're probably always going to have gears you don't use.

I've never used the small ring on my compact double cross bike.