Upgrading Cranksets/Chainrings

I'm confused. 30/14 is a *higher* gear than 42/25. It seems like you should be able to find a gear for the 9/10% grades with what you've got.

Aside from the curious gearing math, I think you should just replace the 42 with a 39 and leave the granny in there. Why bother blocking it off? You'll use the 39 a lot more than the 42, and likely use the 30 a lot less, but you'll still have it. If you really want to lock it out, I suppose you could just crank the limiting screw in, assuming it'll go in far enough to lock the gear out totally.

As far as the parts go, that might be tricky. I'm searching for chainrings for you, but I think you need rings designed for the triple crank's bolt pattern. If this is correct, then this is going to take some searching, because the only 39t triple ring I can find is a Dura-Ace, at $49. All the Ultegra rings I've found are 42t and not 39t.

I'll look some more, and post if I find anything else.

Found something.

I think your crank is uses a 130mm bolt pattern. If so, I've found a less expensive 39t ring for you here.

Scroll down in the list to:
39/130
Reg $16.95
now $12.95

Hope that helps.

wildearth2001 said:

I have a 2003 Shimano 105 triple crank (30/42/52). I have found that on steep climbs 9/10%+ that 42x25 is not low enough of a gear for me to keep my cadence up and that even 30x14 is way to low to keep my speed up (and since I race, speed is the key part) and I end up spinning around 120rpm and still not going anywhere. I would like to replace my 42 with a 39 and then remove the 30 and just block out the derailur so it doesnt toss the chain into the bottom bracket.
1)Where can I find shimano chainrings for a decent price.
2)What would the cost of the new ring be compared to just getting a double crank?

I have very little money and I am looking for the cheapest, effective, way to get this gearing fixed.

Question / suggestion
why not change the cassett to say a 14-28
seems to me it might be less drastic of a change and maybe smoother for ya

Ok thanks for all the help you guys are giving. Let me clarify a few things.
1) I didnt realize it when I was typing but yes 30x14 is higher than 42x25
2) My cassett is a 9speed 12x25 (with the 12 and 13 cogs blocked out for junior gears, so its like I have a 7speed)
3)I am not quite sure how to measure the bolt pattern (I have a 5 bolt crank, if it makes a difference)
4)Another reason I would prefer the 39t in place of ther 42t instead of using the 30 and the say 15or14 is the shifting. I hate shifting into the triple because you also have to shift 2 or 3 cogs on the back. Maybe I am just using a bad shift pattern, can anyone suggest a good pattern for shifting in and out of the small ring?