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-   -   Triple to Compact (https://www.bikeforums.net/general-cycling-discussion/976888-triple-compact.html)

threegz 10-14-14 06:12 PM

Triple to Compact
 
I have a 2010 Trek 2.1 that has the triple that it came with. 60 years old harder and harder to get up hills. I was told I might do better with a compact crank. What parts would I need to be shopping for and not counting labor what kind of money am I looking at. Any help would be greatly appreciated.

headloss 10-14-14 06:21 PM

Why would you want a compact which would have a 34t small ring instead of a triple which I presume has a 30t small ring... I think you are getting bad advice from someone that doesn't like triples. If anything, keep the triple and put the smallest granny ring you can fit!

BlazingPedals 10-14-14 06:36 PM

A compact gets rid of one chainring at the expense of a gear at the high end and a gear on the low end. Do you think that would make hills easier?

I'd stick with the triple.

stephtu 10-14-14 07:04 PM

As stated, compact is going in the wrong direction if you want lower gears. 34 tooth instead of 30 (presumably) tooth smallest ring. To get lower gearing, you can get either a cassette with larger cogs, or a smaller granny ring, or both. You would likely need a new rear derailleur to handle larger max cog + more wrap (mountain bike *9-speed*, even though your bike is 10-speed, because Shimano's MTB 10-speed derailleurs use a different amount of cable pull than is compatible with road STI), and a new chain. For parts cost, shopping online, about $25 for a chain, $45-$65 for a rear derailleur, $30-$60 for a cassette.

qclabrat 10-14-14 07:08 PM

agreed with the other posters, stick with the triple I have 2 myself, compacts are good if you go from regular double down. If the compact are still not working then, I would have suggested the triple.

knobster 10-14-14 07:52 PM

Your bike comes with a 50/39/30 triple and 12-27 rear cassette. That's some pretty low gearing. Don't take advice from whomever told you to go to a compact 50/34. They obviously don't know what they are talking about.

bikemig 10-14-14 08:06 PM

If it's getting harder to get up the hills, get a bigger cassette on the rear like an 11-32. If that doesn't work than get a triple with smaller chainrings. But first swap the cassette as that is more cost effective and see if it works for you.

Caliper 10-14-14 08:17 PM

According to Bikepedia: 2010 Trek 2.1 Triple - BikePedia

You should have a 50/39/30 chainring now and a 12-27 cassette. Do you use the 30/27 currently?

The typical compact double arrangement would involve dropping your 30 ring, swapping the 39 for a 34 and going to a 11-32 cassette to make up the loss of the small ring. You'd end up with a 50/34 chainring and 11-32 or 12-32 cassette for a 34/32 low gear

So, you'd get slightly larger jumps on the cassette and nearly the same lowest gear with less chainring shifting.
But... On the triple, you may be able to go lower than a 30 chainring and could definitely get the same lower geared cassette as a compact double if you need lower gears than what you have now.

bikepro 10-14-14 08:30 PM


Originally Posted by threegz (Post 17217154)
I have a 2010 Trek 2.1 that has the triple that it came with. 60 years old harder and harder to get up hills. I was told I might do better with a compact crank. What parts would I need to be shopping for and not counting labor what kind of money am I looking at. Any help would be greatly appreciated.

If you already have a triple you have a wider gearing range with closer gear spacing than you would have with a compact. I'm not a fan of triples, but if I had a triple and needed lower gears I'd keep it and look for a cogset with lower gearing.

achoo 10-14-14 08:41 PM

If you have a triple, I'll join in the chorus of those saying stick with it. If you need lower gear(s), either get a wider range cassette (if your bike can handle it) or get a smaller chainring.

The reason triples have pretty much disappeared is because with 10 and 11 speed 12-32 and maybe even 12-36 cassettes a compact double crankset gives pretty much the same high- and low-end gearing as triples. And with all those cogs spread over 2 instead of 3 chainrings, there's actually just as many useful gear combinations, maybe even more if you're comparing a new 11-speed compact with an older 7- or 8-speed triple.

threegz 10-14-14 08:47 PM

Thanks for all the great answers, looks like I'll keep the triple and maybe try another Cassette.

knobster 10-14-14 09:11 PM


Originally Posted by threegz (Post 17217595)
Thanks for all the great answers, looks like I'll keep the triple and maybe try another Cassette.

I'd suggest taking it to a bike shop to do this as one you'll need the proper tool to change it, but two, you may need a new longer chain and possibly a rear derailleur. That is if you go with a rear cassette with a large cog of 32. You might be able to get away with a 12-30 cassette without changing anything.

BlazingPedals 10-15-14 06:12 AM

Talking about going to a 50/34 chainring set and then changing the cassette to make up the lost gears is a red herring; because as others have pointed out, you can change the cassette out by itself, in which case you wouldn't be restoring lost gearing you'd be increasing your present range. Many people find that they have to shift the front more with a compact, because there's less gear overlap between rings.

I regard compacts as a half-solution where a full solution already exists.

doctor j 10-15-14 06:26 AM

I changed the granny ring on my triple from a 30 to a 28. That was a good move. For a long time, I ran a 12-28 cassette. Recently, I changed the cassette to a 12-30. That was a good move as well.

Retro Grouch 10-15-14 06:34 AM


Originally Posted by BlazingPedals (Post 17218174)
I regard compacts as a half-solution where a full solution already exists.

:):):)

StanSeven 10-15-14 06:41 AM


Originally Posted by achoo (Post 17217586)
The reason triples have pretty much disappeared is because with 10 and 11 speed 12-32 and maybe even 12-36 cassettes a compact double crankset gives pretty much the same high- and low-end gearing as triples. And with all those cogs spread over 2 instead of 3 chainrings, there's actually just as many useful gear combinations, maybe even more if you're comparing a new 11-speed compact with an older 7- or 8-speed triple.

Good info and explanation. I didn't bother to think about the more useful combinations with compacts and 10-11 speeds now.

spdracr39 10-15-14 06:53 AM

Just changing to a compact front will not make you a better climber in the short term. Long term it will make you stronger thus a better climber but I don't think this is what you are looking for. Stick with what you have or change the rear cassette for something with a lower granny gear if your rear derailleur will handle it.

Darth Lefty 10-15-14 07:10 AM

There are lower-than-road gears available. 9-speed mountain bike cassettes go down to 36. You need a 9-speed mountain derailleur to go with it. Trekking and MTB triple cranks have inner rings that range from 22 to 28. 22-36 is a lot lower than 30-27

fietsbob 10-15-14 08:56 AM

Yea, think Mountain compact triple, all 3 chainrings are smaller . like 22-32-44t..


Cost?
I could ask my LBS what they would charge, (not including shipping 2 ways) IDK what your LBS has for operating expenses .

Wilfred Laurier 10-15-14 10:10 AM

Before the current riding season I swapped my road triple (52-42-30) for a mtb triple (44-32-22), and the easier spinning was such a joy that I rode more this year than I have in a long long time. Although I occasionally wished for a little more on the top end.

fietsbob 10-15-14 11:29 AM

44:11 always seemed high enough in a large wheel bike.

mcmoose 10-15-14 11:39 AM

I was able to go from an 11-28 to an 11-32 on my 9-speed Sora triple without having to replace the rear derailleur; only had to replace the cassette and chain. This gave me the great-granny gear I needed for some of the steep climbs around here.

I agree with the others who suggest taking your steed to the LBS and seeing what can be done with your rear cassette to give you the torque you need. But, no, a compact is not the answer.

Wilfred Laurier 10-15-14 11:48 AM


Originally Posted by fietsbob (Post 17219141)
44:11 always seemed high enough in a large wheel bike.

That was my top gear, and with 700X38c tires (a little extra diameter there too) I could hit ~60 km/h before I was spinning too fast to keep up. The frame broke a few weeks ago and I have a replacement in the back of my car for whenever I get a chance to build it up - then I will go for some higher speeds :)

fietsbob 10-15-14 12:07 PM

I coast down hills and use my brakes to keep my speed down, having memories of many weeks spent in a cast, healing broken bones ..

so I get to see my 68th birthday, (a week from today)

Retro Grouch 10-15-14 12:33 PM


Originally Posted by fietsbob (Post 17218618)
Yea, think Mountain compact triple, all 3 chainrings are smaller . like 22-32-44t..

Everything on a bicycle works together so you might run into some other issues. A road front derailleur might not work so well with the mountain crankset. You could switch to a mountain front derailleur but then the road bike front shifter will be a problem.


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