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Move compact gearset to a triple

Hi there,

I've got a bit of a rookie question. I've got an old road bike from circa 2004 that I got pretty cheap (250euro) but seems to have some pretty good components on it. My dilemma now is that I've got a new touring bike but couldn't splash a lot on it. I'm not using the old road bike anymore so I was wondering if it's possible to take the shimano ultegra gearset (which us a compact) off the old road bike and replace my shimano sora gearset on the new tourer (triple crank) with it. The compact is a ten speed and the new tourer is a 9 speed.
Any help you guys could give me on this would be great!

If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.

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7 comments

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bashthebox | 8 years ago
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2004 Ultegra could very likely be a square taper BB, I've got a bike of that vintage that is.
Actually I imagine your most pertinent question is to do with gearing and the sort of riding you might be doing on your tourer. Currently I imagine your smallest gearing is something like 30 on the front and 27? 28? on the back. With the compact and Ultegra mech it might be 34/28? Unless the mech is long cage you won't be able to put a bigger cassette than that on it. So I think you'd be better off with a fully laden bike going up hills with the Sora.
You'll get far nicer shifting and stiffness on the Ultegra, of course. Plus a compact is easier to maintain than a triple.
There's good arguments for either!

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alotronic | 8 years ago
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Yes, but you would need to swap everything, right down to BB and cassette. And recable eveything. You would certainly learn a lot.

But why? A sora tourer with 27 speeds sounds like a good solid bike.

I would look at buying a second hand or cheap racing/sportive frame and transferring the Ultegra to that - then you would have two bikes, one 'fast' one 'slow'. and you would still learn a lot AND have a functioning bike at the same time.

Two bikes are better than one, it's a (cycling) fact  3

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CXR94Di2 | 8 years ago
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Swapping or modifying can be rewarding but not alway perfect.

My best mod has been on my mtb bike, I converted it from a single 34t crank to a 36,22 front derailleur setup. Made the bike wholly more enjoyable with go anywhere gearing.

Worst was converting wife's bike to a front derailleur setup to help her on the hills, never worked quite right, well did when I changed gear. She manages to drop the chain repeatedly  1

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mike the bike | 8 years ago
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I just love this kind of Sunday morning challenge, sad or what?

Basically, most things are possible but not necessarily desirable, only you will know if it's worthwhile. In the meantime some tips ......

The Sora and Ultegra BBs could both be HollowTech II, which means a straight swap might be possible, if you have the relevant tool, which is cheap to buy. Have a look at the (silver or black) bearing cups that sit next to the BB. Do they look similar? Bear in mind that later Ultegra cups are of smaller diameter.

Fitting a double might put your chain line a few mm out. Would you notice?

The old rear derailleur is probably a long one. You don't need that but it should work with the compact.

The old left shifter has three positions and you will only need two for the compact. This could lead to problems or it might work with careful use. But will you be careful after fifty tiring miles of your sportive? You might get a cheap shifter on ebay?

The 9-speed/10-speed compatibility problem leaves you facing the fact that it's the lever that controls the number of gears. With the old 9-speed lever you cannot get 10 gears. But do you need them? Or could you swap the right levers too? And will the 10-speed cassette fit your existing freehub?

What a wonderful Sunday you will have!

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Bedfordshire Clanger | 8 years ago
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Hi Jules,

Yes, you'll do the cranks with the chainset. You will have to. As for whether it's worth it, you are in a great position to decide as you have both bikes. If you do it ,you'll learn a lot about doing your own maintenance which is a good thing in my opinion but if you really don't notice much difference between the two when you are out riding then why bother? It's always handy to have a least two working bikes as far as I'm concerned. A second bike is always handy for riding in bad weather, locking up for long periods outside, borrowing spare wheels in an emergency or using if there's something wrong with your other bike.

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Jules85 | 8 years ago
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Great thanks. Would I have to change the crank to a compact too? Is the ultegra gearset that much better than the sora that this whole process is worth it?

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Bedfordshire Clanger | 8 years ago
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You can do it but you'll need to swap the lot for best performance - levers, derailleurs, cassette and chainset. If the front mech is a band on then you'll need the seat tubes to be the same diameter or you'll need a new band or new mech. You may need to replace the bottom bracket if the one you have doesn't maych your chainset. I take it that both bikes have rim brakes.

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