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What is involved in switching from a double crank to a triple or a compact? Would I need a new derailure, or bottom bracket, or...?
I'm still looking for my perfect road bike. Missed an opportunity to buy an Orbea Lobular from my LBS for a steal. I note there is one on ebay - it has a double chainring (53-39 :eek:) neither a compact nor a triple - I'm sure I'd need either a compact or a triple. It's a 10 speed Ultegra groupo.
thanks,
Best to talk to a mechanic about this. Just depends on your bike and components and what you are looking for. Usually to go from double to triple you will need the new front chain ring, a longer chain and new derailleur plus there are lots of adjustments. Not all bikes can accomodate the change. You could try a compact crank which will give you some more climbing power but you lose power settings.
I looked into going the opposite direction (triple to double) and was told I'd need to get a new bottom bracket and probably new derailluers as well.
I've recently looked at this (double to triple or compact). To go from double to triple, it looks like you need to change the whole groupset, depends on what levers etc. you start with, eg. Shimano Ultegra or DuraAce you need to change the STI levers, the cranks, the chain, the bottom bracket, and prob. derailleurs and even the cables. Plus you need some tools, maybe a crank puller and a BB remover, depending on what cranks you've got on the bike already.
If you go to a Shimano compact double, you may only need to buy the crank as it comes with an integrated bottom bracket (you'd have to check if your 'cups' are suitable), and then i've read you only need to raise the front derailleur 5mm. I'm not sure about what tools you'll need.
The compact looks to be a much cheaper option and will produce almost same results as going to a triple. Depending on what cassette you have, you'll lose a gear at the top end, but if you don't go screaming down hills at 60kph on your big chainring regularly, you might not miss it anyway. The gears you get at the bottom end will also depend on what cassette you put with it. You can use whatever you've already got, but a 12-27 cassette will give you the lowest gears for going up hills.
I've only read up on this as I'm seriously thinking of doing this myself, so I'm not sure if I'm right. I'll go from double to compact double and also change to the 12-27 cassette. I could find when I do it, that it's not so straight-forward.
mags...
Thanks, the replies were what I expected, not what I'd hoped, but what I expected. At least there is maybe the option of going to a compact.
I also appreciate no one pointing out that I can't spell triple. :o
We put a compact crankset on a customers bike recently. He was moving from a traditional Dura Ace 9spd double. All we changed was the crankset, bottom bracket, and new chain. Shimano's compact does not come with a bottom bracket. We made minor adjustments to the front derailleur. Everything works great.
Worked for me except I had to do the painful :D step from Campagnolo Chorus classical double crankset to a Centaur compact. The Chorus only comes in carbon (too pricey)
Works fine for me and my hill performance has vastly improved.
I was perusing the Campy website recently and saw that they make a front derailleur specifically for compact double cranksets. It may not be absolutely necessary, but it had a specific design to handle the large jump smoothly.
Large jump? How do you mean? for the double? Why would the compact require a larger jump than the classic double?
I did not need to exchange mine. I would have had to for the triple I think. It still works smooth, smoother than boyfriend's 105 he says.
My brand new (well 2.5 month old bike) was destroyed last month in an accident. That bike had a compact double on it (Campy Record, if that matters). I picked up the replacement bike at the shop on Saturday. Because of a knee injury from the accident, I went to a triple this time (still Campy Record). It required a different front derailer, a different rear derailer that was a little longer since the chain would have a larger range of motion to deal with, and a longer chain. So, except for the brakes and levers, everything else was different. It did add .6 pounds to the weight of the bike (everything else is identical to the old bike). I would expect that weight difference to be bigger with other component groups, since Record is about the lightest out there.
That all I know on the subject,
Susie
From the Campy website, the Campy Centaur or Chorus front derailleur specs:Quote:
Originally Posted by alpinerabbit
for double standard crankset - capacity 15 - max. chainring 54 - min. chainring 39
for compact double crankset - capacity 16 - max. chainring 50 - min. chainring 34
Alpinerabbit, what size chainrings does your compact double have? I don't doubt that the standard front derailleur would work fine with a compact, but Campy has apparently designed something that works EVEN BETTER with a compact. The difference is in the inside plate of the cage. The capacity in teeth is misleading because the chainring diameter difference would be more noticable in radius.
That's interesting... I read on Shimano's website in their product specs that the unit includes a bottom bracket (integrated). Then when I was looking at buying it on a few online sites, several mentioned 'does not include bottom bracket'. Well I checked again, the Shimano site said it did. I phoned up my LBS and asked them how much etc and asked them whether we'd also need to buy a bottom bracket. He checked and said it was included. So now I'm totally confused.Quote:
Originally Posted by Bikemom
Would you happen to know if the unit you installed was a R700? As far as I can see they only do one, which is fine for both Ultegra and DuraAce.
My bike is totally DuraAce groupset. I was hoping that if it the compact unit doesn't include the bottom bracket, then the bb I have on the bike - a Hollowtech II double crank - will hopefully work perfectly fine on the Hollowtech II compact crank. Is this unrealistic?
Did you have to replace the chain because the bike was 9sp? or is that something that would need to be done regardless.
Thanks....
I ride an Orbea mitis (it's brilliant, by the way). I got it with Ultegra 10spd (53-39 in front, 12-23 in back), and I replaced the front with a 50-36 Bonty carbon compact and a 12-27 cassette behind. All I needed to change was the BB (which came with the crankset) and the chain (same kind of chain, but a new casstte so a new chain). The front and rear mechs are still normal Ultegra doubles, but get a trusted expert to make the adjustments. Now I can climb anything the Scottish Highlands throws at me, and I've used the bike for road racing as well and haven't been caught short with the 50-12 in sprints or descents either. A great way to go. Good luck!Quote:
Originally Posted by TsPoet