Have questions or want to discuss cycling? Join Now or Sign In to participate in the BikeRide community.

New: Take Part in the September Giveaway to Win the Luckeep X1 Pro ebike


Changing front crank from 2 rings to 3.
#1
Hi guys,
I'm currently fixing up a friend's bike and his front 2 ring chainset was knackered so he decided he wanted to change it for a 3 ring.

I bought a Shimano Alivio front crank (3 rings). The front trigger shifters had 3 pre-sets already so i assumed it would be a simple swap. However, i'm having problems setting the front derailleur: the jump from the inner most ring to the middle is way too high - it goes from inner to outer and i can't get it to smoothly fit on all three.

Am i missing something here?

Thanks,
Matt
  Reply
#2
The 3 position trigger shifter has to match the spacing of the rings; if you got 8 speed rings you need an "8 speed" shifter, etc for 9, 10, ...

Sounds like you are trying to use a 7 speed shifter with 9 speed crankset, or similar.

I prefer to use straight friction for the front, then if the shifter has enough cable travel, no problems. So an older 5 speed (aka 15 speed) front friction shifter will work fine because it has plenty of travel.
Nigel
  Reply
#3
Hi Nigel,

Thanks for your reply. So to confirm: I'll need a new shifter? The back set is an 8 speed and the front is now 3.
  Reply
#4
Hi Matt;

Yes. You need to know what the front was intended to go wit, if recent: 7/8, 9 or 10 if you are going with a "click" shifter.

For example this set is for 7/8 speed:
http://www.amazon.com/Shimano-FC-M410-Alivio-8-Speed-Square/dp/B000GGV1V0/

this one for 9:
http://www.amazon.com/Shimano-Tiagra-9-Speed-50-39-30t-Crankset/dp/B001GSQNL0/

and this one for 10:
http://www.amazon.com/Shimano-M780-Triple-175mm-Crankset/dp/B0050OG1UO/
Nigel
  Reply
#5
You may also need a different front derailleur. Derailleurs for triple cranks are different than for double. You might try this before buying a whole new shifter set. But you may need both depending on the combination of parts.
  Reply
#6
Thanks for all the replies everyone - as always, the help is greatly appreciated.

I found an old twist shifter and it seems to have solved the problem somewhat. It's still not perfect but the shifter isn't that great (the cable pulls out of position at the shifter end).

I've got a spare Deore front derailleur to see if that improves things.

Thanks again!

Matt.
  Reply
#7
(08-11-2011, 08:28 AM)DaveM Wrote:  You may also need a different front derailleur. Derailleurs for triple cranks are different than for double. You might try this before buying a whole new shifter set. But you may need both depending on the combination of parts.

I do not think that this is the case here, because he says that it will go to the smallest and largest ring okay, just will not go to the middle nicely with the click positions.
Nigel
  Reply
#8
(08-11-2011, 07:55 PM)nfmisso Wrote:  
(08-11-2011, 08:28 AM)DaveM Wrote:  You may also need a different front derailleur. Derailleurs for triple cranks are different than for double. You might try this before buying a whole new shifter set. But you may need both depending on the combination of parts.

I do not think that this is the case here, because he says that it will go to the smallest and largest ring okay, just will not go to the middle nicely with the click positions.

Sounds like you were right.
It's tough to get good shifting on a triple with a double der, but the OP's main issue was the shifter.
  Reply


Possibly Related Threads...

Forum Jump:

[-]
10 Latest Posts
Giant Talon 1,2,3 or 4? Recommendations
Today 06:13 PM
R.I.P. Irio Tommasini
Yesterday 11:41 PM
Third best reason to ride a bent or trik...
Yesterday 11:24 AM
Naming a bicycle - Yes or No?
10-08-2024 06:22 PM
Custom built Virtue 7 city/path bicycle
10-08-2024 04:36 PM
Broken Bottom Bracket
10-08-2024 01:43 AM
COLNAGO SUPER (unknown year)
10-07-2024 10:42 PM
SURVEY: Enhancing Bicycle Experience wit...
10-07-2024 12:50 PM
Help finding out my vintage Biachi model
10-07-2024 12:28 PM
Community Discussion Cycling Myths
10-06-2024 01:23 PM

[-]
Join BikeRide on Strava
Feel free to join if you are on Strava: www.strava.com/clubs/bikeridecom

[-]
Top 5 Posters This Month
no avatar 1. GirishH
25 posts
no avatar 2. Jesper
24 posts
no avatar 3. Flowrider
16 posts
no avatar 4. meamoantonio
12 posts
no avatar 5. Painkiller
10 posts