Reduce the size of inner on compact double?

[scraynes]

Hi all,

Just wondering if any off you know if I can reduce the size of the inner chainring on my compact double setup.

I've currently got a 34 inner but would like to reduce it to a 30...some of the hills round here are not nice!!

I have found a 30 chainring from CRC but it's for a triple, but could I just fit that.

I know it might have a knock on effect on the chain, because I'll have increased by 4 links, but that can be solved by changing the cage length on the rear mech.

Thanks in advance for you help,

Spencer

 

[Glover Fan]

Assuming your big ring is a 50, that sound like a massive jump to make. dunno whether it is possible, but not sure I'd want to do it.

What cassette are you running on the back?

 

[2Loose]

The max difference between rings is 16 teeth apparently, so if you reduced your inner ring, you'd need to reduce your outer ring or the front mech wouldn't be able to handle the jump. Changing rings is possible, but some compact chainsets won't allow you to go any smaller than 34.

What model chainset do you have?

EDIT: If you are prepared to change the rear mech\cage, then could you get a cassette with more teeth instead? Cheaper and easier imo.

 

[Will1985]

110bcd (compacts) will not take anything smaller than a 33t ring. You could possibly use an MTB chainset with a 104bcd but it would depend on finding suitable big rings and the right bottom bracket length (or shimming if using Hollowtech cranks). You're better off getting a cassette with a bigger spread.

 

[scraynes]

Thanks for the replies.

I should have mentioned that I'd changed the cassette from 27 to 28, not a massive difference but did help.

Ideally I'd like the inner to be 32 but can only find 30. The outer is 50, so I agree 30 to 50 sounds too much and I hadn't really thought about the jump.

Maybe I need to look for a 30 on the back, or loose a bit of weight ;-) but that will take some time.

My general route has a hill that's about 12% for about 220 metre climb which just kills me, I can't keep the cadence up it it becomes a grind - which would be nice to overcome.

Looks like my idea of a smaller inner is a non starter, can't get a large rear, so just going to have to beat it!

Thanks again.

Spencer

 

[Glover Fan]

Is be inclined to just keep at the training, it does get easier eventually.

 

[MacB]

Yep, you've got to look at the BCB(bolt circle diameter) of any ring to see if it will fit, a compact is normally 110 and that would mean a smallest inner of 33t. You can do it but you'd need to get a triple and mount your two rings in the middle and inner position. I run a 24/40/Bashguard on a triple chainset for road use, but it takes a fair bit more than just buying a replacement chainring I'm afraid. I also have friction thumb shifters so don't have to mess about too much re front mechs.

 

[YahudaMoon]

Hi. I have the same problem as Scraynes.


Anyone tried something like this. I think it allows you to convert a double chainset into a triple ?

http://www.sjscycles.co.uk/thorn-130-mm-pcd-double-to-triple-conversion-chainring-38t-prod9736/

 

[Hacienda71]

I was glad of my triple this morning going up Pyms Chair. 24.6% at its max

 

[YahudaMoon]

Lol. Did you go up past Jenkins Chapel or the easy way ?

Edit (Easier way)

 

[Hacienda71]

Jenkins Chapel. Windgatherer is nice but I wanted more of a challenge.

 

[YahudaMoon]

Last time I went up Jenkins Chapel towards Pyms Chair I dismounted and walked the last 50 metres >>>>>>>>>

Dam compact !!!!!!!. I had just done 190km though. Still annoying.

I can't remember the audax its on though I dread Jenkins Chapel every time. It's a ba**** after 190km

 

[david1701]

550' climb @ 12% is (just) within my reach to tackle out of the saddle in the middle ring (42:32), thats my climb into the village on the way home. You might find that its a hill you can just attack and beast up it if you force yourself too which should make the whole climbing thing a lot easier on every hill?

 

[Ian 74]

I ran a 53/34 for a while. It was a bit of a drop from the big ring to the 34 but it still shifted smoothly and when needed. Then went to 53/39 smashing.... Big day in the mountains tomorrow so I'll tinker it back to 50/34 when I finish watching the vuelta.... Had a look on ebay and couldn't find a 30 110 bcd ring.

 

[Hacienda71]

Last time I went up Jenkins Chapel towards Pyms Chair I dismounted and walked the last 50 metres >>>>>>>>>

Dam compact !!!!!!!. I had just done 190km though. Still annoying.

I can't remember the audax its on though I dread Jenkins Chapel every time. It's a ba**** after 190km

Lol it is mmmm challenging. I can't claim to have ridden more than 20km before I got to it though. Thought it would be good prep for the Macc Monster in October.