[Closed] fitted new front ring on cx bike, shifting is horrid and throws chain over somet

Was it a 46 before? Did you lower the front mech?

yes it was a 46 before, I lowered the front mech and tightened the cable again (maybe too much)?

is it 100% facing the right way - with the pins and cutouts next to the 36t?

Are the chainrings the same in cross section throughout?

Pics should be posted, I'd say. tinypic.com works for that.

the new 44t is on the correct way (text on the outer face) its also positioned correct as I had to fit a nut & washer (which sit behind the crank arm)

maybe I fitted the 36t ring the wrong way? how can I tell

It seems odd that your front and [url= http://singletrackworld.com/forum/topic/new-cableswont-shift-into-smallest-cog-on-the-cassette ]rear[/url] shifting is playing up after a cable change (did you change your front cable as well as fit the new ring?); you're not using brake cables by mistake are you (although I've no idea if this would cause the problems you describe)?

not odd (I usually cock this kind of stuff up)!

I'm pretty sure the correct cables are in place.

front shifting was fine with new cables and old rings.

rear shifting has been dodgy since new cables.

old chain, new chainring, will skip

new chain, new rings, new cassette, new cables.

not sure if the new 44t outer has ramps? if not will this give a crap change?

I think you might be, and please don't take this the wrong way, a ham-fisted spanner monkey.

Take it to t'bike shop.

could be right there!

basically I could have

put the inner 36t on in the wrong position or on the wrong way around

I have positioned the front mech too low or high or twisted it around

I have not put enough tension on the cable or too much tension?

ok just put some more tension on the cable. this has made the change quicker.

I have moved the mech down so there is only a 2mm gap. no more chain throw.

but when changing up the chain moves onto the big ring but it kind of rises up on the teeth at 12 oclock. the chain is seated nicely into the chain at around 3/4 oclock. this is the problem
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I replace the outer on an fsa chainset with a stronglight (cheaper dural) one. I noticed a slight difference in shift quality at first but it was hardly night and day and it soon settled down. (or I got used to it). no: it didn't have ramps but I really don't thinl that had an extreme adverse effect.

of it's overshifting and throwing the chain then I reckon you need to look at the high limit screw and (imo more likely) the front mech angle. is it possibly no longer parallel to the chainrings since you moved it?

That front mech looks like it's not really the same curvature as the 'ring. Google the model no of the mech and check if it's compatible with a chianring of the size. If you've previously had chainsuck and wedged the chain under the front mech it might also have bent it!

If you can be bothered to go through all the steps, [url= http://sheldonbrown.com/derailer-adjustment.html ]this [/url]should get you there.

Failing that, ask a friendly greasemonkey to show you what's wrong and take notes. If you're near Corby I'll be very happy to do it for you for free.

but when changing up the chain moves onto the big ring but it kind of rises up on the teeth at 12 oclock. the chain is seated nicely into the chain at around 3/4 oclock. this is the problem

Once your happy that you've set up the front mech correctly, give it a try and see how you get on.

to it to DJ Cycles near Ramsbottom, he quickly sorted everything out, cheers

Cool. Did you learn why?

what Crikey said!

front shiftings still not great. i have to give the sram lever a good push in-order to make a good change.

if I simply click it it gets stuck between rings.

its like its not powerful enough to make a solid change up

You could try adjusting the limit screw. The one marked H/High - try turning it 1/8th at a time ANTICLOCKWISE.

Try riding that, the shifting should be tested in the smallest, and middlemost sprockets on the cassette, but it wouldn't be fair to expect the shifting to work well on the largest few.

I'd not adjust it more than 3* 1/8th in total, and if you undo it too far it will throw the chain off, and you should do it up again to where it was when it worked better.

With unpinned/ramped Chainrings you may find you have to back off the power substantially, and change by making a well timed "push and hold" with the Shifter.

Good luck.

rode to work on it today, its all good cheers chaps