Gear Problems.

TheModCon

I'm having trouble changing from the small chainring to the large chainring (at the front). The derailleur doesn't push the chain up onto it.

Could someone please tell me how to sort this.

Thanks.

GavH

Could be a couple of things but most likely is the setting of the H and L screws which are the two screws on the top of the front mech. One sets the limit to which the mech will move towards the frame (L) and the other how far out it will move when pushing the chain onto the big ring (H).

Setting up a front mech seems to be straightforward in principle but a bit of a black art in practice. Try googling it or use the search function on here but TBH your best bet is to try searching for a video on YouTube, you'll be surprised at how good some are and you'll have it sorted in no time. Failing that, try taking it to your LBS as it might be a problem with the shifter or the cable. I've been having nothing but problems with my front mech and it turned out to be down to the mech being bashed out of shape of all things.

Smokin Joe

The first thing to check is the cable tension as this can go slack over time. When the chain is on the small ring turn the DT barrel adjuster until the cable loses any free play and it will work again. If your bike does not have a barrel adjuster then undo the clamp bolt on the mech and pull the cable through then retighten.

oldwelshman

Lift the back wheel off floor, then with chain on small ring, do not use the shifter to shift up, just pull the cable where it runs down the down tube. If it shifts up ok it is cable tension and t=not the limit screws, if it does not change it is the limit screws. If it worked before it is unlikely to be limit scres and more likely to be cable tension as it stretches, especially if new.

TheModCon

Thanks for all your info, I'll have a look later and see if I can sort it.

I had this problem recently, putthe bike in for a service and it was all sorted but it's come back again, I don't know if this suggests one problem over another.

Thanks again.