A good rear mech please

[RecordAceFromNew]

no mate,when i re-adjust the rear mech on the work stand i get all the gears spot on,spend 10 mins or so just peddaling and shifting and get it spot on,then i get out on the road and after a few miles the shifting starts slowing between 2nd-1st and 6th-7th until in the end it just wont go into them.It was a cheap bike in a box and the components are cheap tatt too,have replaced brakes etc and now i really need to get shot of the rear mech,its so frustrating.

I had a similar experience with a cheap (new) bike I looked at. It turned out the manufacturer chose to use brake cable housings for gears. Changed that and the gears worked without any further problem.

IME all Shimano derailleurs, including their cheapest costing a few quids, are serviceable - your problem is unlikely to have anything to do with the rear mech. I would put my money on cable housing issues, including the above as well as how cleanly they were cut/shaped, whether they sit snug in correctly sized ferrules, or whether they have correct type/sized inners etc.

 

[Chris-H]

I had a similar experience with a cheap (new) bike I looked at. It turned out the manufacturer chose to use brake cable housings for gears. Changed that and the gears worked without any further problem.

IME all Shimano derailleurs, including their cheapest costing a few quids, are serviceable - your problem is unlikely to have anything to do with the rear mech. I would put my money on cable housing issues, including the above as well as how cleanly they were cut/shaped, whether they sit snug in correctly sized ferrules, or whether they have correct type/sized inners etc.

All cables replaced with stainless jobbies when i converted to hybrid,still same prob.

 

[Glover Fan]

Yeah, I think he is on about the actual outer cable, not the actual cable itself.

 

[Chris-H]

Yeah, I think he is on about the actual outer cable, not the actual cable itself.

they were replaced too at the same time,i'm certain the outers are the right ones.I think it is just a case of getting a decent rear mech now.

 

[black'n'yellow]

the rear mech will either work, or it won't. It won't work 'sometimes'. Sounds like your problem is elsewhere. I'd put money on either incorrect cable routing, or the cable pulling through the retaining nut...