Bicycle Mechanics - Should I purchase a new rear derailleur or . . .?

Thirty years ago, I purchased a Raleigh Seneca Mountain Tour Bike. I think it is a modest, basic mountain bike. I used it to get in shape but hung it in the barn after about three years. I am now 72 and want to get back in shape. I'm telling you this to let you know I'm unlikely to be a competitive mountain biker. I had the local bike shop mount new tubes & tires, and tune up the bike. I have one problem. I don't like the Suntour XC Sport 7000 rear derailleur. It tends to skip rear chain rings when going up hill. My rear speed cassette has six chain rings, the front crankset has three sprockets. Would it make sense to invest in a more recent rear derailleur (and front derailleur) or should I simply clean the rear cassette chain rings and derailleur, adjust everything, and quit griping. What do you think?

you could buy a new cassette and a new rear D while you are at it get a new shifter -and move up to 7 speeds. BUT...

30 years ago is a Loooong time for mountain bikes. you might do better to find a used bike that is just a few years old with less problems - it would probably weigh 20 pounds less that your old bike.

you could fix up your old bike but My personal opinion is your money would be better served buying a modest modern bike.

It's very doubtful that the problem is the rear derailleur. (If it is, it probably just needs lube.)

If the RD is adjusted correctly and the hanger isn't bent (both things that the shop should have checked), then the problem is probably chain and/or cluster wear: a new chain on the old worn rear cluster, or both just worn out. (Did your shop install a new chain?)

Take it back to the shop, tell them it's skipping under load, and ask them to check:
RD Hanger alignment
Chain wear
Rear cluster wear
That the shift cables operate freely
That the RD parallelogram is not binding
That the rear axle isn't bent

This shouldn't cost you since they should have been checked in the previous tune-up.

An outside possibility is a bent frame, but I gather you don't jump the bike all that much. :p


Ride on! :thumb:

It's very doubtful that the problem is the rear derailleur. (If it is, it probably just needs lube.)

If the RD is adjusted correctly and the hanger isn't bent (both things that the shop should have checked), then the problem is probably chain and/or cluster wear: a new chain on the old worn rear cluster, or both just worn out. (Did your shop install a new chain?)

Take it back to the shop, tell them it's skipping under load, and ask them to check:
RD Hanger alignment
Chain wear
Rear cluster wear
That the shift cables operate freely
That the RD parallelogram is not binding
That the rear axle isn't bent

This shouldn't cost you since they should have been checked in the previous tune-up.

An outside possibility is a bent frame, but I gather you don't jump the bike all that much. :p


Ride on! :thumb:

---------------------------------------------------------------------------------------------------

+2 :thumb:

And I'd suggest you take it to a shop to get this work done - if you're not a bike-mechanic. You may need your derailleur-hanger aligned. The RD cleaned and lubed. You freewheel/cassette and chain replaced. And the wheel(s) inspected for hub-problems, etc.

If you can do this and know your stuff - Tally Ho! If not - go to a good bike-shop.

---------------------------------------------------------------------------------------------------

+2 :thumb:

And I'd suggest you take it to a shop to get this work done - if you're not a bike-mechanic. You may need your derailleur-hanger aligned. The RD cleaned and lubed. You freewheel/cassette and chain replaced. And the wheel(s) inspected for hub-problems, etc.

If you can do this and know your stuff - Tally Ho! If not - go to a good bike-shop.

+3
Derailleurs get blamed for a lot of problems that originate somewhere else. Derailleurs are some of the most dependable components on a bike.
DMF said it right.

Al

is Suntour XC Sport really 30 years old? is this like your bike? http://www.mombat.org/1987_Raleigh_Seneca.htm I would look for a suntour 6 spd freewheel and a new chain.

There were no mountain bikes 30 years ago.

Could be my bikes twin. Exactly the same bike.

I could be a year or two off on the purchase date of my bike. I'm now 72 years old and I believe I purchased that bike when I was 42. However, it could have been when I was 44. Still, that is 28 years ago.

OK. My alleged mind is malfunctioning. Take a look at Bianchigirll's post above. The Raleigh Seneca was purchased in 1987 ( that is when the bike was made) when I was 50 years old. Twenty-two years not 30. I stand corrected. Anyway, thanks for the advise. I guess I just wanted a new bike. I purchased an Avalanche 1.0 GT All Terrain w/ Shimano Deore Shifters and Shimano SLX rear derailleuer on Saturday. Very sweet. Had great fun riding this morning.

Now don't give up on your old bike. Still a lot of life left in it. Get it fixed and keep as your spare. You'll need it some day.

you could buy a new cassette and a new rear D while you are at it get a new shifter -and move up to 7 speeds. BUT...

30 years ago is a Loooong time for mountain bikes. you might do better to find a used bike that is just a few years old with less problems - it would probably weigh 20 pounds less that your old bike.

you could fix up your old bike but My personal opinion is your money would be better served buying a modest modern bike.
++++++++
That is what I did. I went to a couple of local bike shops, spent a couple of days riding different bikes and purchased a Avalanche 1.0 GT All terrain with the SR Suntour Mag32 suspension fork, Shimano Deore shifters, Shimano SLX rear derailleur, Shimano Deore front derailleur, and a nine chain ring rear cassette. I have been riding it now for a couple of weeks. Sweet! Much smoother shifting than my previous bike which was my main complaint about the old bike (probably just the difference between six and nine chain ring rear cassette).

I will keep you all posted on my progress . . . weight loss, leg strength, endurance, etc.

Now don't give up on your old bike. Still a lot of life left in it. Get it fixed and keep as your spare. You'll need it some day.

Yes, I am keeping the old bike. It is really in good shape as I took good care of it. If the truth were known, I just wanted to upgrade to a new bike with new technology. Did that . . . Results are excellent.