Bicycle TutorBicycle Tutor

Show off your bike!

Related video tutorials:
How to Adjust Your Front Derailleur How to Adjust Your Front Derailleur
* Now with 3D interactive instructions
Marathon rear derailleur upgrade
#1
Hi everyone,
I have an old raleigh marathon mid eighty's manufacture I think.
Long story short my son borrowed the bike, and broke the rear derailleur.
The front derailleur is marked suntour 7 the rear only says suntour and really looks cheap, not to mention it is broken into two pieces. It is a 12 speed bike and I really want to get it back on the road. My question are do I need a long cage derailleur and how do I determine what will fit.I guess I want to know what my options are.
Thanks In Advance
Brett
Reply
#2
I would first start by checking SunTour's web site to see if that model is still being made. Here is the link to their site: SR Suntour. If they don't show the dérailleur group on their site, do a Google search to see if there are any available and also to see if there are any specs on them so that you can match it with a different dérailleur.
HCFR Cycling Team
Ride Safe...Ride Hard...Ride Giant
Reply
#3
I called Suntour first. I think you people know more about the products they make than they do. They can't do any thing with out a part number I will try and post a couple of pictures later. Hopefully you can tell me if it is a long cage derailleur.
Thanks For the Response
Brett
Reply
#4
You may not need a Suntour derailleur. If the shifters are indexed (click into gear shifting) then you need a Suntour or compatible derailleur. (I think you could probably get away with a Shimano, but am not sure on 6 speed). If it's friction shifting, it doesn't matter what brand derailleur you get.

You should probably get a mid to long cage derailleur. You don't want one of the really tight short cage high end racing bike ones. They are made for very tight gear ranges.

You also need to check if your derailleur has a hook that clamps under the axle nut or if it screws directly into a built in hanger on the dropout.
Reply
#5
Long cage derailleurs are meant for use with a triple front crankset.
( the long cage is to take up the chain slack between the large and small "granny" ring).
As you have a 2 x 6 setup you only need a short/medium derailleur unless you expect to change to a triple crankset in the near future.
Being a mid eighties bike I would think you have a friction shifter changer so any make ( Shimano or other) will suffice.
Get one that will deal with 8 speed or less to accommodate the chain width that six speed uses.

What DaveM is asking "does your old derailleur have a hanger with a "hook" fitting as shown on this one"? :-
http://www.sjscycles.co.uk/sunrace-m2t-6-7-speed-rear-derailleur-with-hanger-long-cage-prod23545/

If so you can get a hanger that will adapt a standard screw type derailleur to fit your frame.:-
http://www.sjscycles.co.uk/shimano-rear-gear-hanger-bracket-fixing-bolt-prod406/

A last requirement - how many teeth are on the largest sprocket at the back? If above 28 teeth then go for an MTB derailleur if below then a "road" version will be O.K.

Have a trip down to your LBS and see what they have to offer Smile
[font=Trebuchet MS]Ride hard or ride home alone![/font]
Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  SRAM rear derailleur arm length jacke 0 1,631 06-28-2017, 04:52 AM
Last Post: jacke
  Road Bike Rear Derailleur Problem Lighttower 5 2,761 05-19-2017, 01:01 AM
Last Post: painkiller
  Rear derailleur rolling chain off It's your boy 0 4,148 06-05-2016, 04:36 PM
Last Post: It's your boy
  What would you use to replace a Suntour alpha 3000 rear derailleur? eab 5 4,963 08-09-2015, 04:33 PM
Last Post: nfmisso
  Replacing old rear derailleur eab 3 8,631 05-14-2015, 09:55 PM
Last Post: DaveM
  What if your new rear Dérailleur nordog 3 3,768 05-08-2015, 12:30 AM
Last Post: nfmisso
  Rear Derailleur Suicide Into Spokes. fribbles 5 5,333 04-25-2015, 05:22 AM
Last Post: nfmisso
  what Rear Derailleur hanger do i need pastaman06 0 4,442 04-24-2015, 08:36 AM
Last Post: pastaman06
  Rear Derailleur.. I have no idea what I'm doing jjc5 4 5,034 04-13-2015, 03:38 PM
Last Post: elmore leonard
  SRAM X9 - Rear Derailleur Pulley - Wobbles columkelly@yahoo.com 2 5,059 03-24-2015, 03:07 AM
Last Post: fredbyte

Forum Jump:



ISSN 1918-3445 © Copyright 2007-2010 Bicycle Tutor / Privacy Policy / Created by Alex Ramon

feed