advice needed on front changer???

[naffets]

hi i have an old brian rourke frame dating late 80s and it has a braze on fitting for the front mech i need a replacement front mech do i need to look for a braze on one only? also it needs to operate a six speed cassette any advice welcome
cheers stef,

 

[Jonathan M]

Has the frame been restored, or are you planning to get it repainted?

If your plans are to get a new paint job then a good frame builder should be able to remove the braze on. If you just want to use it and stay retro, then get a braze on fitting mech.

If you plan to use a compact chainset at all, then you'll have to get the braze on removed, as sometimes the braze on can be too high for a front mech to work with a compact chainset.

 

[Globalti]

I was able to use a compact 50/34 chainset on my 1990 Harry Hall with a braze-on derailleur. The derailleur was mounted right at the bottom of the slot.

One benefit of a braze-on is that it's easier to fit certain types of chain-drop devices.

 

[MartinC]

Yes, you need to check the height of the mech hanger. Usually they're just OK. In the eighties the builder will've probaly set it so that you could use a 55 tooth chainring for a TT and this normally turns out alright for a compact - just.

One other thing to watch for (and it won't apply if you updating to a modern crankset) is the old cranksets need old front mechs. Old ones have straight cranks with the crankarm close to the chainring and old mechs had staraight plates that fitted between easily. Modern mechs have bent plates and there's room for them 'cos crank arms bend outwards too. If you use a modern mech on a old chainset it can foul on the crankarm.