Dawes Galaxy replacement sprockets/derailleurs

[Mikey7094]

Hello, I've never used this forum before but was hoping I could find some tips for improving my old bike.

I believe it's a Dawes Galaxy but I'm not quite sure. Basically, it won't stay in gear, and I suspect this is because the sprockets and/or chain are very worn. Also, the rear derailleur doesn't seem to keep the chain taut. I've attached some pictures to illustrate all this.

I'd like to replace the sprockets and derailleurs, and I was wondering whether you can still find parts that will fit. I've found some parts on ebay - I'd write the links but it doesn't seem to let me. Typing Dawes Galaxy into ebay gives a few bits and pieces - will any of these fit? Ideally, I'd like to replace the current gear set with something a bit more modern, that's more likely to work for longer. Are there many options as to what will fit?

I have some mechanical experience of cars but I'm no expert on bikes, so any help would be appreciated.

Mike

 

[Mikey7094]

Here's another picture - sorry they're all so huge!

 

[Rich34]

First thing it all needs is a good clean by the look of it! There shoudn't be that much oil/gunk all over everything. I have a Galaxy and mine's a '76 model I think, it has Simplex derailleurs and a Nervar chainset, which look like yours. If it's jumping out of gear it might be the cable tension - the teeth look alright from your photos. The cable to the rear derailleur looks to have an odd-shaped bend, probably worth replacing the cables. If the chain is slipping as you pedal that would indicate that it and the teeth are worn but they have to be badly worn for that so I'd suspect cable tension first. Like with cars and motorbikes, best to eliminate the simple stuff first.

As for the derailleur keeping the chain in tension, if you Google "chain tension" you should get some info and Sheldon Browns site (can't remember the name but try putting his name in) is good if you can't find it elsewhere, or here.

 

[hamster]

The derailleur cable outer is way too short and I think that's the problem. You need a new outer to give a longer and more graceful bend. I'd bin all the cables (brake and gear) and start again anyway.

If I see the photos right, those look like a very nasty cheap set of wheels - pressed steel hubs, rustless spokes and I think steel rims. Steel rims always have appalling braking performance, especially in the wet, so you should look to replace them. With cheap hubs like that you are better off with new wheels rather than building onto the existing hub.

I don't know enough about Dawes frames to say if it is a Galaxy.

 

[Mikey7094]

I can vouch for the appalling brake performance - I just never go out in the rain. I don't want to spend too much on it at the moment, but one day I'll replace the wheels altogether.

Thanks very much for the help - I will certainly get some new cables, and that Sheldon Brown's website looks very good.

One more thing - I've noticed there is some play between the pedals, in that you can hold one still and move the other one. I've attached another picture (which I've scaled down this time) which shows one of the pedals hanging limply out of line with the other. Does this mean the shaft is knackered?

 

[hamster]

It might be that the bottom bracket has gone, alternatively the cotter pin in the crank might need tightening. Typically if the pin gets a little loose it then gets a dent worn in it, which will need to be filed out.