Where to buy rear derailleur for Saracen Hardtrax?

[Transporterman]

I'm new here so hello everyone. I was wondering if someone could help me with buying a new rear derailleur and chain for my old Saracen Hardtrax. I must be honest, the bike lives in Spain and and gets ridden anywhere (even on the beach!). Really it's a tribute to the original quality that it taken so much abuse for 18 years!

I think the gears are Shimano rapid fire 21 speed. I after something as cheap as possible because the bike is in such a state, but it still goes perfectly.

I told you it was bad!

 

[Drago]

Christ on a bike, that's an old 96-98 Altus mech, hideous thing. Time to to surf the likes of Evans for an upgrade. Any 7/8/9 speed Shimano mech of comparable cage length should bolt right on an index up nicely.

A new chain and cassette probably won't go amiss either.

 

[Hugh Manatee]

Welcome. Well, it certainly could do with new jockey wheels! If you didn't know, they are the little plastic toothed wheels in the mech itself. Most Shimano stuff from that era could be taken apart. Yours appear to be held together with 8mm bolts. I would try that first.

 

[Transporterman]

Thanks for your speedy replies. I'm not sure about the cage length because I'm back home here in sunny (not!) Cornwall now. I read there is some way of knowing which cage length to use by the number of gears or something but I didn't really understand the explanation. If I buy the whole mech it should come with the two cogs shouldn't it? I'm hoping I can use one of the dirt cheap basic mechs. I even saw some at £12!

The problem was that the fixing (allen bolt) was loose and even when I tightened it up it is still wobbly compared to my wife's Marin and no matter how I adjust the mech or cable the chain catches the spokes in low gear. Also changing up from high to low takes about 3 pulls of the lever. If I tighten the cable it won't get the lower ranges.

Thank you both again and to Shaun for allowing me a pic on a first post.

 

[raleighnut]

Any basic shimano that bolts on should do it, just avoid the really cheap ones with a built in (non removable) hanger.

Oh and get one for an MTB, they're all the same length it's only road bike ones that are shorter.

 

[Transporterman]

I'm getting a bit confused.. Does this sound about right? I think I need a medium cage because the nice cheap short cages only fit MTB's with a single cog at the front. Also, I can't use mechs with the fixed bracket raleighnut mentioned because my mech bolts directly to the frame with no separate hanger so the fixed bracket versions won't fit. This seems to limit the choice for nice cheap £20 mechs. I'd buy something better if the bike was in decent nick but I just need to keep it going for a couple of years.

 

[Drago]

Oh and get one for an MTB, they're all the same length it's only road bike ones that are shorter.

Shimmy MTB cages come in different lengths for otherwise identical models.

 

[Dogtrousers]

To figure out if you need medium or long cage, calculate the required capacity of the derailleur. This is (Biggest chainwheel teeth + biggest sprocket teeth) - (Smallest chainwheel teeth + smallest sprocket teeth). ie the difference between big-big and small-small. Then look in the product technical info and see if it has sufficient capacity. Or, as it's just for a hack, go for long cage anyway.

Would something like a Shimano Alivio mech do? I bought one a couple of years ago for about £20. Dunno if it is still available. It screwed on (ie it didn't have a built in "claw" bracket.

 

[Transporterman]

I'm less confused now! The Alvio does look like it would work but it does look a bit long. I'd like to work it out properly as per Dogtrouser's instructions but I have no access to the bike to find out how many teeth the front sprocket has. I think I am going to risk a medium cage like this one

As you can see from my avatar the bike often gets well loaded up! I have to lift it over big kerbs/rocks sometimes so l think I would keep hitting the longer mech.

Thank you all once again for your help.

 

[Nigelnaturist]

This is not the highest level of R.D.'s Shimano but would be a direct replacement.
Shimano Rear Gear Mech Derailleur Tourney RD-TY21

There are adaptor drop outs so you could use any modern R.D. but can't see suitable one at press.

 

[raleighnut]

This is not the highest level of R.D.'s Shimano but would be a direct replacement.
Shimano Rear Gear Mech Derailleur Tourney RD-TY21

There are adaptor drop outs so you could use any modern R.D. but can't see suitable one at press.

The frame has a integral dropout (Steel frame) but the Tourney would be my idea of the appropriate level of replacement.

 

[Dogtrousers]

As you can see from my avatar the bike often gets well loaded up! I have to lift it over big kerbs/rocks sometimes so l think I would keep hitting the longer mech.

I honestly wouldn't worry about that. You'd have to be in a very weird situation, or have some very odd panniers indeed, where the long cage would hit/catch on something, but the medium wouldn't.

 

[Nigelnaturist]

The frame has a integral dropout (Steel frame) but the Tourney would be my idea of the appropriate level of replacement.

Yea I know, and the link is to a direct bolt on.
I had an Acera which did no more than 12,000 miles and thats one level up from the Tourney so I was merely trying to point out the durability may not be so high as older components may have once been, wasn't fully awake or rather not enough coffee.

 

[Nigelnaturist]

A current Altus on amazon direct bolt £10.49

 

[Transporterman]

Ah, I looked at the Tourney because my wife's old Marin has that but I didn't realise you could get the direct bolt on version.

I keep the bike in Spain and there is a huge (anti-flood thing) kerb I have to get the loaded bike over and despite lifting the back a bit it often catches the cage slightly so I thought I better not go any longer just in case it gets damaged.