Project Diamondback...

[RegG]

I have recently agreed to have a look at my partners sons bike with a view to 'getting it roadworthy' again..... It is a Diamond Back Ascent mountain bike, at least 15 years old I believe, fitted with Shimano STX 7 speed gears with triple chainset. As can be seen from the photos, when I picked it up it was in a rather dirty, grimy condition, but with a good clean with Muc Off it is not looking quite so bad now!

There was a few problems to sort out first.....

The freewheel didn't freewheel but a good spraying of GT85 seems to have sorted that one out, as it has the non-moving thumb shifters! I have managed to adjust the front derailleur although it does need a new cable. Brakes are ok, or will be with a new set of pads and possibly cables. Wheels and tyres seem to be ok too.

One problem I have yet to sort out is the rear derailleur - there seems to be some sideways movement in the mech which causes it to catch on the rear wheel spokes when it is on the large cog on the cassette (i.e. the lowest gear). Could this be due to wear or is it likely to be sorted out when I get the gear adjustment fully sorted?

 

[Drago]

Make that more like 20, perhaps 22 years old, going by the componentry. Very nice machines, decent cro mo frames as I recall.

 

[RegG]

Make that more like 20, perhaps 22 years old, going by the componentry. Very nice machines, decent cro mo frames as I recall.

Thanks Drago - I was being conservative in my estimate of age.

 

[Cycleops]

The rear derailleur problem is probably just adjustment. In your third pic down you can see two screws, one is for large cog adjustment,the other for small. If you put it on a stand and turn the cranks you'll see how it controls the movement as you turn the screws.

Check the mounting bolt too.

 

[Ajax Bay]

I have one suggestion for you and that is to replace the cables and outers (likely they will have a bit of rust on after all that time and the insides of the outers will have deteriorated). When you redo the rear gear cable, cut the outer section from the chainstay to the RD an inch or so longer than current. The curve currently is putting strain on the cable as it enters the RD - the curve would be better with a larger minimum radius. But I acknowledge that with all these renovation jobs, there's a tendency to spend more than necessary for an entirely functional bike. Does depend on how much it's going to be ridden and, perhaps, how grateful/discerning the beneficiary is likely to be.
With a good clean and a good fettle, it should be good ride.

 

[uphillstruggler]

I do like the 'bomb proofness' look of these machines.

my Ridgeback 604 looks similar and I like it a lot. probably similar in age too although yours looks tidier than mine.

I hope the young fella enjoys it, and if he doesn't, im sure you could sell it on here as a do it all

 

[Gravity Aided]

Outside of having a single rear braze on for both fenders and rack, it's a good bicycle, IIRC. Top of the sporting goods store level, on a par with basic bike shop offerings over here. Rigid MTBs are quite good at so many things.

 

[RegG]

I have one suggestion for you and that is to replace the cables and outers (likely they will have a bit of rust on after all that time and the insides of the outers will have deteriorated). When you redo the rear gear cable, cut the outer section from the chainstay to the RD an inch or so longer than current. The curve currently is putting strain on the cable as it enters the RD - the curve would be better with a larger minimum radius. But I acknowledge that with all these renovation jobs, there's a tendency to spend more than necessary for an entirely functional bike. Does depend on how much it's going to be ridden and, perhaps, how grateful/discerning the beneficiary is likely to be.
With a good clean and a good fettle, it should be good ride.

Thanks for that tip. I have bought some new inner cables but, as yet, no outers. Will do so though as I am sure the inside of the outers must have gone a bit rusty over the last few years! May be a silly question but are outers for gear and brake cables the same?

 

[Ajax Bay]

are outers for gear and brake cables the same?

No - different calibre and structure (one coiled, one 'straight-longitudinal). Your LBS will sell you the right length of each, and I guess will cut them for you too (make list before you go down there).

 

[RegG]

No - different calibre and structure (one coiled, one 'straight-longitudinal). Your LBS will sell you the right length of each, and I guess will cut them for you too (make list before you go down there).

Thank you for that Ajax Bay - good idea to ask the LBS to cut them to length!

Now for another question......

Can anyone identify the wheel hubs from the photos and tell me what type they are and if they are adjustable, serviceable etc?

They are, I believe, Shimano (thats what it says on them!) and there appears to be a nut at each end of the axle if that helps. Sorry if I am being a bit vague but I am getting on a bit and sometimes have senior moments!

 

[Ajax Bay]

Like this one - yes, they are serviceable. just undo the locknut and you're away (please note my wheel extracted from garage, hence webs/unclean).

 

[RegG]

Thanks Ajax Bay. Can you give me a little more guidance on what the hub type is so that I can google it for possible YouTube videos etc?

 

[raleighnut]

The 'Parallax' hub is one where the non-drive side flange is pulled in more giving much more even spoke tension, it should be an adjustable (cup and cone) bearing set.

 

[RegG]

The 'Parallax' hub is one where the non-drive side flange is pulled in more giving much more even spoke tension, it should be an adjustable (cup and cone) bearing set.

Thank you.

 

[Ajax Bay]

Cup and cone - google "cup and cone hub service"