Singlespeed Project

[ededwards]

Notwithstanding the comments above about it being a shame to split such a nice period example, if you do experiment ss with it then just keep all the bits and you can easily revert back.

It also looks like you might have enough fore/aft adjustment on the semi horizontal dropouts to not need a chain tensioner (I'd use a nutted axle rather than a q/r skewer though as I doubt you could get the latter tight enough not to slip. Changing the axle would be a simple/cheap job for your LBS).

 

[oaep7]

Thats the thing ededwards I have all the stuff from the frame and if I dont get on with the whole SS thing I will just clean it all up and put it back together.

It does look like it has enough movement at the rear dropouts but there is actually no room for movement, and the rings are biopace so I would need a tensioner anyway I am thinking.

 

[ededwards]

I'd suggest using a regular round ring for the experiment as I'd have thought Biopace ss would be very weird and it would be a shame if that put you off

 

[letmetalktomark]

I'd suggest using a regular round ring for the experiment as I'd have thought Biopace ss would be very weird and it would be a shame if that put you off

Pah! Mr Edwards knows nothing ( ) Only joking!

I ran a 48 x 16 set up which had a biopace front ring.

Due to the eliptical shape of the ring I found I didn't need a chain tensioner

Ed is right though about biopace feeling a bit "Weird" but it worked well for me :?

Here was how the bike was set up:

http://www.retrobike.co.uk/forum/viewtopic.php?t=13986&highlight=

Mark

 

[oaep7]

Would the chainring bolts from the little chainring be ok to use would they be the right size?

 

[one-eyed_jim]

Would the chainring bolts from the little chainring be ok to use would they be the right size?

No, unfortunately not. The problem isn't the bolts so much as the 'top hat' nuts, which are too long for a single ring, and bottom out before they're tight. In a pinch you can file them shorter, but single-ring bolts are neater, simpler, not expensive, and widely available.

If you've got an old, worn out chainring, you can cut off the tabs to make spacer washers, but that's a penny-pinching 'ghetto' fix.

 

[messiah]

My first mountain bike was one of those and it was early 1989 I think. I had the money but I remember waiting a few months because I wanted a Rockhopper with the first of the 7speed Hyperglide cassette's and without the dreaded chainstay mounted U-brake. It was worth the wait and lasted me a good few years - cracking bike BITD.

Build it and use it... in anyway.

 

[oaep7]

Anybody know what chainring type I need to get for this - bcd? its an old LX crank, and wheres best to get the short singlespeed bolts?

Cheers

 

[nimbus]

Chainrings are almost certainly 110/74mm BCD (diameters of the circles formed by the outer and inner bolts on the spider), also known as '5-bolt ATB'. You should find a set of single ring bolts on ebay for about a tenner posted. New chainrings in that size are a bit rarer; try looking for road/touring rings from Stronglight or Specialites/TA.

Your bike looks quite similar to my 89 Rockhopper Comp, although mine is/was grey with pink decals. If you decide to keep it as a singlespeed and want to sell any of the bits let me know.

cheers

 

[doctor-bond]

How are you getting on with this?

I've set my Stumpjumper up as a two speed and would heartily recommend it. The added lightness really improves feel and handling.

I can see the point in a single speed fixed but am too scared to go for it; but if you are keeping a freewheel, then two speeds let you go up and down hills which is what Rockhoppers were meant to do.

You can keep your rear hub and use a cheap spacer kit; the rear mech will take up the slack or you can get a singulator thingy; don't know what your front rings are but I use an 18 rear cog and 44t 32t front set up [just took off the inner ring] and my old knees seem to manage.

Changing gear takes about 20 secs including wiping your oily finger on a nearby tussock; or, if weight isn't a problem keep the front shifter.