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View Full Version : O-Ring chains are cool -- if you get them fitted :D



xwhatsit
7th May 2007, 18:20
Looked at that other thread about O-ring chains and got a bit worried, but it's easier when you get somebody else to do it :D

The chain that came with my bike was not fully used up yet (had plenty of room left on the swingarm), but it was getting pretty nasty due to lots of tight spots. I was having to retension it every four days or so, which isn't much fun. So today I headed off to Motomail to get chain and sprockets (sprockets are in great nick, but there's that rule about replacing them together). No sprockets, chain would have to be ordered. Went to AMPS -- helpful guy told me he could do it, but it'd be fscking expensive due to not having aftermarket bits, try Mt Eden Motorcycles (and gave me directions wot I promptly forgot).

Got to Mt Eden, they said no problem. I decided I wanted the chain today (it was starting to worry me, about snapping or something with all the tight spots), and they told me they could do that -- but I couldn't cut the chain myself. They fit the chain for me, in a crowded workshop, for about $25 which was great in my book. Some rude pricks in the workshop though. Meh, they're mechanics, not salesmen. I pick up the sprockets on Wednesday. I know I should've done them all at once, but waiting a day or two and 50-60kms won't hurt it too much I think. Now that the chain is cut I'm sure I can do the fitting myself.

Plan on looking after this one much better. It's bloody expensive, doing a chain! :shit: Typical story -- rego due, anniversary, Mother's Day, Dad's birthday, chain & sprockets -- and I'm off work (ACC doesn't pay too much, and now I'm back at work I got a while to wait for money again) :whocares:

Went up a tooth on the front, to 15 instead of the 14 that was on there (standard). I understand that this will make the gears quite a lot taller than they were before, and on a low power bike it's not always smart. But it's got a wide powerband, and on the motorway you sit really high in the rev range, so I think it will be a good idea. Low speed 1st gear stuff might mean more clutch slipping, but that's what it's for.

Nothing interesting really here, just that Mt Eden are cool for squeezing me in :D

EDIT: Oh yeah, how much smoother is the bike after that! Gear changes are like silk, and there's no jerkiness at low speed. Very cool.

xwhatsit
9th May 2007, 21:50
So it looks like they got me the wrong rear sprocket. Bitch. Can understand the mistake, though... I just asked for a 1983 CB250RS sprocket set. It's JT sprockets; just did a search at their page, and this is what I got:

CB250 RSA 1980-1983 http://www.jtsprockets.com/52.0.html?&L=0&sel_uid=206&p=

CB250 RSB France 1983 http://www.jtsprockets.com/52.0.html?&L=0&sel_uid=211&p=

CB250 RSD-C,L 1982-1984
http://www.jtsprockets.com/52.0.html?&L=0&sel_uid=207&p=

Looks like they got me the first one, whereas I actually need the last one. The front sprocket looks fine, but then again only the French model is different (and it's hard to tell by eye). What a pain in the arse. Hopefully they can swap them back quickly, I want to minimise mileage on the new chain with the old sprockets. And if they try to charge me money I'll be pissed.

I wonder if they had all three options too? They had my bike in their garage, they could've taken a look.

xwhatsit
11th May 2007, 22:14
Picked up the sprockets today. Dropped the wheel out; got all the bolts off the rear sprocket, except one, which promptly rounded! Spent a long time with WD40 and various implements until I bit the bullet and drilled it out. Used a cap screw and another nut (the hub isn't threaded, the mounting bolts go right through with a nut on the other side), which are a different allen-key size, and different shape, so to balance out vibrations, put an identical bolt and nut on the opposite side of the sprocket. There are 6 bolts, so I'm not too worried about strength here, and the bolts look pretty solid.

Front sprocket has minimal clearance with the extra tooth, so had a heart stopping moment or two fitting it, but it fits OK.

The rear sprocket, they couldn't get me in the original size; had to go down a couple of teeth to a 42. Slightly grumpy about this, as it seems the gearing is now a little too tall, at 2.80 instead of the 2.93 I was aiming for (standard is 3.14). However, in riding the bike, it seems good. Not sure if it's better than before; certainly around-town 50kph riding is great, sitting in 4th just cruising along at low rpm, but still enough to be able to accelerate. On the motorway acceleration and uphill suffers, but I'll just have to get used to staying in 4th gear for longer.

Bike feels smoother and more dignified now. I can live with a little less acceleration for less gear changes and lower rpm, with all the benefits associated with that.