Ovaltech spares

[Drive Blind]

Hello,

My dad has a 25 year old Raleigh MTB with the ovaltech/biopace chainrings. It's his everyday bike just for pottering about.

The middle chainring is now so worn its starting to slip. Can you get replacements for these? I had a quick google but didn't throw anything up.

Markings on the chainring are "SR 346 SAKAE 350 38"

It looks like this (pic stolen from google)



thanks for any advice,

[JEA1K]

I remember those ... pretty sure I had something similar on my Saracen Eiger back then! I think you'll need to drop very lucky to find a replacement ... more likely to be on a full bike than anything else. Bike parts were not sold in the same numbers back then. Ebay is probably your best bet.

[Drive Blind]

theres an example in the glasgow transport museum apparently, you think if I asked nice?

[matt-ITR]

You would be better off getting a new/used chainset, rather than just a chainring.
Look for an old Deore square taper. It would be cheap and do the job.

[Justin S]

Depends on if you want it get the same rings or not. Personally I would bin the rings ( and chain and cassette/ freewheel) and start again. Not all is lost. The chainrings will have a pcd ( diameter of the holes that bolt them on) and there will be plenty of rings that should be available to fit, so the cranks will stay the same. Have a look at wacky shops like St Johns Cycles for stuff like that. If the chain is slipping on the rings, then the chain is probably stretched and dead and also the cassette/ freewheel.

[Drive Blind]

hi

thanks for the replies.

I understand what you are saying about new chainsets, chains, etc but you need to understand my dad is as tight as 2 coats of paint so he wont entertain that.

So if we work out the pcd required then any 38T ring of the same pcd will fit?

[yellowjack]

Drive Blind said:

hi

thanks for the replies.

I understand what you are saying about new chainsets, chains, etc but you need to understand my dad is as tight as 2 coats of paint so he wont entertain that.

So if we work out the pcd required then any 38T ring of the same pcd will fit?

Round rings of the same bolt centre diameter will fit on that crankset as direct replacements. You may, however, find that unless all of the rings are matching (ie: all biopace, or all round) then the chain won't shift smoothly between the rings. When you get into the realms of replacing all 3 rings together, complete chainsets start to look better value, and if you switch, then your dad won't have to go through this same palaver next time. Although you should bear in mind that changing from oval to round rings will change the way the bike feels to ride, and might take a little getting used to.

[Justin S]

It seems your dad doesn't use the outer chainring, just the granny and middle. If you replace the 2 knackered rings, the chain is shagged. It will sound like a cement mixer, grinding the new teeth on the rings away. It depends on if your dad wants it to work or not, to be honest, although the chain looks like the bikes been locked on railings by the beach for a week. A chain is a fiver or so, freewheel is also a tenner to fifteen quid and chainrings probably a tenner each. Not a lot of money for peace of mind.

[Drive Blind]

Justin S said:

It seems your dad doesn't use the outer chainring, just the granny and middle. If you replace the 2 knackered rings, the chain is shagged. It will sound like a cement mixer, grinding the new teeth on the rings away. It depends on if your dad wants it to work or not, to be honest, although the chain looks like the bikes been locked on railings by the beach for a week. A chain is a fiver or so, freewheel is also a tenner to fifteen quid and chainrings probably a tenner each. Not a lot of money for peace of mind.

the pic in my first post is stolen from google. It is not a pic of my dads bike.

[CoolC]

Go to www.retrobike.co.uk and look through the sales page, someone will have one on there.

Edited by CoolC on Thursday 10th April 09:58

[WinstonWolf]

If he's *really* tight just turn the bugger round to eke the last few miles out of it... It'll wear mega! quick though.

As said, just get a square taper with the right crank length, job done

[Drive Blind]

WinstonWolf said:

If he's *really* tight just turn the bugger round to eke the last few miles out of it

he was actually considering doing that

anyhoos, the plan is to get a standard round 110bcd 38T ring. There are ones on ebay for 12 quid.

[Drive Blind]

hang on, just spotted this on the bay. Would this be a suitable replacement?

http://www.ebay.co.uk/itm/shimano-biopace-triple-c...

[anonymous-user]

Brand new square taper triple chainset for £23
http://www.ebay.co.uk/itm/Shimano-Tourney-TY-FC-M1...

The bio pace chainset in the link you posted would fit, looks in good condition but may go for more than £23 as retro hunters may be after them.