What 34T Chainring for a 1985 Raleigh Record Sprint.

[GuyBoden]

I'm thinking about changing my chainring to a smaller 34T on my 1985 Raleigh Record Sprint, it has the Sugino GT chainset.

I think it's a 110mm BCD, but I'm not sure.

Any suggestions?

Thanks.

This type:

 

[KermitGKona88]

Re:

Could try putting in a bid for these, might get lucky

http://www.ebay.co.uk/itm/SRAM-Rival-Ch ... Sw-4BXcYsU

 

[pigman]

Re:

If it's 110bcd, that's easy - it's modern compact size.

Spa cycles do them in silver for about a tenner

But, if you are leaving your outer one and I presume it's a 52T, then 52/34 is a big gap. you may have problems shifting up front (??) and you may end up with a big tooth-count difference meaning you need a long arm rear mech.

I'd be inclined to get something like 34/48 in silver from spa to make it all match and work ok

 

[GuyBoden]

Re: Re:

If it's 110bcd, that's easy - it's modern compact size.

Spa cycles do them in silver for about a tenner

But, if you are leaving your outer one and I presume it's a 52T, then 52/34 is a big gap. you may have problems shifting up front (??) and you may end up with a big tooth-count difference meaning you need a long arm rear mech.

I'd be inclined to get something like 34/48 in silver from spa to make it all match and work ok

Many thanks.

 

[Pionir]

I doubt it's 110bcd. Pretty much everything was 130 back then so you're looking at I think 39.

 

[pigman]

I doubt it's 110bcd. Pretty much everything was 130 back then so you're looking at I think 39.

My initial thoughts too, but the silver spider does look small and the chainring bolts are a long way from the teeth on the outer chainring.
Hard to be sure for definite.

Also, some pedancy here, but you can go down to a 38 on 130bcd

 

[cromoman]

Re:

Best to measure it.

Distance between bolts is sin(36) * bcd.

Approx 65mm for a 110.

In my experience friction shifters cope quite nicely with big jumps at the front. The limiting factor is often how much capacity the rear derailleur has.

 

[GuyBoden]

I doubt it's 110bcd. Pretty much everything was 130 back then so you're looking at I think 39.

I was surprised too, for a 1985, the Sugino GT chainset is 110bcd, about 65mm between bolt centres.

Here's more Sugino GT info:
http://velobase.com/ViewComponent.aspx? ... 7&Enum=115

 

[Velodiversity]

Patterned after the Stronglight chainsets at 110.

 

[bhill22]

Guy
Cant PM you as you have incoming blocked