The BSA A7-A10 Forum

Technical => Frame => Topic started by: TimK on 02.09. 2019 06:16

Title: 18" v 19" Rim
Post by: TimK on 02.09. 2019 06:16
Hi everyone

I need to change my rear tyre (at the moment it's got a way too big 4.60 x 18 on there) and am wondering if there's any advantage in puting a 19" rim on the wheel. The bike is a (mostly) 59 Gold Flash, but as you may have worked out, with an 18" rim on the rear, it's a bitza.

There seems to be a bigger choice of 19" tyres (I'll probably go for a K81 to match the front), but are there any other advantages in either an 18" or 19" rim?


Title: Re: 18" v 19" Rim
Post by: Swarfcut on 02.09. 2019 09:03
Couple I can think of for an original 19" rim...The speedo drive, if standard off the gearbox, will be more accurate, and raising the rear ride height will give an improvement in visual aesthetics, rather than looking to have a softie on the back. Could be the 18" wheel is from a Unit Twin, and  chosen to enable rear wheel speedo cable drive and a cheapo speedo head. You did say it was a bitza!

Title: Re: 18" v 19" Rim
Post by: Greybeard on 02.09. 2019 09:50
Obviously a larger wheel will give literally longer-legged gearing.