Larger front sprocket

[Art]

Too much is made here of reduced wheel base and final drive ratios as if anyone will notice the minimal differences caused by cornering, tyre wear and rear axle placement.

Of course the correct way would be to replace the drive chain and both sprockets as a kit because they mesh and wear in/out together, replacing just the front sprocket will cause premature wear to the drive chain which in turn will cause premature wear to the rear sprocket which means that you'll be replacing the drive chain and sprockets sooner rather than later. That said if you're replacing the front sprocket just in favour of +1 tooth then maybe just put up with the increased wear to get a feel of the higher gearing and how it effects the torque and handling.

Some salient points to note - Of the many folk I've heard of who alter the final drive gearing of a road going motorcycle the vast majority revert back to the standard factory gearing. Negotiating steeper than expected cambered hairpin bends on inclines such as those found on roads like 'The Devils Staircase' (unclassified road between Abergwesyn and Tregaron in South Wales) especially if riding two up with luggage, you will prefer the lower ratio of the stock first gear. The drive chain wear indicator sticker will be misplaced so you will need to keep an eye on chain/sprocket wear. Hooked sprocket teeth are easy enough to spot, chain wear less so best practice is to measure chain wear across 13 link pin centres where 193 mm equals a worn out chain. Lastly +1 tooth on the front sprocket will not necessarily require any adjustment to the drive chain length, 120 links should be fine although you will experience a tighter working tolerance in refitting the rear wheel when engaging the drive chain on the rear sprocket.

[Kevin t]

thanks for the in-depth reply, your correct in every account, having replaced the rear sprocket to a 39t it placed the rear wheel to far back just tipping the red zone, i soon found out this indicator is not just for chain wear but also rear wheel displacement like you mention, it alters the bikes cornering to a point i didn't feel comfortable and i felt the bike frame flexing out in corners, so i went and reverted back to my old sprocket on the rear, thanks again for the reply.