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Hi. I have the AF five speed box fitted and love it, but I now think I should have gone for the longer 5th gear. Before I fork out £110 for the alternative cog from the supplier, I wondered if anyone had bought the longer 5th gear and with hindsight would have preferred the shorter cog.

Would anyone fancy a swap?

I have used the taller 34T fifth cog on my Rapido 250 and must admit it was the correct decision, gives me around 4:61 final drive which was perfect for Poland last year and pulls nice and strong. Reason I went for 34T in lieu of 35T was final drive ratio for 35T was around 4:71 which was not far from the 4;8 had with the four speed.

Knowledge wrote:Hi. I have the AF five speed box fitted and love it, but I now think I should have gone for the longer 5th gear. Before I fork out £110 for the alternative cog from the supplier, I wondered if anyone had bought the longer 5th gear and with hindsight would have preferred the shorter cog.

Would anyone fancy a swap?

I haven’t but wondered: What final drive does the 35 give you?

Dibs, that's what I settled for on my Broady 5-speed, perfecto

Hi Gerry,

I have finally got the Tony Cassidy visualiser in front of me and I can see the effect on the final drive ratio of changing from 35 to the longer 34 fifth gear.

On my 20 x 46 sprockets, the final drive ratio would drop from 4.24 (35j to 4.12 (34). The fourth gear to fifth gear jump will change from 9% to 12%.

You can bump the 34 tooth fifth gear final drive ratio ack up to 4.21 by swapping the sprockets for 20x 47.

Any one up for a swap?

So tempted,
I've the reverse
Sell me yours.

You’ve got a reverse gear! Wow.

Knowledge wrote:You’ve got a reverse gear! Wow.

Be useful for the combo

I fitted 35 to mine and regretting it. ( not regretting the purchase though it’s nice to ride but tops out too soon) Running 18/47 on a Rapido with 60 stroke crank and reed valve but not a revvy pipe (TSR Evo). Seems I got my sums wrong! Looking to fit 34 but given the low % rise of the box I’m wondering whether to just puta a 19 on the front (need a cog, chain and pull down tensioner or possibly 19/46. The cog would be cheaper though but more of a pain if I just want to suck it and see!

Dicky wrote:I fitted 35 to mine and regretting it. ( not regretting the purchase though it’s nice to ride but tops out too soon) Running 18/47 on a Rapido with 60 stroke crank and reed valve but not a revvy pipe (TSR Evo). Seems I got my sums wrong! Looking to fit 34 but given the low % rise of the box I’m wondering whether to just puta a 19 on the front (need a cog, chain and pull down tensioner or possibly 19/46. The cog would be cheaper though but more of a pain if I just want to suck it and see!

I have the same set up 18/47 Rapido 250 with the 34 tooth and must admit although a small % rise (need to be careful of going too tall) it is a joy to ride, 4th is perfect for those slight inclines and head winds and 5th on the straight is no struggle at all

Dibs/SFSC wrote:

Dicky wrote:I fitted 35 to mine and regretting it. ( not regretting the purchase though it’s nice to ride but tops out too soon) Running 18/47 on a Rapido with 60 stroke crank and reed valve but not a revvy pipe (TSR Evo). Seems I got my sums wrong! Looking to fit 34 but given the low % rise of the box I’m wondering whether to just puta a 19 on the front (need a cog, chain and pull down tensioner or possibly 19/46. The cog would be cheaper though but more of a pain if I just want to suck it and see!

I have the same set up 18/47 Rapido 250 with the 34 tooth and must admit although a small % rise (need to be careful of going too tall) it is a joy to ride, 4th is perfect for those slight inclines and head winds and 5th on the straight is no struggle at all

Helpful ta. Think that’s probably the way to go!