My New Conversion

[whiteturbo]

Hiya,
Bought a new Montague Navigator, but got to fit a mid drive as i cant go back to manual(age catching up) so i have ordered another BBS01 250w. The Monty has a 9 speed cassette so i figured to change that to a Sunrace wide ratio 11-40T 8 speed. Will a Shimano Tiagra that i have in my spares box work and will i need a hanger extension thingy or should i just get a new long reach derailleur.

 

[Trevormonty]

It maybe OK with existing gears, depends on your weight and hills you need to climb.

 

[anotherkiwi]

Tiagra GS will work from what I have read on forums. I have just fitted the 8 speed Sunrace 11-40 on the trike and it works out of the box with the Altus derailleur. Any long MTB derailleur will do the trick.

The wide range cassette has just about made the small chainwheel redundant, I bought it in prevision of using with the 32 cog on my GSM really.

 

[whiteturbo]

It maybe OK with existing gears, depends on your weight and hills you need to climb.

I live in Bristol UK and its pretty much hills N.S.E.W. And i live near the top of one so every journey ends with a long hill climb and I am having trouble staying below 15 stone so i am not a skinny lightweight. My main concern though is if i stay with the 9 speed will the chain be man enough.

Just wonder if i need to go as low as the 11-40T maybe a 11-32 or 34 will do.

 

[anotherkiwi]

What chainwheel are you using? There is a 12-36 Suntour 9 speed IIRC.

 

[whiteturbo]

What chainwheel are you using? There is a 12-46 Suntour 9 speed IIRC.

it will be a bling ring 42T or 46T . mm 12-46T i have to climb steep hills, maybe even small mountains but i dont do sheer cliffs LOL

 

[anotherkiwi]

Typo correction 12-36 above, they do 11-36 too. Trying hard I can climb very steep hills in 42:32, I tried on Wednesday, forgot to change down to the 32... I had a trailer full of junk behind too. I am talking hill over 14%, the kind that are steep to walk up.

You will be fine with 42:36 and high assistance level or 540 W.

 

[Trevormonty]

it will be a bling ring 42T or 46T . mm 12-46T i have to climb steep hills, maybe even small mountains but i dont do sheer cliffs LOL

Wifes Shimano Steps bike came with 44T and 11-34t cassette. Found it to high for some steeps hills so switch 38T chainring, now really use 1st gear but we are lot lighter riders. As anotherkiwi will vouch Wellington has no shortage of steep hills.

With 38T chainring and 11-40t cassette you shouldn't have any problems. I'd start with 38T chainring and your current cassette and see how you go.

 

[anotherkiwi]

The thing with the 42 narrow wide is the improved chainline. I am not hostile to the idea of a 38 tooth for a utility bike where you never get to go much over 25 km/h, I think my bike may eventually end up with one.

From memory (haven't been there in 40 years) Bristol hills are not Wellington hills. Some nice rides around there.

 

[whiteturbo]

The thing with the 42 narrow wide is the improved chainline. I am not hostile to the idea of a 38 tooth for a utility bike where you never get to go much over 25 km/h, I think my bike may eventually end up with one.

From memory (haven't been there in 40 years) Bristol hills are not Wellington hills. Some nice rides around there.

My final hill is redcatch hill, years ago bus passengers had to get off the bus and walk up the hill and get back on at the top its 16% even when i was young and fit i didn't cycle up it.