4speed derailleur set up

[ren531]

This last winter on my commuter bike I tried a little experiment of simplifying the gears , ideally I would use single speed but not being so young anymore my knees aren't so keen, so a bit of playing around separating a 8 speed cassette and useing spacers from a single speed conversion kit I made 4 speed , 15-22-28-34 and a 36 tooth chain ring I would have made it a 3speed missing out the 34 tooth sprocket but would have had to modify the rear mec to limit the movement so went for 4 speed but i only use 3 most of the time and it works fine shifting is good , I did think it would struggle but climbs to the bigger sprockets no problem.
The thinking behind this is it's tailored to my route with me using only the 15-22 sprockets for all but one short steep hill so the chain line stays as close to optimum with a very narrow width of movement across the sprockets in total compared to the original 8 speed .
What I'm hoping to do is reduce the amount of wear with this and useing a partial chain case and I got good results far less wear than in the past and it has a lot of foul weather chucked at it .
I have a liking for simple gear systems with big steps between such as Sturmey Archer AW 3speed and this has proven to be a useful experiment, worked far better than i expected.

 

[ColinJ]

I did something similar but had to use 6 sprockets because otherwise the biggest one (29 teeth) was fouling the rear mech. Even with 6 it makes it awkward to get the back wheel in and out.

I find my simplified gearing very good too. I can get up fairly steep hills in bottom gear, and can pedal up to about 45 km/hr in top, which is ample for me.

 

[Ming the Merciless]

What speed chain are you now using, a 5 speed chain?

 

[Punkawallah]

And do you have to ‘double click’ to shift?

 

[ren531]

What speed chain are you now using, a 5 speed chain?

I use an 8speed chain , it still uses 8speed spacers between the sprockets so use the same chain

 

[ren531]

And do you have to ‘double click’ to shift?

No use's the same shifter and same spacer's between the sprockets so the shifting is the same just less of them

 

[ren531]

I did something similar but had to use 6 sprockets because otherwise the biggest one (29 teeth) was fouling the rear mech. Even with 6 it makes it awkward to get the back wheel in and out.

I find my simplified gearing very good too. I can get up fairly steep hills in bottom gear, and can pedal up to about 45 km/hr in top, which is ample for me.

Had no issues with the mec fouling the sprockets, but wheel removal is more tricky because the mec won't move out far enough to clear the end of the axle.
I guess you could do something similar with a narrower chain obviously useing the narrower spacer's too and you would get an even less movement away from the ideal chain line than mine .
As I said I'm really surprised it work so well.

 

[Punkawallah]

Had no issues with the mec fouling the sprockets, but wheel removal is more tricky because the mec won't move out far enough to clear the end of the axle.
I guess you could do something similar with a narrower chain obviously useing the narrower spacer's too and you would get an even less movement away from the ideal chain line than mine .
As I said I'm really surprised it work so well.

’If it’s stupid and it works’.

 

[Ming the Merciless]

No use's the same shifter and same spacer's between the sprockets so the shifting is the same just less of them

That doesn’t make sense. You’d need to pull the cable the same amount to get from one cog to another (in your setup), as you would shifting two gears if all cogs were present. You can‘t shift 2-3 at twist grip and expect it to go 2-4 at back moving past a spacer.

 

[ren531]

That doesn’t make sense. You’d need to pull the cable the same amount to get from one cog to another (in your setup), as you would shifting two gears if all cogs were present. You can‘t shift 2-3 at twist grip and expect it to go 2-4 at back moving past a spacer.

I'm only using 4 incremental movement's out of the 8 available on the twist grip and pulling the same amount of cable between each gear with either 4 movements or 8 , the spacer's between the cogs match the twist grip there's just less of them then managed to use the standard limit screw's at maximum to limit movement of the rear mec to just those 4 gears .

 

[Ming the Merciless]

I'm only using 4 incremental movement's out of the 8 available on the twist grip and pulling the same amount of cable between each gear with either 4 movements or 8 , the spacer's between the cogs match the twist grip there's just less of them then managed to use the standard limit screw's at maximum to limit movement of the rear mec to just those 4 gears .

But you can do it in 4 moments, with 8 cogs, you’re just jumping two cogs at a time. What’s the difference?

 

[ren531]

But you can do it in 4 moments, with 8 cogs, you’re just jumping two cogs at a time. What’s the difference?

I was trying to narrow down the width of total movement to bare minimum to keep the chain line as close to the chain ring as possible most of the time is spent in the 15-22 sprockets and I lined those to be near perfect chain line with the chain ring .

 

[Ming the Merciless]

You are going to get increased wear on the remaining cogs be interesting to see how much above 10,000 miles per chain and cassette you get.