Hello everyone, im new to the forum and also to the bicycle mechanics world .
I have a road bicycle, with 21 speed, (3 front 7 back) , but lately i was thinking to convert it to a 3 speed, which means 1 on the rear and 3 on the front, because i never really use the 7 on the rear wheel.
So what i wanted to do is to put a single speed wheel , leave the Rear Derailleur (adjusted in the correct position) getting rid of the cable and the shifter, and leave the front one as it is.
Does anyone have any experience/advices on doing this? will it work fine?
Forgot to mention is a 9 speed shimano derailleur, was thinking that if this may work i could buy a compact one or something that could take less space ..

thanks

-M

Seems peculiar. Seems it would be easier just leave everything and not use the rear derailleur. I suppose you ride in a place that doesn't have any hills. What benefit do you see in doing this? You won't get the sole advantage of a 3 speed (low maintainence for internal gears).

Yes it will work. The followup to that is: WHY?

Basically, it gives you one gear for the climbs, one gear for the flats, and one gear for the downhill/easy flats.

Why on earth would you want to go for a construction like that?

well i was thinking to get rid of some weight , the 7 rear speed on the wheel seems to be a bit heavy conpared to a single speed, and also initially i was thinking to put a chain tensor instead of the rear Derailleur ,but i dont think that would work .
The all idea was to get rid of things that i dont use at all, and since a single speed in my opinion could be too much or too less in some occasions i thought that 3 or even 2 could be a solution.
Does anyone did it before? the only thing im concerned of is if it will work fine mechanically (if there is something i should know before ) and if i can improve something like getting rid of the rear derailleur for some better and lighter solution..

Hmm. I'd go with a 3sp internal hub if I only wanted three gears. Otherwise just stick with 7. Losing 6 cogs will not save you that much weight at all compared the rest of what is surely a pretty heavy bike.

i forgot to say, that i used a single speed for a while going to work and back, i found it good but sometimes too heavy gear especially when is windy/rainy or im pretty tired and sometimes instead find all traffic lights green and i couldn't go faster without sweating pedaling like a horse ..

Why? The extra weight isn't really making you go slower.

It would work fine. Heck, if you rarely shift, you could get rid of the FD and shift by hand (before getting on the bike)!

Not enough range to be really useful (unless it's flat), I think.

Why not use a flip-flop hub?

Use a tensioner for an IGH, which are sometimes used with multiple chain rings.

Here you go.
https://www.amazon.com/Alfine-CT-S500...ef=pd_sbs_sg_1

3 speed IGHs have a pretty good range. Enough to be useful. You just have to get the right hub.

Since I suspect it wouldn't be enough range for the riding I do, I haven't looked very closely at them. (Hmm, 3 speed IGH and a triple?)

I think it sounds like a fun idea. It has more range of options than a single but with a lot of the simplicy that makes a fixed gear fun in the first place. You have 7 gears now, plenty to see which gear on the rear will work the best for the 3 speed. I think you should ride the bike with the rear locked off and see if the bike will ride without all the fuss in the rear. If it does then more power to you.

You'd definitely need a chain tensioner or just leave the derailleur.. it won't shift right otherwise.

thanks for the replies ,i will give it a go first leaving the rear derailleur and than if i can find a good tensioner that could do the job, ill keep you posted .

Use a tensioner for an IGH, which are sometimes used with multiple chain rings.

Here you go.
https://www.amazon.com/Alfine-CT-S500...ef=pd_sbs_sg_1

Thanks Njkayaker .

I pedicab occassionally with a guy with some insane gearing. Pedicabs (good ones) have an intermediate drive, like a hub where the normal gearing is, and then a cogon the other side that goes back to the rear axle.

This guy might have anoter intermediate or something, bu he essentially has: MTB Triple chainring -> 7sp MTB Cassette -> Nexus 8spd (which replaced a 3 spd that he used to use).

Its pretty rediculous and obviously has a TON of redundant gears, but when it is in low-low-low... Lord, it could seriously pull stumps. You have to spin like 100 revolutions to move like 3 ft it seems like. Outrageous. I never have run out of gearing on my 21spd cab....

IGH hubs actually have a TON of range, has been my experience. The low gear is spin up a tree low, and the high gear is realllllly high, i've busted through city traffic on an IGH cruiser, mashing the highest gear, and didn't run out.

hello,
this morning i tried the new system, wich bike upsidown was working perfectly...as soon as i start pedaling the chain was skipping..i could go forward but was like it was skipping some bits..damn!.. at this time i was still using my rear derailleur , and i could also change the front gears perfectly, only problem is the skipping chain!Is it possible that is the chain not compatible or the front chainring with the back one? or what could it be? i use to have a threaded freeweel and instead my single speed is a cassette. is possible that is that? is there a solution for it?

...sadness.....

Is there a reason no one has suggested 3 cogs in the back right in the middle of the chainline and having one ring in the front? That seems like a much more practical and effective solution.

jbhowat: can you explain intermediate drive? or link me to somewhere that can? I'm curious

I'm scratching my head, asking myself why would you do this, yet I am somehow intrigued and curious as to how it turns out. I'll give ya this though, you will probably be the only kid on the block with this set up, so you got that going on for ya.

hi guys is me again, after the big fail of conversion to a 3 speed, (chain skipping all the time dont know why...is not falling on the side because the chain is straight in line with the derailleur..anyway)
i was thinking to change the rear cog and hub (wich is a freewheel https://www.getprice.com.au/images/up...ewheel-med.jpg ) and buy a new shimano cassette with a cassette hub to put on my current rim.
My question is, if im going to convert from a freewheel system to a cassette , do i need to change my rear derailleur as well or i can use my current one (wich is working with the freewheel?) ??