First- I've removed the front dérailleur to go a single ring up front.
This is a temp fix as I'm going to 8 rear..( is 7 now )

1'ST.-I lost the middle ring ramp position ( compared to the arm position ) It's a shimano sg c-46, This prob won't matter as I'm not running a dérailleur, but I'd like to know for my instruction as to reassembly ( marked it w\ pencil and greased it off..darn! )

2'ND.- I am running mostly mid ring 36 t, I will buy a higher toothed wheel for my single- am on the light metal, ramped mid ring- Is it safe to use this way?

3'RD.- can I use a chain ring intended for 6 speed? ( have a nice solid 36 t, no ramp, but is intended 6 rear ) is this a chain width or tooth spacing compatibility issue?

My lbs didn't have narrow chain ring bolts so all I got rid of was the granny and the dérailleur\shifter- am I looking at road bike parts now? ( single front\7 rear?narrow chain issue again, wish I was doing 10 speeds! )
-And does it really matter if spec wise the manufacturer says intended for mid ring use?
As I don't like this thin 36 I'm on, am really just trying to find a larger, heavier duty ring that will fit mid space on the triple designed crank- ( 46 no way ) a 40 mounted mid might fit.

hmmm.. I respectfully ask that you keep in mind that I'm obviously not knowledgeable about gears, so write for the layman..

Thanks jef.

There's often some sort of marking stamped on the chainring to indicate alignment with the arms. Shimano often uses a little triangle. And the big ring often has a pin on the outside to prevent the chain from jamming between the ring and the arm should you shift off the outside - this would indicate alignment for that ring.

I've never run multi-speed with a single chainring. But I would think you would want a ring designed for single-speed use. A ramped and profiled ring is designed to shift and you might have problems with the chain derailing.

Yes. 6/7/8 speed all use basically the same width chain.

First, what are you using for a rear wheel? If it's a cassette, you will need to do some serious work to convert a 7 speed freehub body to an 8 speed freehub. If it's a freewheel, I don't like 8-speed freewheels because they're like asking for bent axles.

Second, I don't think that it makes a huge difference what kind of chainring you use. You need to make sure that you get the bolt circle diameter right or your new ring won't work. You need to get a chainring that's designed for derailleur use or it might be too thick to handle the derailleur chain. The other thing that's pretty important is getting the chainline right or you'll keep throwing the chain off.

Good luck.

Cassette rear, I may replace the wheel.
Nice Mavic rim on a deore dx, swiss dt spoke.

Are chairings speed AND chain specific? I've some that fit the spider but are from a 5 speed train ( thought it was a 6 ) What speed does the narrow chain come into use- 6?

My present dérailleur can go 8 so I'm part way there-
I've been doing searches and looking @ old threads for info on the 7-8 upgrade.
All info appreciated, thanks Gonzo Bob, Retro Grouch.
Jef.
( sorry about bunches of basic questions, I am learning about bike mechanics and prefer the input of cyclists and home mechanics rather than what specific the Lbs wants to sell me on. like a new bike.)

Back to the net for info! Bike parts all over my bedroom floor. My fingers are black.. . YA!

There are some track chainrings and cogs that require using a 1/8" width chain. But rings and cogs for multi-speed stuff require a 3/32" width chain.

Technically, there is a slight difference in cog and chainring thickness going from 5 to 6 to 7 to 8 to 9 speed, but the difference is very small. The main difference is in the thickness of the spacers between cogs, and in the offset of the teeth on the inner chainrings. In other words, you can use the chainring from the 5-speed bike with 5, 6, 7, 8, or 9 speeds in the rear. The chain you use should match the spacing of the rear cogs.

normal - 5, 6
narrow - 5, 6, Ultra6*, 7, 8
ultranarrow - 9

You can use either a "normal" or narrow chain for both 5 and 6 speed standard spacing. My first 6-speed bike came with a "normal" chain but it ran a little noisy in certain combos so when it came time, I replaced it with a narrow.

*The Ultra6 was a 6-speed freewheel fit in the space of 5 and used approx. the same width spacers as 7 and 8 speed stuff.

What, your LBS doesn't have BMX chainring bolts******************** That's what you need for a single chainring setup.

George

The first thing that I would do would be to measure the distance between your rear dropouts. An 8/9 speed rear wheel is going to need 130mm between the dropouts. Some 7 speeds are 130mm and some are only 126mm. You can work around the 126mm limitation if you have a steel frame. Rear derailleur and chain are the same. Shifter, of course is different.

My dropout space is 148 mm- steel frame only 16 inch (weird build, all the main triangle tubes are different sizes.)

Thanks for the info, the 5 speed chain ring seems close enough to try, spaces are very close-though the teeth line up between ( peaks-valley other ) when the anchor holes are lined up.
I was looking at a rear cluster with a bail out gear I believe it was called.
Should do fine- 7 and a rear granny gear for hills.

My seat tube is oval at the bottom and with no front dérailleur you can see the shape nicely.
Since I'm going to wear this ring fast I will be purchasing a HQ chain ring soon, read bad stuff on BlackSpire- Any recommends on quality rings? (I like old racing parts rather than laser etched graphics- tried and true.)

No bmx chain ring bolts, Ya- I thought to ask that one too.
The old guy wasn't there-Hans, his minion didn't care to go look really- So I wasted his time extracting pertinent info.

Single speed is getting pop for road here and some people are going single front on small mtb frames, A bash guard on either side of the triple and I think smaller than 36 t mid ring. ( I'll be going higher-39 and shorter crank arms to speed up the revs! ) like big bmx.

Going to try the alternate ring tomorrow and I got a suggestion from another post of grinding the teeth off a 46 ring as a bashguard.....
and we got a grinder.
Jef.