Bicycle Mechanics - want to go from 3x9 to 1x9

Want to remove the largest and smallest chainrings on my mtb so I just have the middle. Do u I need to replace the cranks also or can I just remove them?

the simplist thing to do is just get a set of BNX chainring bolts. once you take the outer ring off the existing bolts/nuts are too long.

you may need to pull the crank to get the small ring off though

You will probably need a new bottom bracket to adjust for chainline... otherwise you will find the chain dropping more than it should.

I would swtich the crank, since those exposed crank bolt holes are a hazard for tangling the chain if it drops or they might hit your frame once you adjust for chainline.

I swapped a double chainring to 1 X 8 with only the innner ring. It never once fell off -- and why would it? It's not like the front derailleur being there, doing absolutely nothing, frightens the chain so it won't fall off.

The real issue, is what you'll be gaining -- which is basically nothing. Unless you really really hate shifting your front derailleur or something.

Going to a single ring up front is a nice way to simplify the bike if you get sufficient range with just the rear. If you have a cheap crankset, you may find that the crank is attached directly to the middle ring, with the inner and outer rings being attached to the middle with rivets. In this case, you can just drill out the rivets to remove the extra chainrings. I did this when converting to a IGH with great success.

I swapped a double chainring to 1 X 8 with only the innner ring. It never once fell off -- and why would it? It's not like the front derailleur being there, doing absolutely nothing, frightens the chain so it won't fall off.

exactly...



The real issue, is what you'll be gaining -- which is basically nothing. Unless you really really hate shifting your front derailleur or something.

well i have to disagree...

the elimination of the front derailleur, cable, stops, lever, two chainrings and a set of bolts are not "nothing". and browsing through this forum for questions about front derailleurs makes it clear that people seem to have a LOT of problems with them. i say good riddance to them.

err... if you can live with the limited gearinch range you will have, that is.

I lost my chain a few times on rough trails running a multi-speed 44T without an FD. A change to a single-speed 44T fixed that right up though.

I was using an OLDE rear derailer though, probably had a weaker tension spring than Turbine's.

On a triple the middle ring is in the right spot for a single chainring

Its in the middle.. just get shorter bolts and take off the other 2 chainrings

might be time for a new chain anyhow, make the new one shorter
since no Big ring any more..

I have 9 speed in the back and don't thing I have ever used the other 2 chainrings. Simplifying is my goal. I just installed a brand new sram chain last week. I rode around in my neighborhood lookig for some dirt hills and it popped off. One of the outer links bent and I replaced it with one I removed when I resized it. Rode again and it bent again in a different link. WTF!

anyway back on topic. The large chainring is on the outerside of the crank and the middle and smaller are on the inside between the crank and frame. Think I could just remove them and get smaller bolts without problems?

The large chainring is on the outerside of the crank and the middle and smaller are on the inside between the crank and frame. Think I could just remove them and get smaller bolts without problems?

I do.

And when it comes to ditching the front derailer I'd give you a 70% chance of doing so without problems. They're easy-to solve problems though.

Thanks, I'm just New to wrenching and don't all the ins and outs yet.

Should I get an SS specific 32t chainring or will that require a new crank?

.. Should I get an SS specific 32t chainring .. You dont need to , but , I like the QBP/Surly Stainless steel chainrings,
for my IG hub build.

to keep the chain from bouncing off the chainring ,
there are parts to add to do that.
easiest. the derailleur with the limit screws put in to each other
to center over that ring.

Chainguard discs, in place of the outer chainring,
and chainminders/and the 'jump-stop' are another approach..
on either side of your 1 chainring..

I have 9 speed in the back and don't thing I have ever used the other 2 chainrings. Simplifying is my goal. I just installed a brand new sram chain last week. I rode around in my neighborhood lookig for some dirt hills and it popped off. One of the outer links bent and I replaced it with one I removed when I resized it. Rode again and it bent again in a different link. WTF!

anyway back on topic. The large chainring is on the outerside of the crank and the middle and smaller are on the inside between the crank and frame. Think I could just remove them and get smaller bolts without problems?

This is an issue to sort first, correct chain?

Otherwise you have two options, either continue to use the middle chainring as you're doing or install a SS chainring whose profile isn't designed to assist up/downshifts (to help prevent throwing the chain), that failing, a new crankset.

Brad

Thanks! I'll research into all of these. I will just keep the FD on for now until I decide what to do. Thanks for all the help everyone.