1 x 9 questions: Chain Guide and chainring size

rasped

Hi,

Trying to determine the right setup for my MTB. It is currently a 2 x 9 setup with the largest cog being 34 and the smallest being 11.

Question 1:
Is a chain guide mandatory? Yes, it makes sense and why would I not put it on. But what I am asking is if someone has actually tried to ride without and deemed it unnecessary. Or should I just get something like this:
http://www.chainreactioncycles.com/Mode ... elID=47875
?

Question 2:
I am 40 years old and quite fast. I am doing weights twice a week and have ok output on the hills. So the question is regarding which size I should choose the front chain ring. I am thinking about either 38 teeth or 36 teeth. We so not have big mountains where I live and most climbs are about max. 40 altitude meters.

Question 3:
Should I place the new chain ring as the outher ring or as the middle ring? I guess the middle ring would be a better place as the lower gears would work better.

Thanks.

*AJ*

Q1- without a chain device you will loose the chain when the going gets rough! The chain device you linked to is ideal, but you could use a front mech with the stop screws limited to over the chain ring. It's not as good as a chain device, but it will be better than nothing.

Q2- a 38T chain ring with an 11-34 cassette should give you all the gears you need without spinning out downhill!

Q3- middle position gives you the best chainline over all the gears at the rear. If you put it in the outer position you will probably find the chain is running at a horrible angle in the low gears and will probably rub on the chain device and be noisey!

rasped

*AJ* wrote:

Q1- without a chain device you will loose the chain when the going gets rough! The chain device you linked to is ideal, but you could use a front mech with the stop screws limited to over the chain ring. It's not as good as a chain device, but it will be better than nothing.

Q2- a 38T chain ring with an 11-34 cassette should give you all the gears you need without spinning out downhill!

Q3- middle position gives you the best chainline over all the gears at the rear. If you put it in the outer position you will probably find the chain is running at a horrible angle in the low gears and will probably rub on the chain device and be noisey!

Great AJ. Thanks a lot for the advice. I am still split in whether to pick 36 or 38 teeth for the chainring.

ilovedirt

1. Yep, a chain guide is definitely necessary.

2. I run a 36t ring, it's probably the biggest I'd want to go, it gives you pretty much the best range of gears you'll want. Plus, if you take your bike anywhere hillier, you'll struggle on a bigger ring.

3. Yep, middle ring. A chain guide wouldn't work on an outer ring.

MTBSKiD

I ran this setup for about 6 months in 2010 and raced xc on it a fair bit as well, it definately has its advantages, but you have to be careful in how you do it.

If your in a flat(ish) area then a 36t would probably be fine. A 34t worked for me steep muddy climbs required more leverage than a 36t could give me. Try just riding about on only the 32t middle ring before you swap over maybe? You can see how much more you feel you do or dont need then!.

Also, that e13 guide is great! Better build quality than the MRP version, I ran it with the e13 chainring as well. You'll dfefinately need a guide like the other guys said; it will drop all the time without one!

fcacace

http://www.paulcomp.com/chainkeeper.html

rasped

fcacace wrote:

http://www.paulcomp.com/chainkeeper.html

Nice. Thanks.

rasped

Thanks for the replies ilovedirt and MTBSKiD.

I am pretty much down to this:
a: Should I run 38 on the middle ring and get a cassette with 36 teeth on the largest cog
b: Should I run 36 on the middle ring and use a standard cassette with 34 teeth on the largest cog

There is something (expensive) coming up from SRAM: a cassette with 36 teeth on the largest cog. Would you happen to know about any alternatives. Ie. cheeper options...

ilovedirt

rasped wrote:

Thanks for the replies ilovedirt and MTBSKiD.
There is something (expensive) coming up from SRAM: a cassette with 36 teeth on the largest cog. Would you happen to know about any alternatives. Ie. cheeper options...

There are none as of yet, i don't believe.

Northwind

For cassettes, there's a 36-12 Shimano 9-speed cassette already available, and you can swap around the smaller cogs from a standard chainset to get back the 11 toother. But the cassette's enormously heavy and this approach'll not be that cheap either. Sadly doesn't look like either Shimano or SRAM are keen to make an 11-36 cassette, because they want to keep that as a 10-speed exclusive to make more people switch over.

I'm using 32T on the front and an 11-34T cassette. Best compromise I've found so far, there's times I've wanted lower and higher gears though. But, your terrain will vary. I use 36T as the biggest ring on my other bikes (with a 22T granny) and it doesn't feel undergeared, occasionally you end up spinning pretty damn fast but any time I'm going too fast for 36-11, I either don't want to pedal through terror, or I'm riding something so dull that I don't care if I could go faster

Chain guide wise, you'll want something- but a front mech will do. Superstar's chain guide is very effective and well priced, though the cage isn't that tough, I broke mine with some mild mishandling (I shouldn't have done it, but I reckon it shouldn't have broken either, but fair's fair, if I wasn't a monkey it wouldn't have broken). It does still let the chain ping off the bottom, which happens regularily with mine but not while riding, only while stopped/handling the bike. Just got their Plasma guide to try out, it's got a bottom roller as well but that's probably overkill.

ilovedirt

He makes some good points ^

I'm running 36t up front and 11-32 on the back, though I wish I'd gotten 11-34 sometimes, but hey ho. It can be a slog on some climbs, but mostly it's not too bad. As Northwind says, I very rarely, if ever, spin out while on off-road descents, and if I do, I won't want to go faster out of fear! There's fire roads and roads too, but I don't really care about that.

I'm running the superstar laser chain guide, which is a little heavy, but does the job perfectly, had it for about a year now. I've just bought the superstar XCR top guide, which is a lot lighter, but i'll see how that goes.

Northwind

Oh, the Superstar guides are all on sale just now, the XCR is down a bit but the Plasma- which is similiar to the XCR but also has a bottom guide- is just £35, and comes with an ISCG adaptor too. Adds a bit of weight obviously and probably a tiny wee bit of drag.

Aldo001

What is the difference between bash and non bash guard versions of the Plasma?
Obviously one can take a bash guard, but what prevents the non bash version from taking a bash guard?
Oh and... 1x9 is the way to go

Northwind

The cages are smaller and differently shaped on the bashguard version, to give clearance for the guard while the other one has bigger cages to keep the chain on better without the guard. Mine is a bashring version- might end up with it on the mmmbop- and the top cage is wee, I think if you get the nonbashring version it's the same big cage as on the XCR.

Aldo001

Ahh ok, cheers
Might end up getting one if I ever revive my old bike - seriously considering turning it into a single speed for the hell of it :P

ilovedirt

You don't need a chain guide on a single speed.

Aldo001

I already have a tensioner on my current bike, so it would be swapping that over to the old one, Superstar thing on newer bike.
[/thread highjack]