newbie chainring question

Peanutt

Hi,

On my last outing I snapped a gear cable (the front deraileur one) so I was left with 5 low gears, to be honest I didn't miss the other 10 so I'm thinking of ditching the shifter and the deraileur. Is it possible to remove the two unused chainrings as well? I'm thinking that it would give me extra ground clearance as well as shedding some weight. Also, if I'm only using the small gears could I take out some links in the chain to reduce the sag and wobble? if so, any ideas how many or how to judge how many?

Or am I just so new to all this that it's embarassing just reading this post!!!!

tjm

I would not be embarassed, perfectly reasonable questions!

My first question is do you really think you can live with only the small chainring? I guess it depends on what you do but I could see myself ditching the large ring but not the middle. Actually you can buy bashrings to replace the large ring - it then protect the other rings.

Anyway, if you are happy doing this then yes, most chainsets have the two larger rings on the same set of bolts and the smallest on a seperate set of bolts. So just unbolt the top set and they should both come off over the crank. (this assumes your rings are bolted, not rivetted on of course)

As to chain length - yes it is worth shortening. The standard way of finding the length of a chain is to fit it without going through the rear gears. Large sprocket at the back and largest chainring. Measure the shortest chain possible then add two full links.
However, for a single front chainring I suspect you want a little more length than that but I am not sure how much. I'd probably experiment to get a good compromise between the derailleur being right back in top gear and the chain completely stretched in bottom.

tjm

one thing to add is that it is not considered correct to run from the smallest ring at the front and the smallest sprocket at the rear as the chain has to go through a pretty big angle to do so. Ideally you would then have to get a longer bottom bracket to move the chainring to line up with the middle of your gears.

However, you imply that you have a five speed block. I would guess that will cope but it is worth taking it easy to start with as there is a risk the chain could jump off the chainring when in top gear as there is no front derailleur to restrain it which could have painful consequences!

I guess you could keep the front derailleur (but without the changer) if this is a problem.

Peanutt

Thanks TJM,

My local trail is quite varied but I never get the chance to up the gears so I mainly stay in the lowest set, there are a few nice downhills but even then I'm freewheeling.

I might try your suggestion of a bash guard ring as it would probably double as a chainguard and stop it flying off

It is a five speed block so the angle isn't that severe but better to be on the safe side, thanks again for your help.

shin0r

Not a dumb question at all. Quite a few people ditch one or more chainrings. I've ditched the outer ring and put a guard and chain-retention device on, and haven't had my chain jump off for months.

hoathy

You need to check you can remove the rings at all, some chainsets use rivets to hold the rings on as opposed to bolts, so you may be stuck with them unless you buy a new chainset...

coynie

I've done the same ditched the outer ring & replaced it with a bash ring
but left my small ring i took of my front derailleur but somtimes when i change
to the lower gears my chain jumps on to the smaller ring could i put my front changer back on & use it as just a chain retention device with out the shifter
or whould i be better buying chian guide

tjm

I don't see why you shouldn't use the changer as a guide. The only thing you would have to check is whether it has enough adjustment to get it in the right position for the middle ring.