Will I have to get a chain tensioner?

Hi,

My friend shagged his old chainring (probably 42T) so I bought him a new one (43T). He managed to fit the new ring but he can't get the chain back on.

I showed him how to use a chain tool and told him to take out/put in a few chain elements. He tried it but says that it is either so tight he can't get it back on the ring or so slack it's hitting against the frame all the time and comes off constantly.

Is that possible? Or is he doing it wrong?

Cheers
Lenni

EDIT: The bike has vertical dropouts.

What kind of drop outs does he have ?

I am guessing vertical, he might get away with a half link.

Thanks. yes, i forgot to say: vertical dropouts.

Is it SS or fixed?

Chain tensioner is appropriate to SS, defo no-no for fixed.

It is a SS.

Tynan, what is a half-link? Is that something you buy or is it just an ordinary link used only half way?

EDIT: Found the answer. Google is my friend.

hey guys sorry for the grave dig, but just registered and can't post a new topic...
anyway, converted my vertical dropout frame to single speed and the chain is either too tight or too loose, so was wondering if anybody has ever gone about making their own single speed chain tensioner? i know i could buy one easily enough but short on cash plus i like making things myself, any photos/plans/ links would be awesome! cheers guys

Have you tried using a Half link in your chain? It will lengthen your chain by half a link which should help, and maybe eliminate the need for a tensioner. Also, Google 'Magic Gear' and read up on ratios. Sheldon Brown is also an amazing source of info on this.
Enjoy
D!

thanks donut, i know i can use a half link to try and get the tension a bit better, but I'm still messing around with gear ratios at the moment so I want to able to change rear cogs without changing the chain length every time, a chain tensioner makes it so much more convenient, plus ive seen people make them before but can't remember where, any more ideas?

Theres a nice old retro blue one on Ebay at the moment, clamps to the chainstay. Have seen a couple of rather Heath Robinson methods for chain tensioning on the net. I agree though, making your own would be more rewarding.

Viv, don't forget that you can't really use tensioners with a fixed wheel as they really throw off your rear wheel braking.

thanks for all the replies guys! but I saw a few photos around on the net and made my own in about half an hour, looks pretty neat too! Thanks tom, but I forgot to mention I'm only running free hub not fixie! so should be pretty safe..! I hope, lol

^^ it's really hard to see your picture but i think i can assume the it's one of those tensioners that pull the chain up toward the chainstay? I used one of those for a while, but ended changing to the surly singulator as it still left a little too much slack. But as you made it yourself and it works then well done, how is it working out?

yea sorry bout the pic, only had crappy phone camera, lol, but yea, ill eventually buy a proper chain tensioner but pretty low on funds at the moment and it seems to be working quite well, i just used a piece of aluminium and the jockey wheel from my old deraillure! cheapest tensioner I've ever seen haha

i'm new to singlespeeding and was wondering if it was possible to singlespeed a modern bike without using a chain tensioner,or should i possibly look into getting an old frame with horizontal drop outs and follow that route.

Read thru this thread from the start. It will probably ansewr all your questions.

i'm new to singlespeeding and was wondering if it was possible to singlespeed a modern bike without using a chain tensioner,or should i possibly look into getting an old frame with horizontal drop outs and follow that route.

Magic gear, phantom gear, adjustable stays, ebb.. or read the advice offer by Donut! along with Search. mtbr.com used to have a really good SS faq.. try finding that.

Here it is: http://www.mtbr.com/ssfaqcrx.aspx

if you're going singlespeed, just get a halflink (chain). you'll prolly have a few mm to play with in the dropouts for fine tuning.