Perfect Chainstay Length?

[aener]

I'm thinking of getting a marinobike frame made, and thought that it'd be nice not to have to run a tentioner.

I've seen a few people without tentioners, on stocks, so I was just wondering if anyone knew how long the chainstays on whatever frame it is are, and what gear ratio they were running.

Ideally, I'd like to run 22:18, but 18:15 would be Ok too.

If I'm wrong, and no-one's got that - could one of the mechanics/engineers on here have a crack at figuring it out?

I'd do it myself - but I don't really know how :$

Cheers

[RossMcd]

how about trying horizontal dropouts and getting snailcams?

[Luke Rainbird]

18:15 = 379mm stays from what I remember

BT had a little list of a few a while back, I'll see if I can dig it up

[aener]

I had them on a mod, and I'd rather not go back there, if I can avoid it - and seeing as these frames are custom built... I figure why the hell not?

[Muel]

Your best bet is to have a look at the Koxx frames I reckon, on Tarty it says they are designed for 18:15 I think. Well the Koxx Coust is anyway.

[Luke Rainbird]

The following gear ratios can be used without any chain tensioner (plus more!)

18T-15T -> 379mm chainstays

18T-16T -> 375mm chainstays

20T-17T -> 379mm chainstays

22T-18T -> 381mm chainstays

22T-19T -> 379mm chainstays

[aener]

Perfik.

Cheers Luke

[Luke Rainbird]

No problemo - considering the same thing myself at the mo!

Not sure what gearing I'd be running though which is the killer - might even be gears which makes it impossible of course

[Dan6061]

As soon as the chain stretches you'd end up needing a tensioner anyway!

Get horizontal dropouts, and ask him about the dropout design (onza use it now) which is a bolt that pushes the wheel back. I know he can do that, because I asked him.

[Luke Rainbird]

He's willing to try most things it would seem [/inyourendo]

I think those quoted lengths are for a stretched chain, so you could run it for a while with tensioner to bed it in, then remove the extra link and tensioner afterwards

[Greetings]

You can't actually figure it out because of chain stretch.

Example - ran 18:18 and 18:17 on 372mm chainstays and in both cases the chain was tight. It's just that one chain was fairly old and the other was new.

[aener]

Do they stretch that much, then?

I didn't think it'd be enough to matter, for that.

I'd forgotten about the dropouts with the bolts in... Might have to consider it.

Will this be the first 24" with horizontal dropouts? Haha

[Muel]

Nope Ciguenas have horizontal dropouts.

It's a nice idea, but if your going to be playing around with gear ratios then horizontal dropouts are best, I'm running 16:13 and I get quite a lot of chain slap, but I can't get another link out of the chain. I've got my tensioner set really really tight aswell, so I think I'll just have to wait until my chain stretches, then get a link out. I've got a KHE Collapse though, so waiting for it to stretch might not work.

[thefletch]

chain will stretch, rediculous idea/topic.

[Ash-Kennard]

does a khe chain stretch noticably?

if anything it will shrink because of all the stifflinks

Edited September 12, 2008 by Ash-Kennard

[thefletch]

i've never had a chain that's not stretched

[Ash-Kennard]

i've never had a chain that's not stretched

you had a khe?

[Rebelistic]

I think you will need some method of adjusting/tensioing the chain.

For a while on my Echo pure I had a chain that fitted with no need for a tensioner, then I fitted a new chain and new cranks (still same gears) and it no longer fitted perfectly. I had to go back to using a tensioner.

[Mark W]

Stretching was probably the only thing my KHE was actually capable of doing, apart from 'rusting entirely' and 'forming stiff links'.

[Alex Dark]

my zenith ( 18-16 ) with a k910 chain, 375mm stays has to have a tensioner

[Greetings]

my zenith ( 18-16 ) with a k910 chain, 375mm stays has to have a tensioner

Yeah that's my point exactly. I'm now running 18:16 on horizontal dropouts and the chainstays are bang on 375mm. The chain is really tight too. Either way, even 0,5mm will make a big difference here because that length is doubled when it comes to chain length.

[Alex Dark]

Yeah that's my point exactly. I'm now running 18:16 on horizontal dropouts and the chainstays are bang on 375mm. The chain is really tight too. Either way, even 0,5mm will make a big difference here because that length is doubled when it comes to chain length.

precisely...theres no ideal cs length

[Luke Rainbird]

If all drivetrains were made equal, then there would be

Remember a quoted 375mm stay might not be 375.00mm, there could be a bit of error either way to throw things out

[toyota200x]

I have a Marino frame with 382cs and 22-19 gearing. It is almost perfect with a new chain but I do run a 74 kings type tensioner(homemade) and it works great.

[TRA]

ive your LUCKY you can get a frame with vertical dropouts where you not need tensioner, but when you put on chain it will

ALOT too tight , and after 1 week it will be ALOT too slack and you need to change chain.

Having a KHE chain does not help . I have tried .

Go for a vertical dropout with 385 chainstay and put a tensioner on it.

Alot of people have done aswell as i have, building your own special tensioner which does

not use they mech hanger , as the mech hanger is really almost the only downside by

having one .