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Riding 1x8, front mech useful?
http://www.retrobike.co.uk/forum/viewtopic.php?f=41&t=181261

Author:  bonty98 [ Fri Jan 06, 2012 6:23 pm ]
Post subject:  Riding 1x8, front mech useful?

Hi there,

I´m planning going 1x8 on my privateer.
Can I use my front mech keeping the chain from falling off?
If something more specific is needed, please feel free to tip me :)

I´m planning using my xt m737 crank with a 32T ring.

TIA

/J

Author:  Andy B [ Fri Jan 06, 2012 6:45 pm ]
Post subject: 

You can use a front mech as a chain device to help keep the chain on the chainring

Just use the L & H limit screws to lock it into the desired position

You could use a specific chain device, but if you're using a square taper BB you'll need a seat tube mounted one & I believe that you can only get modern ones such as the E Thirteen XCX ST (pretty expensive, but very high quality) and Superstar XCR ST Chainkeeper - SEAT TUBE MOUNT or Superstar XCR ST Single Ring Chainguide - SEAT TUBE MOUNT

http://www.e13components.com/product_xcx_st.html

http://superstar.tibolts.co.uk/index.ph ... 06db2e2e50

I have the E Thirteen XCX ST on my '95 Marin Team Ti as the Superstar one was not available when I built the bike

I have heard that the Superstar ones are a little flimsy, but at 1/4 of the price of the E Thirteen, I guess you get what you pay for.

Author:  cyfa2809 [ Fri Jan 06, 2012 6:51 pm ]
Post subject: 

Why seat tube mount only?

Author:  Andy B [ Fri Jan 06, 2012 6:53 pm ]
Post subject: 

cyfa2809 wrote:
Why seat tube mount only?
Because the other type use the external BB fitment, you remove one drive side spacer from the BB and the chainguide fits in the BB spacers place

Author:  cyfa2809 [ Fri Jan 06, 2012 7:04 pm ]
Post subject: 

I have fitted them to square taper before?

Author:  bonty98 [ Fri Jan 06, 2012 7:20 pm ]
Post subject: 

Thanks for the replies :)

I´ll try and see if I can use the mech first.
But the e13 version looks really nice.

And yes, it´s a square taper bb.

Author:  J i m s t e r [ Fri Jan 06, 2012 9:22 pm ]
Post subject: 

Sure you need a chain keeper? I've run a 1 x 9 bike for the last two years with nothing but the chain's own tension to keep it there. No problems.

Author:  cyfa2809 [ Fri Jan 06, 2012 9:25 pm ]
Post subject: 

J i m s t e r wrote:
Sure you need a chain keeper? I've run a 1 x 9 bike for the last two years with nothing but the chain's own tension to keep it there. No problems.


Really? I tried that before converting to chain devices as my chain would fall off 3-4 times a ride.

Author:  Andy B [ Fri Jan 06, 2012 10:13 pm ]
Post subject: 

cyfa2809 wrote:
I have fitted them to square taper before?
which ones were you using and how were they secured?

Author:  cyfa2809 [ Fri Jan 06, 2012 10:31 pm ]
Post subject: 

Erm would have just been normal bb's something like un54 etc.
and blackspire ds1 and a truvativ one which i dont know the name of and another truvativ double roller style one and another couple which i cant remember. Secured just by tightening the bb with the device sandwiched in between frame and bb.

Author:  Dead Rats [ Fri Jan 06, 2012 10:44 pm ]
Post subject: 

better safe than sorry I say, get a 'dummy' mech on there and lock it into place, if the L screw fails to push it out far enough you can replace it with a 1-2mm longer bolt - oil the thread as you usually have to really screw it down a lot!

save about 2g by removing the cable clamp bolt / nut / washer! :P

you could use an unramped ring, an outer bash / chainguard too? skinflints like me (and cyfa) make their own bash /chainguards by grinding and filing off the teeth of an old 42 outer :wink:

also don't forget to run the chain as short as poss, and get the chainring right in the middle (in your case just between 4 and 5) on the rear cogs. If you have a choice of running chainline better for low gears or outer gears think which you use most

1x8/9/10 is not kind to your chain!

Author:  Dead Rats [ Fri Jan 06, 2012 10:52 pm ]
Post subject: 

cyfa2809 wrote:
Erm would have just been normal bb's something like un54 etc.
and blackspire ds1 and a truvativ one which i dont know the name of and another truvativ double roller style one and another couple which i cant remember. Secured just by tightening the bb with the device sandwiched in between frame and bb.


while that does affect your chainline, it can be corrected with a big box of washers as I'm sure Josh can testify!

Author:  cyfa2809 [ Fri Jan 06, 2012 11:05 pm ]
Post subject: 

Mmmm damn right. The world of bikes eh, so many possibilities!

Author:  Dead Rats [ Fri Jan 06, 2012 11:08 pm ]
Post subject: 

cyfa2809 wrote:
Mmmm damn right. The world of bikes eh, so many possibilities!


Straight up baby!

As I said in another similar thread recently, I'm starting to think that 1x7 is actually the best set up for a multi-geared single ring set-up, 8/9/10 is just too much for poor old chainy :shock:

Author:  cchris2lou [ Fri Jan 06, 2012 11:30 pm ]
Post subject: 

1 * 10 wuld be ideal for me .

currently running 1 * 9 , with a 34 at the front . would be too hard for bigger climbs . with a 36 at the back , would be a lot easier

Author:  cyfa2809 [ Fri Jan 06, 2012 11:46 pm ]
Post subject: 

1x 8/9/10 is tough on chain? Surely the same as 7? Or is the load ditribution a factor as a 7 chain is wider? And less to shift.

Ahhhh 1x 10 i see as a gimmick. In the end we will all have 1x electric!

Author:  Dead Rats [ Fri Jan 06, 2012 11:50 pm ]
Post subject: 

cyfa2809 wrote:
1x 8/9/10 is tough on chain? Surely the same as 7? Or is the load ditribution a factor as a 7 chain is wider? And less to shift.

Ahhhh 1x 10 i see as a gimmick. In the end we will all have 1x electric!


8/9/10 cassettes are wider laterally than 7 sp

Author:  cyfa2809 [ Sat Jan 07, 2012 12:13 am ]
Post subject: 

So more side to side stress.

Author:  bonty98 [ Sat Jan 07, 2012 2:16 pm ]
Post subject: 

Thanx a lot for all replies :D

I heard that the chain falls off a lot if you don´t have a chain device.
I thought using my old front mech and see if it works.

I really wanted to not use one, ´cause the clean looks would be great :)

Lots of nice tips, thanx!

/J

Author:  Dead Rats [ Sat Jan 07, 2012 2:38 pm ]
Post subject: 

I don't think your chain CAN fall off with a front mech if it's nice and short and the mech is as low as possible :D

Author:  bonty98 [ Sat Jan 07, 2012 5:22 pm ]
Post subject: 

I´ll try my utmost ;)

This will be intermittent.
The goal is making it SS. Problem is I´m not in that kinda shape yet!
But I thought this will be a cool way finding out what gear selection that fits me and my trails. And when I saw bryanus bonty I thought I got to try that!

/J

Author:  Senri [ Sun Jan 08, 2012 5:52 pm ]
Post subject: 

Does it really make such a difference (1x10 vs 1x9)? I mean, going from 34 rear to 36 is not even 6%. And then using the even thinner chain...

Phil has a nice chain keeper as well. Available both in seat tube clamp as well as BB clamp. Yes, the chain line shifts a few mm when using the same BB, but I can''t think that that will make such a difference considering the always moving chain line as a result of the shifting.

9 and 10 speed chain have thinner side plates, so more stress on the bearing surfaces and more stretch.

I have riden a long time 1x9 without a chain keeper. It works pretty well, but when your ring starts to wear it will fall off more and more.

SS does not need a chain device of course, even when you use a tensioner, as long as you use a fixed one (not spring loaded), like the on-one.

Author:  bduc61 [ Sun Jan 08, 2012 7:18 pm ]
Post subject: 

J i m s t e r wrote:
Sure you need a chain keeper? I've run a 1 x 9 bike for the last two years with nothing but the chain's own tension to keep it there. No problems.


I am running a 1X8
but with a bash in place of the big ring
find the bash more elegant than the chain guide or mech solution :idea:

Author:  cyfa2809 [ Sun Jan 08, 2012 7:27 pm ]
Post subject: 

But the bash only works for one side?

Dead rats has used the sandwich bash before which may be useful.

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