Single ring on 857

[Hammer]

Hey single-ring heads..

I am building up Bills old faithful 857 frame for my GF, wantig to keep is easy for her I am going with a single front 36T pre-compact chainring.. and an 8sp block on the rear.

Should I be prepared for the chain to fall off the front right without a front mech??  I want to avoid a noisy chain device to hold the chain on at the front, but I also want to keep it simple and uncluttered so dont want to fit a front mech, only to lock it out with regard to holding the chain in place....

I know somebody here had a loaner bike without a big ring... but I wonder was it only running a midle ring...?

I also know that I rode callums beast for a ride one day... and that had only one ring, but I think it might have had a chain device too.....

Help, advice.....

Hammer.

[shovelon]

Hammer,

I have not run single up front, but did have an experience with a floppy SRAM rear derailluer. I was missing shift like crazy.

What helped was a Billet Industries rear derailluer tensioner. It had a spring that pulled back the pulley cage at the bottom. The arm that the other end of the spring went to bolted under the skewer.

The great thing is that it alowed the derailer to float. This setup may keep the chain tension up enought.

Have not had to use it lately since I exploded that derailluer, and went with XT and XTR.

Terry

[kiwi]

if the chain is the right length and the d has enough tension it will be ok wont it?Perhaps retain the front d adjusted to the right position with no cable just as a guide.

[Hammer2]

Being a plonker, I tried to log on from home instead of the office, and as I am always logged on at work, I have forgotten my password since the last time I punched it in about 2 years ago...!!
So this is me... Hammer, the Hammer.. the Hammerhead hammer.. just with a temp log on until I get it sorted out.

I went with the single ring and had to use a front mech, locked down to stop the chain jumping off when it is on the larger cogs on the cassette... but it is not noisy and GF is thrilled to have a REAL bike now, instead of a rigid singlespeed...
Thanks to Bill, (carbon Angus) for sending it to me... I'll take care of her, and pictures will follow, you ahve my word.

Take it easy,

Hammer

[Carbon_Angus]

Glad you are enjoying the bike and and the adornment on the seat is liking it as well.

are you still running the same BB? just curious as it is original.

please send me the pictures you can't send anyone else....hehehe

Bill

[willem]

Hammer,

I run a single (middle) ring on the front end of my 856 "loaner" bike.

I ran without a roller for a while and it jumped off the ring pretty often.

The 856 pivot just happens to be located perfectly for a top roller wheel. That and a tight rear der spring seem to work great for pretty much everything. It's also very pretty and light. (Functional simplicity is beautiful!)

A non-cabled front der might just do it for you. Fairly light and simple. I didn't go that way cuz I really wanted to eliminate parts.

All the other options I considered were high friction, higher weight, and high $$).

If you're running an external BB on your 857, you might be able to get a fairly simple MRP type setup.

[rapiddescent]

remember to run it in the middle ring place so the chain doesn't jump off and make sure the spring is quite strong in the rear mech.

I do this with the 856 in singlespeed mode.

also, you can get old school chainring protectors that will keep the chain in the right place!

callum
rds