Singlespeed MTB Chain Troubles

[George L. Porte]

I recently built up a ss mtb. I got an old Marin Frame and fork for 10bux. I used an old derailleur
for a tensioner. I cut the bottom jockey wheel off and it acts as a push down type tensioner. I rode
2 rides this past week (about 12 miles each) and did the RI NEMBA ride Sunday (21miles). I had some
slight slippage/noise on the first two rides under force. Sunday at about mile 15, the chain slipped
on every hill so I resorted to running up to prevent damage. I already have a surly singleator on
order and it should be here for next weekend. Anyone use the singleator? Will it cure this problem?
I am only grabbing about 7 teeth now on an 18 tooth cog. I presume this is the reason. I can't
shorten the chain with the derailleur doohickey because it hits the cog. I am just worried about if
it is the freehub missing sometimes. Is there a way to tell if it is the freehub or the chain
slipping. I will have the singleator soon so I will try that.

FWIW I have never lost the chain (except once due to a crash). I measured the chain line and it
looks good. The chain tracks straight leaving the ring and cog. The rear wheel is a freehub with
spacers to put the cog in the right spot and a Shimano MX66 18 tooth cog. The noise is definitely
coming from the rear. The pedal doesn't move much when I hear the noise. It seems like just one
tooth. When I have wrecked freehubs in the past the misses took about 180 degrees to grab but I
have concerns about the freehub. I just don't know if it is able to handle this abuse. There is a
little bit of wobble in the freehub if I try to wiggle it but my XT freehub on the geary does the
same thing.

I just hate to buy a SS wheel because then my chainline will be off. I think most are like 51mm. I
am using a salsa non ramped ring in the middle of a MTB crank (~48mm). Could I just move to the
outside? My $100 project is now $150 with the singleator. I am putting a new chain too after all
that banging this weekend A wheel will put me at about $250.

It is fun to ride though. I don't even want to ride my geared hardtail anymore. 4 years ago, I
needed a new bike (I needed a sus fork and more gears). Now I want to ride a full rigid singlespeed.

Thanks GP

 

[Cashrefundman]

George L. Porter, IV
> I recently built up a ss mtb. I got an old Marin Frame and fork for 10bux. I used an old
> derailleur for a tensioner. I cut the bottom jockey wheel off and it acts as a push down type
> tensioner. I rode 2 rides this past week (about 12 miles each) and did the RI NEMBA ride Sunday
> (21miles). I had some slight slippage/noise on the first two rides under force. Sunday at about
> mile 15, the chain slipped on every hill so I resorted to running up to prevent damage. I already
> have a surly singleator on order and it should be here for next weekend. Anyone use the
> singleator? Will it cure this problem? I am only grabbing about 7 teeth now on an 18 tooth cog. I
> presume this is the reason.

Consider that the most you can theoretically grab on an 18 tooth ring is 9 and you are not
doing badly.

Are you using a old, used front ring? I say that because the last time I had skipping under load,
which seemed like it must be the rear, it was the front.

I finally concluded this because by jumping on the pedal with the bike standing still and the brakes
applied, and watching and listening carefully.

CRM

 

[George L. Porte]

nope, brand new front ring, rear cog, and chain. I can't make it do it by just stomping a pedal like
you said. I can do it going up my driveway but I can't look back at the same time.

The rear wheel is from my old 7speed bike but it was just installed a few months before I got a new
bike. I don't know if the freehub would go that fast. Maybe with the singlespeed it is taking too
much abuse.

GP "cashrefundman" <[email protected]> wrote in message
news[email protected]...
> George L. Porter, IV
> > I recently built up a ss mtb. I got an old Marin Frame and fork for
10bux.
> > I used an old derailleur for a tensioner. I cut the bottom jockey wheel
off
> > and it acts as a push down type tensioner. I rode 2 rides this past
week
> > (about 12 miles each) and did the RI NEMBA ride Sunday (21miles). I had some slight
> > slippage/noise on the first two rides under force. Sunday
at
> > about mile 15, the chain slipped on every hill so I resorted to running
up
> > to prevent damage. I already have a surly singleator on order and it
should
> > be here for next weekend. Anyone use the singleator? Will it cure this problem? I am only
> > grabbing about 7 teeth now on an 18 tooth cog. I presume this is the reason.
>
> Consider that the most you can theoretically grab on an 18 tooth ring is 9 and you are not
> doing badly.
>
> Are you using a old, used front ring? I say that because the last time I had skipping under load,
> which seemed like it must be the rear, it was the front.
>
> I finally concluded this because by jumping on the pedal with the bike standing still and the
> brakes applied, and watching and listening carefully.
>
> CRM
>
>