London Fixed-gear and Single-speed SJS Cycles

Hi guys,
Just joined this website at it looks like a lot of you participate on this.
introduction: i'm a new fixie rider in London - just got my bike 2 months ago 2nd hand and i've only been into cycling for the last 9 months - meaning im not all that good with the mechanics!
the bike: Fuji Track 06 (http://www.fujibikes.com/2006/bikes.asp?id=139)
this is the second time this happens now: chain comes because the lock ring and sprocket get loose, the chain locks in between the sprocket and the spokes - so the wheel gets locked and i see myself skidding over 20 meters (aquaplanning last night after the hailstorm!!). this probably happens becomes im a fan of skid stopping but there must be a way to secure that lockring so it doesnt come out...

I was wondering what i could do to get it sorted! The lockring has got 6 'teeths' and i just cant find the right tool for it... would this work (http://www.hubjub.co.uk/etc/duratoolzm.htm)? also what are the chain attached to the tool for? Could it be because the back wheel is not fixed at the right distance (chain is a bit loose)? How tight should the chain be?

Sorry for so many questions, but i'm sorta new to this!! I hope i can find some answers here :) I dont fancy sending the bike to a store so they 'fix' it and i get to learn nothing new :(

Thanks a mil again!

¬FixAxioN

i used a big flathead screwdriver and a mallet to smash my lock ring on
nice and tightley. havnt had any problems. also when i tightened my sprocket
i broke my chain whip i did it so hard. just be brutal.

The lockring may keep coming loose cause you've buggered the threads. Take it off and visually inspect both the threads on the lockring and the lockingring threads on the hubs.

As for ensuring the lockring stays put you need something like the DA tool you linked too or a Hozan lockring wrench or even an screwdriver and hammer to punch it on. You need to get it nice and snug against the cog.

Now check that theres no gap between the lockring and cog, this can be another reason for the lockring popping off. Some cheapo cogs have narrow shoulders and regardless of how tight the lockring is, the lockring won't touch them to hold them in place.

BTW: the chain bit on the DA tool is for removing the cogs.

heard a few people had problems woth fuji rear hub.
have you tried tightening the lockring with a special spanner?
if this doesn't work the your thread might be gone which unfortunately for you means that you gotta get a new hub.

Could you please rewrite this bit again please


"this is the second time this happens now: chain comes because the lock ring and sprocket get loose,"

It does not make any sense to me.

The hubjub link is a correct tool to do up the lock ring, although if it has come undone several times I would not be suprised if you had striped some threads by now.

Your chainline may be off but it should not be with a newish bike like yours so it prob is your chain tension it too slack, you don't want it too tight either. This is prob what is causeing your chain to come off. Google sheldon and chain tension.

that would suck

if the thread had gone do you
think you could weld it on?

use rotafix to tighten the cog down (http://204.73.203.34/fisso/eng/schpignone.htm). You can put a rag around you BB if you're worried about scratching the paint

If your get a aluminum cog you could but most cogs are steel and most hubs are alu, so in genral no.

ha dt i was about to post that link

arrghh! thanks for your comments.
the bike is about 1 year old (bought it 2nd hand).
i'll try to check if the threads are ok on the hub... i just hope i dont need to buy a new one, but last time i fixed this problem was to put the chain back on the sprocket, and 'pedal forward' so that the sprocket is nicely tight as close as possible to the center of the hub, then use my bare hands to get the lockring (rotating the other way) as tight as i could (obviously i dont have super human strength!). it has been fine for the last 2 weeks...

rewrite, missed out a few words, opps: "this is the second time this happens now: chain comes "off the sprocket"because the lock ring and sprocket get loose"

I will try to check tonight when i get home and maybe also push the backwheel back some more so that there is a bit more tension in the chain.. let's hope the hammer technique works!

you will definitely need to tighten the lockring using more than just your bare hands. the flat-head screwdriver and hammer technique has always worked for me. good luck.

Yep and def use the rotafix method to secure the cog on nice and tight first.

my chain is too short to do the rotafix method.
low gear grrrrrr

You must be doing it wrong un less you chain ring is very very small.

its 38T

38? what are you running at the back? you must be spinning like mad...

i think 15, cant really remember.
i live in wiltshire its quite hilly so i would struggle with anything much higher.

hey guys! thanks for your tips yesterday. I managed to get the lock ring back on after checking if the threads were worn out! I used the technique with the flat driver + hammer :)

The ride into work this morning was great :)

hammer does work but really aint the best method, use a proper chainwhip and lock ring tool, like the dura ace one you linked to. really mate dont just use your hands, that willl never really work. if you are not putting the lock ring on tight this can thread the hub, then you is buggered. maybe try putting a decent lock ring on...dura ace campag (this depends on the thread). but remember no more fingers.

i don't think a lockring is very important, unless you do a lot of skidding - anyone else ride without one?

A lockring is pretty much required if you apply any back pressure to the pedals. Its there solely for safety and in the case FixAxion he obviously needs one if he keeps spinning his cog off.

You may ride without one if you've rota-fixed the bejesus out of your cog, jb-welded it on, used massive amounts of loctite, ride only the track, used vodoo magic [...insert favourite technique for lockring less riding here], but really its a small tiny piece of metal that does a good thing.

the idea of my sprocket being able to spin off when i really need it dont really appeal to me, if you ride on the track you dont need a lock ring, but on the road, better to be safe than sorry. Although i do know of people that have ridden without, though they were quite litttle.

yeah i suppose

The rotafix method is the best bet (if you can work it out). I use it to fit my sprockets without a lock ring on a brakeless bike. After experimenting with tightness it has never come off.

bet i could get it to come off!!

i hope it wont come off again.
but if it does, i would need to change the hub right? Or can i turn the wheel the other way in? It looks like they are the same :O

i do quite a bit of skidding so defo need that ring in!

redrum - can u advise any good shop where to get one in london? I commute from Greenwich to the City.

Also one more thing i wanted to ask about: my backwheel is a bit buckled, when i was adjusting the chain tension last night, i noticed that if i pulled the chain too tight, the wheel would not spin a whole revolution because it touches the side of the frame... I also noticed a spoke which was loose and tried to tight it (by hands again!) but it seems the wheel is not 'true'. Any tips to fix that? :O

you really need to get some tools. get a crank brothers multitool (i've got the 17) which comes with everything you need (including a spoke wrench and chain breaker). as for getting your wheel true, you'll need to do adjust all of the spokes respectively to make the wheel round again. the longer you ride a buckling wheel, the worse it will get.

Well i work at putney cycles in south london, so if you've got spd shoes then you're welcome to come and try (provided you don't weight 18st). Not sure what sort of bet you had in mind, perhaps just a sporting challaenge?

sounds like fun, but must tell you im a fat bastad. the reason the lock ring is used is to keep the sprocket on.





brick lane bikes for bits...jan and others are all good. but im biased because they mates, but there prices are similar to condor. as for the wheel, if the other side has two different size threads...one for sprocket and the other for lockring the its fine to flip the wheel.

truing a wheel....best try http://www.sheldonbrown.com/tooltips/truing.html or http://sheldonbrown.com/wheels/index.html give you an idea of what to do. basically for wheel truing if for example the wheel touches the frame on the left side of the bike then this means that you need to tighten the spokes on the right hand side. if its a long buckle the simply find where it starts and finishes and tighten everything on the opposite side.(although this is only for horizontal truing not lateral)


i hope this makes sense, best to check the links.

Something like this keeps happening to my bike. I got the local shop to tighten up the sprocket and lockring for me so thats not the issue.

I've had a look at the hubs thread an it appears to be slightly damaged at the end of the sprockets section. Would this account for the lockring and sprocket flying off? I would have thought the lockring would have still done its job if its thread was intact?

Any suggestions on what might have caused this in the first place?
My hub is a suzue basic and sprocket is an alloy token 15T. Is it possible that the sprocket is the wrong diameter for the hub, or are these sizes standard?

are you trying to use a bb lockring on a track hub?

Don't think so. I've tried the lockring that came with the hub and a spare a friend gave to me.
They both tighten in an anticlockwise direction or equivalently in the direction of reverse pedaling.

http://204.73.203.34/fisso/eng/schpignone.htm

Know others have mentioned but not sure if anyone's provided a link

^^that is a dangerous link, claiming the technique eliminates the need for a lock ring. It's interesting theoretically, but moronic practically. someone's going to get hurt.

YEah I've seen that before. tried that method aswell and they still both pop off when I break hard. Its really altered the way I ride now which is not very fun.

Is it the case that when the threads go (if only slightly) the Hub is useless?

Have you got a freewheel hub and you are using as a fixed hub? I was told the other day, fixed should have two size but on the hub, one for sprocket and one for the lockring. Freewheel tends to be on uniform size. Correct me if i am wrong.
I know some people use the freewheel hub and then use loctite glue on the sprocket and lr to stop that happening when braking.

I have a flip flop hub and Im using the fixed side.

It seems like the threads are damaged and are casuing my problem. Although the question I had about the diameter of the sprocket was because when I was screwing on the sprocket I noticed there was a little give in its motion, say of about 1-2mm. It seemed like the sprocket was slightly too big for the Hub threads. !

Fucked threads=new hub time.

balls.

any suggestions, as this one seemed a little short lived. I can keep the same Sprocket?

Maybe make sure you get a cog/sprocket that fits the hub properly this time if that was the case?

If you want cheap as chips then go for formula hubs, mine lasted ok, although I did strip the cog thread on one side, oh yeah go fixed/fixed that way you have two sides so if you strip one the hub is still useable. Better quality hubs include Goldtec, Profile, Phil Wood, I personally run goldtec and they seem pretty good so far, a lot of people swear by the other brands mentioned as well though.

cheers

Your sprocket is probably ok being that the sprocket is probably some kind of heat treated/tough steel and the hub shell is most likely alloy so its unlikely the threads on the sprocket are damaged, but clean it up and check just incase, and check that it fits your new hubs properly before fitting it, if not just get a new sprocket.

Get us some HQ pics and we can see if the threads a fooked.

YEah will do. Its been riding fine over the last few days with no problem when braking hard and general commuting though so im a bit reluctant to take it off just now..... but I will get some picks over the next few days.

Damned, just found this thread after a quick search on the forum.
The geometry of my beater (a converted old MTB with 700c wheel) make it quite though to skid with... I have to exagerate puting my weigh at the front of the bike and really have to push hard on the pedals... Comparatively, with a similar gear ratio on my other fixed bike (converted old Holdsworth touring) I can skid quite easily...

Anyway, yesterday, I was trying to skid with my beater and the sprocket started to unscrew. When I arrived home, I took the wheel out to re-tight both the sprocket and the lockring but I destroyed the thread of the lockring. Because it is not the first time it had happened, I really wanted to secure it for good... SHIT! And my hub is not fixed fixed...

Because it's my beater, I don't want to buy a new hub... Is there really nothing to do to that? Would loctite help? I don't mind "killing" the hub by "melting" the sprocket onto it, drilling thru it or whatever, for the lifetime of the sprocket (which is new), and then when it's dead I would change the hub, but for the moment I'd like not to...


(Maybe drilling and fit a spindle in 3 points arround like this? anybody tried?)

Szia

Loic

After weeks of mine being fine it went flying off again. so I'd be up for something like this aswell.

Guess there isn't anything that shouldn't make it more dangerous than having the thing flying off all the time.
Have you tried this yet Vello?
Maybe a shit load of soldering and some superglue aswell?

try using locktite..... the red stuff is permanent..... the blue is a bit more forgiving if you want to remove it again without resorting to a sledge hammer! I use locktite blue on all bolts that could work loose through vibration.... works wonders.

ace. I'll get hold of some of that then. guess any old hardware strore should sell it.