Bicycle Thread

[Birds]

1,000th reply.

[xALmoN]

it's probably still better than wd40, but not gear. As long as you wipe off the excess, which will attract dirt and make your chain wear out faster

of course we wipe off any drippy drippy.

but yeah, its cheap, and works well enough.

[*LOACH*]

Disc brakes plus falling snow equals noise plus perpetual motion.

[mad082]

lol. carbon wheels in the rain are a bit like that. you put the brakes on and it feels like you are speeding up

[*LOACH*]

By the way for some reason when I put a whole bunch of torque on the pedals sometimes it freewheels (goes out of gear) and back in again by itself. Did it a couple of weeks ago and my toe dragged on the ground - little bit of rash and a sprain. Any idea why it would do this? Thanks in advance.

[mad082]

so you are pedaling and it skips/slips? it could be one of 2 things. 1: the freewheel mechanism is slipping due to being sticky or worn. 2: the chain and cassette is worn.

to check the chain for stretch you really need a proper tool, but there are ways to sort of tell. put it into the big chainring at the front and try pulling the chain away from the chainring. if you can lift it away from the chainring (it will only be a mm or so) then the chain is stretched. also run your fingernail along the teeth of the freewheel/cassette from the back of the tooth to the front. if it catches on a burred edge at the front edge of the tooth then the cassette is worn and the chain will be too.

[*LOACH*]

Thanks heaps for the info. sounds like it is not going to be cheap/easy to fix.

[mad082]

if it's only the chain/cassette then they are pretty cheap.

i also found a way to check your chain stretch without needing a special chain checker. you do need a set of vernier callipers though. set them to 132mm, insert the back section (the bit you use for measuring inside diameters) into the chain. they should go in 6 links apart (a link is an inside plate and an outside plate). if you have the left side against the left hand pin in an outside link, the other end should be against the right hand side of an outside plate. make sure it is contacting the roller and not the end of the plate. then expand the callipers. if you have digial ones then they will be best, but you can sort of estimate with analogue ones. if your callipers read anything over about 132.7mm then your chain needs replacing. if you get to 133mm then there is a good chance that your cassette/freewheel will need replacing, and anything over 133.2 and your chainrings should be inspected too, as they may not accept a new chain.

chain wear 101:

the reason why you can't run a new chain with a worn cassette is that the stretched chain doesn't grip on the cogs properly and ends up riding up the teeth. so your pedalling force is over a smaller area of the teeth, which squashes the metal. in some places it will sit where it should, but further around it will sit up higher. when you then put a new, shorter chain on, it will sit up high on the teeth the whole way round, and when you put pressure on it will just skip up over the teeth, resulting in bashing your knees on the bars. replacing your chain before it gets too stretched drastically improves the life you get out of your chainrings and cassettes. you don't have the chain riding up the teeth as much. if replaced before getting too stretched, you should get 2 or maybe even 3 chains per cassette, and 4 or 5 chains to a set of chainrings (unless you spend a lot of time in only 1 or 2 gears, in which case you may get less).

things that increase chain stretch rate are not lubing your chain, 'cross gearing' (for example using the big front chain ring and the biggest cog at the back, or the small front chainring and the smallest cog at the back), and "grinding" rather than "spinning" (riding with a low cadence and pushing hard, rather than using an easier gear and spinning a bit faster).

[ARTZ]

Hey marc you bike guru you...I got an old mtn bike, pretty much everything is clapped out on it but aluminium frame is nice and light...has front and back suspension but needs new shocks on the front especially...also gears ,cassette I want to replace..want to run a single on the crank and it currently has 7 on the rear which I can live with..

want to get some reasonably good quality stuff to get me going again then if I stuff the frame I'll replace it later...

could you give me tips on some reasonable quality stuff without spending a fortune..for starters need Crank with single cog, rear cass and derailer and front forks for a start...needs better wheels and rear shock but will do later.

[ARTZ]

Hey marc you bike guru you...I got an old mtn bike, pretty much everything is clapped out on it but aluminium frame is nice and light...has front and back suspension but needs new shocks on the front especially...also gears ,cassette I want to replace..want to run a single on the crank and it currently has 7 on the rear which I can live with..

want to get some reasonably good quality stuff to get me going again then if I stuff the frame I'll replace it later...

could you give me tips on some reasonable quality stuff without spending a fortune..for starters need Crank with single cog, rear cass and derailer and front forks for a start...needs better wheels and rear shock but will do later. Needs chain,pedals,seat as well (yep it's well stuffed ) but that stuffs basic enough..

[25GTT]

I am no where near as much as a guru as Marc, but to be honest from my knowledge (as minimal as it is) from the shopping and 4 bike purchases i have made, to replace all that you really are better off buying a new bike

Dependant on the terrain and frequency etc, Cogs, derailers, gears, shocks etc to get a decent set will cost you close to 1k Shimano are always nice, but for 1k you can get a nice new Giant or Apollo.....

Edited January 7, 2013 by 25GTT

[ARTZ]

yeah i know im probably bonkers but I dont have 1k, atm, I feel like building something and I like to customize things... .

front forks I am pretty sure I can pick up a good set s/h, lots of people always swapping them out...

the rest of the stuff is reasonably cheap, shimano derailers are under 50$ online cogs are cheap...

cranks are gunna sting me probably...so whats a good way around that...

I guess what i really want to know is what brands and such represent good value for money.. is a 30$ shimano derailer going to work or do i need to shell out 200$ etc..im no crazy downhill racer, hell i barely even ride anymore, but Im sure once i get moving again it will all come back to me...but first I need to get moving again

[25GTT]

shimano and SRAM are always good brands so i would like to say yes.

Keep in mind a derailer is only as good as the rest of the gearing as well. Marc is definately the best to speak to about this stuff but you can get "groupsets" for the bike which would be perfect.

Might i suggest a couple of websites

Bikeexhange.com.au (good sourcing of second hand bikes and parts in oz)

Chainreaction.com (UK based but customer service is fantastic! cheap parts but you must ensure you get their advice on what to get, this would be ideal if for some reason Marc couldnt help)

Wiggle.co.uk (really cheap parts but in my 18 - 20 dealings with them, their customer service is poor, only order from them if you know exactly what you want, trying to get help from them is like trying to squeeze blood out of a stone sometimes....

Obviously shop australian if you can, but if you get stuck try those other 2.

What bike is it and specs from there we can look at what to do. To be honest i am now more knowledgable on flat bar road bikes due to the great info i have learnt on here, i might be a bit limited on Mntain bikes but will try none the less :-)

[mad082]

ok, so there are a few things to consider. i'll start with the forks.

a new set of entry level rockshox forks will set you back about $300 (all the prices i quote will be normal aussie prices, so you could get stuff cheaper online, etc, but some stuff you will need to make sure you get the right ones as there are variations). a set of air spring forks (use air pressure instead of a coil spring) start from about $450 to $500. when shopping for second hand forks you need to check for signs of wear (look on the upper legs around where they go into the lowers). if there is any side of wear, generally on the inside of the leg, then steer clear. also you need to bounce on them to make sure they don't make any noise either going down or when they come back up. as well as making sure that they feel nice and smooth. find out when they were last serviced/had new seals put in, etc. only look at fox or rockshox forks. they are the ones that are the easiest to get spares for and to service.

as for rear shocks, if the bike is a cheaper bike that only runs a basic coil spring setup and not an air shock, then don't even bother. you would probably be better off getting rid of it and get a hard tail frame from somewhere. the problem with bolting a new shock into an old frame is that A: you have to make sure you get the right sized shock for the frame, and B: you have to hope the valving of the shock suits the linkage setup, otherwise it will ride like crap and the shock might not work very well. and rear shocks are expensive. even cheap ones.

as for running a sinlge speed setup on the cranks, if you have cranks with removable chainrings then you can just pull the old chainrings off and get a single speed chainring to suit. don't try and run a chainring off a multispeed crank as a single speed ring. it will throw the chain off all the time as the teeth aren't all cut straight. some are cut at an angle to help change gears. we generally sell renthal single speed chainrings. they are very good quality and not super expensive. we have a customer who rides a lot and wears stuff out much faster than anyone else i've ever met. he's an old guy who just rides a lot. he completely wore a chain out in 3 rides (about 150kms total distance) on his single speed. single speeds (true single speeds) are hard on chains and cogs because you put a lot more stress on everything. you can just click into an easier gear and spin a bit faster. you just have to stand up and grind up hills.

as for the rear gears, if the current setup is only a screw on cluster then you can only stick with 7 gears without changing wheels. if it is a 7 speed cassette, then you may be able to get an 8 speed freehub body and run 8, 9 or 10 gears should you desire. obviously that would require a different shifter, chain, cassette and derailleur. running 8, 9 or 10 speed will allow you to have a greater gear range. 7 speed freewheels are only available in 14-28 or 14-34 gearing. similar for cassettes. but the 14-34 will be mega range, so there is a big jump between 1st and 2nd. 8 speed and greater will have a more even spread gearing, as well as going down to an 11 or 12 tooth on the rear, meaning higher top speed.

for rear derailleurs, running 7 speed will limit you to a certain extent. just stick with an acera or altus 7/8 speed derailleur. they work fine. you won't get much benefit from going to a better one on a 7 speed. they retail for about $40 to $50 from memory.

for cranks, since you will be putting on a new chainring, if your current cranks don't have removable rings, you can just get something second hand off ebay. just take note as to whether you will need a new bottom bracket or not. but if you get something that runs external bearings than it will be stronger and last you longer down the track. something like shimano SLX. i'm not sure if they do an alivio 9 speed 2 piece crankset or not, but i have an feeling that they do.

the only other thing you may need for a single speed is a chain device. you can sometimes get away with running the front derailleur as the chain device (just use the limit screws to position the derailleur in the right spot). you don't need one with a tensioner at the bottom, just the guide at the top. if you go a set of cranks with external bb bearings then you just mount the guide instead of using 1 of the spacers required. the guides are a little bit noisey though. you get a bit of chain rub, as you would also with using a derailleur.

well that should give you a bit of info to start with. if you need anything else, just ask. sometimes it can be easier to try and find a bike second hand that has parts that you want, buying it and then selling off what you don't use.

[ARTZ]

Thanks very much for that wall of text Marc, was very informative.

But after much deliberation a look at my bank balance and realisation the bike probably isnt worth the effort..

i just put a new chain on it

It wasnt as bad as first thought, the back axle was loose and the chain was well rusted ,the combination of this completely stuffed the gear changing of course...but with a new chain alot of wd40 and some fiddling I have nearly all the gears working sweet and they seem to be getting better as I ride it...I tighten the brakes and its as good as new...

the front shocks I think are the old school threaded type so not worth spending cash on, it already has 3 piece cranks too that I cant get off to change cogs even If I wanted too..I belted them no budge

anyway It can do me for now and if I ride enough that it wears out I will just buy or build a new bike...

If it doesnt wear out I obviously dont like riding enough...

I found it at the tip so all up its cost me 60$

weird looking thing hey!!

[mad082]

yeah i wouldn't spend much on that at all. it's a huffy or something like that. something from one of the big retailers (bigw, kmart, etc). and yes, the chainrings on those cranks won't come off. they are pressed on. the ones that will, just have the chainrings held on by 4 or 5 bolts.

as for suspension, you wouldn't get anything worth putting on to fit that (either front or rear).

[ARTZ]

yeah I found a sticker that said "made In china" and another that said "not for off road use"..kinda says it all hey. ..

[Down_Shift]

Hey guys, been wanting to get back in biking so now i have the chance.

I'm just after some casual off road riding and maybe a little bit road but mainly wanting to hit the trails and mountains!

Budget around $600-800

Been to a couple bicycle places and the Scotts Aspect 630, 660 caught my eye. Wouldn't mind the Aspect 940 if the 29er bikes are worth it for me.

I always seem to hear people talk about the Giants, Avanti and Apollo for my price bracket but what about the Scott brand?

Cheers in advance guys.

[mad082]

Scott are decent.

And if it is more open trail/fire road sort of riding you are going to be doing, then definitely go the 29er.

[Down_Shift]

Scott are decent.

And if it is more open trail/fire road sort of riding you are going to be doing, then definitely go the 29er.

Quick question regarding the derailleurs, much difference betweent he Shimano Acera and Shimano Deore? Have you had experience with them or it's not that much of a fuss since they're roughly in the same range...