Bike Upgrade.

[joe-90]

Does anyone know anything about mountain bikes? I've not used mine for about 5 years because the chain keeps slipping when you press hard on the pedals. I'm guessing that the bottom bracket bearings have gone. I think it's a Shimano taper square crank thingy, but I would prefer to fit a Shimano Octilink type thingy. I'll need a couple of special tools, but they are cheap enough. Any advice? (Other than catch the bus).


Also, I only want it to ride in country park type gravel rather than mud so would prefer slick or hybrid tyres. Any recommends? I'd prefer that they are puncture resistant.

The bike nothing special and is only for occasional use so I don't want to spend a fortune, just average.

Cheers.

 

[hansthebear]

Replace the chain and the cassette, worn chain and chainrings are what cause slipping

 

[joe-90]

Is the cassette the bit that fits in the back wheel? I guess I need some kind of tool to get it off.

 

[hansthebear]

Yea you need a tool and a chainwhip

 

[Brigadier]

Just take it to the shop, Joe - they'll fix the bits that need fixing, so you'll pay only for what is necessary. Imo

 

[joe-90]

I did used to take it to the shop but I thought I might find it a bit interesting to do the work and add to the hobby. I'll have a better look tomorrow.

 

[Brigadier]

I bought an mtb maintenance book by Leonard Zinn, I think. But of a maintenance bible, and as entertaining as you could get on the subject.

 

[Brigadier]

Zinn and the art of mountain bike maintenance.. about 15 quid new from Amazon, or a fiver used.

 

[AronSearle]

This is a really easy job once you have the right tools.

You need to replace the front and back chainsets, and the chain.

You shouldn't need to, but I would recommend sticking to the same brand for all parts (so if you buy shimano chain-rings buy a shimano chain).

As well as a normal toolbox (Allen keys, wrenches etc), You will probably need the following (parts may vary slightly, but this should do 90% of bikes).

First you need to remove the chain, with a chain tool (you will also need this to adjust the length of a new chain).

It's probably cheaper to buy a chainset than buying the individual chain-rings.

To remove the existing one you will need a crank puller

Now you need to replace the back cog rings (cassette), there are two types of wheel, in one the freewheel mechanisim is in the cassette itself, the other the wheel, 95% chance you have it in the wheel so you will just want a set of cogs.

To remove the existing one and fit the new, you need.....

A lock ring

And a chainwhip

(you use this to hold the freewheel whilst so you can unlock the nut on the cogs as you unlock it in the direction it spins, you could make one from an old chain and a bit of wood).

When you put the new one on, tighten it up REALLY TIGHT, and after your first ride, take off the wheel and check again it is still VERY TIGHT!.

Now check your rear derailleur cogs and see if they need replacing

Now when fitting the new chain, put the gears into both the smallest cogs (there are different views on this), adjust the lenght of the chain so that when it is on both the smallest cogs, it looks like this...

Use the chain tool above to remove links until it is the right lenght, now use a magic link to fix the chain.

PLEASE VISIT YOU TUBE FOR A HOST OF USEFUL GUIDES ON HOW TO DO ALL THESE PARTS.

Sadly books are just not as good as an instructional video these days.


Cost excluding tools .........

You can get a chainset, rear cassette and chain for less than £50 if you want cheap ****.

The shimano octilinks are about £40, a decent rear set of cogs +£25, and £10-15 for a chain.

 

[joe-90]

Thanks for that, I've come to that conclusion by doing a Google.

One problem I've found is that the three front chain rings are dead loose and I can wobble them around, yet the bottom bracket thing is quite tight. I guess the crankset has lost it's 'squareness' the bike is about 15 years old so has the old tapered square peg fitting. I doubt that the square peg is worn but won't know until I take the crank off. I'll stick with Shimano stuff.

What do you think of these.

http://www.ebay.co.uk/itm/Bike-Hand..._Cycling_Tools_RepairKits&hash=item3f1d4f1145

 

[AronSearle]

That's not bad for £30, some shops sell the chain tool alone for £15.