Questions Regarding Trials Bikes

[Alexthelyons]

First off, what is the preferred/normal place to have the freewheel. One of my mates has one at the front on the cranks, another of my mates has a profile cassette hub on the rear. Where is best?

Second, do all cranks fit into anything, or is there loads of differant sizes. I ride bmx and they just have 3 differant sizes (mid,us and Spanish.) so I thought that trials bikes might have loads of sizes.

Third, my dad says I shouldn't put tar on brakes. I know alot of people on here do, but he says not to. Do you tar both brakes or just one of them?

Fourth, can the sprocket (or whatever you call it) on the back wheel (for fixed rear wheels) be taken off, if so, how?

Fifth, 20" and 19" wheels, can I put a 19" wheel on a bike that comes with a 20" wheel?

Thanks for any replys, I want to have knowledge on bikes before I buy one.

I bought a bmx years ago without any knowledge at all and got a pile of crap.

[Maladie]

First off, what is the preferred/normal place to have the freewheel. One of my mates has one at the front on the cranks, another of my mates has a profile cassette hub on the rear. Where is best?

Second, do all cranks fit into anything, or is there loads of differant sizes. I ride bmx and they just have 3 differant sizes (mid,us and Spanish.) so I thought that trials bikes might have loads of sizes.

Third, my dad says I shouldn't put tar on brakes. I know alot of people on here do, but he says not to. Do you tar both brakes or just one of them?

Fourth, can the sprocket (or whatever you call it) on the back wheel (for fixed rear wheels) be taken off, if so, how?

Fifth, 20" and 19" wheels, can I put a 19" wheel on a bike that comes with a 20" wheel?

Thanks for any replys, I want to have knowledge on bikes before I buy one.

I bought a bmx years ago without any knowledge at all and got a pile of crap.

Where you have the freewheel is completely up to you mate. In my opinion, you should run a front freewheel on a mod (20"), on a stock (26") it doesn't matter as much.

There a few different size cranks yeah, if you want to replace the original cranks that come with the bike, just simply buy the pair of cranks you want in that size.

Your dad is probably right, because you tar the rim, not the actual brake or brake pad

It can be taken off yeah, i dunno how but someone else will tell you

No.

[Alexthelyons]

Thanks, when I said tar my brake, I meant the rim. Can It be done on discs?

[Jamie_Trials]

First off, what is the preferred/normal place to have the freewheel. One of my mates has one at the front on the cranks, another of my mates has a profile cassette hub on the rear. Where is best?

There is no best, freewheels on the front always, otherwise the geaaring is too big, freehubs on the back.

Second, do all cranks fit into anything, or is there loads of differant sizes. I ride bmx and they just have 3 differant sizes (mid,us and Spanish.) so I thought that trials bikes might have loads of sizes.

Don't fully understand you there, there's square taper and ISIS. The pedal threads are the same too,

Third, my dad says I shouldn't put tar on brakes. I know alot of people on here do, but he says not to. Do you tar both brakes or just one of them?

Ok, don't listen to your dad, just apply a small amount and it should be fine, you can always get it off anyway if you want to.

Fourth, can the sprocket (or whatever you call it) on the back wheel (for fixed rear wheels) be taken off, if so, how?

Yeh, it is the sprocket and all you have to do is, put some chain links on your sprocket and clamp it to a vice, spin the wheel. If it has a cassette lockring then you need to buy a tool.

Fifth, 20" and 19" wheels, can I put a 19" wheel on a bike that comes with a 20" wheel?

Bad idea, never tried it but the logic goes against it, don't think the brakes would work.

Thanks for any replys, I want to have knowledge on bikes before I buy one.

I bought a bmx years ago without any knowledge at all and got a pile of crap.

Hope I helped

[Teeboon]

Thanks, when I said tar my brake, I meant the rim. Can It be done on discs?

I was told you cant put it on discs just rims Hope that helped.

[Alexthelyons]

Thankyou, both of you

When you said " buy cranks in that size" what are the sizes. As in bb sizes, not lengths like 170mm and such.

Edit: just realised you answered my question in the quote. So ignore what I just said,

where are these threads on the cranks?

Edited edit: I really need to read and remember more.

Just scrap everything I said in this post

Edited August 16, 2010 by Alexthelyons

[Alexthelyons]

I just googled freehubs and freewheels. So freewheels allow you to coast, and freehubs are locked on the wheel so it can't coast.

But because you have a freewheel on the front you can coast. Is it possible to have a freewheel on the front and back?

So it would be like 16-15 gearing instead of like 18-11?

[Revolver]

I just googled freehubs and freewheels. So freewheels allow you to coast, and freehubs are locked on the wheel so it can't coast.

But because you have a freewheel on the front you can coast. Is it possible to have a freewheel on the front and back?

So it would be like 16-15 gearing instead of like 18-11?

That doesn't sound right.

A freewheel is a type of rachet mechanism that means, when installed on a bike, you can pedal forwards to move forwards, and you can stop pedalling and you'll keep going.

Anyway, a freewheel, whether it's on the front or the back, does the same thing.

A freehub is simply a hub that has the freewheel mechanism built in. On a mountain bike typically it's mounted inside a slotted barrel that you can slide sprockets onto. On a profile, it's a similar system but the barrel is much shorter so you can only fit one sprocket onto it.

If you're using a mod, 20" bike, then you'll be looking at 18-12 gearing. Having a freewheel on the front is usually the cheapest option. If you use a profile, it'll probably come with a 12t sprocket, so you'll need a fixed 18 sprocket on the front.

You CAN use a freewheel on the front and the rear, but it's absolutely pointless, you get no benefits whatsoever, and it costs you more money to set up.

Now your other questions...

Mods usually come with the freewheel on the front, it's the cheaper option. I'd stick to that.

In trials, and mountainbike you have one type of BB shell, which is what you know as Euro.

BBs for trials come in two splines, square tapered and isis.

In BMX your cranks have the axle in the BB, but in trials the axle is inside the BB, hence the need for standard fittings!

You can buy cranks in a few lengths, and to fit square or ISIS. I'd personally recommend ISIS as it seems to be a more durable spline, there's more choice for cranks and BBs in trials, and the cranks don't come loose as much, unless you ruin them.

Tar is an option for making rubbish brakes work better. If you have a standard brake set up - magura's own pads, and a smooth rim, by all means use some, but only use a tiny bit, don't overdo it or else you'll find your brake sticking.

I'd leave it at that. If you have the money, buy a better set of brake pads, an angle grinder, and maybe a brake booster. The angle grinder's used to roughen the rim's surface, which when you think about it, sounds obvious as to how it makes the brake better. However, if you use shit pads like the standard magura pads, they will disintegrate, hence the need for better ones that can cope with a grind. You won't look back.

Next, yes you can get fixed sprockets off from wheels and cranks.

Bear with me -Tartybikes is seen to be the best place to get hold of trials parts.

However they do have a section of videos, some of them explaining products - I suggest you watch them - and some of them explaining how to do mechanical tasks, including how to set up your brake, and... How to get those tricky sprockets off!

FInally, no, a bike made for a 20" rear wheel has brake mounts set up for a 20" wheel, so if you put a 19" wheel in there, you can't use the brake. Unless you have a rear disc brake...

[Alexthelyons]

With the freewheel I meant that. Still confused about freehubs.

Does it allow you pedal and coast forwards or is it fixed?

[Revolver]

It does the same job as a freewheel, its just built in.

[Alexthelyons]

Ah I get it. Arnt those called cassettes? Like the profile.

Is it true that if you have a front freewheel you have to use loctite on it because they come loose?

[Revolver]

No, they're called freehubs.

A cassette is actually the 5, 6, 7, 8, 9, 10 gear cake that you have when you use gears, which fits onto the freehub.

No, that's not true either, otherwise they'd always be undoing. They always get tighter, which is why they're hard to get off.