Building Trials Bike, Need Advice

[samwalon]

hi

im new to trial biking, i have been into 'jump biking' and 'mountain biking' ive built a few bikes in my time, so i know what im talking about. my aim of this project is too make a light weight, inexpensive and strong trials bike and ive got a few questions:

first can you use a standard jump bike frame? because i currently have 3 jump bike frames waiting to be used

and i have noticed that if they have a v-brake it is on the back, can you put one on front and back(to save weight) and i personly think they are easyer to mantain compared to disk xD

also can i use 26" wheels, and if i do will i be able to do the kind of things the 'pros' do after a lot of practice(i know i wont be able to straight off, it will take a lot of time :L)

last question: i am using rigid forks but i have 2 types in my arsenal a bit like these two:

http://cgi.ebay.co.uk/eXotic-JUMP-CREATURE-Carbon-Dirt-Street-Fork-40-5cm-/200506533667?pt=UK_sportsleisure_cycling_bikeparts_SR&hash=item2eaf1ee723

and

http://cgi.ebay.co.uk/GT-Rigid-Fork-Disc-mounts-1-1-8th-steerer-/170531847316?pt=UK_sportsleisure_cycling_bikeparts_SR&hash=item27b47d7c94

which style should i use?

i want to only use the parts i have (ie the forks, wheels, frame ect) and to make it as light weight as possible

many thanks

sam

[Franksx2005]

first can you use a standard jump bike frame?

Yes, you could do trials on any bike with good brakes, its just not ideal and would be harder to learn.

and i have noticed that if they have a v-brake it is on the back, can you put one on front and back

Yes you can, a lot of people do, a decent set work well and are light.

also can i use 26" wheels, and if i do will i be able to do the kind of things the 'pros' do after a lot of practice

Yes you can, after lots and lots of practice.

last question: i am using rigid forks but i have 2 types in my arsenal a bit like these two:

http://cgi.ebay.co.uk/eXotic-JUMP-CREATURE-Carbon-Dirt-Street-Fork-40-5cm-/200506533667?pt=UK_sportsleisure_cycling_bikeparts_SR&hash=item2eaf1ee723

and

http://cgi.ebay.co.uk/GT-Rigid-Fork-Disc-mounts-1-1-8th-steerer-/170531847316?pt=UK_sportsleisure_cycling_bikeparts_SR&hash=item27b47d7c94

which style should i use?

I dont know which ones you should use, but again the geos are probably not ideal for trials.

Edited September 7, 2010 by Franksx2005

[samwalon]

thanks thats really usefull

another point on the 26" wheels, would it be easyer to learn and do tricks with smaller wheels? o and what are geos?

thanks again

Edited September 7, 2010 by samwalon

[Franksx2005]

thanks thats really usefull

another point on the 26" wheels, would it be easyer to learn and do tricks with smaller wheels? o and what are geos?

thanks again

I think it is a lot easyier to learn with 20" wheels, but thats just me. check out tartybikes.com to see geos.

Generally, a short chain stay with high bb is good on the the rear wheel, longer chain stays with low bb's are more stable on two wheels.

[samwalon]

o ok, geos being geonomatry (sorry for spelling) and the high bb's, do they go in the bottom bracket? sorry ive just never heard these terms befor :L

[chris4stars]

for your first bike, dont get caught up in 'geos' and all that chat....untill youve riden for a good while, you wont know what you like.

as for bike choice, the 20" vs 24" vs 26"...they all have thier pros and cons, as someone said, check out tarty bikes and some of the videos on there.

best advice though is to try and find some local riders, meet up and ask to have a go...everyone is more than happy to help, and it could save you alot of money in future!

as for something cheap/light/strong...best bet is to go second hand, have a look at the for sale section on here to get an idea of prices. you may have to make compromises though depending on how cheap you want, light and stong AND cheap dont often go together!

*edit, i know you want to use your own parts...you will know the weights of what you have and what feels nicest, not much we can help you with there. if you are reluctant to buy, just get some decent v-brake pads, a grind on your wheel and go from there

Edited September 7, 2010 by chris4stars

[samwalon]

chris.. .thankyou. you havecleared my mind! at last

i think im going to build this:

heavy tools(i hear its a trials bike frame!)

fsa x-drive w. bashguard crankset-32t chainring

wellgo v8-copys

26" Double rimmed front wheel

single speed conversion rear... what size should i go with? 18t, 17t, 15t, or 11?

the forks, im just going to see which is lightest

handle bars- either general riser mtb handle bars or bmx style(with re-enforced bar joining the two sides of handle bars, like this one:http://www.tredz.co.uk/.DMR-Wingbar-Cro-Mo-Handlebars_16894.htm?utm_source=froogle&utm_medium=froogle&utm_campaign=froogle

but the dmr ones would be more heavy

and if i need it a single speed chain tensioner superstar components

o and on my jump bike im trying to do a rear wheel hop.. any tips?

[JD™]

You must have something smaller than a 32t chainring floating about? Consider that the norm would be 18t, and you'll see just how far out that could be. You seem to be going about this the way most people were when I first started - making do with what you have because trials specific parts weren't about. You'll no doubt get a load of greif from people who started after trials specific parts came along and who don't realise that what you're doing is perfectly fine for a beginner.

What you want to concentrate on is the important bits:

Brakes - get some decent ones, and if not, make sure you set up what you have as well as you can.

Drivetrain - you'll be putting a lot of force through this, more than your jump days. You want a well serviced hub and somewhere around a 1:1.1 gear ratio. 22t chainrings are the normal granny rings on MTB chainsets, see whether you've got one floating about that you could couple up to your 18t sprocket.

Tyres - Always good to prevent pinch punctures in your early days.

[chris4stars]

im hoping you are sourcing most of that fromt hings you already have! for what youre building, it really isnt worth spending very much money at all for the benefits you'll recieve (those carbon forks came to mind)

you'll need to re-look at the chainring/sprocket ratios....considering alot of trials bikes run with 18:14 or close, with a 32 tooth chainring youd be looking at a 23-24 tooth sprocket on the rear

so when that bit is sorted, get some decent pads for your v's, a grind on the wheel and you'll be good to go

[samwalon]

ok thanks ive got a new fsa 22t chainring which il put on and chris what do you mean by a grind on the wheel :L and in your opinion are shimano deore v-brakes good, on my mtb theyre dead stoppers,but can they handle the ruff and tumble of trial biking?

[chris4stars]

im not the person to ask about v brakes im afraid!

the stopping power of a brake needed for trials is huge in comparison...so how it performs elsewhere may not be the best indication

http://www.tartybikes.co.uk/media.php?group=guides&id=2

this is giving a rim a grind, when used with a decent brake pad it gives your brake the bite and hold you need in trials. there are pads specific for smooth rims, but the vast majority of people will use a grind.

[samwalon]

ok il do the grind hopefully i wont much it up :L