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Limited Fork Lock


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My self-modified trials special has insufficient fork lock.  I have ground off the fork stops until the fork legs almost touch the frame.  The bike is supposed to have 45 degrees but it doesn't - close but not quite.  Probably not the best fork trail for trials either.  So, doing full lock turns, a requirement our local trials masters love to require, is difficult.
I am working on decreasing the turning radius by leaning into it with my substantial butt as counterbalance.  I am told to not dip my shoulder (which one?) and to look at where I want to go (over my shoulder?).  There is no way I can move the front or rear around - I only have 'both tires planted' skills.  Floater turn?  Don't make me (or the observers) laugh.

I have been doing this for many decades and, like many of my generation, am baffled by the skills that have evolved.  Nonetheless, I would appreciate any tips or coaching.  Footpeg weighting?  Throttle control (the front tire wants to push)?  Front/rear weighting?  

 

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For flat turns, lean it over. Counterbalance the bike weight with your body so you can ride very slowly. Try it stationary to start with. This trains your brain.

Control speed in the turn using the rear brake working against steady throttle.

If you want to learn to do turns with the front tyre off the ground, one way is to practice turning slowly on steeper and steeper slopes (going up to going down turns). This gets you accustomed to riding turns with little/no weight on the front tyre.

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Altering the chassis geometry can help accomplish your goal.  Lowering the front and/or raising the rear will make the bike turn tighter with both wheels on the ground.  This will help prevent the front from "pushing" too.  But, it's all a compromise and the radical changes will negatively impact other aspects of the bike's operation -- like how easily it wheelies and the amount of ground clearance it has.

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Had to look at your other posts to know the problem is TLR200 related, stock forks and geometry are marginal for a competition trials bike, too much rake and trail.   You are leaning the bike into the turn to make the forks stand up more vertical (steeper fork angle) and thereby reduce the turning radius very slightly, but by applying that lean technique eventually the tire contact patch is too far ahead of the axle and forward travel becomes unstable.  The stock TLR200 forks have a leading axle (axle is forward on the lower fork leg) and that wheelbase lengthening feature is to make the bike more stable at road speed but also increases the bikes turning radius.  

If you are worried about your shoulders, that sounds like you are riding the bars and not the pegs, bend the knees to crouch more and that will have you riding the pegs more and weighting the bars less.  Nice bowleg stance and weighting your pegs on the outside helps give better control, but stock TLR200 footpegs are not good, upgrading pegs to a more modern, wider, more aggressive footpeg is a good upgrade that can improve your riding style.  Need to see the bike and you riding it to know better 👍 but you likely need a motorcycle upgrade to take your riding skills to the next level.

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Thanks for the responses, Konrad and lemur.  

I have ridden trials for 65 years but my skills stagnated about half of that ago.  I have had several this or that trials bikes in the garage continuously, including state of the art (like a new TRS last year).  No, this is not any of those nor the Reflex. 

It is a modified non-trials electric and the geometry has been put as close to ideal as possible without cutting and welding.  But that leaves insufficient fork lock, wrong trail, etc.  It's not bad and fun as all get out to try to ride it through the easier sections. 

So, I need to compensate for the bike's shortcomings with technique.  You gave me some good stuff to try and to think about.  Thank you!

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7 hours ago, feetupfun said:

For flat turns, lean it over. Counterbalance the bike weight with your body so you can ride very slowly. Try it stationary to start with. This trains your brain.

Control speed in the turn using the rear brake working against steady throttle.

If you want to learn to do turns with the front tyre off the ground, one way is to practice turning slowly on steeper and steeper slopes (going up to going down turns). This gets you accustomed to riding turns with little/no weight on the front tyre.

Great stuff.  Thanks!

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So, with maximizing the bike's turning, don't want to go 21" and have not tried sliding the forks (they are already 1/4" from encountering the bars).  Been thinking of trying a riser and see what happens.  Other mods?  Trials tires with sponge-balls in rear (torque overpowers the 3.5 tire) and no room for a 4.0, homemade seat pad, lanyard kill button, "get home" switch if kill button or key fails/gets lost, switch to disable the power-off from the left lever (switch between simulated clutching and rear brake only).  In-process of engineering a 2-position throttle stop for "tick over".  Other oddball stuff.  What fun making burlap purse from a pig's ear.  Eventually getting an Electric Motion but I have such great trail distance with this battery. .

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16 hours ago, jwalsh said:

What fun making burlap purse from a pig's ear.  Eventually getting an Electric Motion but I have such great trail distance with this battery.

Is that a Beta Explorer?

How far can you go on a charge?

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52 minutes ago, konrad said:

Is that a Beta Explorer?

How far can you go on a charge?

Yes - 2024.  I ride 2-3 hours at trials pace at an event or tough trail riding.  My ten bars drop to 8.  Seems to still have full power at end of it.  You might know it has 3 modes, turtle, rabbit, and rocket.  I only use turtle.  It has so much toque/acceleration there I don't need more.  Claimed range is:  

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You might have started with saying it's a Beta Explorer.  If Beta wanted to make the explorer into a trials bike they would have started by not fitting it with USD forks and enduro style geometry.  Your wheelbase is likely about 3 inches longer than a typical trials bike, front fork travel about 3 inches more front wheel travel than a typical trials bike and it can't fit real trials tires, making it about as much of a trials bike as a surron is.  No amount of riding technique or lean angle or grinding down steering stops is going to change the nature of the bikes original design.  

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10 hours ago, lemur said:

You might have started with saying it's a Beta Explorer.  If Beta wanted to make the explorer into a trials bike they would have started by not fitting it with USD forks and enduro style geometry.  Your wheelbase is likely about 3 inches longer than a typical trials bike, front fork travel about 3 inches more front wheel travel than a typical trials bike and it can't fit real trials tires, making it about as much of a trials bike as a surron is.  No amount of riding technique or lean angle or grinding down steering stops is going to change the nature of the bikes original design.  

I said it was a non-trials bike.  Am I being chewed for how quickly I posted details about the bike :) ?  
My post is about how to maximize success with tight turns through technique.  This particular bike is offered as an example of one that does not sufficiently lend itself to it.  Whatever bike, my questions are the same.

On paper, the Explorer encourages experimenting like I am doing.  It is easy to get trials "seating" and footpeg positioning. The Explorer wheelbase is amost exactly the same as my TRS - just under 53".   The fork trail is only 1/2" more.  It is easy to get trials "seating" and footpeg positioning.  Other parameters are on the wrong side but not radically so (fork travel is only 0.2" longer).  USD forks are used on real Trials too - Like the EVO and TRS One.  They are more rigid and tend to give less unsprung weight, but their design does contribute to my problem in that the fat uppers will touch the frame sooner (and mounting a low fender is difficult). 

Yeah, it was not designed for trials but there are things we do for the fun of it and I got to play with electrical for half the cost and still ride in trials (like my putting on real trials tires and engineering a lanyard button.  I still haven't figured out the mandatory spark arrestor :) ).  Where the design mostly departs is fork lock.  We don't typically get specs for that but The Explorer is obviously deficient there.  

It's OK my friends here focused a bit on what I can do with the bike instead of with me.  In many cases they gave me courage to try things I have not yet done - like lowering the front by slipping the forks. Expert suggestions from experts and many thanks.

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6 hours ago, jwalsh said:

....  USD forks are used on real Trials too - Like the EVO and TRS One.  ...

TRS One with USD forks 🤔  Never seen such a thing.

I think it's a bad idea but if you flip the forks around your leading axle will become a trailing axle and that will change your wheelbase, fork rake and fork trail specs.

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4 hours ago, lemur said:

TRS One with USD forks 🤔  Never seen such a thing.

I think it's a bad idea but if you flip the forks around your leading axle will become a trailing axle and that will change your wheelbase, fork rake and fork trail specs.

Thanks.  My memory bad on the TRS I've been so focused on this bike.  I've been eying the Dragonfly a lot recently too.
I agree with the possible fork turn-around being a bad idea on so many levels but that trailing axle is nice to imagine.

Edited by jwalsh
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