Trail

[Jet_Pack234]

I have just Spoken to Draken1, and he offered me some excellent friendly advice on building my first trike.  He has drawn my attention to the importance of trail.  Recommended trail for good handling seems to be in the region of 2.5 to 4".  On my intended set up I have worked out the the trail I would get (using a rake of 45 deg, offset of 1.25" (Suzuki RM yoke), and a 21" rim) would be about 12" !!!!!!  So this means good high speed stability but difficult handling at low speed characterised by heavy steering.  My question is do any of you guys take the trail seriously?  If so what is your trail?  I really like the look of Critches trike but by printing a picture off and drawing a few lines and making one or two assumptions It would seem as though he has a similar trail (11").  I have done this for a few trike pictures on here and they all appear to come out way more than the recommended amount.  I'm now thinking about designing custom yokes (unless anyone has some for sale ) to increase offset, run a 19" rim and lessen rake to around 40 degs.  Even this will only take me to about 7.6" (2.5" offset). 

What do you guys do about this  - put up with heavy low speed handling and slap on some dirty big bars?  Can anyone recommend a good fork/yoke combination without the need to make custom yokes, afterall its my first build and I fully expect to make other mistakes even if I get this bit right?

Thanks for any advice,
Matt

[Manky Monkey]

Hiya,
this has come up a few times now. Mr Dracken, (Wynne at JW Motorcycles), is bang on with his figures, but to be honest, no, we don't really bother about it.
All ours have been around 45 degrees so far, except Flap's orange 'un, which is somewhere between 45 & 50, (never leave him in charge of a tape measure). Our chosen style incorporates wide bars anyway, but Lunatic & PD recently tried a pair of standard clip-ons on the rolling MMMotors trike chassis they bought from Toad &, rolling it down the hill outside their workshop, it cornered fine. Yeah, I know that's hardly an accurate test, but they certainly weren't wrestling with it. Yes, it's heavier than a standard bike at low, carpark type speeds, but then you're not holding the weight of the vehicle up, just sitting there, pushing on the bars. I wouldn't call it difficult handling, just different. The more radical you make your vehicle, the more compromises you have to expect in it's handling, but I'd say, unless you have an illness or injury that affects your upper body strength, anyone could ride any of ours -we're certainly not Arnie Schwarzenegger lookalikes! 

[BikerGran]

Depends what you want to do a bit I guess - Gertie has standard bike front end and the steering is heavy particularly at lower speeds, it's not a problem you just get uysed to it - till the arthritis gets worse and you find that you're just getting too tired on long trips (speaking personally that is).

[Manky Monkey]

I've always found bike riding far more physically tiring than driving anyway.
Standard raked forks have their drawbacks too. They're not as stable -they're more prone to rear wheel bump steer, (if the back wheel hits a bump or pothole, it'll shake it's head quite violently). More rake will stabilise that. Bike/trike conversions typically keep the front of the frame unaltered, so have standard rake. You'll often hear their owners complaining of front end wobble during decelleration. Ours don't seem to suffer from that, which I put down to the low headstock height & rake. Bike/trikes also keep the standard bike saddle, which is much taller than ours, so the centre of gravity's completely different.   

[mouse]

ohhh now this is a intersting post
this is covering all the stuff i need to know right now 
im going to be starting my trike frame buil in the next few weeks 

[Manky Monkey]

I'm sure someone else will come on & assert the complete opposite!
At the end of the day, as long as it's built safely & the style & build quality are to your standards, the rest is just down to personal taste. As I said, if you want radical, be prepared to compromise a bit. If you want utterly predictable, buy a nice little hatchback. 

[TwistedPatience]

Or a moped!

[BikerGran]

I've always found bike riding far more physically tiring than driving anyway.

Must say I never found it so, but then the GT is incredibly stable and designed for riding long distances.

Standard raked forks have their drawbacks too. They're not as stable -they're more prone to rear wheel bump steer, (if the back wheel hits a bump or pothole, it'll shake it's head quite violently). More rake will stabilise that.
Bike/trike conversions typically keep the front of the frame unaltered, so have standard rake. You'll often hear their owners complaining of front end wobble during decelleration.

Gertie definitely does the rear wheel steering thing but you learn how to ride to avoid it.  I don't think I get the deceleration wobble though.

I say I don't think, cos all these problems are quite easy to compensate for, so after a while you simply don't notice them!  Rather like, many years ago I had a Moggy that jumped out of 2nd gear and when someone else drove it I forgot to warn him - I'd got so used to stopping it doing it that I'd forgotten the problem was there!

[Manky Monkey]

 
I find all biking more tiring than driving, doesn't matter what bike I'm on, it's just that constant battering by the wind, road noise etc. 100 miles on 2 or 3 wheels feels a lot further than 100 in a car. I still prefer the 2 or 3 though. 

[VALLEYSBOY]

biking/triking will always be more tiring as we all have to hold on more, just dont do that in a car

[Manky Monkey]

A greater level of concentration needed too. Can't multi-task like you can in a car -making a phone call, eating a donut, picking your nose etc.

[VALLEYSBOY]

rolling a J

[mouse]

A greater level of concentration needed too. Can't multi-task like you can in a car -making a phone call, eating a donut, picking your nose etc.

hey i can pick my nose and ride the trike at the same time 

[TwistedPatience]

Me too! an smoke a ciggy but not at the same time.

I have some steering wobble mainly when I let go of the handlebars.

Rake is 35 degrees I think , got a diagram around here somewhere will post if I find it.

I have 44" wide bars to help with the cornering at all speeds.

[VALLEYSBOY]

nice pic like the brass work ...did u buy the brass or aquire it are u looking for brass still ?