Wobble on touring bike when semi fully loaded – help please!

[bagpuss]

Re:

This is known as speed wobble in the trade .
As said
Balance the load .
frame alignment is right
head set adjusted /forks
wheels true spokes tight
tyre pressure correct .
I rode along this summer with 2 fully loaded rear pannier top bag stuffed .full front bag and some screaming down hills :twisted: no issues .
. How old is the frame ?

 

[hamster]

Re: Re:

This is known as speed wobble in the trade .
As said
Balance the load .
frame alignment is right
head set adjusted /forks
wheels true spokes tight
tyre pressure correct .
I rode along this summer with 2 fully loaded rear pannier top bag stuffed .full front bag and some screaming down hills :twisted: no issues .
. How old is the frame ?

Not sure it's speed wobble uphill - sounds like frame flex to me - which happens if swinging the bike out of the saddle. Speed wobble is oscillation of the steering and frame, usually from a very light front wheel. Very lightweight front tyres seem to be part of the problem with speed wobble (shimmy).

I agree that a decently setup tourer will track fine - mine will happily pull over 45mph with 4 panniers and a barbag and be rock steady. Definitely as you say any slackness or tightness in the headset is asking for trouble.

 

[mattr]

LOL, it's not speed wobble.
It's a massively unstable bike being shaken.
It'd do the same at 3kph or 50kph.

It's one reason I hate those stupid seat pin mounted racks.

 

[Deleted member 30479]

Frame is 5 years old - very new for a Bob Jackson. Rear saddle bag is a Bagman 2 expedition so it attached to my Brooks Cambium saddle but also attached to the frame eyelets where the rack normally is.

 

[oonaff]

i remember now when i was younger, i mean really young, a child infact .we used to mess a bout and give passenger lifts to each other.obviously i couldnt sit down and it was hard to steer and it was all WIBBLY WOBBERLY !

 

[hamster]

If you get out of the saddle and waggle it around the frame will flex and you feel wobble. Most tourers don't ride laden bikes out of the saddle. If you make a frame so stiff that you don't get any flex, it will ride like a jackhammer. Sorry, just one of those compromises I am afraid. Try an old 1970's Dawes Galaxy with 1" top tube if you want to see how bad it can get :shock:

Bob Jackson is a very experienced builder of tourers, so if anything yours will be at the better end of the scale.

 

[mattr]

It's still a high load, and not *massively* rigid for the weight you are hanging on it.

It'll get a good twang going if you force it. By shaking the bars/bike.
Might even be less of a wobble without the rack, as there will be one less spring in the system.

(I bought a similar sized bag with no support, and have heard of no issues at all. Which for an mtb saddle bag is nice! Haven't had the opportunity to use it yet, life git in the way!)

 

[bagpuss]

Re:

Did not realize seat pin mounted rack was been used . Does the wobble happen when using a proper rack ie fastened to the frame top and bottom .

 

[Deleted member 30479]

With a proper rack it does wobble however hardly noticeable with one pannier / 15lbs. Only reason I noticed it was after I was using the saddle bag setup! I haven't been able to test fully loaded with both panniers on.

 

[mattr]

Might be best to just chalk it up to experience and not dangle so much weight off the seatpin next time!

You'll probably have a similar issue with heavily laden panniers as well.