Topic: speed wobbles

[apostrophe28]

so i finished my build and went around my block for a spin. so excited until i noticed the front wheel wobbeling just a bit. not feel like having the front wheel go flying so heres the information on the front end....any ideas/fixes?


backround: 77'k
-crashed and bent forks and tripple tree - both replaced
-sat over winter outside
-same tires
-no front fender
-little to no fork oil possibly (refilling 1 or both when i get home)


any help would be fantastic, i wanted to go riding when i get outta work tom morning 

[mlinder]

so i finished my build and went around my block for a spin. so excited until i noticed the front wheel wobbeling just a bit. not feel like having the front wheel go flying so heres the information on the front end....any ideas/fixes?


backround: 77'k

-no front fender
-little to no fork oil possibly (refilling 1 or both when i get home)


any help would be fantastic, i wanted to go riding when i get outta work tom morning 

Fix these issues.

[BVCB650]

What year and model of bike do you have? Are you certain you got the front wheel on right? On mine, there is a specfic procedure for tightening down the clamp.

[scondon]

If the accident was enough to bend the forks and triple trees, wouldn't it stand to reason that the rim could be bent as well?

[Sporkfly]

If the accident was enough to bend the forks and triple trees, wouldn't it stand to reason that the rim could be bent as well?

+1

[Duke McDukiedook]

+2.

[mystic_1]

-no front fender

No front fender = no front fender bracket = no bracing between fork lowers = fork flex = speed wobble.

mystic_1

[750goes]

Well,

Flat tire - or low pressure,
Wheel alignment
Bent Headstock
Loose Steering Bearings
Bent Rim
Tyre knackered
Swing arm bushes worn out

This list could get quite long

Plus all the other suggestions so far need investigation.

[delay pedal]

-no front fender

No front fender = no front fender bracket = no bracing between fork lowers = fork flex = speed wobble.

mystic_1

does the fender have that much bracing, seems like you could bend the bracket real easy by hand

[mlinder]

It braces quite a bit.

If you don't want the fender, at least grind off the rivets, remove the fender from the brace, and install the brace.

[delay pedal]

will do

[apostrophe28]

the reason i have no front fender is i snapped the bolt into the fork on the caliper side. if i instal it with 3 out of 4 bolts would that be enought to stop the wobbel until i get time to drill/re-tap the hole?

also what size is the allan wrench on the top of my forks?....(i beilive there from a 77f) because they look huge.

[BVCB650]

I USED A 5/8 INCH BOLT HEAD ON SOME VISE GRIPS TO GET MINE OUT. Stupid caplocks.

[apostrophe28]

if i only use 3/4 of the bolts on the front fender with that stablize it enough?

[mystic_1]

if i only use 3/4 of the bolts on the front fender with that stablize it enough?

Probably not, have you tried to extract the broken bolt?

mystic_1

[apostrophe28]

not yet...what would be the best way? i dont have a very powerful drill but i could drill/tap it. maybe a extractor bit on my manual impact driver?

[mystic_1]

Sorta depends on how/why it broke.  Did the head twist off from over-tightening or do you think that the threads jammed up?

I've had a fair amount of luck with square fluted extractors, I dont think the spiral extractors work well at all.  If you use an extractor, make sure to use the largest size you can and use the proper size drill for the pilot hole.

mystic_1

[apostrophe28]

best guess is i over tightened the bolt

[Zaipai]

-no front fender

No front fender = no front fender bracket = no bracing between fork lowers = fork flex = speed wobble.

mystic_1

+1

[Spanner 1]

If this is the same wheel that went through the bent forks/ bent triple tree episode it's got to be bollixed......did you jack-up the front and spin the wheel and look for run-out and flat spot on the rim ??


Word of the day;  'bollixed'

[apostrophe28]

is there a BIG chance the front rim is effed up? the forks were pretty bad and the bottom tripple tre was bent a bit, i would rather not have to add more time to this project by having to source a new front rim (i wanted to go on a trip this sat)


when i get home this morning im going to:
-add fork oil
-inflate the tires
-put on the front fender the best i can
-check for flat spots (the bike sat outside allll winter in the same position)
-get the bike up and spin the front tire to see of it spins straight w out any weight on it

if i can get the front wheel to spin straight w out any weight on it does that mean that its alright? because all of the other issues seem to be in the forks and weight-bearing

[Spanner 1]

Weight on the front wheel would have no effect on whether it's not 'true'......
I would rig a pencil held horizontally against the side of the rim fixed to a coat-hanger , sitting on the floor and bent so to support the pencil just touching the rim...spin wheel slowly..blah, blah you know what I mean, but also see does pencil 'ride' higher or lower on rim ( flat spot )....good luck....

[apostrophe28]

after taking a better look at the front rim i suspected it wasn't tru. i ziptied a old measuring caliper to it and watched as the rim pushed the needle back in about 4-5mm on the top. no up or down movement what so ever just side to side. brought it to a shop and the guy said it would take him an hr to do top. he's getting started tomorrow so hopefully with that i'll be able to go for a ride as scheduled sat-afternoon 


still going to add fork oil when i get home tonite...figure ill have plenty of time to work on the forks cause im soaking my carbs for 2hrs