Twitchy front end on the UFO

Just took the newly built up Orange UFO for a 10ml ride.

Approx 1.5 mls on road to get to the mud, well icy muddy slush and sludge type mud


Anyhoo...front end felt odd..especially on the road part...like it was pulling to one side or the other.

Now, wheels are true & tight, bearings are fine, no play in fork or swing arm.
Brakes aren't binding, nor is the headset. Frame & swingarm appear straight.

Can't figure it out...tried riding no-handed on a few flat bits to get balanced, and it was having none of it. Just kept tipping after a while..and I can normally ride those bits no-handed ( stretching my back.. )

Now fork is at its max 140mm...OE fork was 100mm..but its adjustable and I tried it at less travel...

Is it just a sympton of URT bikes..(never had one before..! )

Or should I be looking at something more sinister...really disappointed TBH..spent a lot of time and effort, and was seriously toying with getting rid. But I changed my mind,built her up and now I am not sure again..sigh.

I am going to take the Univega Ram 9FR out tomorrow on the same ride and see how that performs...maybe its just my own counter weight ( fat gut ..!! ) thats the problem.

K

I was thinking headangle before you mentioned about reducing the travel on the forks. I wonder if even at 100mm your forks have a longer a-to-c measurement and they're still too long?

EarlofBarnet":2az9wc0b said:

I was thinking headangle before you mentioned about reducing the travel on the forks. I wonder if even at 100mm your forks have a longer a-to-c measurement and they're still too long?

Click to expand...

Hmmm,maybe I will check.

But the travel reduces down to approx 50mm..so even below 100mm the unstableness remained.

I have changed the rear shock also..but with one of identical dimensions and stroke as the OE one.

Its not unridable by any means, and may just be a characteristic of the bike..should have had a proper ride on it in its original guise..

Stem is a little shorter at 90mm than the OE ( 120m ) but I wouldn't have expected that to cause the issue.

On reflection, perhaps slow steering would be a better way to describe the problem...using twitchy was wrong I think.

yeah slow steering which is normaally caused by forks being to big

maybe unconsidered but what tyres are you running? new ones? that you havent used before?
i find going from my off road tyres to dj type tyres on my commute such a difference

Smart Sams ...doubt those are the problem. But will try somethng else.

I have a pair of Mountain King 2.2s I can fit...or some Fastfreds..though these will not be much good in the mud..

Will do some fork measurements/calculations tomorrow.

K

Gave the bike another check over this morning..after riding the same route on the Univega...much more satisfying ride.

A to C measurment can be adjusted to the same as the Xverts that were OE on the UFO....rake etc all seems the same.

Noticed some play in the Hope headset though...didn't notice it yesterday.

A tweak on the top cap went from slight play to too tight.

So I pulled it apart and have some lateral & longditudal play in the sealed cartridge bearings...so suspect this is the problem.

TBH the Ram rides nicer...despite a little more bob on the back end, which I am sure I can tune out, or perhaps replace the Coupe deluxe with an air shock.
Also the cockpit is a little shorter..though again this can be rectified with some change of parts.

It probably weighs more, but feels much more planted, and climbs better.

K

That was always one of the good things with urt bikes, they climb well. I think when you stand up on them the rear end effectively locks out. Really nice frame, worth keeping

glad youve probably sorted your problem
are you going to replace the bearings or new headset?

what is urt?

Hmmm not sure it is sorted..would seem the Hope bearings are like that.

Doh...will have another play tomorrow.

K