Sounds like you have tried everything possible and even sworn at it Brian.

Maybe it would be best to just buy the nipples. They should be readily available and cheap enough.  I saw a online UK site HERE.

I am not sure why the spoke nipples are not available from Yamaha UK, they appear to be still available from Yamaha AU- see HERE.

Hopefully a ''nipple guru'' will come along soon and add to this thread though.

Jarrah

I eventually got the rest of the spokes out of the front wheel but it was a struggle! I clamped the individual spokes in the vice lengthwise (not easy!) to cause least amount of damage and managed to get the seized nipples off using Vise grips. I now need 16 replacement nipples to go back on my spare front spoke set. 

I know that our local wheel building guy has got a set of TTR wheels in for rebuilding currently so will check if he can help.

The wheel balancing machine has earned its keep as I now have two good rear rims and one good front rim for future use that were previously not usable 

Brian

 

PS I watched a few You Tube videos and this was a good one:

I've done a few wheels (dirt bikes, bicycle and unicycle) and I invariably mangle some nipples in the process.
It is probably worse if the owner has never checked/adjusted the spokes.
I guess one possibility, after a good long soak in wd40 or something, might be to also try turning the nipples from the flat screwdriver fitting on the tube side of the rim, but that may require filing a slot in the middle of the screwdriver blade to clear the spoke ends - I haven't tried it myself, but it is a possibility if the flats on the nipple have been squashed or rounded.  But anyway with difficult nipples the spoke definitely must be held near the nipple (eg in a vice) while the nipple is turned, as otherwise the spoke shaft just twists.

regarding the re-spoking from scratch, of course you need to watch the spoke cross over pattern - best to have a reference wheel.

one other thing to watch in the truing, is that while of course you should check the lateral and radial runout, you should ALSO check the lateral offset, eg by measuring the perpendicular distance from the rim to a straight edge laid across the brake disc. (otherwise the wheel alignment may be a bit out even though the wheel is totally free from wiggles).

with enough time, truing/rebuilding can be done even without a proper stand. sometimes a marker pen can give a good indication of the extent of the rim that is offset as it wiggles when rotated. For me, what works is to think exactly what direction of force is put on a point on the rim by tightening a spoke, and make sure that you also tighten "partner" spoke(s) to balance that force - to fix a sideways movement that persists for a fair part of the rotation you have to address several spokes - tightening some spokes and loosening others, starting at the center of that "bump" and alternating sides as the more distant spokes are appropriately tightened or slightly loosened (depending on whether they end at the sprocket or disc part of the hub and which way the "bump" went) a bit less than the ones near the center of the "bump" on the rim. What I just said probably doesn't make any sense until you actually do it - but its a relaxing Zen kind of thing (if you have the time, that is). No doubt you discovered this, Brian.

spoke tightening can only go so far in correcting a problem wheel - if it has been hit hard, it has to be trued by a shop with a machine, or thrown out. I reckon you would be lucky to get anywhere by hammering etc on a dirt bike, although bicycle rims can be forced back into shape.

on the subject of rims, it never ceases to amaze me that, with dirt bikes, people will put up with major imbalances (eg from rim locks, or some tyres) without simply fixing it with a few lead weights on the rim.

-- Edited by brindabella on Tuesday 10th of June 2014 06:34:26 AM

I tried Googling and came up with 2 UK firms that can provide spokes and nipples for you:-

Alf Hagon = http://www.hagon-shocks.co.uk/common/pdf/wheels2011.pdf

Central Wheel Co = http://www.central-wheel.co.uk/spokes/spokes.html

I have not used either of them but they have both been in business for years.

Martyn

I didn't think until after I had bought some genuine Yamaha spoke sets to try our local wheel builder (and TRF member) Doug Richardson in South Molton - see here

I know he is rebuilding some TTR wheels with wider rims for  Robin Webb and has some sample f&r TTR spokes that Robin sent him. He can make up any size and shape of spokes so might be worth ringing him for a price?

Brian

random short/long mix seems weird. Maybe the wheel was partially rebuilt in the past?

I haven't ever taken out any spokes from a ttr250, but each side of the rear rim has 50% of the spokes entering the hub at a lower point (slightly closer to the axle) than the others - maybe they are a different length?

By the way, quite likely even the front wheel, where all spokes in the official set are the same length, actually has some differences in installed lengths (in a pattern), which would merely result in more or less thread being taken up by the nipple - the difference being too small to worry about, but possibly evident (in a new wheel) by looking at the spoke ends with tire and tube removed.

I just found a link about wheel building that I liked, and you might find to be interesting background.
troubleshooters.com/bicycles/wheelbuilding/index.htm

yeah, bicycles don't need to handle the same torque and have thinner spokes and probably don't ever use straight spokes, but the general lacing principles are the same.

I have just been asked for measurements by our local wheel builder and these are what I have given him.

Spoke lengths:

• Front spokes - 240mm from under head to tip.
• Rear spokes – long 194mm, short 190mm from under head to tip.
• 36 spokes in each wheel

 

Spoke Nipples:

As far as I understand it the nipples on the TTR are:

8g x .275 (4.00mm x 7.00mm)

9g x .275 (3.60mm x 7.00mm)

 

 

Offsets measured from a straight edge across the disc mounting faces to edge of rim:

• Front rim – 305mm
• Rear rim – 333mm

 

 Rim widths:

• Front – 615mm (J21 x 1.60 3 03 DOT)
• Rear – 785mm (J18 x 2.15 3 99 DOT)

 

 

Has anyone else taken these measurements and can say whether mine are correct please?

Brian

I've just noticed this too.

I must strongly second the idea of speaking to Hagons. They are a blinding bunch and well known up here in the big city. They built a new wheel for my Cagiva after a van driver kindly knocked the bike over a drove over the wheel. They straightened the disc as well! Wasn't that bad, they said. To them, spokes were just a resource they employed but obviously they probably have fairly large buckets of many different sizes, lengths and angles. There was much sucking of teeth about my cagiva wheel saying that that rim type was no longer available and this and that, but the result was astounding. They really know their onions and the old boy that does the wheel building does all the wheel builds for the classic racers. Even the receptionist piped up once to correct the tech I was speaking to about spring rates to remind him that the price he'd given would only apply if the damping remained in range.

Another thing to remember if people are going to come back to this thread is the head angle at the hub end. Friend needed to replace a couple of spokes on an old XT's rear wheel. Breaker helpfully sent him four different types that only someone looking for it would have noticed any difference between. Having said that I'm not near the bike right now and I'm guessing they are all the same on the TTR???

Good luck.


Andy

J denotes the rim style i.e the configuration of the bead lip etc, then its the size, then its the month and year of manufacture I.e march of 1999 and 2003, DOT stands for department of transportation.