A forum for owners of Yamaha TTR250 trail and enduro bikes!

moglie26 · Member

Shock absorber bushes and bearings

TTRfan · Super Guru

Rear Shock Absorber - Q&A megathread

spud351 · Veteran Member

Shock Spring

TTRfan · Super Guru

I have asked around and there is some confusion as to what plastic coating is and how it might be different to powder coating.

A CCM owner had his spring powder coated back along and says its fine and no cracking of the paint. Another biker replied that many shock springs were chromed and that didn't seem to be a problem.

Up to you but I think I would go for powder coating as I knwo where to get that done locally wink

Brian

Cubber · Super Guru

Rear Shock

spud351 · Veteran Member

Rear Shock Absorber - Q&A megathread

TTRfan · Super Guru

Rear Shock

spud351 · Veteran Member

Thanks, as I thought. The oil will have to be released to get the reserviour off. In itself not an issue but to get it pressured again is a ball**** and an expense I could do without. Anyone tried the refurb servive on ebay?

Cubber · Super Guru

I see that the Yorkshire firm will refurbish the TTR rear shock for £100 + p&p - but it doesn't say that it includes re-painting the spring. disbelief

On the other hand, you get a virtually NEW unit for your outlay and it's set up to your requirements. I'm sure they could repaint the spring for a nominal charge. wink

It would save you a whole bunch of hassle and worry.

If mine was farbood then I'd consider their service. After all - it's as Yorkshire as I am, all bar 40 miles. smile

Martyn

spud351 · Veteran Member

Hi Brian, anymore thoughts on taking it apart? I cracked the pipe nut and got a few drops of oil out. It looked and smelled like thinners not oil. probably the original 20 year old oil. I'm thinking whichever way I do it it's going to be refurbed. On a more stupid note I've managed to buy another Raid off ebay thinking this would only be together by winter at the rate I'm going. Oh well hope it's worth it. Maybe I should have just paid someone to rebuild the whole bike. disbelief

TTRfan · Super Guru

Rear Shock Absorber - Q&A megathread

Big Den · Member

RE: Rear Shock

spud351 · Veteran Member

Well since I couldn't be bothered to try and do the shock myself I sent it to Gibbs performance to get rebuilt. Great service with a turnaround in a week.

New seal block, oil, gas, a bump stop (which you can't get from Yam) , powdering the spring , postage, labour came to £120.

Can't complain at that and recommended if you need the same doing.

Cheers Spud.

TTRfan · Super Guru

"Hyperpro Progressive Rear Shock Absorber Spring Yamaha TTR250 04>"

langley91 · Member

1993 OE rear shock absorber questions

Cubber · Super Guru

The "dial" you noticed is for adjusting the suspension but not, perhaps, as you presume. wink

I'd advise you to have a look at this article in the FAQ section. SUSPENSION INFO

The knurled adjuster nut is used to adjust the rebound damping and it can be screwed up or down.

Screwing it upwards hardens the rebound damping and screwing down softens the damping.

The standard setting is 8 clicks out.

The minimum adjustment is 16 clicks out.

The maximum adjustment is 1 click out from fully turned in.

Martyn

TTRfan · Super Guru

More info in the owners manual:

Adjusting rear shock Pt 1.jpg

Adjusting rear shock Pt 2.jpg

Adjusting rear shock Pt 3.jpg

Vancor88 · Member

Rear Shock Spring Wt.

suzbandit987 · Member

Rear Shock Oil

barra8 · Guru

Front is 5W but usually if the back needs oil it means a rebuild is nessesary. Maybe you mean re-gas??

.................

Jarrah.

-- Edited by barra8 on Tuesday 27th of November 2012 06:08:06 AM

suzbandit987 · Member

No I do mean oil. I know N2 goes into the bladder. I'm in the process of re-valving the shock now.

TTRfan · Super Guru

Nothing in the workshop manual to help - sorry!

I am very impressed that you are doing your own re-valve. That is several steps farther than most of us owners would take! However, I am sure we would appreciate a few pics and a short explanation of why and what you were doing the revalve for smile

Greywolf used "Castrol Fork Oil Synthetic SAE 10W-universal oil for forks and shock absorbers" on his rebuild - see here. I opened it in Google Chrome which did the translation wink

Good luck

Brian

barra8 · Guru

suzbandit987 wrote:
No I do mean oil. I know N2 goes into the bladder. I'm in the process of re-valving the shock now.

Oh okay...good work. Can't reccommend anything for the rear as MR YAMAHA kept it a secret wink I have never done this as i sent it in for $300 re-built. It would be interesting to see what is required to do the job. If you can please upload pics & discription of this??

..............

Jarrah.

suzbandit987 · Member

I'm almost done. Don't really have any pics. If you want to know how to do it, then just follow this: (This DR350 shock is 99.9% indentical to the TTR shock.)

http://www.thumpertalk.com/topic/631120-dr-350-shock-gold-valve-install-with-pictures/

Once I get the shims squared away I can post what shims I used. I put a YZ 250F front end on this bike, because the front forks were ridiculous. Then after that it showed how weak the rear shock was (mostly in compression) so I decided to beef up the shims.

suzbandit987 · Member

OK, here is what I did for the rear shock shim stacks. I used 7W fork oil. I'm 190lbs with all of my riding gear on and this shock is now ~90% where it should be. It could still be a bit more stiff in the low speed compression, but its, so, so ,so much better than stock. My situation is a little different though, as I'm really trying to match the stock TTR shock to the '03 YZ front end. Since the YZ is a lighter bike, I used 7W oil in the front forks. Honestly they may be too stiff. Time will tell. I can always go back down to 5W if need be. I barely have the adjusters clicked in at all of the front end, and it's firm already.

Stock Shim Stack 2005 TTR-250

New Stack

Rebound

OD

Thick

OD

Thick

17

0.45

17

0.45

27

0.20

20

0.30

27

0.20

27

0.20

33

0.20

27

0.20

33

0.15

33

0.20

33

0.25

33

0.20

29

0.20

33

0.20

33

0.20

23

0.25

33

0.20

33

0.15

33

0.15

New Stack

Stock Shim Stack 2005 TTR-250

Compression

OD

Thick

OD

Thick

38

0.15

38

0.15

38

0.15

38

0.15

38

0.15

38

0.15

38

0.15

38

0.15

38

0.15

38

0.15

38

0.15

38

0.15

38

0.15

23

0.25

38

0.15

38

0.20

38

0.20

36

0.25

23

0.25

32

0.25

38

0.12

27

0.25

38

0.15

25

0.25

38

0.15

23

0.25

38

0.20

20

0.30

36

0.25

17

0.45

36

0.25

32

0.25

27

0.25

25

0.30

20

0.30

17

0.45

-- Edited by suzbandit987 on Monday 3rd of December 2012 02:18:15 AM

-- Edited by suzbandit987 on Monday 3rd of December 2012 02:19:45 AM

suzbandit987 · Member

I've spent about 400 USD dollars for every bit, nut, bolt, oil, shims, etc for this full suspension upgrade on my TTR. I can say without any doubt this is money well spent. The suspension is leaps and bounds above where it was. It's not even the same bike. Before I felt like I was going to get bounced off of the trail (and off the cliff) at any moment and now that the bike has dampening it stays under control. You'll be very very happy if you upgrade your TTR suspension.

TDVT · Senior Member

suzbandit987 wrote:
I've spent about 400 USD dollars for every bit, nut, bolt, oil, shims, etc for this full suspension upgrade on my TTR. I can say without any doubt this is money well spent. The suspension is leaps and bounds above where it was. It's not even the same bike. Before I felt like I was going to get bounced off of the trail (and off the cliff) at any moment and now that the bike has dampening it stays under control. You'll be very very happy if you upgrade your TTR suspension.

Thanks for the information.

I have been researching the fork swap for a few evenings now, lots to take in.

I also appreciate the post of the shock shim stacks. This is all new to me as I've done nearly all my wrenching on 4-wheeled rigs but I'm slowly getting it. Where did you source out your parts? (I am also state-side)

We are also around the same weight, so I am reading all of this with great interest.

-- Edited by TDVT on Monday 3rd of December 2012 10:41:00 PM

suzbandit987 · Member

I bought the YZ front end off thumpertalk.com. I got some other odds and ends from ebay. I had two rear shocks and that is where all of my shims came from. I combined two sets of stock shims. There is some place where you can buy whatever shims you need (I have their web-address at home.) Their shims were ~2 dollars a piece in low qty's.

suzbandit987 · Member

Would someone help me out? I need someone to take four measurments on their STOCK TTR-250 (With the bike off of the kick-stand and straight up.)

I would like the following (if someone would be so kind):

the distance between the ground and the drain plug

the distance between the ground and the top side of the lower trip clamp.

the distance between the ground and the top side of the upper trip clamp.

the distance between the ground and the bottom of the fork tube.

I understand the measurements can be different based off of someone's preload settings, etc, etc. I don't need a lesson on all that. I know already. I just need to make sure my front and rear suspension, modified TTR is sitting close to the stock geometry. Thank you for your time and help.

TTRfan · Super Guru

31cm - the distance between the ground and the drain plug

92.5cm - the distance between the ground and the top side of the lower trip clamp. corrected!

112cm - the distance between the ground and the top side of the upper trip clamp. corrected!

23cm - the distance between the ground and the bottom of the fork tube.

The measurements are a bit approx. as I was in danger of the TTR falling on me whilst trying to balance it and use the tape measure at the same time disbelief

-- Edited by TTRfan on Thursday 20th of December 2012 08:39:14 AM

suzbandit987 · Member

Rear Shock Absorber - Q&A megathread

TTRfan · Super Guru

I am sure you realise that with spacers under the handlebar clamps and bar risers you will be able to drop the front forks through even more smile

A mate reversed his bar clamps which move the bars back a tad and this allowed the bars to clear the forks so he could drop his through a lot without doing anything else.

Brian

suzbandit987 · Member

TTRfan wrote:
I am sure you realise that with spacers under the handlebar clamps and bar risers you will be able to drop the front forks through even more
A mate reversed his bar clamps which move the bars back a tad and this allowed the bars to clear the forks so he could drop his through a lot without doing anything else.
Brian

This is exactly what I did. I went to work and machined myself some 1.125" tall spacers. I'm just happy I'm able to get back to stock geometry with the new front end. I didn't want to be raked out like a chopper guy, on this "offroad" bike.

barra8 · Guru

Upgrade shock?

66T · Veteran Member

barra8, I did see them, but thanks for the idea.

I'm mystified here. No-one knows everything, least of all me, but I've been around bike for a while and still can't see how a spring by itself can transform a shock's action, assuming the stock spring is ballpark, which, for me, the TTR one is.

Can someone enlighten me? All info gratefully received!

barra8 · Guru

If you fit the progressive spring & gold valve it will be the best it can be.

The standard spring is just very tall & requires a different style of riding. More balancing when going slow. I like the extra travel though.

For info on the gold valve see here Never fitted a gold valve kit yet so can't tell you how much difference it makes.

...........................

Jarrah.

brindabella · Senior Member

66T, I can offer some thoughts about springs..

I have to say first off that if someone makes a change, and it works for them, improving the ride for their taste and their riding conditions, then good for them (so different springs will work for some people).

But to go into history, once upon a time progressive springs were much more common, and I believe that this was because shock absorbers were then much, much more primitive.

Nowadays, the spring is merely a source of rebound energy to "power" the shock absorber system, which is far more complex than it used to be. Designing a shock absorber these days requires massive computing power, and precise engineering, as well as teams of test riders, and the result is that progressive resistance is delivered mainly by the shock, rather than the spring.

In fact the shock designers would consider the spring as almost an impediment - they just hope that owners set the sag so the ride height will be at the point they assumed in their shock design. There is not much to spring design to choose from but a straight wound spring might retain its spring coefficient better when hot.

Another relevant point is that even a straight (non progressive) spring actually is NOT linear but IS progressive from the point of view of the shock. This is because of the linkage system - the leverage ratio actually varies with travel, due to the complex linkage geometry. As the leverage ratio varies, the spring behaves like a stiffer or softer spring at that point in the travel. This is one reason why there have been so many linkage designs in the past - engineering evolution.

Throwing a non standard progressive spring into the mix would upset the leverage curve in a hard to predict way not anticipated by the shock designers - so for optimum handling after changing to a progressive spring you would want to spend a lot of (expensive) effort on the shim stack. Too hard for me.

To go on a slight tangent now (considering the front forks), some forum readers might be surprised that, as recently as 3 years ago, a highly regarded multiple ISDE gold medal winner, parts supplier, and race team owner actually changed from USD forks to modified TTR forks because he thought they were better in certain enduro conditions.

In this light, the following link may be of interest:

http://www.dirtbikeworld.net/forum/archive/index.php/t-68384.html

TDVT · Senior Member

Rear Shock Absorber - Q&A megathread

66T · Veteran Member

RE: Upgrade shock?

barra8 · Guru

66T wrote:
Thank you all for your info, and interesting reading..

I get it about rising rate likages etc; I was just curious as to how an aftermarket shock spring on its own of equal specs can improve the shock action, like the Hyperpro seems to suggest.

I was about to describe the progressive spring better but my internet dropped out because of the floods

Okay i'll try to keep it simple....The reason that the progressive spring is better....

The progressive spring is wound differently than the standard spring. Instead of being practically the same wind right through it is progressive....meaning that at the top of the spring it is soft-this helps to keep the wheel firmly planted for handling.

It then gets harder & harder as the spring goes down more- So you don't bottom out (as much)

The travel will become less because this spring will be harder at the bottom therefore stopping the travel.

It should sit down a bit more for you (squat) giving better handling.

..................................................................................................................................................

That's the theory anyway,take from it what you will.

................................

Jarrah.

66T · Veteran Member

Thanks barra8. I see what you're saying.

But if the progressive spring is softer initially, won't the static sag and rider ride height be wrong? And if the shock sits further into the stroke, will it be stting into the rising rate area of the linkage and thus be harsh? What am I missing? ashamed

barra8 · Guru

66T wrote:
Thanks barra8. I see what you're saying.
But if the progressive spring is softer initially, won't the static sag and rider ride height be wrong? And if the shock sits further into the stroke, will it be stting into the rising rate area of the linkage and thus be harsh? What am I missing?

The ride height i have already mentioned....It should sit down a bit more for you (squat) giving better handling.

It will be sitting further down the stroke as you say but SHOULD not be harsh as the spring should counteract this,but i do see what your saying.

..............................

Jarrah.

sinasia · Member

is rear shock absorber tube include air or nitrogene

Cubber · Super Guru

Welcome to the TTR forum,Sinasi

A TTR rear shock is not normally owner serviced and is best left to specialists who have the necessary tools, experience and equipment to service.

It's a rather involved and tricky sevicing operation for the amateur owner/rider and is best left to the specialist.

I certainly wouldn't try and service mine.
If no specialist was available I would consider another used shocker rather than attacking it myself.

Martyn

TTRfan · Super Guru

I know that Greywolf has a step-by-step repair guide here but I agree with Martyn that any repairs or servicing are best left to the specialist with the right gear - and knowledge.

To the best of my knowledge the TTR's shock uses nitrogen. I use Justin Gibb to service and repair my shocks and this is what it says on his website:

Shock Service

Completely strip, clean and inspect shock for any wear or damaged parts. Replace the main seal, dust seals and bushes if required. Re-build on purpose built vacuum pump and re-gas with nitrogen

sinasia · Member

Thank you very much martyn and ttrfan for data. i filling nitrogen gase to suspension tube.this sites (offer ttrfan)in link that filling 150psi air bycle pump but today i filling only 45 psi because nitrogen pump machine only fill 45 psi.may be later i will send suspension to technician for repair.

TTRfan · Super Guru

Rear shock absorber - red spring puzzle!

Cubber · Super Guru

Rear Shock Absorber - Q&A megathread

scotty72 · Veteran Member

Shock

TT-R250M · Super Guru

Sorry to hear of the ''shocking'' news, it has made me ''shocked'' biggrin

You may be ''shocked'' to find out the price is $515.91 from the cheapest online source (I know, it's shocking ).

You can use any Open Enduro shock or even the blue bikes. Check eBay or wreckers for one that isn't in a ''shocking'' state. smile

Well, I hope there is an end to this ''shocking'' news soon. wink

Jarrah.