Yamaha TRX850 Enthusiasts Forum

OK, so my bike's just turned 17,000 miles (27,000 km) and I'm thinking the shock must be needing some attention, so what are my options:

1) leave it, as it's good for more.
2) get it rebuilt/refurbished
3) replace it with new

Replacements are probably Ohlins, WP, Penske, Hagon etc

Rebuild could be Maxton or Eibach or a few others


So...............


Anyone got any comments or suggestions or done anything similar recently?

Any shocks off other bikes a direct swap which may be more easy to get, new or second hand?

Don't really want to spend UK£700+ on a Ohlins full monty new racing shock but apart from that, what do you reckon?

Cheers,

Dave.

Kais Suspension. I had a shock serviced, resprung and revalved by them for £120 a year or 2 back. Shouldn't cost more than £180 now.

Excellent service and made a huge difference.

Agreed - rebuild is the way to go unless you want to buy new. You can also have it resprung for your weight

Maxton are very good

In addition to YZF750 rear shocks, YZF600 Thundercat shocks go in relatively easily and automatically raise rear ride height. Some grinding is required, but I believe it's just the width of the top spacers need to be filed back.

I contacted Maxon in the UK and they sent me a spec sheet with their comments and suggestions for the TRX standard suspension, as follows.....



YAMAHA TRX850
--------------------------------------------------------------------------------
FRONT

The forks work reasonably well for general road use but if you ride the bike hard or carry a pillion they need to be modified. The forks are underdamped and undersprung , we revalve and respring them fitting harder springs to suit your rider weight and also to suit what the bike is being used for, this gives the bike alot more feel in the corner and also alot more stability under heavy braking. The cost of the fork conversion is £250 plus VAT. Seals are £20 plus VAT for the pair and Bushes £20 plus VAT if required.

--------------------------------------------------------------------------------
REAR

The rear of the bike feels hard and has a tendencey to kick you out of the seat on bumpy roads, this is because the spring fitted to the shock absorber is on the hard side. You'll find if you carry a pillion the bike handles better. We respring the unit and fit a softer spring measured to suit your rider weight and to suit what you use the bike for, the cost of this is £60.00 + V.A.T, we can also service the unit for £55.00 + V.A.T . We also supply a replacement unit for this bike which is an Alloy bodied high pressure gas unit and is fully adjustable via a shim stack system, the unit is built to order so is sprung and valved to suit your rider weight and what you use the bike for. The unit costs £405.00 + V.A.T, but we also make a 4 way adjustable unit that is mainly for racing or track days and is £490.00 plus V.A.T.



...seems to me like they've got it about right, so may enquire about the shock rebuild service.

Cheers,

Dave.

You may wish to enquire about turnaround times with Maxton - many stories abound of work taking weeks or months.

I can vouch for Maxton, they transformed my GSXR. they can take a while especially close to the start of the racing season as they give priority to racers.
Now would be their "quiet" time

trixynut wrote:I contacted Maxon in the UK and they sent me a spec sheet with their comments and suggestions for the TRX standard suspension, as follows.....

--------------------------------------------------------------------------------
REAR

The rear of the bike feels hard and has a tendencey to kick you out of the seat on bumpy roads, this is because the spring fitted to the shock absorber is on the hard side. You'll find if you carry a pillion the bike handles better. We respring the unit and fit a softer spring measured to suit your rider weight and to suit what you use the bike for, the cost of this is £60.00 + V.A.T, we can also service the unit for £55.00 + V.A.T .


...seems to me like they've got it about right, so may enquire about the shock rebuild service.

Cheers,

Dave.

Rebuilding the shock is the way to go, but maybe not with that crowd...

Any suspension shop that hands out general recommendations without first asking your weight sould be given a wide birth.

I weigh 95kg in my gear. For me the TRX rear shock is UNDERSPRUNG, and it feels harsh because it crashes through to the "stiffer" part of the rising rate linkage too easily.

I had my shock rebuilt by Terry Hay, a well known suspension in Sydney with racetech goldvalve piston and shim kit, upgraded shaft seal ( for quick re shimming) and a 9.5kg/mm spring. Stock spring is 7.5kg/mm although mine had sagged to 6.8kg/mm.

The bike was much better after the rebuild, and much more compliant because the linkage worked in the proper range, but it still squatted under hard corner exits.

I was talking to Terry at a track day year after the job was done he said he would fix that day. Rather than wind up the shocks low speed compression damping ( treating the symptom, not the cause) Terry swapped the spring for a 10kg/mm and bingo its even better.

Hope this helps

DFH

Hmm yeah....Maxton don't know shit.

HA HA HA

I love sarcasm but im with you there marty, think the years maxton have been suspension guru's to some fecking major race teams, i reckon they might just know their onions.

billy budge wrote:HA HA HA

I love sarcasm but im with you there marty, think the years maxton have been suspension guru's to some fecking major race teams, i reckon they might just know their onions.

Well they may have a reputation in the old dart, but they are treating Trixynut like a mushroom.

Firstly how do Maxton "revalve" a damper rod fork? There is no fekkin valve in there in the first place. All they have done is palm off Trixynut with a generic cut'n'paste.....

Ask the spokes-model from Maxton what you actually get for your 250 pommy pounds?

As a comparison that many pounds buys 600 of our beer tokens. For that much cash I have personally, note that word, bought TWO SETS of Eibach fork springs (.9kg/mm & .95/mm) and a set of Racetech Cartridge emulators. These little jiggers fit between the top of the rod and the spring and control compression damping in the same way a shim stack works in a cartridge fork, providing variable damping based on damper velocity. My personal experience is these mods work very well on bikes like TRX850's SV650's & GS500s with el-cheapo damper rod forks. Racetec are imported to the UK, and I belive K-Tec ( a UK company with a good world rep) offer a similar product to upgrade damper rod forks. Talk to the folks who race SV650's in your local one make series for more info.

If Maxton are charging 250 quid for a set of springs, fork oil, and a slight resizing of the holes in the damper rod with a hand drill then they are ripping you off. I would expect substantive hardware changes for that money.... ask them exactly what do you get.

As for my advice on the rear shock, well that is based on my personal experience. That is what Trixynut was asking for in the first place. Some imput from listers to help him make an informed decision.

My personal opinion, based on having three different springs fitted to the rear shock of my TRX is that Maxton are wrong in their recommendation to fit a softer spring. I also note that will "service" a shock for 55 pounds. Thats a lot of money for a re-oil and re-gas.

As for their replacement unit for 405 pounds.. the standard TRX shock is already a pressureised adjustable unit with shim stacks. I had the shimstacks, piston and piston seal completely replaced with an after-market upgrade, and an upgraded spring fitted for the the Oz equilivent of 215 pounds


Billy Budge, do you have any personal experience of Maxton modified shocks on your TRX? In fact any personal experience of anything other than the stock shock? Why dont you enlighten us with that rather than defending Maxtons' treatment of Trixynut because you just like the graphics of their sticker kit.

DFH [/quote]

Thanks for tha comments.

DFH, Maxton are a long established company with a good reputation and who regularly work for big teams, although their email enquiry service offers a standard factsheet by return, which is what's copied above. I'd presume if I spoke to them, and then used them, they'd refurbish the shock and tune it to my needs/weight.

I've spoke to another couple of companies too (like Kias, as Mart suggested) who do the same service for about the same UK£.

My forks I'm happy with. One of my mates races in the SV650 minitwin series (currently leading the championship) and I've talked to him about front end set-up: he uses K-Tec, but I'm happy with my Ohlins springs and standard oil weight/volume.

You can only get personal experience by buying/trying, and then the personal experience can be good or bad, and if it's bad it's too late. Thats the beauty of these forums: you can ask for personal experience from informed people who know, then you can make your own choice, see how it goes, and then have your own personal experience to pass on to others.

Thanks for the comments: probably gonna whip the shock out, replace it with a piece of scaffold pole and go drag racing instead: who needs corners!

Dave I wouldn't touch K-Tech with a bargepole - very bad experiance with them a few years ago.

That's not to say others haven't had good experience with them, but I wouldn't give them any of my hard earned again.

Kais were good for me and I'd use them again.

If you go with Maxton ffs let us know how you get on with them, good or bad. It shouldn't be a secret and could benefit others in future.

WHOAH!!!! Who the hell rattled your cage dude.

I bow to your superior knowledge of all things suspension and must apologise for expressing my opinion and will stick to putting on transfers of all my favourite things in the world on my trx.