In an attempt to get a Yorkshire bargain, I noticed that MT-09 rear shocks appeared to have the correct dimensions to fit the 900, and that Ohlins MT09 shocks were cheaper than the same Ohlins shock for the TDM900.
The market for the MT-09 rear shocks is more lively than for TDM's because the standard shock has been said to be quite poor, so lot's of shock changes are being done and competition in the aftermarket is therefore more intense, which is why I think they're priced lower than for the TDM900
Anyway, the top mount is a 30mm x 10mm, and the bottom is 30mm x 12mm, the TDM spring length is 185mm and Ohlins can be found at 190mm (spring codes starting 01096 are 190 mm long, and for a 180mm spring length the code begins with 01095)
Spring strengths end in -49 for 130N/mm (standard TDM rate), -54 for 140N/mm and -59 for 150N/mm
I found the strength of the standard 900 spring by scouring a lot of websites, which usually gives a variety of results due to typos and bad editing, but I settled for 130N/mm.
The MT-09 rear spring is 90N/mm so a straight swap to a TDM900 from an MT-09 would probably only work for an extremely lightweight rider The MT-09 has a longer travel rear suspension, hence the lighter spring required, which is due to the lever ratios in the bottom shock linkage being different to the TDM.
I've always felt the TDM spring was too light for me at 130N/mm, and considered the replacement Ohlins spring rates of 140N/mm and 150N/mm, settling on 140N/mm. Every 50mm of shock travel therefore requires another 50kg of weight, and as I'm 112kg fully loaded and the standard spring seems to be selected for an average rider weight of about 75kg I'm still in the same ballpark, but more but towards the firmer side.
The spring for the Ohlins I settled on was the 57mm ID, 190mm long, 140N/mm, which has a part number 01096 -54 ( the part number for the 150N/mm is 01096 -59)
The Ohlins replacement for an MT-09 is part number YA335, which I found for £414 from an Italian supplier, who agreed to replace the spring free of charge. But muggings here forgot that sometimes duty charges are applied and that was another £95 to UPS, making this a more expensive option then going to a UK supplier !!!.
There's probably cheaper ways to check other shocks, like buy one from a scrapyard, but hey-ho
The length of the Ohlins shock, measured eye to eye, is actually about 5mm longer than the standard TDM, but has no effect at all because the spring is adjustable for preload (ride height).
I haven't gone through a full setting up yet, but the way the Ohlins arrived gave me 10mm static sag. I set the rebound to a slightly firmer than middle setting and just went for a quick test.
It's a great difference. Very settled through bends and extremely well controlled over rolling crests, especially when there's multiples of them in quick succession, which is a vast improvement over the standard TDM shock.
Anyway, I thought it might be of interest for future reference, to keep in mind that an MT-09 shock (years 2014-2019) seems to be a possible direct replacement for the TDM900 (if there's no additional awkwardly mounted reservoir on the shock body), except for the required spring change.
If you don't need to increase the spring rate then the existing TDM spring can probably work on the MT-09 shock body
I've seen some secondhand performance shocks for MT-09's with low mileages sell for very reasonable prices, the standard MT-09 shocks seem to be considered to be pretty worthless, judging by the prices they sell for, but either way if you needed a replacement shock in an emergency it might be beneficial to remember it as an option, as long as you also replace the spring (which might make it more expensive, not less !)
The YA335 is also listed as being suitable for the following bikes, which seems to make them suitable donors
- MT-09 (’14-’19)
- MT-09 SP (’18)
- MT-09 Sport Tracker ('14)
- MT-09 Street Rally ('14-'15)
- XSR 900 (’16-’19)
Edited by fixitsan, 12 September 2021 - 10:33 am.