Karl
Active Member
This is my write up on replacing the rear shock spring on a 2014 Super Tenere with electronic suspension. I am 6’2” and 250lbs, my Tenere has a tank bag, akro pipe, pannier frames and a Givi Trekker top box so far, apart from that it is stock. I do not ride two up (my Mrs has a Yamaha Tracer). My issue with the bike started the day I picked it up, within 1hr I was scraping the LH peg. Further investigation revealed that with full preload, I had a pitiful 83mm rider sag. 57mm is the magic rider sag figure, 190mm of travel and 30% sag = 57mm. I was far from that even unloaded...
When riding my favourite twisties I had to crank the preload to full hard, damping to hard and remove the peg feeler before I stopped scraping the bloody thing when riding like I am used to (on my old R1150GSA). What would it be like with some decent luggage on?
I can’t afford yet to discard the stock suspension, so time to re-spring. No help on the forums, or google so I went to racetech, who also have no information on the S10 ES but wanted me to up the spring rate by almost 50% (for the standard bike). It was not going to be that easy. The bike specs for the shocks (see attached pic) says the stroke of the ES is longer (+21%) and the spring rate is significantly less (43%). Coupled with the fact that the lower 3 point link and the dog bones are a different Yamaha part number for the ES bike, says to me, that the rate through the linkages is different and a 50% spring rate increase could be too much.
The stock ES spring rate is 75N/mm or 430lb/inch. A 30% spring rate increase would be a 550lb spring. If I keep the same set of the spring (free length 213.5mm minus installed length 197mm = 16.5mm). A quick sanity check says that if I put the new spring in, set the same way, the initial load set will go from 280lb to 357lb. So I figured a 77lb (35kg) static, non preloaded increase, will go some way to offsetting my 250lb (114kg) ass and make me more like a Japanese man.
The next problem was which spring? An 8 inch (203mm) spring with a 10mm spacer should match the current spring length well (at 213.5mm). As can be seen from the shock specs, the ES shock spring is larger diameter than stock and tapers in at each end, 56mm inner diameter at the bottom end, and 59mm at the top end and about 62mm through the guts. 62mm is 2.44 inch ID, so I went for a 2.5 inner diameter spring, Eibach 0800.250.0550. The clearance through the swingarm is tight but it looked like a couple of mm overall increase would not be too much of a drama.
Next step to get the thing out. This is not so hard because the preload motor, compression reservoir and electric connections are outside the rear frame. It looks like it won’t come out though the frame but it does. Disconnect it each end, drop it down as much as you can, twist it out of the top mount and bring it up and out through the subframe beams. I pulled the spring out using my home made spring compressors and removed the bottom seat.
Then I went to the CADD and designed a 10mm spacer that would fit the bottom seat and the spring. I purchased a 101.6mm diameter block of aluminium and turned up the spacer on my lathe at home. Installation is the reverse and thank goodness, there is no clearance areas anywhere. The sag is now:
1up = 70mm
1up plus luggage = 65mm
2up = 56mm
2up plus luggage = 52mm
To be honest, you could go up further in spring rate, particularly if you are 2up. The rate through the linkage looks to reduce the pre loading effect by approximately half. I worry about the pre-load motor struggling and the shock running out of damping with more spring rate. For my conversion, the preload motor seems fine, no real change. Test riding 1up plus luggage with normal damping seemed fine but I was unable to get to my favorite twisties. The damping over the small bumps was good I thought.
In the end of the day, the rear is sitting between 13 and 30mm above what it was (on full preload) depending on the preload selected. As a bonus, it will also sink less on those mid corner bumps. I will let you know my opinion about the handling and damping when I can really hook in, but we know how subjective that is.
Attached Pictures:
1. specs on the difference between the ES and non-ES shocks and springs.
2. ES Shock Just removed.
3. Spring Compressing.
4. Difference between the springs
5. Old bottom seat and new spacer
6. Shock re-assembled.
When riding my favourite twisties I had to crank the preload to full hard, damping to hard and remove the peg feeler before I stopped scraping the bloody thing when riding like I am used to (on my old R1150GSA). What would it be like with some decent luggage on?
I can’t afford yet to discard the stock suspension, so time to re-spring. No help on the forums, or google so I went to racetech, who also have no information on the S10 ES but wanted me to up the spring rate by almost 50% (for the standard bike). It was not going to be that easy. The bike specs for the shocks (see attached pic) says the stroke of the ES is longer (+21%) and the spring rate is significantly less (43%). Coupled with the fact that the lower 3 point link and the dog bones are a different Yamaha part number for the ES bike, says to me, that the rate through the linkages is different and a 50% spring rate increase could be too much.
The stock ES spring rate is 75N/mm or 430lb/inch. A 30% spring rate increase would be a 550lb spring. If I keep the same set of the spring (free length 213.5mm minus installed length 197mm = 16.5mm). A quick sanity check says that if I put the new spring in, set the same way, the initial load set will go from 280lb to 357lb. So I figured a 77lb (35kg) static, non preloaded increase, will go some way to offsetting my 250lb (114kg) ass and make me more like a Japanese man.
The next problem was which spring? An 8 inch (203mm) spring with a 10mm spacer should match the current spring length well (at 213.5mm). As can be seen from the shock specs, the ES shock spring is larger diameter than stock and tapers in at each end, 56mm inner diameter at the bottom end, and 59mm at the top end and about 62mm through the guts. 62mm is 2.44 inch ID, so I went for a 2.5 inner diameter spring, Eibach 0800.250.0550. The clearance through the swingarm is tight but it looked like a couple of mm overall increase would not be too much of a drama.
Next step to get the thing out. This is not so hard because the preload motor, compression reservoir and electric connections are outside the rear frame. It looks like it won’t come out though the frame but it does. Disconnect it each end, drop it down as much as you can, twist it out of the top mount and bring it up and out through the subframe beams. I pulled the spring out using my home made spring compressors and removed the bottom seat.
Then I went to the CADD and designed a 10mm spacer that would fit the bottom seat and the spring. I purchased a 101.6mm diameter block of aluminium and turned up the spacer on my lathe at home. Installation is the reverse and thank goodness, there is no clearance areas anywhere. The sag is now:
1up = 70mm
1up plus luggage = 65mm
2up = 56mm
2up plus luggage = 52mm
To be honest, you could go up further in spring rate, particularly if you are 2up. The rate through the linkage looks to reduce the pre loading effect by approximately half. I worry about the pre-load motor struggling and the shock running out of damping with more spring rate. For my conversion, the preload motor seems fine, no real change. Test riding 1up plus luggage with normal damping seemed fine but I was unable to get to my favorite twisties. The damping over the small bumps was good I thought.
In the end of the day, the rear is sitting between 13 and 30mm above what it was (on full preload) depending on the preload selected. As a bonus, it will also sink less on those mid corner bumps. I will let you know my opinion about the handling and damping when I can really hook in, but we know how subjective that is.
Attached Pictures:
1. specs on the difference between the ES and non-ES shocks and springs.
2. ES Shock Just removed.
3. Spring Compressing.
4. Difference between the springs
5. Old bottom seat and new spacer
6. Shock re-assembled.
