I live in Tokyo and bought a pair of MKS Chain Tensioners (MKS chain tugs) from Tokyu Hands for around 4200 yen. I began by loosening the screw attached to the circle end that goes around the hub ends. The screw became quickly de-threaded.
Then I put the rear stays on (which attach to the dropouts) and tightened the MKS bolt a bit, and the screw de-threaded even more.
I then adjusted my rear wheel so that the chain was at a reasonable tension (not tight not loose), tightened the lug, then proceeded to tighten the bolt. A few turns and the screw snapped.
I then decided to try on the other MKS tensioner. This time, the screw breaks, and the screw end gets stuck on my hub end. I could not remove the MKS hoop (circle) end from my hub. The screw was too tight and jammed into the hub end.
I went back to return the MKS chain and brought my wheel in. They removed the MKS bolt from my wheel free of charge, but said it was my faut for breaking them because I put the bolt in too deep - it's not supposed to touch the hub end. Fine - so I bought another pair.
The second time, I was extra careful not to tighten the bolt too much. But again, before I even put the tensioner on, while adjusting the tensioners, they began to de-thread.
I was able to get one side on without any damage to the tug, but the other side became even more de-threaded the more I tightened it. I had to keep the tugs super steady, and force screw them in, just to make the bolt stay.
Finally, the MKS chain tensioner BROKE while I was riding.
I went back to Tokyu Hands with the broken tensioner and they absolutely refused to refund my money.
I have used stock Bianchi chain tugs, and some red custom chain tugs from DEPT store in Tokyo in the past, and never had any problems. I WOULD NOT recommend MKS chain tugs for street use. Unless you are a seasoned Keirin bike tuner, I would stay far away from these. They are super delicate, and don't stand up to any kind of road use.
I live in Tokyo and bought a pair of MKS Chain Tensioners (MKS chain tugs) from Tokyu Hands for around 4200 yen. I began by loosening the screw attached to the circle end that goes around the hub ends. The screw became quickly de-threaded.
Then I put the rear stays on (which attach to the dropouts) and tightened the MKS bolt a bit, and the screw de-threaded even more.
I then adjusted my rear wheel so that the chain was at a reasonable tension (not tight not loose), tightened the lug, then proceeded to tighten the bolt. A few turns and the screw snapped.
I then decided to try on the other MKS tensioner. This time, the screw breaks, and the screw end gets stuck on my hub end. I could not remove the MKS hoop (circle) end from my hub. The screw was too tight and jammed into the hub end.
I went back to return the MKS chain and brought my wheel in. They removed the MKS bolt from my wheel free of charge, but said it was my faut for breaking them because I put the bolt in too deep - it's not supposed to touch the hub end. Fine - so I bought another pair.
The second time, I was extra careful not to tighten the bolt too much. But again, before I even put the tensioner on, while adjusting the tensioners, they began to de-thread.
I was able to get one side on without any damage to the tug, but the other side became even more de-threaded the more I tightened it. I had to keep the tugs super steady, and force screw them in, just to make the bolt stay.
Finally, the MKS chain tensioner BROKE while I was riding.
I went back to Tokyu Hands with the broken tensioner and they absolutely refused to refund my money.
I have used stock Bianchi chain tugs, and some red custom chain tugs from DEPT store in Tokyo in the past, and never had any problems. I WOULD NOT recommend MKS chain tugs for street use. Unless you are a seasoned Keirin bike tuner, I would stay far away from these. They are super delicate, and don't stand up to any kind of road use.