Want Some (More) Low End Grunt

Hi RIF,

For chain length calculation add one link for every tooth added. Based on your year TW (look up chain length here- http://www.yamaha-motor.com/sport/parts/home.aspx ) You will find the chain length under the rear wheel heading. Mine is a 2007TW with a 122 link stock chain so I had to order a 130 link and cut it down to 124 links (measure twice- cut once). My suggestion is to wrap the chain around both sprockets to see where you need to cut keeping the rear wheel forward a bit allowing to adjust for chain stretch and the master link. Your final result should be two links more than stock. The O-ring chain was such a luxury upgrade from stock- You won't be sorry for the extra expense. Thanks to QWERTY for the recommendation of the EK chain- http://www.ekchain.com/ . I ordered sprockets and chain through my dealer since they buy from the big distributors and I knew they would order the correct stuff. (used a Christmas discount coupon on the chain which took some of the sting out of the price.)



As for the suitability of the 14/52 off road- I remember Tracy (goldnhtr) put them on a couple of his TW's and they performed very well for them on the single track they were riding (old forum).

Keep in mind that no sprocket is going to let you just chug up a long steep hill- we would need all-wheel-drive for that (Rokon). A large rear sprocket will be a big help to keep the engine revs up through slow going but for a long steep hill you still need speed and momentum to get to the top. Without that your rear tire is just going to start spinning and you will be stuck somewhere on the slope trying to figure out how to keep your bike from sliding backwards down the hill- a very disturbing situation. http://www.youtube.com/watch?v=-c_7fRq_19s Ouch http://www.youtube.com/watch?v=ht3DMDx1spo&feature=related



Hope this helps.

Dave

RIF said:

I have the stock sprockets on my bike and am looking for a little more low end grunt.....

Click to expand...

Years ago on my 1987 TW200 I switched to a 14/55 setup to take advantage of a specific local off-road area (small, tight trails, and short but very steep hills, with no rock at all - soft forest loam and/or clay). I didn't mind the loss of 10% of the top speed since the "play area" was only 3 miles from home. By switching to a 55 tooth rear sprocket, I got the engine speed right up to the torque curve literally at walking speeds! I could climb slowly up "steps" in the hillside, one step at a time at walking speed or less, and was the envy of many with faster bikes.



But I quickly learned I'd gone too far. The TW already has an extremely low 1st gear. I found I couldn't lower my rear tire pressure to further increase traction, since that effectively decreased the circumference of the rear tire and thus further reduced the final drive ratio, especially noticeable in 1st gear. Truth is, I basically lost the use of 1st gear in many circumstances and ended up climbing most hills in second gear. Frankly, some short very steep hills are best climbed with more speed due to the limited traction of loose soil or slick clay. By making such a major change, to 55 teeth on the rear sprocket, I drastically reduced the utility of 1st gear.



So if I needed more low end grunt on my stock 2001 TW, I'd certainly agree with the others above that 14/52 would be the first ratio I'd try. I suspect that would allow me to get pretty close to 14/55 just by letting air out of the rear tire. And if speed up the hill was more valuable than increased traction, leaving the air in the tire would retain the "higher/faster" final drive ratio, and create a little tire slippage when needed.



Only in special circumstances - like where all your time is spent rock-crawling - would it seem to make sense to take a TW with stock knobbies beyond 14/52. But hey, that's why they sell different sprockets!

- - - Happy Trails, Jim

I agree with all that has been presented. Those that have expended the energy, have found the correct sprocket size for them. I fall into the 14/55 (generally) category, and here's why. I am 62 and like to move slow. I understand momentum but am weary of the speed it takes to produce it. For me, traction is seldom an issue, if the real wheel is breaking loose, likely, I should not be on that trail/incline. I want slow speed and torque on demand, to me, that generally means more horse power or higher rpm's (lower gears).



This is a situation where everyones correct. What you need to do is weigh your wants against your abilities (factor in healthcare coverage) Just another perspective, Gerry