Some more gears

Some more gears

While cruising around on my Rover from Day 1, I felt I needed some more gearing. Our terrain here around Panama City Beach is pretty flat and I was finding on most of it I was in 7 or 8 gear depending on the headwind. If there was any down grade I was spinning out at about 80-90 rpm and ‘tadpoling’. My comfort range was about 60-70 rpm that moved me at 17-19 kph. I was hardly ever using 4th gear and below.

The only time I geared down was climbing the parkade and a couple of small hills, where the lowest gear was barely adequate

Looking at the BikeCalc.com gear charts I felt that something on either side of my stock 38T ring would help. I purchased a Shimano M131 Crankset (170mm, 48/38/28) set from Amazon for $26.12 and figured if it did not work out I could the cost down to education. All the literature said I would probably have to change the bottom bracket spindle which on a Rover is 118mm. The new one rec is 123mm- less than ¼ inch more. I thought I’d try the new chainring before ordering a new bottom bracket. It seems to fit perfectly although the hold bolt fit pretty snug in the sleeve of the new pedal. The inside ring is closer to the frame rail but the big ring lines up just about dead on with the stock ring.

I tried it out on a 30 km ride and it works extremely well. The chain that I mentioned in the last post as slightly too long is still too long even on the 48T ring. I will split it and adjust it in the near future.

I have been shifting from ring to ring simply by lifting the chain from ring to ring. Not a high speed operation unless you don’t care about running your fingers through the front sprocket, but for the time being it certainly does the job. 

In the 28T ring, I can just about climb straight up… just right for that parkade ramp. Out on the road on the 48T ring and the 4,5, and 6 gear match up pretty well where 7 and 8 do on the 38T.The added advantage of using the larger gears in the middle of the cassette should result in better wear characteristics. These gears give me 14-18 kph at a comfortable 60-70 rpm range cadence. 

The 7 and 8 gears give me the speed I was looking for on the level, w/ down grade or tailwind up into the 25 kph range. If I pedal above that cadence I find a bit too much tadpoling. 

Control and cornering of the Rover is very good at this speed as I gain confidence and experience. Don’t think I will get above that speed as the hills just aren’t here and I’m out to enjoy the view not to race… although it is fun when I hit 28-30 kph on a couple of grades.

I have a Shimano FD-M360 Acera Triple Front Derailleur 31.8mm TP TS HDC for 19.99 ordered. Just need to get that bolt on boom mount fabricated

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