Haibike sDuro Hard Seven
- Thread starter Vennwood
- Start date
No, not the hard seven. The machine I have is the sDuro Trekking, so I can only speak about that.
The first thing I will mention is the noise level from the Yamaha PW drive. When new, the sound was a sort of metallic rasping, although the amplitude (or whatever the proper word is) remains constant throughout the power band, unlike the Bosch classic drive which rises to a screaming crescendo at the maximum 60 nm of torque. My machine now has 120 miles on the clock and already the drive has quietened considerably, the "newness wearing off" as they say.
My regular ride includes a ½ mile climb, 18% slope at the steepest point. Another bike I have with 50 nm at the crank ascends the hill at a minimum speed of 11 mph, another with 60 nm of torque climbs the hill at 12 mph. Both of these machines powered by the Bosch classic drive. Therefore, I expected the sDuro with 70 nm under the bonnet to cruise up the slope at 14 mph minimum....but it took five attempts to achieve that speed. Here's why.
The Bosch classic drive has only a single-stage reduction of 8.38:1 into a 28" wheel. To get the motor armature speed up into it's power band the pedals have to be spun quickly, not super-fast, a cadence of 75 rpm will get the classic drive screaming it's little heart out. The Yamaha PW drive needs a different technique.
The first climb with the sDuro, I adopted the same technique of "spinning" up the hill, and failed to better 13 mph. I knew the 70 nm's were there as I had often seen the power graph shown on the display right at the top, when spinning up the hill I could not get the bar-graph much more than half way the scale....I was spinning the pedals too quickly. On Thursday last I finally cracked it. This time I climbed the hill in a much higher gear, the rpm counter (cadence) on the display showed 55 rpm, the power meter in the top left hand corner on the display hitting the top of the scale with every pedal stroke (70 nm)....minimum speed at the 18% point, 14 mph....result!!
So, if hill climbing power is what you are looking for, keep the cadence down in the fifties. The Yamaha drive clearly has a multi-stage reduction gearing...pedalling too quickly will spin the motor out the top of it's power band.
Power consumption is of course subjective, for me, over a seventeen mile ride including ascending that hill as fast as possible is 9.8 watt-hours per mile. I would confidently expect in excess of forty miles on a charge for an old codger like me.
Hope you enjoy your test ride, looking forward to hearing your first impression of this excellent drive system.
Have fun
Bob
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I'm not sure a Bosch motor ever 'screams its little heart out' - the Germans don't design things that way.
There is a technique to getting the best out of the motor, but 'spinning up hills' just about covers it.
The Yamaha sounds a bit more complicated, but I imagine most owners won't be interested in an extra fraction of an mph up hill, just so long as the ruddy thing gets them up hills.
There is a technique to getting the best out of the motor, but 'spinning up hills' just about covers it.
The Yamaha sounds a bit more complicated, but I imagine most owners won't be interested in an extra fraction of an mph up hill, just so long as the ruddy thing gets them up hills.
Thanks for that Bob. I'll certainly let you know how I get on. I'm assuming that the trecking and sDuro have the similar mechanicals. I've also noticed that they offer a "tuning kit" for off road work - did you go for that option and is it any good? I suspect that it drains power quickly.
You clearly have no personal knowledge of the Yamaha PW drive, why are you replying to the thread?
Oh well! At least you kept it polite this time...what's up, mislaid your guttersnipe's phrase book then ... eh!
No, the machine is as supplied. The assistance tapers off at around 16.4
mph. That is my usual cruising speed on tarmac and hardpack. plenty fast enough for me.
You made no contribution whatsoever to the thread topic, preferring to pick holes in everything I said, ridiculing my use of decimal points and questioning my hearing.
Not very good at stalking are you.
Oh well! I expect you will improve when reaching full maturity. wink-wink
Your use of decimal points is ridiculous.You made no contribution whatsoever to the thread topic, preferring to pick holes in everything I said, ridiculing my use of decimal points and questioning my hearing.
Not very good at stalking are you.
Oh well! I expect you will improve when reaching full maturity. wink-wink
The kit you have is incapable of accurately measuring a tenth of a mile an hour, apart from the stupid notion that climbing a hill a fraction a mile an hour faster is of any practical relevance.
Questioning your hearing?
You've lost me there, seems to me you are reading sleights where there are none.
I'm not keen on your insults and name calling, but carry on if it floats your boat.
We all know what happened to the last members who went too far in that direction.
Hi Venn wood, yes I have the same bike and it's bloody great. I test rode several different bikes before making the leap and this was the best motor for my needs by far, the bosch is a beautiful motor but I preferred the instant power you get from the sduro yamaha line up. I use mine every day to commute to work and back and the only thing I'm now sick of is cleaning the thing every other day but it saves me over £3000 a year by cycling to work so I can't grumble. Im sure you'll enjoy the test ride.
I have test ridden quite a few of the xduro, sduro and Raleigh crank drives. I must admit that the Hard Seven is probably the best value for money out of the lot. However the spec offered in the models above it is also worth going for if your budget allows. You'll only wind up wanting to upgrade for the time you have your hard seven. To be fair spec is all it is as I do not see a noticible difference in performance between the HS and the Sduro Hard Nine.
Another hidden jewel in Bosch powered bikes is the Raleigh Motus. At £2,000 the spec is impressive. Again the Sduro Trekking trumps it in spec if you can afford it. I myself will be upgrading soon and am torn between the Sduro Trekking and the Sduro Full Nine. I know this seems a leap but if the Trekking had that rear suspension....................
Back to the Hard Seven, it is a great bike at a very good price. I am giving a tip of the hat to "Blew It" for the advice on getting the most out these kinds of drives. My Panasonic works much the same, higher gear selection, more power. What ever you choose both the Yamaha and Bosch systems have their highs and lows. Test ride, it's the only way to make a truly informed choice. Cheers all, safe journey
Another hidden jewel in Bosch powered bikes is the Raleigh Motus. At £2,000 the spec is impressive. Again the Sduro Trekking trumps it in spec if you can afford it. I myself will be upgrading soon and am torn between the Sduro Trekking and the Sduro Full Nine. I know this seems a leap but if the Trekking had that rear suspension....................
Back to the Hard Seven, it is a great bike at a very good price. I am giving a tip of the hat to "Blew It" for the advice on getting the most out these kinds of drives. My Panasonic works much the same, higher gear selection, more power. What ever you choose both the Yamaha and Bosch systems have their highs and lows. Test ride, it's the only way to make a truly informed choice. Cheers all, safe journey
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