How Haibike has overcome the new Bosch motor chain line / integration problems..
Time for another of my structured explanations of how something technical works. Now before you ‘Switch Off’.. This is not a copy and paste explanation, this is written in my own words (and time) for others to learn how the new S.E.S (Sprocket Equalizing System) system works on the latest Bosch motor.
Although nice for people to know about this it also cuts down the amount of time I spend on the phone every day explaining to people various factors; so well worth my time writing it!
Before you start make sure you have read my other post explaining the new 2014 Bosch System in Detail.
This explains the changes the newer Bosch motor has undertaken.
The position of the small sprocket and the way the newer motor has to be mounted means that the bikes swing arm has to be much longer to situate the motor on a full suspension bike. Ultimately making the bikes wheel base a lot longer. This is because the pivot point of the swing arm has to be behind the motor. See image below
Now some of you may say what’s the difference if the swing arm is just a few inches longer?… Well it makes a massive difference to the bikes agility and how well it performs over terrain. A short wheel base is very important.. Its the difference in handling between an sports car and a family estate!.
By bringing the swing arm pivot in, the design looks like this See image below:
Now this creates another problem. Note in the picture difference in position between the highlighted ‘R’ & ‘S’. The ‘S’ is where the chain would normally run from. The ‘R’ Is where the rear end pivots from. This not only creates chain line problems as their is such a big drop in chain line when using the massive sprocket ratio’s at the back. But as the bike travels over bumps in terrain the whole rear end will move up and down with the suspension which causes the chain to move with it. This has major implications on the gear system. The chain will move all about the place causing loss of energy and be very noisy / rattly. This is not welcomed on mountain bikes at all.
So to overcome this Haibike have created the S.E.S (Sprocket Equalizing System). Its basically a small jockey pulley wheel mounted exactly on the pivot point See image below:
Not only does this pull the chain up to work perfectly with the rear swing arm, but it holds the chain in exactly the right place and keeps it under tension, ultimately leading to more engagement and no chance at all of the chain coming off. It also brings the chain up to allow smooth changing of the rear cassette even on the biggest sprocket. The chain length also stays the same whether the suspension is pushed all the way down or in its fully extended position. Perfect!
So here you can see the final design before and after See image below:
Now that’s pretty much job done… But Haibike doesn’t stop there. To finish it all off they stick on a really neat chainguide over the S.E.S pulley wheel. This neatens everything up, it also makes sure that its almost impossible for the chain to come off in pretty much any condition!See image below
Haibike have always been ahead from the start with their previous inverted motor design.
This again proves that Haibike is way ahead of the game when incorporating the Bosch motor into a MTB frame. Haibike currently holds a Patent Pending Approval over the new design.
As the UK’s largest Haibike dealer we are always the first in the country to receive these models into stock. Although not currently advertising these models we are taking deposits and expecting the first drop in limited numbers in early Jan 2014.
Contact me should you require any further details.
P.S – This is the only brand of ebike I saw at the NEC this weekend that have finished off the motor integration by mounting a bash plate under the motor so it all sits snugly. Not only does this plate protect the motor further from debris but in my mind it looks unfinished without it!
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