February 7, 20179 yr Need advise please on whether I should buy a new speed dongle or not. I keep changing my mind, so maybe you can help me make my final decision. I already have an e-mtb with shop fitted dongle. This dongle works well, (no idea which one it is) uses the walk button to activate and it reads out correct speed and takes bike to max 33mph assisted. Currently i have a 18t chain ring on bike. I'm now thinking about putting a 20t on front and getting the bikespeed rs dongle which may take the top speed up to +40mph?. There is cost to consider i.e. dongle £120 and new Haibike chain ring £70 (I prefer this ring as cheaper rings run close to casing). The RS dongle seems reliable but the ease of switching on and off isn't a one button operation. I currently have more than enough gears for climbing so still think the 20t will be fine, and really like the idea of having the extra speed if I want it. Do you think it's worth it?. Eddie don't shoot me down as I now your no fan of dongles.
February 7, 20179 yr this might work, it will get the chain away from the case and 50 quid cheaper http://www.pro-cycling-golla.de/Kettenblaetter/22_Zaehne_gekroepft_artikel585d08fd6c282.html
February 7, 20179 yr I can't understand why you'd want to go 40mph on an emtb? I think the tyres couldn't cope? The fastest I've been on mine on a fireroad is 36mph and I was crapping myself. I've raced Moto X so I know the need for speed but I don't think these bikes are built for this? Now I get my kicks from tight, twisty, technical trails at a fraction of that speed. If its adrenaline you're after, get to a mtb centre and use the bike for it's intended purpose.
February 7, 20179 yr it will hurt alot more when you crash and have been over 50mph on mine but you will be pushing the brakes to the absolute limit why i have hope 2 part rotors and 4 piston brake calipers those rotors get to hot to fast and there is no brakes. also a crash at these speeds will do alot of damage to the bike given the waight of it and if it has a carbon frame id take a bucket with you to take it home in my 25t should be here any day now
February 7, 20179 yr Author These are good points and ones I've already been considering, hence the reason why I haven't bought a new dongle. I've been +40mph on my race bike, not down hill either (now sold) and it felt fine. I should admit I just touched 40mph. I've also been downhill with it at 52mph (my max ever) and yes it felt unsafe. Valid point about braking distance and accidents at this speed. I think a lot of this is psychological i.e. my car will do 155mph, but I'd never dream of going anywhere near that fast.
February 7, 20179 yr Author Let me know how you get on with the 25t, i was thinking 20t would be plenty
February 7, 20179 yr it is way over the top imo not even seen one on the german site but will have to be careful i dont snap the chain in half as dont have a spare atm so might limit what gears at the rear i can use. problem is if i can hit cut off speed and still got more left gearing wise id have to get a unlimited dongle like the asa one lol if i can get a avg speed of around 30mph id blow away every road bike rider of strava
February 8, 20179 yr I've have a Black Ped dongle on my Haibike for a couple of years and wouldn't be with out it. (for off road only use of course !) Easy to fit and works from my iPhone . Works from the light switch.
February 8, 20179 yr Author I think the bikespeed rs is limitless, at least that's what they told me, and gives correct reading. I went out last night and averaged 20mph over 27 miles on eco/tour mode. I was limited by the dark and pot holes . I think a 20t on front = (50t std) with bikespeed rs would give you the ability to cruise at about 30mph in right conditions of course. I'm still debating whether to leave mine as is, or go down the bikespeed rs / 20t route hmm.
February 8, 20179 yr The only thing that's stopping me is that I'm a bit loathe to opening up a brand new bike. When I had a Yamaha Haibike I managed to strip a thread on one of the engine mounting bolts whilst installing a dongle.
February 8, 20179 yr well looks like ill need a longer chain to use this sprocket as the rear mech is near snapping point in the 42t at the rear as it has no movement left forward wise and any force will prob snap it in half b4 the chain snaps. looks like i need an extra 3-4 links in the chain but not sure i can add links to the chain i have so will just get a new one for it another 19 quid lol. cant use the 18t on the inside either as it wont fit the other way round as you cant push it in far enough so cant get the 25t on as well as no thread there to hold it in place. if they made a bloody spacer you could mix and match sizes to a point say 4-5t difference in size b4 you will get chain length problems like above.
February 9, 20179 yr Author It actually look clean on bike, and clearance from casing. The derailleur is long (i assume), so longer chain only way to go. Be interesting to see what speed you can average comfortably, also if you have enough gearing for steep hills. My problem is i like to tinker with bike set up as well. Great when it works. Keep posting, as interested in outcome. I've done last 4 evening rides around 22-26 miles each night, playing with batter life, modes and cadence. The best so far was this evening, cadence 85 average, 21mph average, 26 mile ride, sport mode and 20% battery life left. I'm trying to find the sweet spot between battery life, speed, mode and cadence. Still thinking i might tinker with the bikespeed rs and 20t combo.
February 9, 20179 yr i can add power links but 4 off them is 11 quid on ebay or a hole new chain is 19 quid so best off just getting a hole new chain tbh. that is the ex1 in 48t on the rear and 50 on the eagle http://singletrackworld.com/wp-content/blogs.dir/1/files/2016/03/Screen-Shot-2016-03-24-at-09.41.34-640x358.jpg
February 10, 20179 yr if you have a 20t connex sprocket then all you need do is get a smaller 14t sprocket then use that as the spacer and then the 20t will clear the case. eddie pj might have a worn sprocket he could post out to you.
February 10, 20179 yr Author Had to do a a small mod to bike tonight. The hanger is attached to frame via a m4 bolt about 10mm long. when i changed tyres noticed the hanger thread had worn and was loose. Also, noticed the m4 bolt only threads halfway through the hanger (not great design. Luckily i had same m4 bolt but 15 mm long. this now fixes hanger to frame much better. stupid why they didn't put a longer bolt through to use all of available thread. hate my keyboard so have given up using caps lock
February 20, 20179 yr i might just have enough spare chain as that is 6 extra links so should be long enough now i went up 7 from 18t so extra 6 links should do it tho not sure i should link 11 spd chains like this as bit of a bodge job tbh as just re used the link pin.?
February 20, 20179 yr Author Good effort, see how it goes, but yes i would be better off with a new chain knowing the pressure its under.
February 20, 20179 yr well it took 4 extra links but had the same problem as the connex sprocket as felt grinding from the motor in most gears so used the 15t i had as a spacer as the ses wheel put the chain on a angle inwards on the 25t sprocket. i can still feel it grinding in some gears but might be the spacer in the ses wheel for the dual kit but it soon goes when i shift down to a smaller sprocket. it is helping with lower rpm of the pedals but top speed hit a wall at about 34mph i only went round the block and is blowing a gale outside but i cant see you getting to 40mph on the flat and doubt if you did get going that fast would not be there very long at all as the motor is just doing nothing assist wise. or im just not very fit lol i also had to adjust the b screw to get the shifting right again. i also have to use the 42t at the rear just to get going and then just use the gears so on the flat using the full range of the cassette but my 42t is made of alu so will wear it out fast imo. ill leave it on for a few rides and see how it goes but i think 25t is a bit to much on a mtb that is as heavy as mine 21kg. ill add some pics later
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