Dengfu E82

[kaaskopf]

threw on some saint levers i had laying around
'shmavens' and while its good, ny other bike with xtr levers and mavens feels much better so im moving brake levers soon again

also other exciting things are coming

 

[kaaskopf]

Small update

I got an amazing offer for an 3x3 hub with belt and electric shift. As a bike nerd i always wanted to try it.

It will make the bike even more heavy but doing a full suspension belt drive seems like a nice challenge and has a cool factor for me.

Currently i have the linkglide madrone setup that works also very good,
so i will move the madrone to my other bike (e10) and will try todo a belt drive conversion on this e82, mainly for the low maintance aspect of the whole setup.

parts ordered;
3x3 hub 12x148 32h
3x3 E.TR.CMD electric MTB trp shifter
3x3 electric actuator
3x3 BRK.203.TRP 2.3 203 disc
3x3 BS.28 Gates cdx sprocket
3x3 CS.24 chain sprocket as backup if belt project is not possible
3x3 brake adapter 180-203
3x3 AP.TA PM1 torque plate

Found cheap aliexpress Gates CDX parts

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i roughly calculated my belt length at 117t with the gates calculator and 39-28t sprockets(smallest that 3x3 offers, and smallest gates offers in 104bcd) i added 3 tooth for belt-growth and tensioner.

My plan is so fab a iscg05 tensioner or go for a hanger mounted tensioner option. I got a pinion bt1 tensioner so i only need an adapter plate
this was quickly throw together for illustration purposes only. it needs to be bigger for 39t cdx sprocket

my plan to power the electric shift actuater is to take a 1t3(lights display battery) bafang canbus cable and tap into the 12v front light cirquit
some might say that is a risk..
but i found out that this 3x3 is closely copied the rohloff design in some places. the electric shift actuater seems similar, and with rohloff it only uses 0.6w at 12v
the bafang front light output is 12v 0.5amp so that is about 6 watts, 10x as much as needed. should be good and no need for extra adapters/wiring
but lights need to be activated on display.

the shifter handle bar controller works on a small watch battery so no wires needed there, its also has ev-spec mounting

 

[kaaskopf]

i figure shit out as i go

today i looked into chain/belt alignment

the m510 has a 53mm belt/chain line
the 3x3 has a 54.7mm belt line

so i need 1.7mm of bottom bracket spacers under the spider to push the spider out to align the belt

 

[bram.biesiekierski]

1.7mm is so small it likely will have no problem. The rear triangle probably flexes laterally more than that

 

[kaaskopf]

good point. but e82 doesnt flex, or very litle at least

most stiff carbon frame i ever had,
my e10 feels like a flexing banana compared

 

[curufinwe_wins]

good point. but e82 doesnt flex, or very litle at least

most stiff carbon frame i ever had,
my e10 feels like a flexing banana compared

For 2mm spacing, I'd recommend doing that at the chainring bolts instead. Lots of spacer options

 

[kaaskopf]

For 2mm spacing, I'd recommend doing that at the chainring bolts instead. Lots of spacer options

on m510 the chainring fits inside the spider and thus spacing it the wrong way with chainring bolts

 

[curufinwe_wins]

on m510 the chainring fits inside the spider and thus spacing it the wrong way with chainring bolts

Oh duh, you're right of course. Just looked back at mine. Unfortunate, but there should be about that much extra thread for the lockring so you should be fine there too.

 

[kaaskopf]

oke so i measured the growing chainstay length in size Large and 230x65 shock and 190 rear travel, ifs about 33mm

i tried to make a tensioner myself but any bb mounted option will run into the chainstays, now i know why all the pinion belt drive bikes run a higher chainstay..

also i Tried to contact PRI innovations for their derailleur mounted belt tensioner

(photo from interwebs. belt on a dengfu e22) (link to the build thread ; Belt Installation on the Wattwagons Hydra )

and it could work with the 28t cog of the 3x3 nine hub, but according to their calculations i run into a issue with growing belt length and the gates belt coming in 3 tooth increments which make it to short and too long compressed/uncompressed

might work with 170 rear travel but im not changing the rear shock, i like the amount of travel

or going with different ratios with reduces climbing. both not realy an option for me..

was worth a try

now the chain route

finding a good tensioner that will work with 24t (smallest cog in chain) is another challenge..
i will use a 32t narrow wide front chainring, so my input ratio is going the be 1.33

they sure didnt make it easy with 3x3 Nine's limited cog selection

i have a rohloff DH shorty tensioner and i ordered a UDH direct mount hanger. because its longer. the tensioner normally has a 17t max but maybe this hanger might boost it some to 24t ? worth a try