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[ESokoloff]

Nice!!!
Built like a brick you know what (I trust).

I’m rethinking my comparison of ICE to EV on belt abuse.
On one hand EV IS  harder on the belt due to instant torque but on the other hand EV lacks the power pulses of ICE.

[Specter]

smithy i really do not think you are going to need a tensioner for that.  all that is another something to need adjusting rob hp and wear out,
have you really romped it yet to see what she'll do when needed?

what happens worse case the belt starts stretching gets a bit loose, it slips a notch on the pulley?  shouldn't be catastrophic right? you should absolutely feel that and say, hmm need to tighten it a bit.  i think you hit it on the head and it's right the first time out of the gate here.

time will tell though, still want to romp it see how she behaves
aaron

[smithy]

smithy i really do not think you are going to need a tensioner for that.  all that is another something to need adjusting rob hp and wear out,
have you really romped it yet to see what she'll do when needed?

what happens worse case the belt starts stretching gets a bit loose, it slips a notch on the pulley?  shouldn't be catastrophic right? you should absolutely feel that and say, hmm need to tighten it a bit.  i think you hit it on the head and it's right the first time out of the gate here.

time will tell though, still want to romp it see how she behaves
aaron

Hi Aaron,

I have been "romping on it" of late, hard acceleration off the traffic lights and out of roundabouts etc...Nothing strange is happening, so I guess that's a good thing.

I removed the front pulley last weekend to check the "sprocket to pulley" mounting bolts were still tight and ok.....and to check if anything was moving or fretting etc....I found nothing so I have been giving a bit of a hard time over the last week, (close to 1000km) and I can report I've seen no issues or skipping of belt teeth etc....I have been religious with the belt tension as I'm still a bit unsure if the swingarm movement will cause grief...so far so good. I've been using BMW's F800GT belt tension specs...seems to work pretty well I guess....the rear pulley and belt are the same as those used on the BMW.

These belts don't "stretch" as far as I am aware....I've scoured the BMW forums and nobody has reported any belt stretching....and some of the owners have well over 50k miles on their belts.

I'll report back next week after fitting the new front pulley and after I have a few hundred km's on it. I'll be fitting a brand new Continental "Contitech 1208" belt to go with the new pulley...and I'll just keep the original belt as a spare in case I get stone damage or some other issue.

The bike has just under 42,000km's on it thus far.....so whilst I have the swingarm out I'm going to remove the rear shock, clean and inspect all shock pivot mounts, swingarm pivot & dog-bone linkage needle bearings and internal bushings etc....and re-lube as necessary......quite a simple job really while the swingarm is out........just a maintenance thing.

Smithy.

[CagivaRider]

My F800GT has over 40,000 miles with no belt issues. Interestingly, my F800GT weighs about the same as my 2019 SR. The belt widths are dramatically different with the BMW's belt substantially wider.

[Specter]

i was not aware if synth belts stretched significantly over time or not, which is why i brought it up just to be sure all bases are covered.  i figured they stretched a bit, hence the need for a tensioner to keep the tension on them when they did stretch, and/or movement made overall loop length change.

if you are gittin on it and she's behaving then id say you are golden. id say the biggest killer of a belt is going to be at speed under power, hitting a pothole or something, causing a momentary unloading then sudden slamming of the load back on it along with a large swing of the suspension loading it up that way too, being enough to pop it.  either that or dead heading it against a curb or something and trying to pick the bike up over the curb with just the engine torque, yanking on that belt, trying to lift the rear wheel.

maybe you can sell your design to energica and they can give you a brand new bike for the idea heh!!  although i think i still prefer a chain on my ego.

aaron

[smithy]

maybe you can sell your design to energica and they can give you a brand new bike for the idea heh!!  although i think i still prefer a chain on my ego.aaron

Highly unlikely, I'm sure their engineering staff would have already thought about using a belt... and ended up using a chain instead. Chains & sprockets are a bit cheaper to produce than belts & pulleys. The belt itself costs as much as a good quality chain and sprocket set.....although they do last a lot longer.

I suspect a lot would depend on the use case for each owner...in my case, I mostly use my bike for commuting to work and the occasional weekend blast... Some others may use their bike to tour on, some just a weekend blast machine...each to their own I guess.

A belt drive suits my use case...plus I detest constantly lubing & adjusting chains every few hundred km's and the associated mess that goes with it. Once set up correctly, a belt is essentially maintenance free....other than a quick check over to make sure it's still in good condition.

Smithy.

[Specter]

well the Experia is really the perfect candidate for what you describe.  it's meant to run around town, long rides in the country or touring, with the occasional need for speed.  Do belts last longer?  Chains can last many many miles if taken care of, hell even if not taken care of. and if someone is not really stomping on it, you can run the thing until it rusts off, just like you could run a belt until it rots off if you wanted to neglect either.

The Experia sounds like a perfect candidate for belt drive and you just proved it.  Now if you want to romp and have that kind of fun, you get a ribelle with a chain.  They may not have thought of using a belt.  They have a chain and it works and is proven.  why mess with something that works and is easy?  That doesn't mean it's not doable or even better for the use it  really is designed for.

the lubing yah it's a pain in the ass, but, lets say you live in a shitty area, dirty roads etc etc, don't you have to do maintenance on the belt too? i can't see them being totally maint free.  I mean as least clean them, which is not much less than cleaning then spraying a chain.  They make lubes now that dry on, Chain Wax, and it don't spatter all over.

you have to be careful but what i tried that worked well is set cruise control for a few mph with bike chocked up.  get the chain brush so it's constantly moving past you, spray the shit on and hold the brush in place and let it go roundy r0undy for a minute or two while you are scrubbing the chain crud loose, then a good blast without the brush but with a rag or just enough to flush the shit off onto a cloth, i use an old coffee bag, then spray lube it and give it a little pump to help disperse it and it's really pretty easy.  The rear brake pedal is right there if something goes wrong, basically just touch it and CC disengages and bike comes to quick stop.

Aaron

[smithy]

New pulley is on...along with new belt...all fitted and aligned, adjusted for tension etc...

I took the bike for a ~100km run yesterday to check for strange/silly noises and make sure all clearances are good, a mix of normal riding and hard pulls from a standstill and out of slow corners and roundabouts etcc.....no issues to report thus far. Smooth, clean and quiet.

Smithy.

[smithy]

Another pic:

I've so far found no need for a tensioner...so I'll do without to see what happens to the belt long term.

Smithy.

[smithy]

Whilst I had the swingarm out I serviced/re-greased the swingarm pivot needle bearings, shock linkages and dog-bone needle bearings.....they were actually in good condition and well greased from the factory....not bad considering the 41+k km the bike has done. No signs of excessive wear on the tool steel bushings or needle bearings, they appear to be good quality items.

Smithy.

[PWM]

Nice work...I think the conversion looks great.

[smithy]

Nice work...I think the conversion looks great.

Thank you Sir...I hope the belt lasts as long as it does on the BMW it came from....have heard some of them get 40-50k miles out of them..!

Also hear horror stories of some belts failing very early....although it is rare.

Just wish a compatible front pulley was easier to come by....there's a lot of work to get anything from other belt driven bikes to fit.

Smithy.

[smithy]

Hi All,
Just another minor update...I've run the bike to work & back for the last week and runs on the weekend without issue...essentially to get some more miles up on the system and to determine if any changes or adjustments are required. I've not had to adjust the rear wheel alignment and the belt tension seems to be fine. Yesterday I had my "360" camera on the rear of the bike watching the rear pulley & belt during a brief 1/2 hour run...the belt didn't appear to change it's tracking during power/overrun that I could see, which is a bonus. I can find no reason to fit a tensioner so I will not bother to fit one unless something strange happens which requires it.

I plan to run the camera looking at the front pulley and upper & lower belt runs in the next week or so to see if anything strange is happening, I suspect not but you can never be too sure with an "unproven" system.

Thus far, the system appears to be doing as I had hoped...smooth, clean and essentially maintenance free. Not having to do the normal chain lube & adjustment, not having lube mess all over the rear wheel, under the front sprocket cover & chain guard and up under the top box is also a pleasant thing....all still clean after giving the bike a good clean last weekend, although I don't run the front sprocket cover any longer, it doesn't fit with the new front pulley...I may "3D print" a front pulley cover but at this stage it's not a major issue.

Full power/torque lauches from stop lights and sprited acceleration out of slow corners and roundabouts is as good as it was with the chain...just smoother and quieter..! The BMW F800GT the belt was taken from only has modest power/torque @ 64kw (~87hp) and 91nm (~67lb-ft) compared to the Experia's 75kw (just over 100hp) and it's buckets of instant torque from nothing compared to the BMW....but it seems to handle the power and torque without any issues. Time will tell if the belt suffers any ill effects. I suspect not after seeing some Harley's with a tiny 1" belt, more weight and comparitively higher hp and gobs of pulsing torque.

Cruising on motorways @~100kmh is a pleasure now without the chain/sprocket vibration/noise.

Smithy. 

[smithy]

Hi All,

All is still running well at this stage and I'm racking up the miles/kms, nearing 4000km on the belt drive system, nothing to report really....the system is still clean, quiet, adjustment and fuss free. I joined a few of my riding friends this last Saturday just gone and we did some spirited winding/twisting road riding approx 200km, (~125 miles), all up with a short break in the middle, plenty of slow corners and up/down hill acceleration/deceleration, I'm no GP rider or knee dragger but the Experia held it's own against some pretty quick machinery, a couple of GSXR1000's, Kawasaki ZX10's and a Yamaha R6. The Experia is surprisingly quick between corners and out of slower corners where torque is most utilised, it loses out against the other bikes when we get above 120kmh though...where hp rules...I keep having to remind myself that the Experia only has ~100hp and weighs in excess of 260kg compared to the 200hp and under 200kg of the Gixxers and ZX's ....belt is holding up fine and I can see no ill effects or untoward noises or marks on the belt. 

So far I'm still smiling..! 

Smithy.

[princec]

Your Experia has 20bhp more than everyone else's then  ... you've got a mere 80bhp to play with I think so you're doing even better than you realise.

Cas