First build, 2006/07 Specialized Epic Expert/BBSHD

[KennVFRidr]

First build milestone...test ride, FINALLY. :-)

2006/07 Specialized Epic Expert, BBSHD (68mm - 73mm), Luna Wolf V2 52v battery pack, Luna 860 Display, Luna right full twist throttle, Luna Eclipse Face/42T sprocket.

Pretty straight forward conversion to date...although possibly slowest build ever. Snagged the donor bike from eBay, and ordered parts as they became available. Lots of questions answered here on the forum (thanks guys!), and fortunate to have a small DIY friendly Independent bike shop here in Port Angeles, WA. Only needed the Park Tool BBT-9 to remove the bottom bracket, and the BBSHD installation was a breeze. The Eclipse Face and 42T sprocket just fit without needing any spacers, and provided a good chain line. The display install is a no-brainer, and the speed sensor just needed a bit of trial and error to fit...but, three hands would make it easier to attach.

*(One possible glitch - my speed sensor magnet was packaged with three screws, one small black phillips head to lock the bracket adjustment, one very small allen head screw and one slightly larger allen head with locktite on the threads. I assume the one with locktite is for the magnet attachment...but there was a small pin in the hole which prevented my allen wrench from being inserted...either a funky defect, or a special wrench I’m not aware of). The smaller screw seemed a bit loose, but a dab of locktite and it worked, so far.

I snagged both the hydraulic brake sensors, and shift sensor kits...but, looking at the install info, asking a couple questions and coming from a more motorcycle oriented background I decided to test ride without them first. At this point I don’t think I’ll use them, at least for the time being.

Finally...a couple short test rides...I think more noise from the tires (Specialized Fast Track Elite), than the motor or sprockets, but not obnoxiously loud. Curiously the bike arrived with the tires installed backwards, so maybe that is contributing to the road noise. I’m hoping the Schwalbe Super Moto-X will fit...if and when they become available...and thinking they’ll likely be quieter. A bit more noise from the chainring and sprockets when climbing, so I’ll be watching that. I wish the throttle had a bit more friction, but I’m certain I’ll get used to it as is.

I’ll be doing a number of shorter test rides and getting the battery balanced over the next few days...but very happy to be on the road.

[TNC]

Very clean looking install. On the brake sensors, I think if you're not riding technical trail, one can get away without them. However, this is a fairly preferential element. Strictly opinion here, but if you're riding trail that has a lot constant slowing, starting, turning, going over decently rough spots in a real off road trail, I think at least one brake sensor is required. Here's my take. I have what I believe is as smooth but powerful a power delivery as I can tune with the program cable. Even with that, however, coming fast into tight turns around trees or whatever, you really benefit from being able to tap at least one of the brake levers to kill the motor immediately when needed. On the other hand, I find I like not using the brake sensor when coming into a corner/turn at times when I want power on tap immediately either midway or coming out of the turn. To do that, I have my rear brake on the left...motorcycle style, always have had my MTB's set up that way...and the only brake shutoff switch is on that brake. The front brake, right side, has no sensor, so I can lightly ride that brake without killing the motor and have full pedal assist power the whole time into, midway, and out of the corner immediately. This is not too different from dirt motor riding technique. Having one active brake sensor is a crucial to me but not both.

Now, one other brake sensor issue IMO is the need to kill the motor or keep the motor inactive while off the bike when wrestling it over something or if you've stalled out on a rocky climb and you're pushing the bike through rocks with no way to really jump right back on the bike and take off. Whether you're using a thumb throttle or a full twist grip Luna or Bafang throttle, it really helps to be able to keep some pressure on the brake lever with the sensor to keep from bumping the throttle in a precarious situation. OP, I have the same Luna throttle you do, and I found it extremely touchy. By "touchy" I don't mean the power delivery was harsh, abrupt, or touchy. I programmed that down to a very nice, smooth delivery. I'm talking about a twist throttle that had no play or slack from a fully closed/off position to starting to engage the throttle. You being a motorcycle guy, you know you almost have to have some play in the throttle tube from full off to where it starts to engage the carb or FI. My Luna unit had zero play. I made a thread on here about that and how I fixed that. Still, I think a brake sensor is fairly critical if you're ever going to be wrestling, lifting, or yanking the bike around while you're on or off the bike while trying to get going again in a precarious situation...like a rock pile or getting over a log. A twist throttle in particular is easy to get bumped.

On the requirement of the shift sensor, some of my above applies there too, but only as it covers shifting in harsh off road conditions. It's a nice feature to have and is usually much easier to install than the brake sensors. On the brake sensor install, this can be a royal pain depending on how your brake lever/master cylinder is designed. I spent a ton of time digging through my shop extra/spare parts bins to come up with a truly functional mount for my left/rear brake sensor. I think there is some reward with trying to find a creative way to mount the sensor so that it has a little room to move fore and aft in its orientation to the magnet...a form of adjustment. Invariably you'll find brake lever adjustment and wear will cause the distance to change and can cause your brake sensor to shut off the motor or you get no motor shutoff when you want/need it. Having the sensor firmly attached but having some adjustment movement is important to me. The magnet can more or less be permanently attached to the lever IMO once you find a suitable spot.

[KennVFRidr]

I have basically zero time in the dirt...unless you count zooming around on my balloon tire’d Schwinn Corvette as a kid in the mid/late 60’s. Most of my dirt riding (at least for now) will be DNR/Forest Service roads and easy trails, so at least initially, nothing technical. Who knows what the future brings, so I appreciate your perspective...it’ll help me figure things out as I go. For the time being, I need to convert almost 30 years of street motorcycle skills and habits into powered bicycle skills...and I’m sure I’ll have plenty of sorting and adjusting to do as I learn. Just getting used to pedal assist is going to take some time... :-)

[73Eldo]

Looks good. Whats with the sort rides? Lets get s full ride report!

On the speed sensor Bafang changed to that security screw design for some reason. Earlier ones were a larger unit with a slotted screw that was very easy to chew up. I doubt it is due to people just stealing those off bicycles, more likely its for some other application where security of that part is more critical. You can buy those bits. They often come as part of larger sets where you get around 100 bits in a little box. Just look for the mention of security in the description.

[KennVFRidr]

I was wondering about that security bit.

Hard to complete a real report yet. Pedal assist is going to take some getting used to, but I’ll be appreciating it as soon as I drop down off the mountain and start the climb back up. I need to play around with low pedal assist compared to no assist. At the moment, at least mentally...no assist is easier to ride, something I’m sure I’ll adapt to as soon as I get a bit used to the bike itself, as well as settings and gearing. I did notice a little extra noise from the chain/sprockets as I rode up a short steep hill...which I didn’t anticipate, but could be normal. I lubed the chain but have not had a chance to get out for a better ride yet.

[KennVFRidr]

Someone mentioned that they thought the chain looked to short on my conversion. As soon as I read that comment I recalled the sound/sensation I heard/felt as I climbed a steep hill on my test tide...and realized it seemed the same as an overtightened and/or excessively dry chain on the VFR. The comment made sense until I counted teeth on the old chainrings...I went from a 44 tooth large chainring, to a 42 tooth...so my logic says it shouldn’t make any difference. I lubed the chain...but have not been out to test again...just wondering if there might be something else I should look at...and I’m wishing I spent more time getting familiar with the bike before doing the conversion.

[Dshue]

How many links in the chain? Typically on mountain bikes and especially 1x mountain bikes, the chain is as short as possible. It helps keep the chain on and reduces the dreaded chain slap.
In the picks your derailleur looks awful straight in 2nd gear. How much clearance does the upper guide wheel have when in first gear?

[KennVFRidr]

How many links in the chain? Typically on mountain bikes and especially 1x mountain bikes, the chain is as short as possible. It helps keep the chain on and reduces the dreaded chain slap.
In the picks your derailleur looks awful straight in 2nd gear. How much clearance does the upper guide wheel have when in first gear?

Looks like 110 links...and not much clearance.

I’m going to replace the chain on general principal at this point...and it’s well past time for me to input some maintenance details into my brain. The last time I adjusted a derailleur it was probably 1975, on my old Raleigh Record. I’ll be digging through my "Big Blue Book"...I also have a copy of “Zinn and the Art of Mountain Bike maintenance”, that might help with some mountain bike specific info as well.

[Dshue]

I think you'll be fine with a standard 116 link chain then if yours is only 110 now.
In those last pics the chain is entirely too straight through the derailleur.

[TNC]

One other component these days to stop/limit chain slap is a clutched derailleur. It wasn't until I went to a BBSHD on my SC Nomad that I personally used a clutched derailleur, though I had dealt with them at the shop I work at. Going to the single chainring setup and rear 11-50 cogset pretty much required a clutched derailleur. In my past use with this Nomad on fast, choppy, gnarly downhill runs, I should have gone to a clutched derailleur when they first appeared. They are very effective. Kenn, from your pic, I'd suggest a longer chain. However, since you're not going to do any serious off road, you may not really require a clutched derailleur. Just throwing that out as an option.

[KennVFRidr]

Always good to have options moving forward, I’ll have to research that clutched derailleur. Just picked up a new chain and a couple tools at the local independent shop...I feel pretty fortunate to have a cool bike shop with an owner/wrench turner who stops to answer questions and is more than happy to help and answer questions. He was working on a bike with Bafang mid drive when I went in... :-)

[KennVFRidr]

Looking at the chain line with the bike on the lift and pedaling through the gears, both high and low gears create a little noise as the chain meshes with the teeth because of the deflection of the chain while on those sprockets. I imagine the farther off center the chain gets, that potentially, more noise produced? At what point do I need to be concerned with excessive deflection/wear of the chain and sprockets? This is a 9 speed cluster... I’ll be replacing the chain today, and getting out for a better test ride this afternoon, hopefully getting a few miles under my belt this time.

[TNC]

Kenn, from the looks of one of your first pics with the Luna Eclipse chainring, I'm going to bet your chainline is pretty good. When you have a frame with a 68-73mm BB that will take the Eclipse chainring, that's about as good as you're going to get. Your rear cogset position is pretty standard for that era. That coupled with your Eclipse chainring usually provides a very decent if not perfect chainline. The noise you mention at the extremes on each end of the cogset is normal. The chain and cogs are designed to accept that. With the right length chain you should be good to go. You mention you're not going to be doing any serious off roading, so I'd say your gearing will be sufficient too.

[KennVFRidr]

Just did a quick test with the new chain...noise/sensation when climbing improved, and both high and low gears seem to have an equal amount of it. I think I may not have gotten it into high gear while riding prior to today. Played a bit more with the pedal assist, and just need some time in the saddle to get used to the whole package. Next step will be to install the shift sensor...and get some dirt time in on the local DNR land.

[73Eldo]

Make sure to look at your new chain to see if its got a direction and an up and down. Some do and work a lot better if you put them on correctly. Some it makes no difference so its an easy mistake to make.

[KennVFRidr]

Installed a KMC X9, no directional orientation issues and definite improvement when climbing.  I’ll definitely keep an eye open for the directional issue next time.

[Dshue]

For the noise in high and low, go to Park Tools YouTube page and search for rear derailleur tuning. If you follow along hrough the entire video you most likely will be able to get rid of the noise. His procedure looks like a lot of redundancy and he doesn't do a great job of explaining why he does what he does.
What he is doing is indexing the derailleur. The shifter is indexed to the cog spacing but for the smoothest shifting the derailleur needs indexed as a starting point. You are looking for the starting point that is the happiest across the range.

[KennVFRidr]

Excellent...I’ll take a look at it.

[KennVFRidr]

Did a few miles this morning. Got the bike kitted up with everything, weighed it on our clunky old bathroom scale...it came in right at 60lbs. I rode a loop on the back roads up here with a pretty good climb, some pedaling and some just on throttle. Everything stayed attached, I could see the GPS app on my iPhone, and the new chain worked well (I will follow Dshue's suggestion and try indexing the derailleur to see if I can get a bit of improvement). Definitely need to get the shift sensor installed, shifting on the throttle can be pretty harsh. I’m finding 18/20mph to be the edge of my comfort zone at this point, running these knobby tires on the chip seal the’ve laid down up here...but I did manage to get the bike up to 31.5mph on the flat. I’m looking forward to the day when Schwalbe Super Moto X become available again...running these knobbies on the pavement leaves a bit to be desired...but next ride should get out in the dirt where I’m sure I’ll appreciate these tires a bit more...

[TNC]

Kenn, what rear hub is on your bike?...brand/model.

[KennVFRidr]

Shimano FH-M525 VIA・M

[TNC]

Kenn, I see your mention of the shifting harshness. I agree that the shift sensor will help with some of that for sure. However, that and other Shimano cassette bodies in that category don't have a lot of pawls in there. For pedal-only that's not usually a really critical issue. However, with the way these mid-drives deliver power, you're probably going to get a bit of that "clunk" much of the time between pedaling, coasting, and braking. The motor is taking up the slack in the cassette body/hub every time you let off or brake. It won't do that every time, but depending on how quickly you reengage the pedal assist, what gear you are in, and other factors, it will not be unusual to feel this occasional clunk. This sometimes gets misdiagnosed as a bad or failing clutch, but with a low count pawl rear hub, a similar noise is not unusual. Will this cause the hub to fail prematurely? It probably will, but these older style Shimano cassette hubs are pretty tough. Who knows? The perfect fix is to get a low count pawl rear hub or a sprag-type rear hub like an Industry 9 or Onyx, but you're talking big bucks and a complete rear wheel build. I have an XT rear hub similar to yours, and I will probably just run it until it blows. For aggressive mountain biking like I do, it's surely harder on the pawls with so much on/off power with PAS and some throttle. For more sedate use, it may never be an issue of failure...just a little noise.

[KennVFRidr]

Thanks for the info…good to understand what I’m hearing…and always something morebetter to spend $$$ on.