XV920RH - Suspension Update

Some of you might have seen my overly ambitious attempt at a hybrid build so after thinking about it for a while I decided to shelve the CB750 build for a while and focus on something simpler.

I've been considering doing an XV for a while but every one for sale around here was a shaft drive bike and the wheel choices were severely limited without going overboard on fabrication which I knew from experience was going to get me into trouble. So I waited for a chain drive model and it finally popped up. Sadly it wasn't a running example and this one had plenty of electrical gremlins like the rectifier and stator being soldered directly to one another. Several parts of the harness were pushing nearly 1M Ohms of resistance due to corrosion but after trimming and hacking some temporary items together I managed to confirm that the whole charging and ignition system still functioned.

So after stripping a bunch of things off here's how she sits.




I did still have the GSX-R Front end from the CB built so I sized it up and the stem measurements between the XV920 (*235mm) and the 06-07 GSX-R 600/750 (*230mm) are nearly spot on. This left me without the special washer and the top locking nut had only 2/3rds of it's threads in use. While it's not government work it's close enough to work.






First fork swap I've tried to do that didn't involve anything more than a special order of taper bearings which I would have had to do any way as I managed to loose a few of the ball bearings when I tried to remove the original forks...

Better yet, the ignition switch appears to fit, needed the holes bored out a bit to fit the larger bolts for the suzuki clamp but nothing too drastic, and if I weld on a new stop to the neck of the bike I can even keep my steering lock.





As for my wheel options I still want to match the front and rear wheel. I've measured all of the other 3 spoke wheels in the garage, the DL1000's is too wide and the R6 would fit but I'd have to forgo a rear brake or do something odd to center it. The beast of a wheel the GSX-R 1000 rear I have for the CB build just won't fit without some major customization. After some searching the generation 1 SV650's share the same rear axle diameter so my first goal is to borrow one and size it up to see what my options are. I intend to borrow one this coming weekend from a friend if all goes well.

I put the front wheel up on the truing stand Tuesday evening and going to have to trash it. Wheel isn't true so I'm off hunting for another option. That's not all, one thing I noticed was the front end sitting awfully low when I had it back on it's wheels I kickstand was hitting the ground at 4 oclock... bummer. I really want to lean off this bike but if the left side case is at risk of hitting the ground It's going to be a mess. so I need some more clearance.

Digging through the parts bin I found a lowering top triple clamp from an 07 GSX-R that I must have gotten a while back What do you know It works as a lift clamp when you flip it over! Still a good deal of dive in the front end. yes it's on a rear stand and yes the front is pushing 0psi because of the bent rim but the front is much lower. The lowering clamp earned me nearly 2.2cm of extra height.. lol Should be able to grab another 2cm of height by running a 120/70-R17 vs the 120/60-R17 that it's currently wrapped in.





No Fancy stuff here just spacers to clear the bottom of the triple.


Sadly I lost some stem length with the top bearing I hadn't installed last time. so I'm only able to thread one of the two stem locking nuts I may do the trim method for the lower edge of the clamp to get the extra clearance I need.

Sunday Updates

So I've been helping my brother with his foxbody mustang which has kept my busy this week parts actually came in but I haven't bothered with it because I've been busy.

last sunday I picked a wheel up from a friend of mine from a fixerup SV650 that's on hold for a while he was fine with my parking it on a stand in his garage why I borrowed his rear wheel (the blue one...) With the leftmost spacer hitting the swing arm the wheel centers in the swing arm but the sprocket carrier will need some modification to make this whole thing work. I've order a rear wheel from a second gen SV650 that should be here by next weekend but in order to clear sort out the chain alignment I'm going to have to take nearly 15 mm out of the carrier which has me nervous about there being enough meat to keep it on there securely.




The sealed chain drive really does it's job. I cracked the assembly open and the chain while it has been replaced at one point (FSM says DID was the oem supplier this had a sunstar sprockets and chain in it). The whole config just needed a wipe down with paper towels no solvents needed probably the least amount of time I've spent cleaning the sprocket area up on any bike. Without the extra grit in there it kept the wear down on sprockets too the second photo is a vortex sprocket that had maybe 4k miles on it and has been scrubbed with solvents and is missing some of its coating.




New wheel showed up, this is an 07 GSX-R 600 wheel so narrower spokes while it'll create some visual disparity between the rear I prefer this wheel over the thicker spokes.


Lastly I prepared some slugs to start on the rear subframe, I'm trying to schedule time with a friend of mine to go and bend some tubing but that's been problematic and exhaust shops around here don't have 1" dies or I'd go bother them. And yea... that rear shock is not in good shape It needs to be replaced.

Looks like the start to an awesome build. I am in the process of a similar build. Using a cb360 tank, gsxr front end, r1 rear wheel. Debating on using the stock swingarm or doing the r6 swing arm. Keep the picks and posts coming.

I always get jealous when I see you guys with chain drive XV's since we don't get those here in USA. Makes doing anything but stock wheels a total nightmare.

the XV920RH was available in the US, only in 81-82 though. All 81's are chain drive.

Parts showed up this weekend but my sunday was cut out due to problems at work and me being the lucky guy on call. I'll have pictures once I'm able to do something with them.

So, This evening I spent some time trying to figure out the gearing situation when I run the SV650 rear wheel. The stock gear ratio the XV has is 16/35 which is an odd ratio which doesn't translate well to 17" supersport tire downsize. Main limitation was matching the front sprocket diameter. the least custom option is getting an XS650 18T (largest available) front sprocket and drilling/tapping it for the lock nut on the XV920RH. The closest I'll be able to match the stock ratios is looking like a 18T front and a 37T rear

Graph of what that will look like.



This should ensure the bike is still able to reach 100mph without sacrificing any torque. If I stepped down to a 36T rear or stepped up to a 19T in the front it would give me a little more breathing room on top speed and the weight loss + the lower rotating mass from the new wheels/chain would probably even out. Either way it won't be a downgrade from stock.

The holiday is the worse time to get parts in I didn't really get anything done.

Super boring update,

I was working on making a tool roll for the bike but I ran into technical difficulties halfway through the process, I'm going to use an antique phrase "Gotta call the sewing machine repairman tomorrow" Shame too It was actually looking really cool! The factory tools are in good shape no rust but they do have a little cosmetic rubbing damage from one another, plan is to leave them alone just give them a tool roll to stay in. Only thing that has me confused is the adapter tube that was in the kit. None of the other wrenches fit it close enough to make it usable.. So I have no idea what Yamaha was aiming for with it.

One of the new toys I bought myself is a media blasting box. Cheap one from Tractor Supply it's really not that special but after trying it wrapped up in my welding gear with respirator and goggles I decided I didn't like having to vacuum my clothes and hair. (I'm using Fine Coal Slag)

I need to finish cleaning this up, I was maybe 10 mins into cleaning it when I got called and invited to dinner.






This box has quite a few flaws if I were to do it again, I'd take the whole thing apart and use a silicone sealer on all mating surfaces. If you're removing paint on a bunch of metal parts (that can fit inside of this box) This will ultimately be cheaper than chemical strippers.

So my least favorite game by far is "sit and wait for parts" especially when a long weekend comes and you're wanting to make progress. I did get other goodies but one of the items I was really hoping would show up didn't show.

So Daytona 955i Rear shock showed up this week, also had to order a 12mm drill bit to widen one end (Holywood did it so We'll see if it holds up, if not I'll have a bushing made to fit.)





So per measurements by others who have done this swap this is about 14.75 in vs the factory 15in which should net a .5in drop if it were on the stock wheels however it will be slightly greater due to the smaller wheel/tire combination. Originally I was prepared to do a spacer on one end however the pillow ball bushing on that end it will not work and will most likely fail after a few bumps. If the height disadvantage is a huge issue I will likely move the rear mount back to compensate. This is a dry fit, I've already sent measurements to a machinist friend of mine to get spacers made.

Really excited to get to work on the next step tomorrow

Any further updated on this build - I'm doing something remarkably similar and your discoveries have certainly helped me along the way.

It's been a while, Supermoto season has me focused on the track bike and with odd jobs coming in and the horrid humidity it's been unpleasant to say the least when it comes to working on the bike. So what have I managed to accomplish?

well I painted a few bits and made some brackets for the headlight, Even cleaned up the rear sets and started working on a rear brake master bracket however I quickly learned that wasn't going to work if I was to keep the stock seat, I will however be able to mount it to the rear subframe so it's no big worry currently. I bought an XV750 rear brake rotating assembly (the splined section that actuates the rod) becase I didn't want to cut up the less available XV920RH unit. There's more work to do on getting the Hydro rear brake functional but Its coming along.





I did get a new front sprocket a good while back that is going to work on my XV it's a 530 chain, I ordered a new RK chain to properly size everything up however the SV650 needed head gaskets so I borrowed it's chain to see how lined up everything was and so far the sprocket alignment looks good bolt holes don't match but I have no clue what bike the holes are meant for.




And the Elephant in the room is the tank... 1976 Honda CB750K tank. Why is it on there? because I dropped the XV with it's R tank and dented it that's why I pulled in to hot with my touring bike and it fell and the top of the tank grazed the footpeg of my supermoto putting a decent sized dent. I had some one who specializes in paintless dent repair pull the dent out so I wouldn't have to resort to body filler once I went to get the tank painted. but till I'm ready for paint the tank is hiding away safely inside the house. though I've gotta say I've been tempted to make the CB tank work (drop it down 3 inches), but that'll be down the road if it happens.



Crappy Photoshop of CBTanked XV920

So this probably should have been in the last post but I didn't get to it Sunday as I was helping my buddy teach his girlfriend how to ride. so less time to dedicate to the bike.

One issue I had when I bought the bike was the sad state of the wiring harness. Between wire nuts, crimp connectors and a repurposed house lamp power cord. there was a significant amount of bodging and most of it had lead to corroding wires and increased resistance on just about half of the harness. The original controls were broken and replaced with a hacked up later years so I opted to use the 07 GSX-R 600 switches, if I used the same year wiring harness as a base it would be plug and play connector wise and I would have access to more modern relays and fuses available too.



After de-looming the harness I purged all EFI/CDI wiring which left me with all of the factory lighting, charging and warning systems. There are two sub harnesses to finish making, (connectors in the bag) for the coil pack to TCI and the new GSX-R connector to allow the XV's stator to connect to the GSX-R harness, keeping factory style connectors is making servicing this in the future clean and simple.



I also spent some time talking to the guys over at TC Brothers as they offer an affordable exhaust kit for the XS650 and I was able to confirm the XS650 header clamps will secure nicely onto the XV920 (and by proxy the TR1 and 750's) heads just fine.


The only downside to this was the difference in size of the mating surface and the offset of these blanks that's going to prevent this from fitting it's best. so first order of business is to send these off to my machinist to trim them down so I can have more thread on the head studs and if the seal becomes an issue I'll see about getting new ones made with a larger lips.

Loving this, going to look amazing.