tvking63 Posted July 4, 2011 #1 Posted July 4, 2011 While searching I saw some talk of using a 15'' Vmax rear wheel but couldn't find anybody that had actually done it on a 1st Gen. So, can this be done? Has anyone done it? And if so, what's involved?
dingy Posted July 4, 2011 #2 Posted July 4, 2011 (edited) While searching I saw some talk of using a 15'' Vmax rear wheel but couldn't find anybody that had actually done it on a 1st Gen. So, can this be done? Has anyone done it? And if so, what's involved? Some what appropriate timing, asking this question. I am finishing up this afternoon putting the VMax 15" stock rim on the bike. I was told by a member that he had done it and all he could recall was something about a shim. I think his memory was clouded. I got a good stock rim from Pinwall and a brand new 150/90-15 Pinelli Route 66 tire for $150. At some point in the process of mounting this I realized that it was going to take a little more McGyvering than a shim. The VMax rim is about 5/8" wider at the axle hole. What this means is there is no way an unmodified Venture caliper mount can possibly fit between the right side of the hub & the swing arm. Not only the caliper mount arm but the MKII floating 320mm rotor is impossible to fit on due to its offset design. The VMax brake mount requires a 280mm rotor, same as what is on the front of an MKII. So I start looking at VMax pictures and how they mounted the caliper on a stock bike. The VMax attaches the caliper basically at the top of the rotor and use a torque arm to restrain the motion of the caliper arm. So I acquired a VMax caliper mount, a brake caliper, a torque arm and a rear brake line. After getting these parts there was still not room to get the VMax caliper arm in the swing arm. I talked to a guy modifies VMax's for a living and he told me that they have to thin up the caliper arm whenever they mount custom wheels to a stock swing arm. So I take my VMax caliper arm and get it modified to the needed width. I am comfortable with the modification to it, and that it is still strong enough. Required removal of almost 5/8" at the axle line. At this point I get the wheel fitted in with the caliper and arm mounted and realize that it is not going to clear the saddlebag as I had hoped it would, so back to the drawing board. Last night I came up with a plan to mount the caliper underneath the swing arm as far forward as it could be rotated. This has required some modification to the stock torque arm in order to get it in a configuration that it would be mountable. This plan has one drawback, it will be a little annoying but I can live with it. The caliper is now mounted upside down from its original designed position, it is in the position that FJR calipers are. The drawback is the bleeder screws are on the bottom of the housing, so in effect about as useful as tits on a boar hog as granny often said. What I will have to do to bleed brakes is to remove caliper from mount arm with brake line attached, invert it so bleeders are now topside, put a spacer between the pads, bleed brake, then remount where its new home is. Sounds like a PIA, it will be, but brakes don't get bled that often so I will accept this as a necessary evil. There are a few pictures attached, I will put some more up tonight when I get this back together. Gary Edited July 4, 2011 by dingy spelling
painterman67 Posted July 4, 2011 #3 Posted July 4, 2011 reason he is asking Dingy and Ive been following along too. Will this give enough room to run a car tire on the 15 inch rim? Any input is apreciated. DAvid
dingy Posted July 4, 2011 #4 Posted July 4, 2011 reason he is asking Dingy and Ive been following along too. Will this give enough room to run a car tire on the 15 inch rim? Any input is apreciated. DAvid This is one of the things I agree with Goose's position on, car tires are not made for bikes. Unless it is a trike, on the rear. But I will put up some pictures tonight when I get it on bike. Right side clearance is good, left side looked to be about 1/2" with the 150-90 tire. The rim is J 15 x MT 3.50 DOT I am not doing this because of the car tire option, I wanted the smaller rim as it will improve acceleration ability about another 5%. Gary
Condor Posted July 4, 2011 #5 Posted July 4, 2011 I am not doing this because of the car tire option, I wanted the smaller rim as it will improve acceleration ability about another 5%. Gary So Gary, when are you going to start riding that thing???
dingy Posted July 4, 2011 #6 Posted July 4, 2011 So Gary, when are you going to start riding that thing??? My back has not been in good shape for about 3 months now. Just the last couple of weeks I have been able to work on the scooter. I have surgery scheduled again on the 25 of July to fix it. Gary
painterman67 Posted July 4, 2011 #7 Posted July 4, 2011 This is one of the things I agree with Goose's position on, car tires are not made for bikes. Unless it is a trike, on the rear. But I will put up some pictures tonight when I get it on bike. Right side clearance is good, left side looked to be about 1/2" with the 150-90 tire. The rim is J 15 x MT 3.50 DOT I am not doing this because of the car tire option, I wanted the smaller rim as it will improve acceleration ability about another 5%. Gary I hear what you are saying Dingy. Im not going through all that just to put a ct on. BUt original poster if Im correct has a sidecar on his bike and as memory serves me hes only getting 3000 miles on a rear mc tire David
painterman67 Posted July 4, 2011 #8 Posted July 4, 2011 My back has not been in good shape for about 3 months now. Just the last couple of weeks I have been able to work on the scooter. I have surgery scheduled again on the 25 of July to fix it. Gary Prayers sent for oyu Gary. Godspeed and heal well my friend David
dingy Posted July 4, 2011 #9 Posted July 4, 2011 Here is what it looks like mounted on the bike. Brake line will get replaced with a S.S. one now that I can determine a length. The one I put on last year won't reach this caliper. Also replaced the MKII rear master cylinder (17.46mm dia.) with a Master from a VMax (12.7 mm dia.) this should help out with the stopping power. I had to give up the MKII system I put on last year to make the wheel work. If I don't like this setup I can go back to my stock setup. I didn't modify anything that would prevent returning to the MKII style. Just have to buy a new rear tire for the 16" rim. Few bolts need tightened, brake needs bled, then tank and rear sub frame can go back on tonight. Gary
barend Posted July 5, 2011 #11 Posted July 5, 2011 I hear what you are saying Dingy. Im not going through all that just to put a ct on. BUt original poster if Im correct has a sidecar on his bike and as memory serves me hes only getting 3000 miles on a rear mc tire David I can understand wanting a CT on a rigid, but only 3K on the rear tire "because he runs a sidecar", that would seem to be a totally separate issue, and possibly not even related to the hack. I would have to go back to my old computer to find the exact number, but I would submit that I got 8 to 12K out of my last Dunlop 404.
painterman67 Posted July 5, 2011 #12 Posted July 5, 2011 I know nothing about running a side car but just going by op's original thread. 3000 miles on a d404 http://www.venturerider.org/forum/showthread.php?threadid=61388 thats the thread he started out on. Hope you guys can help as Im out of my range and payscale here. David
tvking63 Posted July 5, 2011 Author #13 Posted July 5, 2011 Great info Dingy. It's a little more involved than I had hoped but definitely do-able. I always struggle with how much time, effort and money to invest in a bike that's over 25yo. Just to clarify, you're using a Vmax wheel, rotor, caliper mount arm, caliper, and torque arm, and master cylinder? And only the mount arm and torque arm need to be modified. What year Vmax pieces will work or are they all the same? IIRC, they didn't change much, if at all, for a long time. Are the pistons in the Vmax caliper the same diameter as the VR one? Is the curve in the torque arm to clear the caliper? It looks like it might clear without it. Hope the back surgery is successful. Been there, done that.
twigg Posted July 13, 2011 #15 Posted July 13, 2011 Hey Gary ... I get that you are not in favour of car tyres on a bike, but that's an old argument that really doesn't appear to have any "rights or wrongs", just preferences. Anyway, as to your "bleeding" problem .... What is to stop you from simply drilling and tapping the caliper to take a bleed screw in the position you now want one?
dingy Posted July 13, 2011 #16 Posted July 13, 2011 Great info Dingy. It's a little more involved than I had hoped but definitely do-able. I always struggle with how much time, effort and money to invest in a bike that's over 25yo. Just to clarify, you're using a Vmax wheel, rotor, caliper mount arm, caliper, and torque arm, and master cylinder? And only the mount arm and torque arm need to be modified. What year Vmax pieces will work or are they all the same? IIRC, they didn't change much, if at all, for a long time. Are the pistons in the Vmax caliper the same diameter as the VR one? Is the curve in the torque arm to clear the caliper? It looks like it might clear without it. Hope the back surgery is successful. Been there, done that. I did use a front rotor from an MKII, think it was an 88. It matched the look of the front rotors I had on with the cooling slots in the pad area. 282mm dia. Same as a VMax rear rotor. Little different thickness than the VMax, think it is 1mm thicker. All the 1st gen VMax rear brake & wheel parts are essentially the same. None of the parts I used are from the same year VMax. Pistons are close to an MKI 1st gen. It uses a two piston caliper. My original intent was to use a 12.7mm vmax rear master, but I could not get the one I had to bleed the system, probably plugged small hole in it. I had to make an adapter plate to get it to mount in place. I will revisit using the VMax master at some point after riding it and getting a feel for the rear brakeing power. The smaller VMax master will increase PSI at calipers a bunch. I ended up using the MKII master I had on last year. Way to big of a bore dia. I think though, around 17.5mm. I could not mount the caliper in the 'normal' position as it would have interfered with the saddle bags. I had to modify the torque arm a lot to get it to work. Shortened it about 4 inches and bent a curve in it. The torque arm was hitting the casting on the caliper bracket when I swung it around 180 deg from its designed position. I welded a mounting tab to the swing arm in the area where the gussets are for the shock mount, I wanted to keep this new tab short, so I had to put bend in torque arm to get stuff to line up. Caliper mount bracket was narrowed by about .62" at the axle line boss on the outboard side. There was still plenty of material left that I feel it is still safe. At this point I have a VMax brake line on it, but will get a S.S. steel line once I see if I like this setup. Nothing I did would prevent me from going back to the MKII setup I put on last year. The main disadvantage of the caliper being mounted below swing arm is location of bleeders. They are now on the bottom of the caliper. I unbolted caliper from mount arm and set it in intended position on top of rotor and bled it, then remounted it at its new home. Twigg mentioned about tapping caliper for new bleeders, that might be possible. The existing bleeders are tapped into bosses on the casting now and there wouldn't be a place to do that though. Also the VMax caliper has two bleeder screws, one on each side of caliper. the inboard one would be almost impossible to get to if it were to be relocated. I only figure I would bleed brakes at the most once a year so I will put up with this setup. Gary
greg_in_london Posted July 13, 2011 #17 Posted July 13, 2011 If I could get the parts economically I'd be very interested. The only tyre getting 4K on the back I've had was a Continental Tour and that's not available any more. The worst I had was a kenda that only managed 1K. I do have quite a heavy sidecar and often pull a big trailer, but I don't travel at high speeds like that. 60-65mph maximum. I'm running an Avon Venom atm.
tvking63 Posted July 15, 2011 Author #18 Posted July 15, 2011 Thanks for the details Gary. Like you said, no more often than you'd bleed it, the bleeder on the bottom is no big deal. Now to fine a C/T narrow enough to clear the swing arm......
Carbon_One Posted July 16, 2011 #19 Posted July 16, 2011 Gary a simple solution for the bleeder screw would be to replace it with a speed bleeder. Wouldn't matter then what position it points then. Larry
dingy Posted July 16, 2011 #20 Posted July 16, 2011 (edited) Gary a simple solution for the bleeder screw would be to replace it with a speed bleeder. Wouldn't matter then what position it points then. Larry Larry, Wouldn't the air bubble tend to rise to the top of the caliper piston pocket? The way the bleeder ports are laying at about a 45 deg downward angle. 1st picture below. Imagine the entire caliper and arm rotated around the axle center line to where it is at the top of rotor. Then the bleeders are at the top of the piston pocket. 2nd picture is of swing arm on bench upside down. The bleeders are seen here. Torque arm not yet attached or mount welded on. 3rd picture is with torque arm attached. I don't think a speed bleeder would make a difference. Could be wrong though. I am very happy with ANY suggestions though. Gary Edited July 16, 2011 by dingy
Carbon_One Posted July 16, 2011 #21 Posted July 16, 2011 You could be right about that trapped air. Didn't think it thru far enough I guess. Only one way to find out. Larry
tvking63 Posted July 16, 2011 Author #22 Posted July 16, 2011 You could be right about that trapped air. I'm almost certain he is. As a former auto mechanic I've seen issues on some cars where the bleeders are just on the side, and it's a PITA to bleed. I used to have a CBR1100XX and they have a linked brake system that could be hard to bleed and the answer there was to reverse bleed it by pushing fluid in the bleeder, up through the system, into the master cylinder. That would probably work here too but probably as easy to take the caliper off.
Carbon_One Posted July 16, 2011 #23 Posted July 16, 2011 I'm almost certain he is. As a former auto mechanic I've seen issues on some cars where the bleeders are just on the side, and it's a PITA to bleed. I used to have a CBR1100XX and they have a linked brake system that could be hard to bleed and the answer there was to reverse bleed it by pushing fluid in the bleeder, up through the system, into the master cylinder. That would probably work here too but probably as easy to take the caliper off. You're right cause after thinking this thru I realize air will be trapped if the bleeder is lower than any part of the calipers piston. Larry
tvking63 Posted July 16, 2011 Author #24 Posted July 16, 2011 Don't sweat it. I speak without thinking all the time.
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