Triple clamp swaps?

Lots more work than it's worth. Even if the stem length doesn't call for a bearing spacer (which usually looks like hell) or having a new stem made and pressed in the triples, the disc will be a minimum of 1" inboard of the caliper mount. The axle hole will be different and you'll need custom axle spacers. The above issues would be easier to deal with if you started with a TW hub, but then you'd still need to lace it to a 21 to get the look he was after in the first place. $$$$$



The quickest route is to lace a 21 to the TW wheel and call it done. Next is to do some very serious homework regarding stem lengths and bearings and directly swap the forks, triples, wheels and brakes as a complete assembly from a single front end. If you can't lace wheels yourself this can actually work out cheaper in the long run, but only if you do your homework.



Swapping front ends ain't rocket science, but there are a lot of things to consider or the project can pretty quickly get out of hand.



As Mackbig suggested one good indicator of possible candidates are bearing sizes. If it were me I'd spend a long night on the 'net perusing all the Yamaha models which share the same bearings as the TW. The AllBalls applications list might get you started.



Your little Virago could very well be a good candidate. Check the bearing and race sizes and compare them with th TW. If the stem of the Virago is larger or smaller in diameter than the TW look to see if there is an existing bearing and race which will accomodate both.Then the tiebreaker will be the length of the stem. That info will not be as easy to obtain, so you'll have to get your hands on one to measure.

Just trying to save you some grief, but I fear I've made it sound complicated. It isn't, but the homework can be. Some of us did this stuff in the pre-internet days. Nowadays there's no need to drag a front end home and hope for the best when with a little digging you can grab all the bearing sizes right off the internet and avoid spending money on a used front end that "looks" like it will bolt on only to find that you can't locate a bearing combination for it. If you're really careful you will eventually find one which comes real close to being a bolt on.



These are just a few of the potential YAMAHA candidates which share bearings AND stem diameter with the TW. This makes these bikes good potential donors. But these are just the very early dirtbikes. Tons more probaby exist between the later Yamaha street bikes and cruisers, the big four and a boatload of Chinabikes. You can probably use dozens of others as well as those with larger or smaller diameter steering stems than the TW as long as you can find bearings and races which will accept the new steering stem diameter while maintaining the TW race diameter. Many Yamahas shared the same steering head, so they're potentially more likely to share stem length.



Obviously not all these bikes had 21" front wheels, some had leading or trailing front ends and some were long travel, which is probably not quite the exact "look" you have in mind. The little Virago front end looks about right to me. The lighter look of the early DT style front end, no offset, a disc brake and steering stops roughly configured similarly to the TW.



Anyway the entire point of this is that with a few cups of coffee and a bit of sleep deprivation you can get what you want with zero custom machine work, wasted dinero or monkey buisiness.



This info only took about 2 minutes to collect:



Yamaha BW200 1985 - 1988

Yamaha BW350 1987 - 1988

Yamaha BW80 1986 - 1990

Yamaha DT100 1974 - 1983

Yamaha DT125 1974 - 1981

Yamaha DT175 1974 - 1981

Yamaha DT250 1975 - 1979

Yamaha DT400 1975 - 1978

Yamaha DT50 1988 - 1990

Yamaha DT80 1981 - 1983

Yamaha GT80 1974 - 1980

Yamaha IT125 1980 - 1981

Yamaha IT400 1976

Yamaha MX100 1974 - 1983

Yamaha MX125 1974 - 1976

Yamaha MX175 1974 - 1981

Yamaha MX250 1973 - 1975

Yamaha MX400 1975

Yamaha MX80 1980 - 1982

Yamaha PW80 1983 - 2006

Yamaha RD60 1973 - 1975

Yamaha RS100 1975 - 1976

Yamaha RT100 1990 - 2000

Yamaha RT180 1990 - 1998

Yamaha SC500 1973 - 1974

Yamaha SR185 1981 - 1982

Yamaha TT250 1980 - 1982

Yamaha TT500 1976 - 1981

Yamaha TTR90 2000 - 2007

Yamaha TW200 1987 - 2009

Yamaha TY250 1974 - 1977

Yamaha TY80 1974 - 1975

Yamaha XT125 1982 - 1983

Yamaha XT200 1982 - 1983

Yamaha XT250 1980 - 1983

Yamaha XT500 1976 - 1981

Yamaha YSR50 1987 - 1992

Yamaha YT125 Tri-Moto 1980 - 1985

Yamaha YT175 Tri-Moto 1982 - 1983

Yamaha YTM225 Tri-Moto 1983 - 1984

Yamaha YZ100 1976 - 1981

Yamaha YZ125 1974 - 1976

Yamaha YZ175 1976

Yamaha YZ250 1974 - 1976

Yamaha YZ400 1976

Yamaha YZ50 1980

Yamaha YZ60 1981 - 1983

Yamaha YZ80 1974 - 1983

mE TWo. ToO. teW.



And just to further confirm that I have no life I'll do the rest of the homework:



Check the stem length and upper bearing step height of the XV250 before you buy. That will be the only potential snag in your swap. If it's the same as a TW and you don't need a bearing spacer, go get yourself tapered roller bearings in 48x30x12 and one in 43x25x11 because both bearing steps in the steering stem are identical diameter to a TW. The XV uses tapered roller bearings and a 48mm race top and bottom, so the only difference is the upper bearing.



Bolt on your front end, figure out your steering stops and go forth and multiply, er sumpin.



20 minutes on the internet.

MIK20B said:

WOW!



It's 4am here, ive just been called to attend a job, just had a quick read of this and I'm amazed!

So you're basically saying it fits?? Bar stem length right?? I'm going to have to read this properly after work!



Thanks though!

Click to expand...

I really can't recall ever seeing more than a couple of XV250's in this country ,but they appear to be common down there.



What I said was that the upper and lower bearing I.D.'s are the same, making it a likely candidate.



The stem length and location of the upper bearing could still be a dealbreaker. You'll need to physically get your hands on one to verify this. But this is one way you can at least narrow things down with no wasted investment.



Suppose you found a front end which used a 27mm i.d. top bearing and a 29mm i.d. lower bearing. In order for it to fit your TW you'd first need to find out if a 48x29x12 and 43x27x11 bearings exist. If they do you have a potentially viable candidate because the "48" and "43" dimensions are the diameter of the TW's races. Those dimensions are pretty much set in stone, but the hole in the center of the bearing can be a number of different sizes which are pretty much standardized in the bearing industry. If no bearings exist, move on.



Then there's the matter of stem length and the placement of the upper bearing. The lower bearing is rarely an issue with front end swaps. As long as a bearing and race exist in the proper dimemensions the lower triple tree will usually fit.



The upper bearing has a shoulder on it which places the bearing at a given height range. If this height is too tall your bearing will protrude above the top race in the steering head and you won't be able to tighten down your upper bearing. If the shoulder for the bearing is the same height or slightly lower than that of the TW you can usually get the top bearing to seat fully in the race.



But you're not totally out of the woods yet.



If the steering stem is too long you may not be able to tighten down your upper stem bearing nut, which holds the bearings in proper tension. In some cases you may not be able to tighten down the upper triple clamp, as well. Generally the cure for this is either cutting deeper threads on the steering stem or putting a bearing spacer between the stem nut and the bearing. Relatively inexpensive machine work and it usally looks fine as long as the spacer is less than 3/4" or so.



We're talking bolt-on or nearly bolt-on here. Other options exist including pressing the steering stem from your TW into the lower triple of your donor front end (not always possible) or having a complete new stem turned which duplicates the TW dimensions, but they can become prohibitively costly and the process of pressing stems in or out of a steel lower tree like ours often only results in a bent and unusable stem. The upper bearing shoulder can sometimes also be lowered on a lathe, but it usually requires that the stem be pressed out in order to do the machining.



I've had this stuff go well and I've had it go badly due to an overlooked minor detail, but sometimes everything just clicks.

I lifted this pic of a really sad specimen of an XV bottom clamp, which shows another thing to consider in a swap.



The steering stops appear to be arranged similarly to the TW, and that detail is worth its weight in gold. However most cruisers usually have less range of steering motion built into their steering stops than dirtbikes or standards. If that proves to be the case with the XV triple I'd recomend grinding equal amounts from both sides of the steering head tab on the frame a little at a time rather than thinning down the castings on the triple tree. It may mess up your paint but that can be resprayed and it's a danged sight safer. It takes very little removed material to get a few more degrees of motion, so treat this as if your life depended on it because in a tankslapper or emergency evasive maneuver, it will. If you get crossed up without fork stops yer on yer head in a millisecond. Having reduced turning radius is far safer than having too much.



Don't get carried away. Limit it to roughly equivalent to the TW and no further. If tank clearance is an issue you may need to limit it anyway.

You'll need to build up your steering stops.



There are two ways to do this. You can add material to the sides of the tab on the steering head or you can add material to the face of the tabs on the triple tree.



The traditional quick and dirty method is to drill and tap the triple tree tabs for short bolts. The heads of the bolts become your new stops. IMO there really isn't enough material on the TW trees to do that safely. Another way is to silver solder brass "pads" to the stops.



The best way would be the hard way. You'd need to build up the ends of the stop tabs on the frame. This requires welding and removal of the front end and lower bearing and races for the welding, grinding the stops for clearance and some touchup or repanting of the steering head.



Look up "steering stops chopper" or some such combination of words on Google. You'll probably find a lot of versions of one of the above. Most are going to require some form of welding or brazing.

Do you have access to both? The best way would be put calipers on the steering stem bearing shoulders. A bird in the hand is worth 300 on the internet.



The Allballs chart is a quick reference to see which bikes share the SAME bearing sets. Their part numbers for kits dont reflect the actual bearing sizes, but this does:



http://www.allballsracing.com/media/productshowcase/AllBallsSteeringBearingSizes.pdf



Nice chart, but you'll need the actual bearing O.D. and I.D. to see if a bearing/race combo exists. I.D. will be the diameter of the Honda stem, O.D. will be the race diameter of the TW as will the bearing width.



Allballs ain't the only game in town, either. I'd go hang out at a bearing supply house. Anything you can get from Allballs you can get anywhere else and a sympathetic bearing house counterman will be your best friend. Prices will generally be fairly close between the two. The advantage of Allballs is that they've scienced out all the combos pertaining to specific motorcycles. All the bearing house guy needs are the dimensions and he'll hand you a bearing with the same qualities as the Allballs units. A lot of these guys really dig figuring out stuff for their customers.



I'm sure you're aware that you can in some cases also have the TW stem pressed into other triples or even have a new stem turned and pressed. This is either a no-brainer or involves a ton of expensive machine work. Most of the info I've provided on this thread was in trying to help MIK find a cost-effective near-bolt-on. The statistical likelihood of this is generally better if you stay within brands and in his case it worked out.