The 50-year saga of Har­ley-david­son’s XR-750

Cycle World - - ORIGINS - By AL­LAN GIRDLER / Pho­tog­ra­phy from the CY­CLE WORLD AR­CHIVES and HAR­LEY-DAVID­SON

BBe­fore we can truly ap­pre­ci­ate Har­ley’s age­less won­der and its half-cen­tury of win­ning and los­ing, we must hit the way-back but­ton all the way to 1968 and the an­nual meet­ing of the Amer­i­can Mo­tor­cy­clist As­so­ci­a­tion’s com­pe­ti­tion com­mit­tee.

They had a prob­lem. For 30-plus years, the AMA’S na­tional cham­pi­onship had been con­tested by bikes pow­ered by side-valve 750s or OHV 500s. The ri­vals were roughly equal in per­for­mance, were the sport­ing mod­els of their day, and were what Har­ley-david­son, In­dian, and the English im­porters had to sell. The world’s econ­omy was in ru­ins and the sport was nearly dead; and any­way, this equiv­a­lency formula had pro­vided years of close and fair rac­ing.

But that was then. Now—in 1968, that is—the 750 side valves and OHV 500s no longer duked it out at the top of the heap.

There­fore, the com­mit­tee voted for pro­duc­tion bikes, made in fleets of 200 or more, lim­ited in mod­i­fi­ca­tions suit­able for rac­ing.

The English were ready, with a va­ri­ety of sport­ing 650 twins.

The Amer­i­cans, that is Har­leydavid­son, were not. Their chal­lenge to the Brits’ 650s was the 883cc Sport­ster, and any­way, the Mo­tor Com­pany was in fi­nan­cial trou­ble.

By lucky chance, that 1934 formula had an ex­cep­tion: an open class for TT, which was sup­posed to at­tract the big twin back then. In 1968, H-D had a stripped Sport­ster, the XLR.

The rac­ing de­part­ment did what it could. It de­vel­oped a de­stroked, to 747cc, ver­sion of the XLR, fit­ted with larger valves, mag­neto ig­ni­tion, and a sin­gle Tillot­son car­bu­re­tor.

It’s worth not­ing here that Har­ley did not make all its rac­ing parts; it made the en­gines and de­signed the frames, but or­dered frames and the fiber­glass tank and seat (and fair­ings

for the road­race XRTT) from re­li­able sup­pli­ers, and used top-qual­ity sus­pen­sion, as in Ce­ri­ani forks and Gir­ling shocks, then it as­sem­bled and tested the fin­ished ma­chines, to be sold to the pub­lic through the H-D dealer net­work. “Race what you sell and sell what you race” would be the slo­gan to­day.

Oh, and the Har­ley rac­ers had to look like Har­leys.

The new rules—750 four-strokes for miles, half-miles, TTS, and road­races; 250cc sin­gles for short track— went into ef­fect in 1969.

Har­ley-david­son wasn’t there, not hav­ing built all the 200 ex­am­ples in time.

So, in the lobby of the Houston Astrodome at the open­ing of the 1970 Grand Na­tional sea­son, a pro­duc­tion XR-750 was parked.

The en­gine’s left side case half was stamped “lcl” for com­pe­ti­tion en­gine, then the se­rial number fol­lowed by “HO” for 1970, the eighth decade of the 20th cen­tury, all in Rail­road font, which is tough to copy.

The XR in­tro­duced there was as clean, func­tional, and at­trac­tive as any mo­tor­cy­cle ever made, and no one has im­proved on that pro­file. That said, next must come the fact that the orig­i­nal XR-750 was a mit­i­gated dis­as­ter.

First, dis­as­ter. Al­though H-D had been fit­ting its big twins with alu­minum heads since 1948, the XR used iron heads and bar­rels, as in the XL se­ries. The re­worked ver­sion made too much heat, not enough power, and broke down, as wit­nessed at the 1970 Day­tona 200 when all the team bikes dropped out.

Some­thing like 100 iron XRS went out the door, fol­lowed by fac­tory

bul­letins telling the new own­ers how to im­prove the han­dling and reduce heat by re­duc­ing power. Sorry, but that’s the truth. They won a few races be­fore the next chap­ter be­gan.

That is the al­loy chap­ter, bikes ar­riv­ing early in 1972, not quite early enough to make the Day­tona cir­cus. The new and im­proved XR750’S heads and bar­rels weren’t merely alu­minum; they were some sort of space-age mix. En­gine cases and the trans­mis­sion were mostly carry-over, but the bore was wider and the stroke was shorter, the fly­wheels were one-piece forg­ings, each cylin­der got its own car­bu­re­tor, the gear case (as H-D calls where the camshafts go) still had the four sin­gle shafts in a wide vee, with roller lifters, pushrods, and rocker arms.

Re­peat­ing a theme here, the ’72 XR was of­fered to the pub­lic; OK, it helped if you held an ex­pert li­cense and knew a dealer who liked rac­ing, but the business plan was the dealer sold you the bike. The dealer had a parts book, and he got the parts for you ’cause the com­pe­ti­tion de­part­ment did not sell di­rect.

No names here, but at least one of rac­ing’s he­roes won ti­tles with the only fac­tory ma­chine in the se­ries, the other rid­ers being spon­sored by them­selves and rid­ing bikes prepped in the back­yard.

The XR-750 has been the ex­act op­po­site.

The AMA Grand Na­tional Cham­pi­onship (and now Amer­i­can Flat Track, or AFT) has al­ways been close; wit­ness Mert Lawwill win­ning the 1969 title with his KR, Gene Romero get­ting the No. 1 plate in 1970 on Tri­umphs, and the 1971 title go­ing to Dick Mann and his BSA.

And then we had 1972, won by Har­ley team­ster Mark Brels­ford. There were some brides­maids, so to speak, with Cal Ray­born win­ning a road­race with a wildly modified iron XR and Brels­ford us­ing his 300-pound, 100 bhp XLR to fin­ish fourth in the Houston TT. The new XR was as good at its de­but as the iron XR had been at its re­tire­ment, and a match for the Tri­umphs and BSAS and Nor­tons.

And then the world shifted, if not turned upside down. The rules by this time al­lowed pretty much any mod you cared to make while Yamaha was sell­ing squads of 350 rac­ing twins—and let slip that it would make 200, yes 200, 700cc two-stroke four-cylin­ders.

We also got great rac­ing, and a se­ries of he­roes.

Yamaha had the best se­lec­tion,

with 650 twins for miles, halfmiles, and TT, mo­tocross-pow­ered sin­gles for short track, and the all-con­quer­ing TZ750 for road­races.

Kenny Roberts won the se­ries in 1973 and ’74, while in the other camp, the last of the 1972 XRS went out the door, so in 1975, the rac­ing de­part­ment built 100 new XRS, us­ing frames from Terry Knight and Mert Lawwill, and in­cor­po­rat­ing an­other ma­jor im­prove­ment that led to 85 bhp, up from the 73 of 1971.

The 1975 title went to Gary Scott, a loosely backed mem­ber of the Har­ley team who was al­lowed to ride a Tri­umph in TTS. It started a long string of cham­pi­onships for the XR and in­tro­duced us to some of the big names in the canon. For ex­am­ple, Jay Spring­steen, who won from ’77-79 with ex-scott tuner Bill Wer­ner, al­ready ac­com­plished but a fu­ture leg­end.

This isn’t in se­quence, but it is a good time to re­mind XR buffs that be­tween the in­tro­duc­tion of the XR in 1970 and the shipment of the last fac­tory-spec frame in 1989, the XR went from mag­neto to CD ig­ni­tion, one plug per cylin­der to two, timed

oil-pump breather to Bill Wer­ner’s mini sump, roller to Su­perblend main bear­ings, and then from one to two per side, at least two mixes of al­loy in heads and bar­rels, wasted spark to sin­gle fire, and in­take ports from round to oval. For­mer team tuner Steve Storz came up with an un­break­able (well, nearly) crankpin, Wer­ner per­fected the Twingle, with both cylin­ders fir­ing on the same rev­o­lu­tion, al­loy bar­rels to al­loy plain to al­loy nickel-plated… Suf­fice it here that if you park a 1970 XR-750 next to a 1990 XR-750, they will both click right into the im­age most of us carry for the bike in our minds, no mat­ter what era we were watch­ing com­pe­ti­tion.

Now then, back to rac­ing his­tory. Honda first fol­lowed the spirit of the rules and made ma­jor changes to the CX500 in the early ’80s. Not even Fred­die Spencer could make the thing work. Late in 1983, Honda went from the spirit of the rules to the let­ter of the law.

Its com­pe­ti­tion de­part­ment bought at least one XR-750, and its de­sign­ers took ev­ery­thing apart and did what Har­ley would have done if Har­ley-david­son had Honda’s money; that is, it de­signed a fore-and-aft V-twin, 45 de­grees, but with over­head camshafts and four valves per cylin­der. When the fac­tory’s frame dis­ap­pointed, it got a bet­ter ver­sion from C&J. It hired re­tired champ Gene Romero to run the team, and he scooped up both winners for other teams. And the rid­ers? Up­com­ing Texan Bubba Shobert and, yes, Ricky Gra­ham, a cham­pi­onship win­ner with Tex Peel tun­ing on an XR in 1982. On a Honda, Gra­ham won the se­ries in 1984, and Shobert like­wise in 1985. Quot­ing Gra­ham here, the RS750S “are just a bet­ter bike.”

At this point, two other de­vel­op­ments: One, the AMA was con­cerned with Honda’s achieve­ment. Seems Har­ley fans didn’t want to watch los­ing, and Honda fans didn’t care about win­ning dirt track as op­posed to su­per­bikes or mo­tocross. Oh, and the best Hon­das and Har­leys were burn­ing up the tires of the day, to the ex­tent that GN races were short­ened.

Tests by air­flow ex­pert Jerry Branch showed an av­er­age XR-750 to de­liver 92 bhp, ditto a stock RS750, while a Wer­ner-tuned XR had 100 bhp, and an RS by Hank Scott cranked out 107 bhp.

The AMA’S so­lu­tion? Restric­tor plates for the Honda and Har­ley

750s, and WOT for the con­verted 650 twins. (Watch this space.)

Two, Har­ley-david­son was in deep fi­nan­cial trou­ble in 1985, so it shot down the rac­ing di­vi­sion. It let Randy Goss go. Spring­steen and new kid Scott Parker were given bikes and parts and a bud­get, and told to hire their own tuners and crew.

Parker, like Spring­steen, was an­other Flint, Michi­gan, nat­u­ral. He earned his ex­pert li­censes at 17, the youngest ever, and got his first GN win in 1979.

His 1985 con­tract said only that he had to hire some­one of proven com­pe­tence. He of­fered the job to Bill Wer­ner, at the time one of the two men keep­ing the rac­ing shop’s lights open. H-D man­age­ment said he couldn’t do it. Parker’s at­tor­ney sug­gested that H-D’S at­tor­neys read the con­tract again.

Wer­ner got the job, and got to do his work at home.

Why did this mat­ter? Be­cause when Wer­ner worked for the rac­ing di­vi­sion, he shared his dis­cov­er­ies. When he worked for Parker, he kept his finds to him­self.

The re­sult: Parker won 94 GN races and nine na­tional cham­pi­onships, five in a row, adding up to sev­eral records al­most cer­tainly not to be bro­ken. He re­tired from the team in 1999, came out for fun in 2000, and got his last win at the leg­endary

Spring­field Mile.

Some­time in here, Honda quit dirt track to con­cen­trate on road­rac­ing and mo­tocross. It quit cold; no more parts. Thanks, guys.

In con­trast, in 1990, H-D’S re­vived sort of rac­ing di­vi­sion com­mis­sioned 90 new sets of cases for the XR750. Re­ward­ing this good deed, the ma­chin­ing was off just a bit here and there, and the project had to be re­done in a ma­jor loss of face.

The next hero here was Chris Carr, who’d been signed as the next top gun, which he proved to be; Wer­ner hav­ing not re­turned to the team, Carr signed on Kenny Tol­bert, an­other deep-thinker. Us­ing his XR750, he won the title seven times.

Honda’s in­va­sion shook the AMA com­pe­ti­tion staff into ac­tion, and they’d drafted a new equiv­a­lency

formula, with large-dis­place­ment road-bike en­gines lim­ited and smaller twins un­re­stricted, with the pur­pose-build Har­ley and Honda race­bikes still run­ning restric­tor plates.

No sur­prise that Wer­ner worked out that it is bet­ter to im­prove the small en­gines than hand­i­cap the large ones. He built a low-buck Kawasaki 650 and, hey presto, the Wer­ner Spring­steen Rac­ing Team, yes that Spring­steen, with Brad Smith up, won the 2010 Indy Mile.

More good rac­ing fol­lowed, with Kawasaki and Har­ley closely matched, but with Yamaha, Du­cati, and Tri­umph rac­ers also in­volved.

This gets com­pli­cated. Po­laris In­dus­tries re­vived the clas­sic In­dian name, the AMA shifted pro­fes­sional dirt track to Amer­i­can Flat Track, which in­vented a bunch of new classes, and Har­ley brought out a new line of XG street twins—wa­ter­cooled, fuel-in­jected, etc.—in 500cc and 750cc form.

There was a lot of team re­align­ment, with Smith, Brad Baker, and Jared Mees win­ning na­tional ti­tles for Har­ley, Kawasaki, and In­dian, the most im­por­tant for us being the 2016 Indy Mile in the XR-750’S fi­nal team ap­pear­ance.

The Mo­tor Com­pany has al­ways tried to race what it sells and sell it to the rac­ers, so when the (fi­nally) re­vived In­dian said it had com­mis­sioned a race-only 750, the guys at Har­ley let slip they had rac­ing in mind when they drew up the new 750—to scant avail, sad to say. Specs for the two are sim­i­lar, but since In­dian’s FTR750 ar­rived, it has ruled the roost while the XG750R might as well have been left in the truck.

Why? No one has ex­plained this, but the rac­ing de­part­ment is not in-house, plus if Wer­ner and Tol­bert were still with H-D, things would be dif­fer­ent. But that’s personal, eh?

So what for the XR-750? It’s still el­i­gi­ble for GNC rac­ing, and there are enough parts and ex­per­tise in­side the fac­tory and out to en­sure that you will al­ways dare to start your XR750, as­sum­ing you have the scratch to buy one.

As a dis­tant hope, re­call that back in 1969, when the 750 went into ac­tion, and the Brits were ready and H-D wasn’t, two-time No. 1 Gary Nixon showed up for the Nazareth, Pennsylvan­ia, mile with a shiny new Tri­umph OHV 750, ev­ery­thing up to date.

Har­ley team­ster Fred Nix, not one to ex­per­i­ment, opted for his KR with rigid rear and no brakes.

Nix won the main by half a straight.

“What happened?” the stunned crowd asked.

Nixon could dish it out—and he could take it.

“I got beat,” he said.

It could hap­pen again.

One of the purest mo­tor­cy­cle forms ever pro­duced, the Har­ley-david­son XR-750 is also the win­ningest rac­ing mo­tor­cy­cle, thanks to its long com­pe­ti­tion life.

ABOVE LEFT: Early iron XR-750S ran a sin­gle Tillot­son car­bu­re­tor be­hind their right-side air-fil­ter hous­ing. ABOVE RIGHT: The XR’S three-row pri­mary drive chain con­nect­ing the en­gine out­put sprocket to the clutch and gear­box is re­vealed in this 1977 cut­away. OP­PO­SITE: The XR-750’S lean form and at­trac­tive pro­file made it a pop­u­lar ba­sis for a street tracker. This 1983 Cy­cle World ar­chive photo shows the cus­tom XR-750 street tracker built by the au­thor of this story, who was ed­i­tor-in-chief of the mag­a­zine at the time. Girdler is also the au­thor of Har­ley-david­son XR-750, the Com­plete His­tory, first published in 1991.

LEFT: Al­loy XR-750S switched to twin Mikuni car­bu­re­tors with large clamp-on air fil­ters on the right side, while ex­hausts now exit on the left. BE­LOW: Ten cham­pi­onships be­tween them, Jay Spring­steen (9) and Chris Carr (20) raced the XR-750 through the bike’s hey­day.

ABOVE: Scott Parker is the win­ningest racer in dirt-track his­tory, with 94 vic­to­ries and nine cham­pi­onships, won four in a row and then five in a row be­tween 1988 and 2000.

ABOVE: Not just a racer: one slightly used XR-750. Evel Knievel rode his 1972 model for this ill-fated at­tempt to jump 13 buses at Wem­b­ley Sta­dium in 1975.

BE­LOW: In the mod­ern era, Jared Mees suc­cess­fully cam­paigned XR-750S for much of his ca­reer, with four of his six Grand Na­tional Cham­pi­onships Har­ley-david­son mounted.

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