Chap­man BSA

Classic Trial - - CONTENTS -

This story came about, as do so many, af­ter an af­ter­noon of rem­i­nisc­ing over old pho­to­graphs amongst the ca­ma­raderie of tri­als-minded in­di­vid­u­als. The main pro­tag­o­nists in this story, Mick Chap­man and Si­mon Shad­bolt. They were more than happy to share their mem­o­ries of a near-for­got­ten project from long ago with my­self, who at the time was a mo­tor­cy­cle mad in­di­vid­ual who on find­ing that my own tri­als skills were lim­ited fol­lowed as much as pos­si­ble the best of the day. Be­ing thor­oughly im­mersed in all things two-wheeled I typ­i­cally ‘hung out’ at the lo­cal mo­tor­cy­cle shops or found a trial to go on most week­ends. Go­ing to Eve­sham was a rea­son­able jaunt on my 125cc at the time, but then the re­ward of a warm shop with a cup of tea and the op­por­tu­nity to just be in­volved in some way was enough of a pull to make the jour­ney worth­while. In this pe­riod the Chap­man BSA came into be­ing, and I was for­tu­nate enough to see it tak­ing shape in the work­shop and to ac­com­pany our small band of rid­ers from Eve­sham and Strat­ford clubs to the Isle of Man in 1980, where the new ma­chine caused some­thing of a stir. Here then is a short tale of those far off days. Words: Neil Shad­bolt with John Hulme • Pic­tures: The Chap­man BSA Col­lec­tion, Bob Light, Nigel Pert Pho­tog­ra­phy and Neil Shad­bolt

By the late 1970s, the world of tri­als had seen the demise of the Bri­tish mo­tor­cy­cle in­dus­try as the Vil­liers pow­ered work­horses of the 1960s were be­ing con­signed to his­tory, and Dave Row­land’s hero­ics of the 1967 Scot­tish were en­deav­ours that were be­gin­ning to fade in mem­ory. The Span­ish in­va­sion was fal­ter­ing, and Ja­pan had reined in their ef­forts, and the Ital­ians were com­ing with the Fan­tics. When the term 175 BSA is men­tioned, it res­onates with the two-stroke ring of time. It was in the sum­mer of 1978 that Derek and Mick Chap­man de­cided that it was time to re­vive the leg­end, us­ing the ex­ist­ing and neat BSA Tracker 175 as a ba­sis to try to em­u­late the glo­ries of the past un­der their ban­ner: ‘The Bri­tish are Back!’

Eve­sham Mo­tor­cy­cles

It was the height of the Ja­panese mo­tor­cy­cle craze when Derek Chap­man opened his shop Eve­sham Mo­tor­cy­cles. It was his in­ten­tion to make a point of sell­ing Bri­tish mod­els. From this dis­tance, it was dif­fi­cult to imag­ine how far out of fash­ion the once mighty Bri­tish mo­tor­cy­cle had fallen. Their rep­u­ta­tion for oil leaks, vi­bra­tion and gen­eral un­re­li­a­bil­ity in com­par­i­son with the gleam­ing, clean and of­ten faster ‘Japs’ meant that such a move would sharply fo­cus opin­ion but also prove to be a mag­net for diehard Bri­tish rid­ers. The Tri­umphs were sourced direct from the fac­tory, de­pen­dent on the spo­radic out­put, with var­i­ous mod­els in­clud­ing Thun­der­birds and the TSS mak­ing their way into the Eve­sham show­room. Be­sides, In­dian made Royal En­fields that were im­ported and sold, were man­u­fac­tured in the same way with vir­tu­ally no changes since the 1950’s. As an ex­am­ple of the dy­namic vi­sion of the in­ten­tion to re­turn Bri­tish mo­tor­cy­cles to the fore the team also built a new frame for the ‘En­field’ to make a 500cc model us­ing Tri­umph run­ning gear. This was de­signed and built by Ken Sprayson; mod­elled af­ter the feath­erbed frame he orig­i­nally de­vised back in the hey­day of the mar­que. The shop also stocked Silk, Hes­keth and other Bri­tish refugees and had a rep­u­ta­tion as the go-to place for Bri­tish iron. Derek had also pur­chased the jigs and pat­terns to the Healey Square Four and the Mick­mar 250 tri­als en­gine built by Mick Martin as well as a cou­ple of pro­to­type ma­chines — one be­ing given a few out­ings by Alan Wright. Ad­di­tion­ally, there was a plan to fit the en­gine in a re­vamped BSA chas­sis and thus cre­ate an all-new Bri­tish Tri­als ma­chine. Sadly, this did not hap­pen as it ap­pears that it was deemed to be too un­re­li­able at that time. Mick Chap­man de­scribes those days: “Dad (Derek) had a good re­la­tion­ship with the Tri­umph peo­ple and ended up buy­ing all their pro­to­type mod­els in­clud­ing the Ban­dit, Fury and the 1000cc Quad­rant four cylin­der en­gine, to men­tion a few! Even­tu­ally, they were all sold on but would be valu­able now, I think.”

BSA Tracker

The BSA Tracker, by con­trast, was a smart, mod­ern mono-shock pow­ered by the re­li­able and easy to main­tain Yamaha DT175 en­gine, and as such of­fered a de­cent power to weight ra­tio. Hail­ing from Birm­ing­ham at the much-re­duced but still kick­ing BSA fa­cil­ity these ma­chines kept the busi­ness tick­ing over. It was at this time that Bill Colquhoun and Ber­tie Good­man owned and ran BSA and kept the name alive af­ter the demise of the orig­i­nal all-Bri­tish BSA.

Many of the cy­cle parts for the light­weight trail bike were sourced from Italy and as­sem­bled in the UK. The main sell­ing point of the Tracker model was the can­tilever frame, which is un­der­stood to have been de­vised by 1960's tri­als rider and vi­sion­ary Ken Sed­g­ley. The po­ten­tial of the light and easy to ride 175 tracker mod­els as a tri­als ma­chine was seen by both Mick Chap­man and Si­mon Shad­bolt; both noted Mid­land Cen­tre rid­ers with bags of en­thu­si­asm and an ex­ten­sive en­gi­neer­ing back­ground.

Si­mon takes up the story: “I was par­tic­u­larly keen be­cause of my loy­alty to Ossa, who had a one-off can­tilever frame model that they spon­sored John Reynolds on. He had some good rides on that ma­chine. We talked about how to mod­ify it to make it a com­pet­i­tive tri­als model, which would al­ways be dif­fi­cult be­cause it had the wrong en­gine char­ac­ter­is­tics be­ing a ‘buzzy’ Yamaha DT175 en­gine. Derek agreed that we could mod­ify one ma­chine as a pro­to­type and I said that I would work on it if I could mod­ify it to suit”.

Derek Chap­man made the de­ci­sion that there would be two pro­to­types; one for Mick and one for Si­mon. The team set to work, and it was agreed that some changes to the frame were needed to en­able dif­fer­ent footrest po­si­tions and to re­move a lot of the un­nec­es­sary brack­ets. The steer­ing angle would also need to be changed. Af­ter pro­duc­ing draw­ings of the frame and can­tilever and talk­ing to Bob Tait, who had al­ready de­signed his frames and forks, it was found that by jack­ing up the back end it gave close to the right steer­ing head an­gles needed for it to be use­ful for tri­als!


Mick again de­scribes it: “We ex­per­i­mented with shock ab­sorber lengths and spring weights, and in the end used a Girling shock which suited our re­quire­ments for tri­als use”.

The BSA made use of Akront an­odised rims, Grimeca hubs and Mar­zoc­chi forks while WES made the air box and ex­haust si­lencers. The Ossa pat­tern fuel tank and fi­bre­glass tank/seat cover were fab­ri­cated lo­cally af­ter the fash­ion of the Mon­tesa tri­als mod­els.

Si­mon adds: “The only prob­lem was that the yokes were 3” 1/8 from the cen­tre line of the steer­ing head to the fork tubes; they needed to be 1” 5/8. It was ap­par­ent that un­til the ma­chine had new fork yokes, there would be a ten­dency for it to tuck in if you were go­ing down­hill with a tight turn at the bot­tom."

In the mean­time de­vel­op­ment of the pro­to­type con­tin­ued at a pace as the project started to come to­gether, con­vert­ing the trail ma­chine into a proper tri­als con­tender.

The pro­to­type BSA was fit­ted with a steel ring around the DT175 fly­wheel to make it heav­ier. Metal was taken from the bot­tom of the bar­rel to lower the port­ing, and another mod­i­fi­ca­tion in­creased the height be­tween the in­let and ex­haust ports to soften the power and had a spacer fit­ted un­der the cylin­der head.

When the ma­chine was ready, Mick rode it in cen­tre tri­als, and it showed how good the BSA was over rocks, etc. Shad­bolt then car­ried out the same work to the sec­ond pro­to­type, with the only dif­fer­ence be­ing the pref­er­ence for the footrest po­si­tion. He re­calls mak­ing the fly­wheel weight out of denser steel to pro­vide more weight. The port­ing re­mained un­changed af­ter it was found that it didn’t make enough dif­fer­ence. At this point, it was still an ex­per­i­men­tal ma­chine, and lessons were be­ing learned as the ma­chine evolved.

Sat­is­fied that they had a pack­age that would be suit­able to look at man­u­fac­tur­ing on a com­mer­cial scale, the frame draw­ings drafted at that time were sent with Mick and Derek to Birm­ing­ham for BSA to look at.

Bert Good­man, known for his as­so­ci­a­tion with Ve­lo­cette, took them over mainly to en­sure that the Ital­ian jigs could be cor­rectly set up as if the ma­chine was to reach pro­duc­tion, the BSA fa­cil­ity at Gar­rets Green would have to turn over fac­tory space to get the line up and run­ning.


The pro­duc­tion model was as­sem­bled by Ber­tie and Mick at the fac­tory in Birm­ing­ham, and while the cost of some com­po­nents from Italy was found to be cheaper the re­main­der of the items were sourced from the UK in­clud­ing fuel tank, ex­haust, bars, boost bot­tle, sprock­ets etc. The new BSA tri­als mod­els were made ex­clu­sively for Chap­man and the Eve­sham ven­ture was to be the only re­tail out­let for them.

Even­tu­ally the BSA fac­tory de­liv­ered the pro­duc­tion run, which in to­tal num­bered just 20 ma­chines all fea­tur­ing TR pre­fixes. They had made a nice lit­tle mo­tor­cy­cle which they wanted to sell for un­der £1000 and ended up at £995.

All of the BSA man­u­fac­tured pro­duc­tion mod­els were fin­ished in a smart blue with con­trast­ing red frame and white mud­guards, while the words Chap­man-BSA were em­bla­zoned on the tank cover with a Union Jack mo­tif in case any­one was in any doubt about the ori­gin of the con­cept! It is worth not­ing that the port­ing was to re­main stan­dard on the pro­duc­tion mod­els too but the Chap­man BSA had an ex­tra weapon in its ar­moury, the boost bot­tle.

With a grin Mick ex­plains: “The boost bot­tle was a lit­tle trick we had that stored up en­ergy; when you asked for power it de­liv­ered plenty of punch. Plus we used Boye­sen reeds from Amer­ica so that it would work even bet­ter”.

Mick con­tin­ued to per­se­vere with the Bri­tish-backed chal­lenger and com­peted in the prime Tro­phy Tri­als in­clud­ing the fa­mous Col­more Cup, Cotswold and other events, with a fine col­lec­tion of cups to show for it. The ma­chine along with the ma­jor­ity of other man­u­fac­tur­ers’ prod­ucts was even­tu­ally eclipsed by the all-con­quer­ing Yamaha, of which enough has been said. The writ­ing was on the wall for the plucky ef­fort, though as can be seen this hand­some and com­pact ma­chine had the mak­ings of a real win­ner.

In the last out­ings of the Chap­man BSA the ma­chine lost its tank/seat cover which was re­placed with a new sep­a­rate tank and set ar­range­ment and ap­peared in red, and fi­nally in strik­ing or­ange liv­ery.

It has al­ways been a mys­tery as to why Yamaha, who had seen the ad­van­tage of ‘mono’ over tra­di­tional twin-shock ma­chines, hes­i­tated to cap­i­talise on their en­gi­neer­ing ad­van­tage but their pro­cras­ti­na­tion meant that the Chap­man BSA claims the ti­tle of ‘World’s first fac­to­rypro­duced mono-shock tri­als ma­chine’.

Over the years the ma­chines fell out of use, as tends to hap­pen to com­pe­ti­tion ma­chines, and it is be­lieved that there are only a hand­ful left. Re­search dur­ing this fea­ture has found very few.

Mick says: “I would love to know how many of these are left, we put a lot of ef­fort into the project and it’s a shame if they’re lost. I’ve got one and I know of maybe two or three oth­ers af­ter we helped one chap with a restora­tion, and that started me think­ing about where they all went. I’m still ac­tive in tri­als and of­ten ask if any­one knows of any of ‘our’ old ma­chines are out there”.


It’s a good job that ‘word of mouth’ still works won­ders even in this in­ter­net­con­nected-iPad age as just such an en­quiry threw up an un­be­liev­able find only re­cently. Mick’s per­sis­tence in throw­ing out op­por­tunist en­quires re­sulted in him be­ing con­tacted by some­one that had a Chap­man BSA and was even­tu­ally per­suaded to sell back to its maker.

When the van ar­rived, and the ma­chine was dropped down from the back, Mick could not be­lieve what he saw. It turns out that pro­duc­tion num­ber TR012 was se­lected for some very spe­cial treat­ment as none other than Majesty Yamaha wiz­ard John Shirt Snr breathed some magic onto the stan­dard 175 and cre­ated the one-an­donly Chap­man-BSA 200.

Mick: “We were be­ing out-gunned just be­cause of the DT en­gine’s per­for­mance so we de­cided to try and bore one out to see what we could do with it. John Shirt got in­volved, and we made a spe­cial which went re­ally well”. How­ever by then, the de­mand for the ma­chines was very low, and so only one 200 model was made, which had a dif­fer­ent tank de­sign from the stan­dard mod­els. It took a while for the ini­tial pro­duc­tion run to sell and so fi­nally the project came to a nat­u­ral end. Ex­cept that it’s not the end as the 200 is cur­rently be­ing re-as­sessed by Mick with a view to a proper re­fur­bish­ment and even per­haps some lat­ter-day mods to make it into a com­pet­i­tive steed once more.

Mick: “I in­tend to change the yokes as had been sug­gested and maybe try and lower the ma­chine as it's got more ground clear­ance than is needed, and maybe a few en­gine mods as tech­nol­ogy has moved on since the eight­ies. I hope to ride it in the Kia Cham­pi­onship and the odd cen­tre and club trial later in the year”.

It is fair to say that the Chap­man BSA project was a valiant ef­fort at the time and clearly ahead of it in many ways. It also showed that the vi­sion of two en­thu­si­as­tic en­trepreneurs and Bri­tish en­gi­neer­ing prow­ess could still pro­duce a com­pet­i­tive ma­chine in the face of stiff op­po­si­tion. It de­serves to be more than just a foot­note to tri­als his­tory and stands proudly among the ranks of hope­fuls that kept our sport alive all those years ago. If you have an ex­am­ple of one of these won­ders, you could do worse than let Mick Chap­man know about it or con­tact Trial Magazine.

Spon­sored school­boy rider Steven West. Majesty Yamaha wiz­ard John Shirt Snr breathed some magic onto the stan­dard 175cc and cre­ated the one­and-only Chap­man-BSA 200cc. In the last out­ings of the Chap­man BSA the ma­chine lost its tank/ seat cover, which...

1980: In the snow at the Col­more Cup. 1981: Col­more Cup. Mike Chap­man’s BSA at­tracted so much at­ten­tion.

Eve­sham Mo­tor­cy­cles. One of the two pro­to­types built. The Chap­man BSA tri­als was based on a BSA Tracker like this.

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