BSA TRACKER PROJECT..............................

Work com­mences on Odgie’s dirt-track scram­bler. He be­gins with big bits from a BSA A65, adds a sprin­kle of Tri­umph T140, Moto Morini and Can-Am com­po­nents, and sets to with the weld­ing kit…

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Work com­mences on Odgie’s dirt-track scram­bler. He be­gins with big bits from a BSA A65, adds a sprin­kle of Tri­umph T140, Moto Morini and Can-Am com­po­nents, and sets to with the weld­ing kit…

My apolo­gies if last month’s scene-set­ting was a tri­fle off piste, but rest as­sured we’re start­ing off in a good and proper clas­sic vein this month. As I told you, we’re build­ing a BSA A65 as a fast road bike / flat-track racer. The A65 has many good qual­i­ties. Far from be­ing a sim­ple unit con­struc­tion con­tin­u­a­tion of the A10, which is how many peo­ple think of it, the A65 was very much a clean sheet. True it shares some sim­i­lar­i­ties, the her­itage is plain, but con­sider the dif­fer­ences. The most cur­sory of glances will tell you that while ev­ery other Brit­bike owner was fid­dling with bent feeler gauges, A65 own­ers were set­ting their tap­pets with ease and aplomb.

When you dig deeper in­side the A65, you find an en­gine that is a com­par­a­tive joy to work on. Strip­ping and re­plac­ing the top end is a dod­dle com­pared to the end­less pushrod­jig­gery-pok­ery in­volved with Tri­umph, Nor­ton or the ear­lier A10. The gear­box is the cas­sette type, as­sem­bled out­side the cas­ing and then in­serted com­plete – what price strug­gling with rulers and in­dex­ing marks now, eh? A triplex pri­mary chain tells you the en­gine prob­a­bly makes some power, and a quick peer down the in­let ports makes it im­me­di­ately ap­par­ent why it does. No won­der they were all the rage in side­car rac­ing for so long, this is a wellde­signed and con­structed, pow­er­ful en­gine.

Of course, th­ese days ev­ery­one prat­tles on about the bushed tim­ing side main bear­ing. But an­swer me this; did we see end­less A65s, or in­deed A10s, or in­deed 350 and 500 Triumphs stranded by the side of the road with blown bear­ings when they were in their hey­day? Would BSA ever have con­sid­ered car­ry­ing on with the same de­sign if had any ma­jor in­her­ent flaws? Of course not. A10s went to work and back ev­ery day and then went up and down the coun­try on hol­i­day with dou­ble-adult side­cars at­tached, year af­ter year. A bear­ing-fed en­gine isn’t and wasn’t the anath­ema it has be­come, all the the­o­ries of cen­trifu­gal force and oil star­va­tion fall into dis­re­pute when you stop to con­sider that all car en­gines are fed their oil in ex­actly the same way.

No, what hap­pened was… as Bri­tish bikes fell down the food chain, as they be­come more worth­less and more abused, as oil changes be­came less fre­quent, and main­te­nance fell by the way­side, they sim­ply wore out. A worn oil pump, worn bear­ings, an­cient oil, blocked sludge trap, not ex­actly sur­pris­ing when the drive side big-end goes, is it? In all fair­ness, for highly tuned, high speed, rac­ing mo­tor­cy­cle en­gines, a roller bear­ing is prefer­able for longevity. But ev­ery ex­pert en­gi­neer I know thinks the same. If your mileage in­volves nor­mal us­age, just get the bush bot­tom end reamed and aligned prop­erly and keep your £1500 plus in your pocket.

No, the main is­sue with the A65 isn’t with bear­ings, it’s with weight. A fully kit­ted A65 is over 30lb heav­ier than its con­tem­po­rary Tri­umph coun­ter­part. It’s weight you feel too. Just lift­ing an A65 off its side­stand and push­ing it around makes the mass im­me­di­ately ap­par­ent. And it isn’t just gross weight, but also weight rel­a­tive to rider in­put that counts. Bear in mind that I’m a ten stone rider, so the heav­ier the bike, the ef­fec­tive less my body English will be at con­trol­ling a slid­ing mo­tor­cy­cle. So one of the main con­sid­er­a­tions in this build is go­ing to be weight loss (the bike, not me, I re­li­giously keep my­self at ten stone for rac­ing pur­poses).

We’re go­ing to try and make it lighter. That may in­volve sim­ple, cheap tricks like coun­ter­sink­ing head bolts, and it will prob­a­bly also in­volve rather more ex­pen­sive but mul­ti­facetedly ef­fec­tive ones like al­loy bar­rels for the en­gine (a 6kg weight loss in one fell swoop isn’t to be sniffed at, John Hill is the man to see here). But first, we have to make a start on the rolling chas­sis...

Pho­tos by Odgie Him­self

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