marg26 Posted January 30, 2020 Report Share Posted January 30, 2020 Sorry, lots of questions! Been using HTII cranks for years... Got a square taper Middleburn crankset with the pro trials bashguard and replaceable 22t chainring. The cranks show scars from my crap riding but otherwise fine but bb, bashring & chainring all need replacing. Just wondering what the options for replacing the Pro Trials Bashring are? It's loose on the crank. Didn't want to get too spendy if possible. Is the fitting "type-x"? And if the above, any recommended 5 bolt 22t chainrings recommended? Otherwise, are there any other bashring/chainring options to fit on the Middleburn cranks? It has a VP BB (68x127.5) at the moment, with the metal thread sleeves rather than the lighterweight plastic-like ones, can't seem to find it available now (VP 80 iirc). Will probably stick with it for now but in future, are the Shimano square taper BBs (with hollow axle) decent enough for trials (thought I remember thinking they were quite flexy before replacing them on a new bike)? Cheers Quote Link to comment Share on other sites More sharing options...
Luke Rainbird Posted January 30, 2020 Report Share Posted January 30, 2020 In what way is it loose? They run a lockring, so make sure that's done up tight. If it still moves around it may be due to wear but first step would be to confirm. Regarding replacements, there were a few Middleburn-own options, plus the likes of TNN offered aftermarket stuff too. If you're sticking with a 5 bolt 22t ring, something like the Middleburn Hardcote rings will be spot on In terms of BB options, you're obviously a little more limited these days than yesteryear when looking for a square taper setup. To be honest, just go with anything the right size and you'll probably be fine. Quote Link to comment Share on other sites More sharing options...
marg26 Posted January 30, 2020 Author Report Share Posted January 30, 2020 Cheers for reply. The lock ring was loose enough to remove without the proper tool. Is it normal for a degree or two of movement before tightening it up? Quote Link to comment Share on other sites More sharing options...
Luke Rainbird Posted January 30, 2020 Report Share Posted January 30, 2020 You need to do it right up properly or it'll rattle about. I forget the exact tool from memory but some kind of Shimano BB tool (XTR rings a bell) will do the trick. 1 Quote Link to comment Share on other sites More sharing options...
marg26 Posted January 30, 2020 Author Report Share Posted January 30, 2020 Ta! was just expecting it to be more snug. Lifeline 8 prong tool from crc ordered last night. Quote Link to comment Share on other sites More sharing options...
Luke Rainbird Posted January 30, 2020 Report Share Posted January 30, 2020 Yeah it should be fairly snug if it's pushed onto the splines properly - do the splines look worn at all? I've never had one with any discernible wear on them, but 90% of the population are idiots so who knows what might have happened to the parts in their history. If they were used with a loose ring (ahem) then all bets are off 1 Quote Link to comment Share on other sites More sharing options...
marg26 Posted January 30, 2020 Author Report Share Posted January 30, 2020 Yeah over past couple of rides noticed a bit of a knocking but stupidly assumed it was pedal bearings. Both bb and lock ring had worked loose. Will see if doing lock ring up properly helps... Quote Link to comment Share on other sites More sharing options...
Ross McArthur Posted January 30, 2020 Report Share Posted January 30, 2020 Its a truvativ external locking ISIS BB tool you need. Try putting a smidgen of light Loctite on the treads before nipping up - Should make it less likely to come loose. Make sure your chain ring bolts and threads are nice and clean before fitting the chain ring too (for husbandry and peace of mind). Check for play in the crank to bb interface. Quote Link to comment Share on other sites More sharing options...
marg26 Posted February 3, 2020 Author Report Share Posted February 3, 2020 Yep the LifeLine X-Tools BB Tool 8 Prong fits nicely. Cleaned it up and refitted to cranks. Reasonably confident it should be ok. Just going to clean the rest up and refit until I sort out replacement chain, chainring, rear-cog. I'm trying to find a replacement chainring, preferably steel for durability, but not sure what BCD is needed. Activesport.co list it as 94mm whereas CRC (unavailable) list it as 104mm, but then the Middleburn 22t 5arm chainring is listed as 58mm. Quote Link to comment Share on other sites More sharing options...
Luke Rainbird Posted February 3, 2020 Report Share Posted February 3, 2020 Definitely nowhere near so large as 100mm territory, which would be "middle/large" chainring figures (though most run 1x now), so it may be that you've found a PCD for a standard Middleburn XC spider, rather than for the trials bash. 58mm sounds much more like it Quote Link to comment Share on other sites More sharing options...
Ross McArthur Posted February 3, 2020 Report Share Posted February 3, 2020 Stacks of chain rings on eBay dude. £7. Boom. https://www.ebay.co.uk/itm/Granny-Ring-58BCD-Chainring-22-Tooth-cb3133/282837641104?hash=item41da6fe790:g:SR0AAOSwQiFaeZnQ 1 Quote Link to comment Share on other sites More sharing options...
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