April 30, 2025Apr 30 I’m looking to replace the front 42t chainring on my cheapo Chinese e-bike (Samebike LO-26/II). I’d like to replace the current 3x-ring with a larger 1x. I removed the crank and rings for a better look, and the three current chainrings plus the crank look to be a single assembly (see photos). Is this a normal thing on a budget bike, or are the fixings just buried under paint? I don’t want to spend ages scraping the paint off to find that the fixings are rivets not bolts. I’d rather not have to replace the cranks as well, but if its all one piece then I guess I’ll have to. Any guidance appreciated.
April 30, 2025Apr 30 I think the three chainrings are riveted together - not sure from the photos but can't you just use a crank puller to get the crank off ? https://www.pedelecs.co.uk/forum/threads/pedelec-nirvana.47347/post-717660
April 30, 2025Apr 30 Been there, tried it. You'll probably find it's cheaper to buy a complete crank set. I know, crazy !
April 30, 2025Apr 30 The crank is already off, but with the chainrings firmly attached oh yeah - I remember - i bought this https://www.ebay.co.uk/itm/266784780573
April 30, 2025Apr 30 I think the three chainrings are riveted together As above ^^ the rings themselves are riveted, though it does look like the ring group are bolted to the spider. That said, might find getting replacement rings isnt going to fit as it would have to exactly match the mounting system, and that might not be possible given its probably a case of all parts designed and constructed just to fit each other and nothing else. I would probably opt for a new set of cranks, but there again theres a slight niggle over whether the bottom bracket axle length the new crankset uses is compatible with the BB you have in there, or you might have to replace that as well oh yeah - I remember - i bought this For the OP its going to hinge on whether his BCD is the same, and I dont think it is.
April 30, 2025Apr 30 oh yeah - I remember - i bought this https://www.ebay.co.uk/itm/266784780573 https://www.ebay.co.uk/itm/335930297031?_skw=crankset+48t&itmmeta=01JT3YCVGK9BH60CN4PVT6X6WF&hash=item4e37018ac7%3Ag%3AwzUAAeSwjGhoC9lO&itmprp=enc%3AAQAKAAAA8FkggFvd1GGDu0w3yXCmi1fOLecv8clLoja5ceuRHMpQAOP%2BJMAYAC9YeSEAIpMp23YtSLmoLfiS%2Fxj3ic0B4cODvmMoC7HPd9PbGCnJsQivTUbZG4dY5PZ1KP6Ds5dPtHOl9oZpm%2FZVWFUPlJ3O6r9Ue9bzVm5WVZixddoL1b2FwYM%2F3d2i%2BWHVbXOdvaAI6tTE4zNzR4VGrpHjoM--lSkOSqEAqtLGDVDQZY6kvWDDzT4HURpo998cy1cbhvd7PGzRC%2FwyAny79qDaaKZL91ikLc4BlrLIOhWVTZxgeZyVJnzYxjHQr%2FIz9MHI477DeA%3D%3D%7Ctkp%3ABk9SR7K4s_7QZQ&LH_ItemCondition=3000
April 30, 2025Apr 30 https://www.ebay.co.uk/itm/335930297031?_skw=crankset+48t&itmmeta=01JT3YCVGK9BH60CN4PVT6X6WF&hash=item4e37018ac7%3Ag%3AwzUAAeSwjGhoC9lO&itmprp=enc%3AAQAKAAAA8FkggFvd1GGDu0w3yXCmi1fOLecv8clLoja5ceuRHMpQAOP%2BJMAYAC9YeSEAIpMp23YtSLmoLfiS%2Fxj3ic0B4cODvmMoC7HPd9PbGCnJsQivTUbZG4dY5PZ1KP6Ds5dPtHOl9oZpm%2FZVWFUPlJ3O6r9Ue9bzVm5WVZixddoL1b2FwYM%2F3d2i%2BWHVbXOdvaAI6tTE4zNzR4VGrpHjoM--lSkOSqEAqtLGDVDQZY6kvWDDzT4HURpo998cy1cbhvd7PGzRC%2FwyAny79qDaaKZL91ikLc4BlrLIOhWVTZxgeZyVJnzYxjHQr%2FIz9MHI477DeA%3D%3D%7Ctkp%3ABk9SR7K4s_7QZQ&LH_ItemCondition=3000 Oops, I just offered 5 quid and snagged it!
April 30, 2025Apr 30 The bottom bracket axle length is smaller for a single chainring crankset. Your chainring will be affected if you are using a single chainring on a triple sized bottom bracket This site goes into more detail https://www.sheldonbrown.com/bbsize.html
April 30, 2025Apr 30 The bottom bracket axle length is smaller for a single chainring crankset. Your chainring will be affected if you are using a single chainring on a triple sized bottom bracket This site goes into more detail https://www.sheldonbrown.com/bbsize.html That's right. It can make your chainline incorrect.It's the same when you fit a crank-motor. I've converted a couple of MTBs from triple to single chainwheels. They worked OK, probably because the chains weren't new, but when I did my last crank-drive with a new chain, the chain kept coming off when I selected a low gear, so I fixed it with a chain guide, and the chain hasn't come off in hundreds of miles since:
May 1, 2025May 1 The bottom bracket axle length is smaller for a single chainring crankset. Your chainring will be affected if you are using a single chainring on a triple sized bottom bracket This site goes into more detail https://www.sheldonbrown.com/bbsize.html Yes, I put some spacers and longer bolts in to compensate
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