Need Help 17 DCT Sprockets changed. Speedo reading 15%-20% too fast

[fr1234]

Took my my 17 DCT (~26k miles) to the garage for a chain and sprocket replacement last week and my speedo is now over reading 15%-20% (suspicions roused while I was riding along the motorway yesterday at 80/85 and getting passed a lot more than usual - glanced at the speedo over cars beside me to confirm and then double confirmed by using Waze speedo).

I've counted the teeth on the new rear sprocket this morning and it's got 41 - not been able to get in to see the front sprocket yet. What size should they be? I've seen both 43 and 39 described for the rear.

I've had it replaced once before but provided my own sprockets and chain that time - DID, bought on ebay, but no mention in my order history of the number of teeth, just that it was compatible with my bike and I didn't count or record this anywhere - this change, I had the garage order the parts.

Going to call the garage this morning to arrange getting it sorted but it might be a week or so before I can get the bike in as I live in the middle of nowhere, the garage is 30 minutes away and I've work all week.

Presumably it won't cause any damage and will just affect the speedo and the DCT gear ranges?

(@mods: apologies, I posted this in the nc700 technical forum by mistake so reposted here. Please feel free to kill the other thread)

 

[670cc]

Check your owner’s manual. The specifications section might show the sproket tooth count for your particular model (mine does).

If the garage installed the wrong sprocket, they may have also installed a chain with the wrong number of links.

 

[dduelin]

39 tooth for your year and model. Verification should be in your owners manual.

I’m actually surprised the DCT shifted out of limp mode ( no shifts beyond first gear) with that big of a change in gearing.

 

[fr1234]

39 tooth for your year and model. Verification should be in your owners manual.

I’m actually surprised the DCT shifted out of limp mode ( no shifts beyond first gear) with that big of a change in gearing.

Initially it wouldn't shift into 6th. I hadn't clocked that there was an issue with the sprocket or the speedo reading at that point so stopped for fuel and did the DCT reset procedure. Shifted into 6th no problem after that. Could be coincidental.

I've spoken to the garage and they admitted they'd put the wrong sprockets on as their supplier was out of stock. They thought they'd balanced it with a complimenting front sprocket though. Taking it in on Thursday to get sorted.

 

[670cc]

I've spoken to the garage and they admitted they'd put the wrong sprockets on as their supplier was out of stock. They thought they'd balanced it with a complimenting front sprocket though. Taking it in on Thursday to get sorted.

Ask the garage for compensation as they knowingly installed the wrong parts and didn’t bother to tell you. Free labor, maybe? Then don’t do business there again.

 

[dduelin]

Initially it wouldn't shift into 6th. I hadn't clocked that there was an issue with the sprocket or the speedo reading at that point so stopped for fuel and did the DCT reset procedure. Shifted into 6th no problem after that. Could be coincidental.

I've spoken to the garage and they admitted they'd put the wrong sprockets on as their supplier was out of stock. They thought they'd balanced it with a complimenting front sprocket though. Taking it in on Thursday to get sorted.

A clutch initialization should not have anything to do with not shifting into 6th. Glad the shop stepped up.

 

[mzflorida]

Initially it wouldn't shift into 6th. I hadn't clocked that there was an issue with the sprocket or the speedo reading at that point so stopped for fuel and did the DCT reset procedure. Shifted into 6th no problem after that. Could be coincidental.

I've spoken to the garage and they admitted they'd put the wrong sprockets on as their supplier was out of stock. They thought they'd balanced it with a complimenting front sprocket though. Taking it in on Thursday to get sorted.

That is really shady and will do nothing but perpetuate the dislike most riders have with dealer’s service departments, rightfully so. I know I’m stating the obvious but man that’s crappy.

 

[MZ5]

Going from 17/39 to 17/41 isn't enough to throw the speedometer off by 15 - 20% (there's only a 5% difference between those ratios). I wonder if they also put a 15-tooth front sprocket on, thinking they were compensating for the larger rear, but in fact going the wrong way.

I'm sure the shop will get it sorted, but I'd be curious to hear what all is done.

 

[fr1234]

That is really shady and will do nothing but perpetuate the dislike most riders have with dealer’s service departments, rightfully so. I know I’m stating the obvious but man that’s crappy.

To the “credit” of a dealer’s service apartment (sort of ), it’s a small independent motorcycle garage that I’ve sort of defaulted to using as there’s no other bike garage within a reasonable distance (that I know of. I’ll be looking now though)

 

[fr1234]

Going from 17/30 to 17/41 isn't enough to throw the speedometer off by 15 - 20% (there's only a 5% difference between those ratios). I wonder if they also put a 15-tooth front sprocket on, thinking they were compensating for the larger rear, but in fact going the wrong way.

I'm sure the shop will get it sorted, but I'd be curious to hear what all is done.

I’ll find out the exact configuration they installed and report back

 

[7ncx]

If the speedo is that far off, I'll take a guess they installed 16/41 sprockets which is for the NC700X, manual. I think on the NC750 models all Honda changed was the front sprocket from 16 to 17 teeth. Might want to check the number of links in the chain too, since the DCT uses a shorter chain. All the information is listed in the operators manual.

 

[mzflorida]

To the “credit” of a dealer’s service apartment (sort of ), it’s a small independent motorcycle garage that I’ve sort of defaulted to using as there’s no other bike garage within a reasonable distance (that I know of. I’ll be looking now though)

I do see your point. But if they are going to experiment on your bike give you the option or ask you if you want to wait for the part. My two cents. At least they owned it.

 

[fr1234]

I do see your point. But if they are going to experiment on your bike give you the option or ask you if you want to wait for the part. My two cents. At least they owned it.

I'm not excusing the garage, just making a quip that it wasn't a Honda servicing dept so Honda are innocent (at least on this occasion)

 

[fr1234]

Latest update: took it into the garage this morning. They'd installed 16/41 as suspected by @7ncx . I asked them to confirm what they were planning to replace it with and they'd ordered 17/43 - I had to show them the manual and they counted the teeth on the one they'd removed to convince them that the rear still wasn't right. They've now ordered a 39 and I have to take it back again on Saturday.

 

[mzflorida]

I'm not excusing the garage, just making a quip that it wasn't a Honda servicing dept so Honda are innocent (at least on this occasion)

I see. I hope I didn't seem argumentative ( i could see how my comments could be interpreted that way). Just ranting.

 

[fr1234]

I see. I hope I didn't seem argumentative ( i could see how my comments could be interpreted that way). Just ranting.

Not at all Same here. I can see how my comment may have come off like that but it was not intended at all. I appreciate you and your input

 

[7ncx]

Latest update: took it into the garage this morning. They'd installed 16/41 as suspected by @7ncx . I asked them to confirm what they were planning to replace it with and they'd ordered 17/43 - I had to show them the manual and they counted the teeth on the one they'd removed to convince them that the rear still wasn't right. They've now ordered a 39 and I have to take it back again on Saturday.

Hope you also asked them to check/change the number of links in the chain if it specifies a shorter chain. Info on number of chain links should also be in the manual.

 

[fr1234]

It finally got sorted last week. Wife was away so I had to cycle over there to pick it up and got a bit inventive with the bungee netting to carry my push bike home

Thanks all for the input and advice

 

[Dailyridersg]

Wow hats off to you. I've transported a whole lot of huge and sometimes heavy items using bungee cords and nets over the years but never an entire bicycle and its not taken apart even.